Interactions between corticotropin releasing factor signaling and prophylactic antibiotics on measures of intestinal function in weaned and transported pigs

The study objective was to evaluate the interaction between corticotrophin releasing factor (CRF) receptor signaling and prophylactic antibiotic administration on intestinal physiology in newly weaned and transported pigs. Pigs (n = 56; 5.70 ± 1.05 kg) were weaned (20.49 ± 0.64 d), a blood sample was taken, and then pigs were given an intraperitoneal injection of saline (SAL; n = 28 pigs) or a CRF receptor antagonist (CRFA; n = 28 pigs; 30 μg/kg body weight; Astressin B), and then were transported in a livestock trailer for 12 h and 49 min. A second and third intraperitoneal injection was given at 4 h 42 min and 11 h 36 min into the transport process, respectively. Following transport, 4 SAL and 4 CRFA pigs were blood sampled and euthanized. The remaining 48 pigs were individually housed and given dietary antibiotics [AB; n = 12 SAL and 12 CRFA pigs; chlortetracycline (441 ppm) + tiamulin (38.6 ppm)] or no dietary antibiotics (NAB; n = 12 SAL and 12 CRFA pigs) for 14 d post-transport. Blood was collected at 12 h and on d 3, 7, and 14, and then pigs were euthanized on d 7 (n = 24) and d 14 (n = 24) post-weaning and transport. Circulating cortisol was reduced (p = 0.05) in CRFA pigs when compared to SAL pigs post-weaning and transport. On d 7, jejunal villus height and crypt depth was greater overall (p < 0.05) in AB-fed pigs versus NAB-fed pigs. On d 14, ileal crypt depth was reduced (p = 0.02) in CRFA pigs when compared to SAL pigs. Jejunal CRF mRNA abundance tended to be reduced (p = 0.09) on d 7 in CRFA pigs versus SAL pigs. On d 14, jejunal tumor necrosis factor-alpha was reduced (p = 0.01) in AB-fed pigs versus NAB-fed pigs. On d 7, change in glucose short-circuit current tended to be increased (p = 0.07) in CRFA pigs fed the AB diet when compared to CRFA pigs fed the NAB diet. In conclusion, CRFA pigs and pigs fed AB had some similar biological intestinal function measures post-weaning and transport.

Ractopamine does not rescue Halothane and Rendement Napole metabolism postmortem

The objective of this study was to determine if ractopamine (RAC) impacts postmortem muscle metabolism and subsequent pork quality in Halothane (HAL) and Rendement Napole (RN) mutant pigs. All RAC fed pigs had increased (P < 0.04) L* values. HAL and RN mutants muscle had lower (P < 0.01) pH values but RAC feeding had no effect. RN mutants had higher and lower (P < 0.05) muscle pH and temperatures, respectfully at 15 min and RN mutant pigs had greater (P < 0.0001) glycogen initially but lactate levels similar to wild type (WT) pigs at 24 h. RAC lowered (P < 0.05) glycogen in RN mutants but not in HAL mutated or WT pig muscle. These data show RAC feeding changes postmortem energy metabolism but does not change pH and pork quality hallmark of two major pig gene mutations and supports our contention that ultimate meat quality traits and their biochemical drivers may be more complex than originally reasoned.

Investigating the effects of jute nesting material and enriched piglet mats on sow welfare and piglet survival

Domesticated sows are motivated to perform nesting behavior prior to farrowing, and nesting material can reduce piglet cold stress. However, nesting material may not be practical in most production systems due to the potential for clogging slurry systems. Therefore, the study objectives were to assess an alternative nesting material provided prior to farrowing on sow welfare and piglet survival, and to investigate the effect of the entire nesting environment on piglet survival and growth performance. We hypothesized that the provision of jute nesting material would decrease sow stress and farrowing duration, and that nesting mat provision would allow piglets to remain euthermic and improve survival and growth. Sows (N = 20) were randomly assigned to one of two treatments: a farrowing crate with three pieces of 40.6 × 21.6 cm jute nesting material (Nest; n = 10) and two enriched piglet mats made from an acrylic board (28.0 × 86.4 cm) covered with a microfiber material, or a farrowing crate without nesting material (Control; n = 10) and one standard plastic piglet mat (28.0 × 86.4 cm). Jute pieces were attached to the front of the crate to prevent substrate from falling through the slatted floors. Saliva samples were collected to measure cortisol and immunoglobulin A (IgA), on days -1, 0, 1, and 2 relative to farrowing, and a final sample was collected at weaning (day 16.9 ± 0.18). Blood was collected from four piglets per litter to measure immunoglobulin G (IgG) at 48 h, day 7, and weaning. Piglet skin temperature (TS) was measured on two piglets per litter using an infrared camera for 3 d after birth at 0800, 1200, 1600, and 2000 h. One piglet was randomly chosen from the heat lamp and nonheat lamp side of the crate to measure TS. Video was continuously coded for observations of jute- and crate-directed interactions. Data were analyzed as a mixed model analysis of variance in SAS 9.4. Nest sows performed less crate-directed behavior than Control sows (P = 0.02). Cortisol tended to be reduced in Nest sows (P = 0.08) when compared to Controls, but no differences in IgA concentrations (P > 0.40) were detected. Nest piglets tended to be heavier on day 7 (P < 0.10), had greater IgG concentrations (P = 0.03), and had greater TS (P = 0.02) versus Controls. No farrowing duration or number of stillbirth differences were observed (P > 0.70). The jute material and piglet nests positively impacted sow welfare and piglet measures but did not translate into improved piglet survival.

Feeding a whole-cell inactivated Pichia guilliermondii yeast to gestating and lactating sows in a commercial production system

A total of 606 sows (PIC 1050) and their progeny (PIC 1050 × 280) were used to determine if feeding gestating and lactating sows a proprietary strain of Pichia guilliermondii as a whole-cell inactivated yeast product (WCY; CitriStim, ADM Animal Nutrition, Quincy, IL) improves sow and litter performance in a commercial production system. Once confirmed pregnant at d 35 post-breeding pregnancy check, sows were fed a basal gestation control (CON) diet (0.55% SID lysine) or the control diet fortified with 0.15% of the WCY replacing corn in the CON diet. Dietary treatments were also fed in lactation (1.05% SID lysine) once sows were moved into farrowing crates on approximately d 112 of gestation until weaning. Sows supplemented with WCY in gestation and lactation had increased total born piglets by 0.45 pigs (P < 0.04), piglets born alive (14.27 vs. 13.85; P < 0.04), and, therefore, heavier born alive litter weights (P < 0.001) compared to CON fed sows. A greater post cross-foster litter size (P < 0.001) meant that litter size at weaning was increased by 0.54 pigs when sows were fed WCY compared to CON (P < 0.001). However, litter weaning weights and 21-d adjusted litter weaning weights were similar (P > 0.158), although numerically greater, for WCY fed sows. Pigs from CON fed sows were 0.35 kg heavier at weaning compared to pigs from WCY fed sows (P < 0.001). This increase in weaning weight of pigs from CON fed sows is partially explained by their 0.93 d longer lactation (P < 0.001) and may also be due to the smaller litter size throughout lactation. The percent of litters treated for scours decreased from 38.3 to 14.2% when sows were fed WCY (P < 0.001). The distribution of birth and weaning weights was not impacted (P > 0.2461) by treatment. In conclusion, feeding gestating and lactating sows a proprietary strain of Pichia guilliermondii as a whole-cell inactivated yeast product increased the number of pigs born and weaned, and decreased the prevalence of scours during lactation.

The effect of reduced CP, synthetic amino acid supplemented diets on growth performance and nutrient excretion in wean to Finish swine

Mixed sex pigs (n = 720) were placed in 12 rooms (Purdue Swine Environmental Research Building) to measure the effect of reduced crude protein (CP), amino acid (AA)-supplemented diets on growth and the carcass. Pigs were blocked by body weight (BW) and gender and allotted to room and pen (10 mixed-sex pigs/pen). Pigs were fed a nine-phase, wean-finish program. Control pigs consumed corn-soybean meal-distiller's dried grains with solubles (DDGS) diets containing no to minimal (Met) synthetic AA. The 2X diet was formulated to meet the seventh most-limiting AA, and balanced using synthetic AAs to meet all AA needs. The 1X diet was formulated to meet a CP value halfway between the control and 2X diet, and also balanced using synthetic AAs to meet all AA needs. Diets were formulated to identical net energy concentrations and balanced to meet standard ileal digestible NRC 2012 AA requirements. Pit vacuum samples were collected at the end of each growth phase for analyses of nitrogen, C and dry matter (DM). Pigs fed the Control and 1X diet grew faster (P < 0.005), had greater gain:feed (P < 0.001), and were heavier at market (P < 0.001) than animals fed the 2X diet. No consistent effects of diet were observed on average daily feed intake. Carcass data were analyzed for sex, diet and sex*diet effects. Reductions in dietary CP resulted in a linear reduction in ammonium nitrogen excretion per kg of BW gain in Nursery (P < 0.001) and Grow-Finish (P < 0.001) phases. Reductions in dietary CP, with synthetic AA supplementation resulted in a linear reduction in total nitrogen excreted per kg BW gain in the Grow-Finish phase (P < 0.001) and overall (P < 0.001). Total mineral excretion per kg gain was reduced in pigs fed 1X and 2X diets compared with control-fed pigs (P < 0.005). Reductions in dietary CP of ~3 and 5%-units from wean-finish result in reductions of total N excretion of 11.7 and 24.4%, respectively. Reduced performance and carcass characteristics observed in pigs fed the 2X diets indicates an inaccurate estimate of NRC 2012 AA requirements or ratios to lysine in a low CP diet.

Characterizing the postnatal hypothalamic-pituitary-adrenal axis response of in utero heat stressed pigs at 10 and 15 weeks of age

In utero heat stress alters postnatal physiological and behavioral stress responses in pigs. However, the mechanisms underlying these alterations have not been determined. The study objective was to characterize the postnatal hypothalamic–pituitary–adrenal axis response of in utero heat-stressed pigs. Pigs were subjected to a dexamethasone suppression test followed by a corticotrophin releasing hormone challenge at 10 and 15 weeks of age. Following the challenge, hypothalamic, pituitary, and adrenal tissues were collected from all pigs for mRNA abundance analyses. At 10 weeks of age, in utero heat-stressed pigs had a reduced (P < 0.05) cortisol response to the corticotrophin releasing hormone challenge versus controls. Additionally, the cortisol response tended to be greater overall (P < 0.10) in 15 versus 10-week-old pigs in response to the dexamethasone suppression test. The cortisol response tended to be reduced overall (P < 0.10) in 15 versus 10-week-old pigs in response to the corticotrophin releasing hormone challenge. Hypothalamic corticotropin releasing hormone mRNA abundance tended to be greater (P < 0.10) in in utero heat-stressed versus control pigs at 15-weeks of age. In summary, in utero heat stress altered some aspects of the hypothalamic–pituitary–adrenal axis related to corticotropin releasing hormone signaling, and age influenced this response.

PSVI-3 Effect of feeding resistant starch on sow and piglet farrowing performance and blood parameters

Hyperprolific sows can have a long duration of farrowing, negatively impacting piglet survival and vitality. This study’s objective was to assess the effect of a diet containing 6.6% resistant starch (RS) on sow and piglet farrowing performance. We hypothesized that a diet containing RS would decrease sow farrowing duration and improve piglet survival. Forty-two sows were balanced for parity and randomly assigned to 1 of 2 treatments: standard lactation diet (n = 21) or diet containing RS (n = 21). Sows were fed their respective diets from approximately 7d prefarrowing throughout lactation. Sow blood was drawn at three time points on d106±1.0 and d113±1.0 of gestation (pre-feeding, 2 and 6 h post-feeding) and during farrowing to measure blood glucose. Piglet umbilical blood (~3/litter; beginning, middle, end of birth order) was collected at birth and analyzed for glucose, lactate, pH, PCO2, PO2, TCO2, HCO3, BE, and sO2. Piglets were visually assessed at birth to score meconium staining. Data collected included farrowing duration, piglet birthing intervals, number of stillborn piglets/litter, sow and piglet weights, piglet mortality, and sow feed and water intake. Average litter sizes post-crossfoster for control and RS were similar, 12.1±0.4 and 11.6±0.4 piglets, respectively. Litter weight gain was similar between control and RS (44.97 vs. 47.54 kg, P = 0.33), respectively. Feeding resistant starch had no effect on number of stillborn piglets or pre-weaning survival (P &gt; 0.75). Farrowing duration (178.9±17.6 min vs 165.2±18.0 min, P = 0.59) and piglet birth intervals (16.57±1.7 min and 14.89±1.8 min, P = 0.51) did not differ between control and RS, respectively. There was difference in sow blood glucose between diets (P = 0.02), day of sample (P &lt; 0.0001), time point (P &lt; 0.0001), and a day by time point interaction (P &lt; 0.0001). Feeding RS to sows prefarrowing can modify sow blood glucose, but did not result in reduced farrowing duration or improved piglet survival.

Effect of short-term high tryptophan diet fed to sows on their subsequent piglet behavior

Housing sows in groups create the challenge of decreasing fighting amongst sows. One proposed method to do so is to feed a high tryptophan diet, but the effect on the fetus is unknown. To investigate this, 66 sows were fed one of three diets: Control (0.14% SID tryptophan), Medium (0.28% SID tryptophan), or High (0.42% SID tryptophan), from days 28 to 35 of gestation. Sows gestated in standard gestation stalls. Blood samples were taken on day 27 prior to and on day 35 after tryptophan supplementation. On days 1, 2, and 3, nursing bouts were observed so as to record disputes and displacements from teat competition. The piglets' activity and fighting were recorded on days 3, 7, and 11 from 0700 to 1700 h. On day 12, four piglets per litter were blood sampled: two to be used in later behavior tests and two to act as controls for blood cortisol levels. On day 14, the two behavior test piglets from each litter were subjected to a 10-min Isolation Test and 5-min Human Approach Test. On day 15, the behavior test piglets were paired by sex and treatment (for example, a male Medium piglet paired with another male Medium piglet from a different crate) and each pair was subjected to a 10-min Social Challenge Test and immediately blood sampled. Piglet cortisol and serotonin did not differ among treatments (P > 0.10). There were no differences (P > 0.10) for number born (12.7 ± 0.4), born alive (11.7 ± 0.4), or mortality (1.1 ± 0.2). Behavior during nursing bouts was similar, with no treatment differences in number of disputes or displacements, and similar bout lengths among treatments (199.5 ± 4.6 s, P > 0.10). No differences were detected for any of the variables for Isolation or the Human Approach Tests (P > 0.10). During the Social Challenge Test, High piglets had more contacts approaching the head of the companion piglet than did either Medium or Control piglets (14.3 ± 1.1, 10.7 ± 1.1, and 9.69 ± 0.8, respectively, P < 0.02). Total number of aggressive interactions during the test tended to be greater for Medium piglets compared to High piglets (9.3 ± 1.5 vs 5.1 ± 0.9, P < 0.07). Time budget data of the litter indicate that piglets from all three treatments spent equal amounts of time active and inactive (P > 0.10). Aggression was low with 0.3 ± 0.04% of piglets displaying aggressive behavior. Feeding high concentrations of tryptophan for a short duration early in gestation does not have a negative impact on sows' subsequent offspring.

Replacing dietary antibiotics with 0.20% l-glutamine in swine nursery diets: impact on intestinal physiology and the microbiome following weaning and transport

Previous research demonstrates that supplementing 0.20% l-glutamine (GLN) in the diets of newly weaned and transported pigs improves growth rate to a similar extent as providing dietary antibiotics (AB). However, research comparing the effects of GLN vs. AB on intestinal physiology and the microbiome is limited. Therefore, the study objective was to compare the effects of supplementing nursery diets with GLN, AB, or no dietary antibiotics (NA) on intestinal physiology and the microbiome of pigs in a production environment following weaning and transport. Mixed-sex piglets (N = 480; 5.62 ± 0.06 kg body weight [BW]) were weaned (18.4 ± 0.2 d of age) and transported for 12 h in central Indiana, for two replicates, during the summer of 2016 and the spring of 2017. Pens were blocked by BW and allotted to one of the three dietary treatments (n = 10 pens/dietary treatment/replicate [8 pigs/pen]): AB (chlortetracycline [441 ppm] + tiamulin [38.6 ppm]), GLN (0.20% as-fed), or NA fed for 14 d. From day 14 to 34, pigs were fed common AB-free diets in two phases. On day 33, villus height:crypt depth tended to be increased (P = 0.07; 7.0%) in GLN and AB pigs vs. NA pigs. On day 33, glucagon-like peptide 2 (GLP-2) mRNA abundance was decreased (P = 0.01; 50.3%) in GLN and NA pigs vs. AB pigs. Crypt depth was increased overall on day 33 (P = 0.01; 16.2%) during the spring replicate compared with the summer replicate. Villus height:crypt depth was reduced (P = 0.01; 9.6%) during the spring replicate compared with the summer replicate on day 33. On day 13, tumor necrosis factor-alpha and occludin mRNA abundance was increased (P ≤ 0.04; 45.9% and 106.5%, respectively) and zonula occludens-1 mRNA abundance tended to be greater (P = 0.10; 19.2%) in the spring replicate compared with the summer replicate. In addition, AB pigs had increased (P = 0.01; 101.3%) GLP-2 mRNA abundance compared with GLN and NA pigs. Microbiome analysis indicated that on day 13, dietary treatment altered the microbiota community structure (P = 0.03). Specifically, the AB pigs tended to be distinct from both the NA and GLN pigs (P = 0.08), and Lactobacillus was increased nearly 2-fold in AB compared with NA pigs (q = 0.04) and GLN pigs (q = 0.22). In conclusion, GLN supplementation tended to improve some morphological markers of intestinal health similarly to AB pigs, while the microbiome composition in GLN pigs was more similar to NA pigs than AB pigs.

PSIII-13 Effects of Saccharomyces Cerevisiae Fermentation Products on Lactating Sow Performance

Lactating sows (N=140, York x Landrace) were used to evaluate the effects of a liquid prototype (LIQP) and dry (XPC®; Diamond V) Saccharomyces cerevisiae feed additives on sow and litter performance. Sows were fed a common gestation diet (0.55% SID-Lysine) until d112 of pregnancy and then allotted to lactation treatments: 1) Control diet (CON; 1.00% SID-Lysine), 2) CON +15 mL of LIQP from d112 to weaning (LIQ), 3) CON +0.20% of XPC from d112 to weaning (DRY), and 4) DRY +15 mL of LIQP from d112 to d7 post-farrowing (D+L). The LIQP was given once daily using an oral dose gun and XPC was included in the feed. Immunoglobulin concentrations were estimated on colostrum samples using Brix refractometer and piglet d 1 serum immunocrit ratio and plasma IgA and IgG. Daily sow water intake and daily feed intake (DFI) from d112 of gestation to d7 post-farrowing and weekly feed intake (ADFI) were recorded. There were no treatment effects on sow BW, backfat, or loin depth (P &gt;0.05) although sows from LIQ group had numerically smaller BW reductions compared to CON sows (4.9% vs 7.2%, P=0.19). LIQ sows had greater DFI and CON lower DFI during week 1 of lactation (P=0.04) as well as ADFI for weeks 2, 3, and overall lactation period (P&lt; 0.01) with DRY and D+L sows being intermediate. Water intake, immunoglobulins, and litter performance did not differ among treatments (P &gt;0.05) although pigs from LIQ sows, compared to CON, had numerically increased weaning (6.14 vs 5.82kg, P &gt;0.05) and litter weights (63.2 vs 60.1kg, P &gt;0.05). LIQ sows had 0.7 d reduced wean-to-estrus interval (P&lt; 0.001) and tended to have greater conception rates (P=0.07). In conclusion, LIQ supplementation of lactating sows improves feed intake, allowing sows to keep body reserves, and have better subsequent rebreeding performance.

241 Evaluation of a DFM and OA, Alone or in Combination, on Sow Reproductive and Litter Growth Performance

Forty-seven sows and their progeny were used to determine if feeding gestating and lactating sows a Bacillus licheniformis direct-fed microbial (DFM), an organic acid blend of medium chain and short chain fatty acids (OA), or in combination improves sow lactation feed and water intake, litter growth, and subsequent reproductive performance. On approximately d80 of gestation, sows were fed one of four diets in a 2 x 2 factorial design: 1) gestation control (CON; 0.55% SID Lysine), 2) CON with DFM (1.6x109 CFU/kg of complete feed), 3) CON with 0.4% OA, 4) CON with both DFM and OA. Dietary treatments were also fed throughout lactation (1.00% SID Lysine) starting on approximately d112 of gestation when sows entered farrowing facility. There was a tendency (P = 0.079) for DFM to decrease the amount of sow body weight loss in lactation by approximately 6% compared to sows not consuming the DFM, likely related to DFM sows numerically (P = 0.124) consuming 8.4% more feed during d7-14 of lactation. Sows fed the OA diets had fewer mummies/litter (P = 0.038) compared to diets not containing OA. Sows fed diets with the DFM gave birth to lighter pigs born alive (P = 0.003) compared to non-DFM fed sows, and a tendency for an interaction (P = 0.092) existed where feeding OA+DFM lessened the decrease in born alive BW. There was an interaction tendency (P = 0.133) where sows fed DFM returned to estrus 22 hours sooner than CON, but only 8 hours sooner when sows were fed the OA+DFM diet. In conclusion, feeding a Bacillus licheniformis DFM to sows may decrease pig born alive weight but reduce sow BW loss through 6.4% more lactation feed intake, quickening the return to estrus. Feeding the OA alone or in combination did not improve sow reproductive and litter growth performance in this study, and may require a larger sample size.

259 Effects of Saccharomyces Cerevisiae Fermentation Products on Lactating Sow’s Blood and Uterine Cytokine Profiles

This study evaluated the effects of a liquid prototype (LIQP) and dry (XPC®; Diamond V) Saccharomyces cerevisiae feed additives on blood and uterine cytokine profiles in sows (n = 40). On d 112 of pregnancy sows were allotted to dietary treatments: 1) Control diet (CON), 2) CON +15 mL of LIQP (LIQ), 3) CON +0.20% of XPC (DRY), and 4) DRY +15 mL of LIQP until d 7 post-farrowing (D+L). Interleukin (IL)-1β, IL-4, IL-6, IL-8, IL-10, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) were quantified from serum samples collected on d 112 of gestation, d 2 and 6 post-farrowing, and from uterine fluid collected on d 2, 4, and 6 post-farrowing. Serum C-Reactive protein (CRP) and haptoglobin concentrations were evaluated. No interactions between treatments and day of collection were observed (P &gt; 0.13). LIQ and D+L sows had the greatest serum IL-10 concentration (P &lt; 0.001) and sows fed CON tended to have lower concentration of IL-8 (P &lt; 0.06) vs. other treatments. Serum CRP concentrations were greatest on d 2 (P &lt; 0.001), serum IL-10 (P &lt; 0.04) and IL-4 (P &lt; 0.07) linearly decreased while serum haptoglobin (P &lt; 0.02) and INF-γ (P &lt; 0.001) linearly increased post-farrowing. In the uterine fluid, LIQ and D+L sows had greater INF-γ (P = 0.04) concentrations and CON tended to have the least concentration of TNF-α (P = 0.08). Uterine fluid IL-1 tended to linearly increase (P &lt; 0.07) and IL-6 linearly decrease (P &lt; 0.01) post-farrowing. No strong correlations were detected between cytokines in the serum and uterine fluid within day. LIQ sows had the greatest daily feed intake and CON the least during the first week of lactation (P = 0.04). Providing LIQP post-farrowing to sows modified immune response increasing both pro- and anti-inflammatory cytokines in serum and uterine fluid in an independent manner, allowing animals a quicker recovery and increased feed intake.

242 Evaluation of a DFM and OA, Alone or in Combination, on Sow Offspring’s Nursery Growth Performance

Progeny from sows fed diets containing a Bacillus licheniformis direct-fed microbial (DFM), an organic acid blend of medium and short chain fatty acids (OA), DFM+OA, or a control (CON) diet from d80 of gestation until weaning were used to determine if feeding CON, DFM, OA, or DFM+OA to the dam and/or progeny post-weaning improved nursery growth performance. Weaned pigs from 47 dams (n = 384, Initial BW=6.15 kg) were blocked by initial BW and sex and allotted (6 pigs/pen, 8 pens/treatment) to one of 8 nursery treatments. Pigs from CON sows were fed a negative (NC; no antibiotics, pharmacological Zn or Cu) or positive [PC; Neo-Terramycin phases 1 and 2 (827 and 551 ppm) and Carbadox phase 3 (55 ppm)] control diet. Pigs from sows fed DFM, OA, or DFM+OA were fed the NC diet or a diet representative of their dam. Diets with DFM contained 1.6x109 CFU/kg DFM and diets with OA contained 0.5, 0.4, and 0.3% OA in phases 1–3, respectively. Weaning weight was used as a covariate for nursery performance. For all phases and overall, PC fed pigs had greater ADG, ADFI, and G:F (P &lt; 0.05). Feeding DFM or OA in sow diets improved (interaction; P&lt; 0.042) nursery pig G:F, but DFM+OA offspring had no improvement for d7–14, 0–14, and 0–21 G:F. Feeding DFM or OA to sows and their progeny decreased ADFI (interaction; P &lt; 0.042) but improved G:F (interaction; P &lt; 0.028) for d7–14 and 0–14 with DFM+OA having no improvement above CON. For d14–21 and 0–21, feeding DFM or OA to sows and their progeny decreased ADFI whereas DFM+OA increased ADFI above CON (interaction; P &lt; 0.019). In conclusion, feeding DFM or OA to sows or their offspring may improve nursery feed efficiency and feeding DFM+OA diet to sows and their progeny may increase ADFI late in the nursery period.

56 The Effect of a Developmental Bacillus Direct-fed Microbial on Nursery Pig Growth Performance and Health

A developmental Bacillus based direct-fed microbial (DFM) was added to nursery pig diets to evaluate the effect on growth and health in two 35-d randomized complete block design experiments blocked on initial BW and sex. Experiment 1 used 315 weaned pigs (20.1 d of age; 6.11 kg initial BW) allotted to one of three diets: 1) Negative Control (NC; no antibiotics but with pharmacological Zn or Cu), 2) NC+DFM 0.55x109CFU, 3) NC+DFM 1.1x109CFU. Experiment 2 used 376 weaned pigs (17.8 d of age; 5.99 kg initial BW) allotted to one of four diets, the same 3 diets from Experiment 1 plus a lower inclusion rate: 4) NC+DFM 0.275x109CFU. Both studies had 15 replicates/treatment, 6–7 pigs/pen. Pigs were budget fed phase 1–3 diets (1.13 kg/pig; 2.72 kg/pig; and 6.35 kg/pig, respectively) and ad libitum fed Phase 4 diet to d35. For Experiment 1, during week 1 pigs fed the DFM tended to linearly decrease ADFI (P = 0.086) and linearly increase G:F (P = 0.085). During day 21–35 of Experiment 1 pigs fed DFM linearly increased ADG (P = 0.035) and quadratically increased ADFI (P = 0.027). Overall for experiment 1, ADG (P = 0.114) and ADFI (P = 0.104) tended to quadratically increase and G:F linearly increased (P = 0.012) with increasing concentrations of DFM. Experiment 2; during week 1 and 3 ADFI (P = 0.084, P = 0.050, respectively) quadratically increased and G:F (P = 0.081; P = 0.022, respectively) quadratically decreased as DFM increased in the diet. During d21–35 of experiment 2, ADG (P = 0.064) quadratically increased and G:F (P = 0.012) quadratically decreased as DFM increased. Overall for Experiment 2 ADFI numerically increased (4.3%) with no increase in ADG, resulting in a quadratic decrease in G:F (P = 0.010) as the DFM increased in the diet. Summarizing these two studies, the DFM product had its greatest effect increasing ADFI while inconsistently impacting gain and efficiency.

PSVI-17 The Effect of Dacitic Tuff Breccia Alone or in Combination with Poultry By-products on Nursery Pig Growth Performance

Dacitic tuff breccia (DTB) and poultry by-products (PBP) were added to nursery pig diets to evaluate their effects on growth performance in a 35 d experiment. A randomized complete block design based on BW and sex was used. Newly weaned pigs (N=564, 20.1 d of age, 6.18±0.006 kg initial BW) allotted to four diets (15 replicates/treatment; 9 or 10 pigs/pen): 1) Negative control (NC; no DTB or PBP), 2) NC+DTB (0.5% inclusion), 3) NC+PBP (4% chicken by-product meal + 2% feather meal – replacing fishmeal, corn, and synthetic amino acids in the NC), 4) NC+DTB+PBP. Phase 1–3 were each 7-d and Phase 4 was from d21-35. During week one there were no differences (P &gt;0.10) among treatments. In week 2, pigs fed DTB tended to increase ADG (323 vs. 303 g/d; P=0.068) and ADFI (376 vs. 356 g/d; P=0.055) compared to pigs not fed DTB and pigs fed PBP tended to have increased ADG (P=0.093). In week 3 pigs fed PBP had reduced ADG (460 vs 483 g/d; P=0.011) and G:F (0.689 vs. 0.723; P&lt; 0.001), and there tended to be an interaction for G:F (P=0.083) with DTB improving G:F when fed in combination with PBP but reducing G:F in the control diet. In week 4, feeding PBP decreased ADG (384 vs 415 g/d; P&lt; 0.01) and ADFI (629 vs 666 g/d; P&lt; 0.01) compared to pigs fed no PBP. There were no differences among treatments during week 5. For Phase 4 (d21-35) pigs fed PBP had decreased ADG (479 vs 497 g/d; P=0.041) and tended to have reduced ADFI (P=0.092) compared to pigs fed no PBP. Overall (d 0–35), there were no significant differences among treatments. In conclusion, DTB improved nursery pig growth performance early, however, pigs fed PBP had decreased ADG and feed efficiency late in the nursery period.

In utero heat stress alters the postnatal innate immune response of pigs

The effects of in utero heat stress (IUHS) range from decreased growth performance to altered behavior, but the long-term impact of IUHS on postnatal innate immune function in pigs is unknown. Therefore, the study objective was to determine the effects of early gestation IUHS on the immune, metabolic, and stress response of pigs subjected to an 8 hr lipopolysaccharide (LPS) challenge during postnatal life. Twenty-four pregnant gilts were exposed to thermoneutral (TN; n = 12; 17.5 ± 2.1 °C) or heat stress (HS; n = 12; cyclic 26 to 36 °C) conditions from days 6 to 59 of gestation, and then TN conditions (20.9 ± 2.3 °C) from day 60 of gestation to farrowing. At 12 wk of age, 16 IUHS and 16 in utero thermoneutral (IUTN) pigs were selected, balanced by sex and given an intravenous injection of LPS (2 µg/kg BW mixed with sterile saline [SAL] and injected at 2 µL/kg BW) or SAL (2 µL/kg BW). Body temperature was monitored every 30 min, and blood was obtained at 0, 1, 2, 3, 4, 6, and 8 hr following the LPS challenge. Blood samples were analyzed for glucose, insulin, non-esterified fatty acids (NEFA), cortisol, and cytokine concentrations. In addition, white blood cell counts were determined at 0 and 4 hr. Hour 0 data were used as covariates. Body temperature was increased (P < 0.01) in LPS (40.88 ± 0.08 °C) vs. SAL (39.83 ± 0.08 °C) pigs. Eosinophils tended to be decreased overall (P = 0.09; 43.9%) in IUHS vs. IUTN pigs. Glucose concentrations were reduced overall (P = 0.05; 5.9%) in IUHS vs. IUTN pigs. The NEFA concentrations tended to be greater (P = 0.07; 143.4%) in IUHS-LPS pigs compared with all other treatments, and IUTN-LPS pigs tended to have greater (127.4%) circulating NEFA concentrations compared with IUTN-SAL and IUHS-SAL pigs. Cortisol was increased (P = 0.04) in IUHS-LPS compared with IUTN-LPS pigs at 3 hr (21.5%) and 4 hr (64.3%). At 1 hr, tumor necrosis factor α was increased (P = 0.01; 115.1%) in IUHS-LPS compared with IUTN-LPS pigs. Overall, interleukin-1β (IL-1β) and interleukin-6 (IL-6) were greater (P < 0.04; 281.3% and 297.8%, respectively) in IUHS-LPS pigs compared with all other treatments, and IUTN-LPS pigs had increased IL-1β and IL-6 concentrations compared with IUTN-SAL and IUHS-SAL pigs. In summary, IUHS altered the postnatal cytokine, metabolic, and physiological stress response of pigs during postnatal life, which may have negative implications toward the innate immune response of IUHS pigs to pathogens.

Ractopamine changes in pork quality are not mediated by changes in muscle glycogen or lactate accumulation postmortem

Pork quality is a product of the rate and extent of muscle pH decline paced by carbohydrate metabolism postmortem. The beta-adrenergic agonist ractopamine (RAC) alters muscle metabolism but has little impact on pork quality. The objective of this study was to determine how feeding RAC alters postmortem carbohydrate metabolism in muscle. Muscle pH was higher early postmortem in pigs fed RAC for 2 wks compared to control, while other time points and temperatures were largely unaffected. Early postmortem, muscle lactate levels were reduced (P < 0.05) after feeding RAC for 1 and 2 wks. Similarly, pigs fed RAC for 4 wks had reduced (P < 0.05) glycogen levels early postmortem compared to control pigs, but unexpectedly, L* values (lightness) increased (P < 0.05) after inclusion of RAC in the diet for 4 wk. These data show RAC feeding reduces glycogen content and changes lactate accumulation postmortem, but raise questions about the role glycolytic flux has in driving pork quality development.

Evaluation and mitigation of the effects of in utero heat stress on piglet growth performance, postabsorptive metabolism, and stress response following weaning and transport

In utero heat stress (IUHS) increases the energy requirements of pigs during postnatal life, and this may compound weaning and transport stress. The study objective was to evaluate and mitigate the negative effects of IUHS following weaning and transport through the provision of a nutrient-dense (ND) nursery diet formulated to meet the greater energy requirements of IUHS pigs during the first 14 d postweaning and transport. Twenty-four pregnant gilts were exposed to thermoneutral (TN; n = 12; 17.5 ± 2.1 °C) or heat stress (HS; n = 12; cycling 26 to 36 °C) conditions for the first half of gestation (day 6 to 59) and then TN conditions (20.9 ± 2.3 °C) until farrowing. Nine TN gilts and 12 HS gilts produced litters. At weaning (16.2 ± 0.4 d), mixed-sex piglets (N = 160; 4.78 ± 0.15 kg body weight [BW]) were transported (loading + transport + unloading) for 11 h 40 min. Following transport, piglets were blocked into pens (n = 4 pigs/pen) by in utero and dietary treatments: in utero thermoneutral (IUTN) + control (C) diet (n = 10 pens), IUTN + ND (n = 10 pens), IUHS + C (n = 10 pens), and IUHS + ND (n = 10 pens). Treatment diets were fed from day 1 to 14 postweaning and transport (period 1), and the C diet was fed to all pigs from day 14 to 35 postweaning and transport (period 2). Production measures were taken in 7 d intervals to calculate average daily gain (ADG), average daily feed intake (ADFI), average daily net energy intake (ADEI), gain:feed, and gain:net energy intake. Blood samples were collected prior to transport, following transport, and on days 2, 7, 14, 28, and 35 postweaning and transport to analyze cortisol, glucose, insulin, and nonesterified fatty acids. Behavior was assessed through video-recording on days 3, 5, 8, 11, and 13 postweaning and transport. In period 1, ADG was reduced (P = 0.04; 20.0 g/d) in IUHS vs. IUTN pigs. Pigs fed ND diets had reduced ADFI (P = 0.02; 9.3%) compared with C diet-fed pigs during period 1, which resulted in similar ADEI (P = 0.23; 1,115 ± 35 kcal/d). During transport, cortisol was decreased (P = 0.03; 25.8%) in IUHS vs. IUTN pigs. On day 2, glucose was decreased (P = 0.01; 13.8%) in IUHS vs. IUTN pigs. No in utero treatment-related behavior differences were observed but lying was reduced (P = 0.03; 6.5%) and standing was increased (P = 0.04; 14.1%) in ND vs. C pigs overall. In summary, IUHS reduced growth performance in pigs following weaning and transport, and providing an ND diet did not rescue the lost performance.

PSIX-6 Effect of dacitic tuff breccia in nursery diets on pig growth performance, blood parameters, and intestinal morphology

Trace element and mineral intake are important for proper function of the immune system and various metabolic processes. The objective of this experiment was to evaluate the effect of a dacitic tuff breccia (DTB), classified as a hydrated sodium calcium aluminosilicate, in the diet of nursery pigs. Dietary treatments were: 1) Control diet (CON), 2) CON + 0.25% DTB (DTB1), and 3) CON + 0.50% DTB (DTB2). Pigs (6.79 + 0.064 kg; 26d of age) were individually housed and fed dietary treatments for 21 d (n=48; 16/trt). At the end of the experiment, blood, jejunal, and ileal samples were collected for a typical metabolic panel and basic histologic and morphologic measurements. DTB2 fed pigs tended (P=0.07) to have greater ADG than CON and DTB1 fed pigs (392, 397, 430g/d for CON, DTB1, DTB2, respectively), and greater (P=0.008) ADFI (591, 592, 669g/d for CON, DTB1, DTB2, respectively). Gain:Feed was not different (P=0.75) among treatments (0.655, 0.663, 0.644 for CON, DTB1, DTB2, respectively). Crypt depth in the jejunum was greater (P=0.04) for DTB1 compared to CON fed pigs but did not differ from DTB2 fed pigs (254.7, 292.0, 275.6mm for CON, DTB1, DTB2, respectively). Villous height, villous:crypt, number of goblet cells and intraepithelial lymphocytes did not differ among treatments in both ileum and jejunum (P &gt;0.17). Total white blood cell (WBC) count did not differ (P &gt;0.10). However, the proportion of WBC that were monocytes was lower (P=0.024) in DTB1 compared to CON and DTB2 fed pigs (1.27, 0.79, 1.45% for CON, DTB1, DTB2, respectively). Blood Urea Nitrogen (BUN) concentration tended (P=0.06) to be linearly decreased with increasing DTB concentrations (9.27, 8.80, 7.75mg/dL). DTB inclusion at 0.5% in nursery pig diets tended to improve growth performance, while inclusion at 0.25% increased jejunal crypt depth and reduced monocytes:WBC and increasing DTB concentrations tended to decreased BUN linearly.

36 Evaluation and mitigation of the effects of in utero heat stress on pig performance following weaning and transport

In utero heat stress (IUHS) negatively affects swine productivity and is a growing concern for the swine industry. The study objective was to evaluate and mitigate the negative effects of IUHS on pig performance following weaning and transport. Based on previous research, we hypothesized that IUHS pigs would have reduced performance relative to in utero thermoneutral (IUTN) pigs due to greater maintenance costs and supplementing a nutrient-dense (ND) diet would improve IUHS pig performance to similar levels as IUTN pigs fed a common (C) diet. Therefore, 24 bred gilts were assigned to either thermoneutral (TN; n = 12; 17.5 ± 2.1°C) or heat stress (HS; n = 12; cyclical 27°C to 37°C) conditions for the first half of gestation (d1 to 58) and then TN conditions for the remainder of gestation. At weaning (16.2 ± 0.4 d), pigs (N = 160; 4.78 ± 0.15 kg BW) were transported (loading + transport + unloading) for approximately 12h. Pigs were then blocked into pens (n = 4 pigs/pen) by in utero and dietary treatments which were fed for 14 d (Period-1): IUTN-C (n = 10 pens), IUTN-ND (n = 10 pens), IUHS-C (n = 10 pens), IUHS-ND (n = 10 pens). Following Period-1, all pigs were fed the C diet from d15 to 35 post-weaning and transport (Period-2). Production measures were taken on d 0, 7, 14, 21, 28, and 35 post-weaning and transport to calculate ADG, ADFI, and G:F. During Period-1, ADG was reduced overall (P = 0.03, 10.6%) for IUHS pigs compared to IUTN pigs. Pigs fed ND diets had reduced ADFI during Period-1 (P = 0.02, 8.8%) relative to C fed pigs, regardless of in utero treatment. During Period-2, ADFI was increased (P = 0.03, 4.7%) in ND versus C pigs, regardless of in utero treatment. In summary, increasing the nutrient density of the diet did not rescue the lost productivity of IUHS pigs as indicated by an overall reduction in ADG.

275 Feeding a whole-cell inactivated Pichia guilliermondi yeast to gestating and lactating sows in a commercial production system

A total of 606 sows (PIC 1050) and their progeny (PIC 1050×280) were used to determine if feeding gestating and lactating sows a proprietary strain of Pichia guilliermondi as a whole-cell inactivated yeast product (WCY; CitriStim, ADM Animal Nutrition, Quincy, IL) improves sow and litter performance in a commercial production system. Once confirmed pregnant at d 35 post-breeding pregnancy check, sows were fed either a basal gestation control (CON) diet (0.55% SID Lysine) or the control diet fortified with 0.15% (1.36 kg/ton) of the WCY replacing corn in the CON diet. Dietary treatments were also fed in lactation (1.05% SID Lysine) once sows were moved into farrowing crates on approximately d 112 of gestation until weaning. Sows supplemented with WCY in gestation and lactation had a greater number of total born piglets by 0.45 pigs (P=0.040), born alive (P&lt; 0.04), heavier born alive litter weight (P&lt; 0.001), and greater post cross-foster litter size (P&lt; 0.001) compared to CON fed sows. Litter size at weaning was increased by 0.54 pigs when sows were fed WCY compared to CON (P&lt; 0.001). However, the average piglet weaning weights from CON fed sows were heavier by 0.35 kg compared to WCY (P&lt; 0.001). This increase in body weight of piglets from CON fed sows is partially explained by their 0.93 days longer lactation (P&lt; 0.001), and may also be due to the smaller litter size nursed throughout lactation. The percent of litters treated for scours decreased from 38.3% to 14.2% when sows were fed WCY (P&lt; 0.001). The distribution of birth weights by body weight range was not different (P=0.2461) between treatments. In conclusion, feeding gestating and lactating sows a proprietary strain of Pichia guilliermondi as a whole-cell inactivated yeast product increased the number of piglets born and number weaned as well as decreased the prevalence of scours during lactation.

234 In utero heat stress alters the postnatal immune and metabolic response of growing pigs subjected to a lipopolysaccharide challenge

In utero heat stress (IUHS) reduces swine productivity and welfare but little is known about the long-term impact on immune function. The study objective was to determine the effects of IUHS on the immune and metabolic response of pigs subjected to an 8 h lipopolysaccharide (LPS) challenge during postnatal life. Twenty-four pregnant gilts were exposed to thermoneutral (TN; n = 12; 17.5 ± 2.1⁰C) or heat stress (HS; n = 12; cyclical 27°C-37°C) conditions from d 1 to 58 of gestation, and TN conditions from d 59 of gestation to farrowing. After farrowing, all piglets were housed under the same conditions. At 12 weeks post-farrowing, 16 IUHS and 16 in utero thermoneutral (IUTN) pigs were selected, balanced by sex and given an intravenous injection of LPS (2 µg/kg BW) or saline (SAL). Treatment combinations were: IUTN-SAL, IUTN-LPS, IUHS-SAL, IUHS-LPS. Body temperature was monitored in 30-min intervals and blood samples were obtained at 0, 1, 2, 3, 4, 6, and 8 h. Blood was analyzed for glucose, insulin, non-esterified fatty acids (NEFA), and cytokine concentrations. Body temperature increased (P &lt; 0.01; 1.05°C) in LPS versus SAL pigs, regardless of in utero treatment. Glucose concentrations were reduced overall (P = 0.05; 5.9%) in IUHS versus IUTN pigs. Non-esterified fatty acid concentrations tended to be greater (P = 0.07; 143.4%) in IUHS-LPS pigs compared to all other treatments, and IUTN-LPS pigs tended to have greater circulating NEFA concentrations (127.4%) compared to IUTN-SAL and IUHS-SAL pigs. At 1 h, TNFα was increased (P = 0.01; 115.1%) in IUHS-LPS compared to IUTN-LPS pigs. Overall, IL-1β and IL-6 were greater (P &lt; 0.04; 56.0 and 46.8%, respectively) in IUHS-LPS compared IUTN-LPS pigs. In summary, IUHS altered the postnatal immune and metabolic response of pigs during postnatal life, which has negative implications towards future disease susceptibility.

185 Effect of dacitic tuff breccia in nursery diets on pig growth performance and nutrient digestibility

For proper function of many metabolic processes trace element and mineral intake is important. The objective of this experiment was to evaluate the addition of a dacitic tuff breccia (DTB), a hydrated sodium calcium aluminosilicate, on nursery pig growth and nutrient digestibility. Dietary treatments were: 1) Control (CON) and 2) CON+0.50% DTB (DTB). Pigs (7.73±0.205 kg; 26 d of age) were individually housed and fed for 20d (n=24, 12/trt). Nutrient digestibility was evaluated using individual metabolism pens for 3d total collection of feces and urine during the last week of evaluation. DTB had no effect on pig performance during week 1 (P &gt;0.28). Week 2 ADG (128 versus 302 g/d; P=0.02), BW (10.63 versus 11.77 kg; P=0.03), and G:F (0.275 versus 0.608; P=0.02) were improved for DTB compared to CON fed pigs. Week 3 ADFI was greater for DTB fed pigs compared to CON (642 vs 768 g/d; P=0.01). Overall (d0-20), DTB fed pigs had greater ADG (279 versus 352 g/d; P=0.04), final BW (13.3 versus 14.8 kg; P=0.04), and numerically greater ADFI (497 versus 558 g/d; P=0.16) and G:F (0.562 versus 0.624; P=0.22) compared to CON. During the collection period, ADG was numerically increased (396 versus 427 g/d; P=0.69) and ADFI (544 vs 668 g/d; P=0.03) was greater for DTB versus CON fed pigs. Nutrient digestibility was not affected by inclusion of DTB in the diet (P &gt;0.05). Digestibility coefficients for CON and DTB, respectively, were: 0.863 and 0.856 for DM; 0.842 and 0.842 for digestible energy; 0.824 and 0.814 for nitrogen; 0.701 and 0.667 for phosphorus; 0.873 and 0.816 for sodium; 0.481 and 0.431 for zinc; 0.517 and 0.458 for iron; and 0.438 and 0.392 for manganese. DTB in nursery pig diets improved growth performance and tended to improve feed intake, but had no effect on nutrient digestibility.

30 Uterine flushing as a non-invasive method to access inflammatory cytokines in sows reproductive tract after parturition

Inflammatory mediators, such as cytokines, can reduce feed intake and drastically modify the partitioning of nutrients. Thus, it may increase the animal’s maintenance requirements, reduce milk production and piglet growth, impact reproductive performance, and reduce sow lifetime productivity. The objective of this experiment was to evaluate a non-invasive method, not tested before in swine, to assess cytokine profiles from post-partum uterine lavage. The uteri of second and third parity sows (n=14) were flushed with sterile saline solution (0.9%) on days 2, 4, and 14 post-parturition. An artificial insemination (AI) catheter, in its plastic covering, to avoid vaginal contents, was inserted through the vagina into the cervix. A flexible inner catheter was passed through the outer AI catheter and into the uterine horn. Sterile saline (30-40 mL) was flushed through the inner catheter into one uterine horn. After inner catheter removal, a tube was attached to the end of the outer AI catheter to allow collection of the natural back-flow of uterine lavage fluid (avg 24.7% recovery). Uterine fluid collected was immediately centrifuged and the supernatant stored at -20°C. Samples were freeze-dried, re-suspended in sterile saline (2 mL), and stored at -80°C. Cytokine profiles of the uterine fluid were evaluated using a multiplex ELISA panel including interleukin (IL)-1β, IL-6, IL-8, IL-4, IL-10, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ). Cytokine concentrations were calculated relative to protein content (pg/mg of protein). IFN-γ and TNF-α were lower than the limit of detection in most samples (5/38 and 1/38, respectively). IL-4 and IL-10 concentrations did not differ among days of collection (P &gt;0.14). IL-8 was greater on day 4 than on days 2 or 14 (P&lt; 0.05). IL-1β and IL-6 were greater on days 2 and 4 than on day 14 (P&lt; 0.05). Uterine flushing is a novel non-invasive method to access uterine inflammatory cytokines in sows.

154 Evaluating the effects of prophylactic antibiotics on intestinal health in pigs given a corticotropin-releasing factor antagonist during weaning and transport

Prophylactic antibiotics improve intestinal health in pigs; however, it is unknown whether their efficacy interacts with a pig’s stress response following weaning and transport. The study objective was to determine whether a corticotropin-releasing factor (CRF) antagonist would impact the efficacy of prophylactic antibiotics on improving intestinal health in transported weaned pigs. Mixed-sex pigs (n = 56; 5.70 ± 1.05 kg BW) were weaned (20.49 ± 0.64 d), a blood sample was taken, pigs were given an i.p. injection of saline (SAL) or a CRF antagonist (CRFA; 30 µg/kg BW; Astressin B), and then were transported for 12 h. Pigs were given a second and third i.p. injection at 6 and 12 h of transport, respectively. Following transport, 4 SAL and 4 CRFA pigs were blood sampled and euthanized. The remaining 48 pigs were individually housed and assigned to an antibiotic [A; chlortetracycline (441 ppm) + tiamulin (38.6 ppm)] or no antibiotic (NA) diet treatment balanced by injection treatment (n = 12 pigs/treatment combination). Blood was collected at 12 h and on d 3, 7, and 14 and pigs were euthanized on d 7 (n = 24) and d 14 (n = 24) post-weaning and transport. Plasma adrenocorticotropic hormone was reduced overall (P = 0.05; 9.1%) in CRFA versus SAL pigs. On d 7, jejunal villus height was greater (P = 0.04; 33%) in A versus NA pigs. Jejunal zonula occludens-1 (58.8%) and ileal claudin-1 (100.5%) mRNA abundance tended to be increased (P = 0.09) in CRFA+NA versus SAL+NA pigs on d 7. On d 14, jejunal tumor necrosis factor-alpha mRNA abundance was reduced (P = 0.02; 29.9%) in A versus NA pigs and jejunal glucagon-like peptide-2 mRNA abundance was increased (P = 0.03) in CRFA+NA versus SAL+NA (48.4%) and SAL+A versus SAL+NA (55.8%) pigs. No intestinal health parameter differences were detected (P &gt; 0.05) between CRFA+NA and SAL+A pigs. In conclusion, CRFA and A impacted weaned pig intestinal health measures at similar levels.

Ractopamine-induced fiber type-specific gene expression in porcine skeletal muscles is independent of growth

Feeding ractopamine (RAC), a β-adrenergic agonist (BAA), to pigs increases type IIB muscle fiber type-specific protein and mRNA expression. However, increases in the abundance of these fast-twitch fiber types occur with other forms of muscle hypertrophy and thus BAA-induced changes in myosin heavy chain (MyHC) composition may simply be associated with increased muscle growth known to occur in response to BAA feeding. The objective of this study was to determine whether RAC feeding could change the MyHC gene expression in the absence of maximal muscle growth. Pigs were fed either an adequate diet that supported maximal muscle hypertrophy or a low nutrient diet that limited muscle growth. RAC was included in diets at 0 or 20 mg/kg for 1, 2, or 4 wk. Backfat depth was less (P < 0.05) in pigs fed the low nutrient diet compared with the adequate diet but was not affected by RAC. Loin eye area was greater (P < 0.05) in pigs fed an adequate diet plus RAC at 1 wk but did not differ among remaining pigs. At 2 and 4 wk, however, pigs fed the adequate diet had greater loin eye areas (P < 0.05) than pigs fed the low nutrient diet regardless of RAC feeding. Gene expression of the MyHC isoforms, I, IIA, IIX, and IIB, as well as glycogen synthase, citrate synthase, β 1-adrenergic receptor (AR), and β 2-AR were determined in longissimus dorsi (LD) and red (RST) and white (WST) portions of the semitendinosus muscles. MyHC type I gene expression was not altered by RAC or diet. Feeding RAC decreased (P < 0.01) MyHC type IIA gene expression in all muscles, but to a greater extent in WST and LD. MyHC type IIX gene expression was lower (P < 0.05) in WST and LD muscles in response to RAC but was not altered in RST muscles. RAC increased (P < 0.05) MyHC type IIB gene expression in all muscles, but to a greater extent in RST. β 1-AR gene expression was unaffected by RAC or diet, whereas the expression of the β 2-AR gene was decreased (P < 0.001) by RAC. No significant RAC * diet interactions were observed in gene expression in this study, indicating that RAC altered MyHC and β 2-AR gene expression in porcine skeletal muscles independent of growth.

Effects of increasing dietary L-glutamine to replace antibiotics on pig health and performance following weaning and transport

Supplementing nursery diets with 0.20% L-glutamine (GLN) may provide similar growth and health benefits as dietary antibiotics, but it was unknown if greater inclusion levels may provide additional benefits. Therefore, the study objective was to evaluate the impact of replacing dietary antibiotics with increasing GLN levels on growth performance, therapeutic antibiotic treatment rates, welfare measures, and production costs in pigs after weaning and transport. We hypothesized that withholding dietary antibiotics may negatively impact performance and increase therapeutic treatment rate, and that diet supplementation with 0.20% to 1.00% GLN may incrementally improve productivity and reduce therapeutic antibiotic treatment rates compared with dietary antibiotics. Mixed sex pigs (N = 308; 5.64 ± 0.06 kg body weight [BW]) were weaned (19.1 ± 0.2 d of age) and transported in central Indiana in 2017. Pigs were blocked by BW and allotted to one of seven dietary treatments (n = 8 pens/dietary treatment): dietary antibiotics (positive control [PC]; chlortetracycline [441 mg/kg] + tiamulin [38.6 mg/kg]), no antibiotics or added GLN (negative control [NC]), 0.20% GLN, 0.40% GLN, 0.60% GLN, 0.80% GLN, or 1.00% GLN fed for 14 d. From d 14 to 35, pigs were provided nonantibiotic common diets in two phases. Overall, average daily gain (ADG) was reduced (P = 0.01; 17.7%) from d 0 to 14 in NC, 0.20% GLN, 0.60% GLN, 0.80% GLN, and 1.00% GLN pigs compared with PC pigs, but no ADG differences were detected between 0.40% GLN pigs and PC pigs. Increasing GLN in the diet tended to increase ADG (linear; P = 0.10). Overall, d 35 BW was greater (P = 0.01) in 0.80% GLN and PC pigs compared with NC, 0.20% GLN, and 0.60% GLN pigs, and was greater for 0.40% GLN and 1.00% GLN pigs vs. 0.20% GLN pigs. However, no d 35 BW differences were detected (P > 0.05) between PC, 0.40% GLN, 0.80% GLN, and 1.00% GLN pigs. Increasing GLN in the diet tended to increase (linear; P = 0.08) d 35 BW. Overall, income over feed and therapeutic injectable antibiotics cost (IOFAC) for enteric and unthrifty challenges were greater (P = 0.02) in 0.80% GLN pigs compared with NC, 0.20% GLN, and 0.60% GLN pigs, but no IOFACs for enteric and unthrifty challenges differences were detected between 0.80% GLN pigs and 0.40% GLN, 1.00% GLN, and PC pigs. In conclusion, GLN supplemented pigs had improved performance after weaning and transport compared with the NC pigs with 0.40% GLN being the most effective level.

Replacing dietary antibiotics with 0.20% l-glutamine and synbiotics following weaning and transport in pigs

Dietary antibiotic use has been limited in swine production due to concerns regarding antibiotic resistance. However, this may negatively impact the health, productivity, and welfare of pigs. Therefore, the study objective was to determine if combining dietary synbiotics and 0.20% l-glutamine would improve pig growth performance and intestinal health following weaning and transport when compared with traditionally used dietary antibiotics. Because previous research indicates that l-glutamine improves swine growth performance and synbiotics reduce enterogenic bacteria, it was hypothesized that supplementing diets with 0.20% l-glutamine (GLN) and synbiotics (SYN; 3 strains of Lactobacillus [1.2 × 10^9 cfu/g of strain/pig/d] + β-glucan [0.01 g/pig/d] + fructooligosaccharide [0.01 g/pig/d]) would have an additive effect and improve pig performance and intestinal health over that of dietary antibiotics. Mixed-sex pigs (N = 226; 5.86 ± 0.11 kg body weight [BW]) were weaned (19.4 ± 0.2 d of age) and transported for 12 h in central Indiana. Pigs were blocked by BW and allotted to one of two dietary treatments (5 to 6 pigs per pen): antibiotics (positive control [PC]; chlortetracycline [441 ppm] + tiamulin [38.5 ppm]), no antibiotics (negative control [NC]), GLN, SYN, or the NC diet with both the GLN and SYN additives (GLN + SYN) fed for 14 d. From day 14 post-weaning to the end of the grow-finish period, all pigs were provided common antibiotic-free diets. Data were analyzed using PROC GLIMMIX and PROC MIXED in SAS 9.4. Overall, haptoglobin was greater (P = 0.03; 216%) in NC pigs compared with PC pigs. On day 13, GLN and PC pigs tended to have reduced (P = 0.07; 75.2% and 67.3%, respectively) haptoglobin compared with NC pigs. On day 34, the jejunal goblet cell count per villi and per millimeter tended to be greater (P < 0.08; 71.4% and 62.9%, respectively) in SYN pigs compared with all other dietary treatments. Overall, jejunal mucosa tumor necrosis factor-alpha (TNFα) gene expression tended to be greater (P = 0.09; 40.0%) in NC pigs compared with PC pigs on day 34. On day 34, jejunal mucosa TNFα gene expression tended to be greater (P = 0.09; 33.3%, 41.2%, and 60.0%, respectively) in GLN pigs compared with SYN, GLN + SYN, and PC pigs. Although it was determined that some metrics of pig health were improved by the addition of GLN and SYN (i.e., haptoglobin and goblet cell count), overall, there were very few differences detected between dietary treatments and this may be related to the stress load incurred by the pigs.

Effects of Three Distinct 2-Week Long Diet Strategies After Transport on Weaned Pigs' Short and Long-Term Welfare Markers, Behaviors, and Microbiota

Alternative feed supplements have shown promising effects in terms of performance, but their effects on welfare have had little evaluation. In the present study, we aimed at evaluating the effect of diet supplementation on welfare indicators. A total of 246 piglets were weaned and transported for 12 h. After transport, they were assigned to one of 3 diets for a 14-day period: A-an antibiotic diet including chlortetracycline and tiamulin, NA-a control diet without any antibiotic or feed supplement, GLN-a diet including 0.20% L-glutamine. After the 14-day period, all piglets were fed the same diet. Tear staining was measured 11 times post-weaning (from d0 to 147). Skin lesions were counted before and after weaning (d-2, 2, and 36). Novel object tests (NOT) were done in groups 4 times post-weaning (d17, 47, 85, 111). Samples for 16S rRNA gene composition were collected prior to transport (d0), following the 14-day period (d14) and at the conclusion of the nursery phase (d34). The NA pigs appeared less interested in novel objects. On d17, they avoided the object less than A pigs (P < 0.05). They spent less time exploring the object on d85 and took longer to interact with the object on d111 than A and GLN pigs (P < 0.05). NA pigs also appeared more sensitive to environment and management. They had larger tear stains than GLN pigs on d84 and 110 (P < 0.05). On d2, NA pigs had more lesions than A and GLN (P < 0.01). In terms of microbiota composition, GLN had higher α-diversity than A and NA (P < 0.001). Differences between dietary treatments were absent at d0, were demonstrated at d14 and disappeared at d34. Pearson correlations between aggression, stress and anxiety indicators and bacterial populations were medium to high from 0.31 to 0.69. The results demonstrate that short-term feeding strategy can have both short- and long-term effects on behavior and welfare, that may partly be explained by changes in gut microbiota composition. Supplementation with GLN appears to confer similar benefits to dietary antibiotics and thus could be a viable alternative.

Effects of antibiotic-free pig rearing on ammonia emissions from five pairs of swine rooms in a wean-to-finish experiment

Antibiotic use and ammonia (NH₃) emissions during animal production are two environmental issues of worldwide concern. However, the role of antibiotics on NH₃ emissions is still unknown. This study evaluated the effects of rearing pigs without antibiotics on NH₃ emissions from a swine experimental building starting with 657 piglets during a wean-to-finish production cycle of 154 days. Pigs were reared in two groups of 10 rooms that were divided into five 2-room pairs (P1-P5) and fed in nine dietary phases. Each pair consisted of one room without antibiotics (no antibiotics in the diet, water, or injectable) and another room as a positive control. Control animals were fed diets containing carbadox-10 (phases 1-4), chlortetracycline (CTC, phase 5), lincomix (phases 6-7), and tylan 40 (phases 8-9). Temperatures in the pig living space and the under-floor manure pit headspace were continuously measured. Ventilation rates at all wall fans and pit fans were obtained by continuous monitoring. Ammonia concentrations in the wall and pit fan exhaust air, and in room inlet air were measured with two multi-gas monitors. Only days that contained at least 18 h of data each day were validated and used. The study generated 1337 room-days of valid data of NH₃ emission rates, with a data completeness of 88.6%. Daily mean NH₃ emission patterns demonstrated large variations between the paired rooms and among different pairs. Within the individual 2-room pairs, no NH₃ emission differences were found in P1 (rooms 1 and 2, p = 0.34) and P2 (rooms 3 and 4, p = 0.44). Significant differences were found in P3-P5 (p < 0.01). The antibiotic-free rooms emitted more NH₃ from P3 and P4, but less NH₃ from P5. However, the combined cycle mean NH₃ emissions from the group of five antibiotic-free rooms and the group of five control rooms were 41.6 ± 10.5 and 39.4 ± 10.6 g d^-1 AU^-1 (mean ± standard deviation. AU = 500 kg live body weight), respectively. Therefore, there was no statistical difference in combined cycle mean NH₃ emissions from rearing pigs with or without antibiotics (p = 0.78). This study also revealed that experiments with multiple replicates and long NH₃ monitoring durations were necessary to avoid potential misinterpretation of experimental results.

Replacing dietary antibiotics with 0.20% l-glutamine in swine nursery diets: impact on health and productivity of pigs following weaning and transport1,2,3

Antibiotic use has been limited in U.S. swine production. Therefore, the objective was to determine whether supplementing l-glutamine at cost-effective levels can replace dietary antibiotics to improve piglet welfare and productivity following weaning and transport. Based on previous research, we hypothesized that withholding dietary antibiotics would negatively affect pigs while diet supplementation with 0.20% l-glutamine (GLN) would have similar effects on pig performance and health as antibiotics. Mixed sex piglets (N = 480; 5.62 ± 0.06 kg BW) were weaned (18.4 ± 0.2 d of age) and transported for 12 h in central Indiana, for 2 replicates, during the summer of 2016 and the spring of 2017. Pigs were blocked by BW and allotted to 1 of 3 dietary treatments (n = 10 pens/dietary treatment/replicate [8 pigs/pen]); antibiotics (A; chlortetracycline [441 ppm] + tiamulin [38.6 ppm]), no antibiotics (NA), or GLN fed for 14 d. On days 15 to 34, pigs were provided common antibiotic-free diets in 2 phases. Data were analyzed using PROC MIXED in SAS 9.4. Day 14 BW and days 0 to 14 ADG were greater (P = 0.01) for A (5.6% and 18.5%, respectively) and GLN pigs (3.8% and 11.4%, respectively) compared with NA pigs, with no differences between A and GLN pigs. Days 0 to 14 ADFI increased for A (P < 0.04; 9.3%) compared with NA pigs; however, no differences were detected when comparing GLN with A and NA pigs. Once dietary treatments ceased, no differences (P > 0.05) in productivity between dietary treatments were detected. On day 13, plasma tumor necrosis factor alpha (TNF-α) was reduced (P = 0.02) in A (36.7 ± 6.9 pg/mL) and GLN pigs (40.9 ± 6.9 pg/mL) vs. NA pigs (63.2 ± 6.9 pg/mL). Aggressive behavior tended to be reduced overall (P = 0.09; 26.4%) in GLN compared with A pigs, but no differences were observed between A and GLN vs. NA pigs. Huddling, active, and eating/drinking behaviors were increased overall (P < 0.02; 179%, 37%, and 29%, respectively) in the spring replicate compared with the summer replicate. When hot carcass weight (HCW) was used as a covariate, loin depth and lean percentage were increased (P = 0.01; 4.0% and 1.1%, respectively) during the spring replicate compared with the summer replicate. In conclusion, GLN supplementation improved pig performance and health after weaning and transport similarly to A across replicates; however, the positive effects of A and GLN were diminished when dietary treatments ceased.

356 Young Scholar Presentation: An applied approach to studying heat stress: Effects of cyclic heat and zinc supplementation on body temperature, gut health, and pork quality

Heat stress (HS) has depletory effects on intestinal morphology, induces metabolic changes, and disposes pigs to oxidative stress. Zinc has roles in gut health, nutrient and insulin mediated metabolism. To better understand the effects of cyclic heat and dietary Zn supplementation on gut integrity, carcass composition, and pork quality, commercial crossbred mixed-sex pigs (n = 400; initially 72.2 kg) were housed under either thermoneutral (TN; 18.9–16.7°C) or cycling HS conditions simulating chronic summer heat (30°C/26.7°C for 12h:12h on days 24–65) with acute heat periods of 32-33°C/29-30°C for 12h:12h on days 21–24, 42–45, and 63–65. Treatments were arranged in a 2×2×2 factorial with main effects of environment (HS vs. TN), added Zn level (50 vs. 130 mg/kg available Zn), and added Zn source (inorganic from ZnO vs. organic from Availa®Zn; Zinpro Corp, Eden Prairie, MN). Relative to TN, HS elevated (P < 0.050) body temperatures during the growing period. Heat stress was correlated with ileal villus height (r=-0.51, P = 0.015) and HSP-70 expression (r=0.46, P = 0.041). Growth was reduced such that carcasses from HS pigs were lighter (P = 0.011) and exhibited improved carcass quality with higher (P = 0.001) 24-hour loin pH, decreased (P = 0.034) drip loss, and greater (P < 0.050) subjective color and firmness scores compared to TN carcasses. Relative to TN, loin chops and sausage patties manufactured from the HS carcasses had similar oxidative stability (CIE L*a*b* color, 2-thiobarbituric acid reactive substances) throughout a 10-day simulated retail display. The HS induced fatty acid profile differences in the pork product but were not sufficient to shift IV (P > 0.10). Belly firmness and slice lean were also unaffected (P > 0.10) by HS. Zinc supplementation had minimal impact on the carcass quality characteristics studied. Further research is necessary to better understand the impact of HS duration, combination with additional stressors, and refine the ability to utilize thermal monitoring to manage negative impacts of HS.

146 Effects of feeding soluble fiber (dextrin) to pigs pre- and post-weaning on growth performance and volatile fatty acid (VFA) production

Thirty-two barrows were used in a 35-d experiment with the objective of evaluating effects of supplemental soluble fiber (dextrin) pre- and post-weaning on growth performance and VFA production. Pigs were blocked by genetics and BW, and randomly allotted to treatments in a 2x2 factorial design with or without fiber pre-weaning and with or without fiber post-weaning. Fiber was suspended in chocolate milk and administered orally through a syringe from 14 d prior to weaning until 4 d post-weaning, after which it was included in the diet at 1%. At weaning, pigs were group housed by treatment and allowed ad libitum access to a common starter diet. On d 4 post-weaning, pigs were moved to individual pens and fed diets with or without 1% fiber. Weights and feed intake were recorded 14 and 3 d prior to weaning and on d 0, 4, 11, and 21 post-weaning. On d 21 post-weaning, pigs were euthanized, and large intestine contents were collected for VFA analysis. Data were analyzed using the GLM procedure of SAS with pig as the experimental unit. Growth performance was not affected (P > 0.10) by treatment. A trend for an interaction of pre- and post-weaning fiber supplementation was observed for acetate (P = 0.052) and butyrate (P = 0.087) concentrations in large intestine contents. Pigs fed fiber only in the nursery had the highest acetate concentration, while pigs never receiving fiber had the lowest concentration. Pre-weaning fiber supplementation followed by no fiber in the nursery resulted in the highest butyrate concentrations with all other treatments being similar. Fiber supplementation pre-weaning tended (P = 0.053) to reduce isobutyrate concentrations. Pigs not receiving fiber post-weaning had increased valerate concentrations (P = 0.0245). There were no changes observed in propionate or isovalerate concentrations (P > 0.10). Fiber supplementation caused alterations in VFA concentrations when fed during pre- and post-weaning, indicating possible shifts in the microbiome, immune status and barrier function of the intestinal tract.

PSV-14 Effects of Cordyceps mushroom powder on nursery pig performance

The objective of this study was to determine the optimal level of Cordyceps mushroom powder inclusion in diets for nursery pigs. One-hundred sixty crossbred pigs [(Duroc × (York × Landrace)] weaned at 18.8 d of age and weighing an average of 5.94 kg were used in a 35 day, 4 phase growth trial to evaluate Cordyceps mushroom powder as potential alternative to carbadox in nursery pig diets. Pigs were allotted by weight, sex, litter, and assigned to body weight (BW) blocks. Within BW blocks, sex ratios were constant in each pen. Each pen within a BW block was randomly assigned a dietary treatment. Growth performance was analyzed as a RCB design using BW, ADG, ADFI, G:F using GLM procedure of SAS 9.4. There were 5 or 6 pigs/pen and 6 pens/treatment. Five diets were used in the study: a negative diet or a positive control (Carbadox, 55 ppm); 300 or 600 ppm mushroom powder, and a step down treatment (900, 900, 450, 300, 150 ppm mushroom powder during weeks 1 through 5, respectively). At various points of the study, pigs fed the 300 ppm and the step-down mushroom powder treatments tended to have improved (P &lt; 0.10) growth performance compared with those fed the negative control diet. During Phase 4 of the study, pigs fed Carbadox had greater ADG (P &lt; 0.02) and improved feed efficiency (P &lt; 0.09) compared to pigs fed the negative control diet. However, overall data showed that there were no statistical differences among treatments (P &gt; 0.05). In summary, pigs fed 300 ppm mushroom powder or the step-down treatment showed comparable growth performance to pigs fed Carbadox. However, future research is needed under a greater disease challenge to examine mushroom powder’s full potential as an alternative to antibiotics.

PSIV-12 A fortified protein blend as a replacement for animal and fish proteins in nursery pig diets: Effects on growth performance, immune status, microbial metabolites, and fecal scoring

This experiment observed the effects of replacing animal and fish proteins with a fortified protein blend (PROPLEX MVP) on growth performance, immune status, microbial metabolites, and fecal scoring of nursery pigs. A total of 244 barrows and gilts [Duroc x (Landrace x Yorkshire), avg. 19 d age and BW 5.88 ± 1.38 kg] were used in a 2 × 2 factorial design (2 dietary treatments × 2 feeding programs). The dietary treatments were: 1) Control diet (CONT) with animal and fish proteins and 2) PROPLEX MVP (MVP100): CONT with MVP replacing 100% of the animal and fish proteins. The feeding programs for each feeding phase were: high budget (H): Phase 1: 2.3 kg/pig; Phase 2: 4.5 kg/pig; Phase 3: 6.8 kg/pig and low budget (L): Phase 1: 1.1 kg/pig; Phase 2: 2.3 kg/pig; Phase 3: 3.4 kg/pig). For d 0-7, pigs fed CONT had greater ADG, ADFI, and G:F (P < 0.001) compared to MVP100. From d 7 to 14, ADG and G:F were greater (P < 0.05) for pigs fed MVP100 compared to CONT pigs and greater for pigs fed the H budget compared to the L budget (P < 0.05). Overall, d 0 to 35, there were no differences (P > 0.05) in pig final BW, overall ADG, and G:F. For week two and most of the experimental period, pigs fed CONT had greater (P < 0.05) fecal scores, more soft and watery feces, and increased diarrhea incidence compared to MVP100 pigs. The total concentration of fecal volatile fatty acids was greater (P < 0.05) in CONT compared to MVP100 fed pigs. In conclusion, the MVP protein blend can be used as a cost effective alternative to animal and fish proteins in nursery pig diets without compromising overall growth performance, immune status, and post-weaning diarrhea.

PSVII-15 The effects of feeding a fortified protein blend as a replacement for animal and fish proteins in nursery pig diets

The objective of this study was to evaluate the effects of total or partial replacement of animal and fish proteins with a fortified protein blend (PROPLEX MVP) on growth performance of nursery piglets. PROPLEX MVP is a blend of two distinct fermentation biomass streams, refined soybean products, select amino acids, and a NSP enzyme complex. A total of 306 barrows and gilts [(Duroc x (Landrace x Yorkshire), avg. 22 d age and BW 6.37 ± 1.24 kg)] were used in a randomized complete block design with three dietary treatments, each with 19 replicates (pens) of 5 piglets. Dietary treatments were: 1) Control diet (CONT) with animal and fish protein sources (Blood meal, Spray-dried Plasma, and Fish meal); 2) PROPLEX MVP (MVP): CONT with MVP replacing Fish meal; 3) PROPLEX MVP 100 (MVP100): CONT with MVP replacing 100% of animal and fish proteins. Pigs were fed a budgeted amount per head of the assigned experimental diets for the first three feeding phases (Phase 1: 2.3 kg/pig; Phase 2: 4.5 kg/pig; Phase 3: 6.8 kg/pig). A common diet was provided in Phase 4 until day 42 post-weaning. Pigs fed CONT had greater ADG (P &lt; 0.05) compared to MVP100 pigs d 0-7 post-weaning. From d 7 to 14, pigs fed MVP and MVP100 had a significantly greater ADG and G:F (P &lt; 0.05) than pigs fed CONT diet. For the remainder of the experimental period (d 14 to 42), no differences (P &gt; 0.10) were observed among treatments. The use of MVP100 reduced (P &lt; 0.05) the total nursery feed cost by US $1.03/pig and feed cost/kg of weight gain by 12%. In conclusion, MVP protein blend can effectively substitute for animal and fish proteins sources without compromising overall nursery pigs’ growth performance and results in significant feed cost savings.

PSVI-14 Interactive effects of Cordyceps mushroom powder and carbadox on nursery pig performance

The objective was to evaluate the independent and additive effects of Cordyceps mushroom powder and carbadox to pharmacological copper+zinc in nursery pig diets. Two hundred-ten crossbred weanling pigs [(Duroc × (York × Landrace)] avg. 19 d of age and 5.8 kg were used in a 33 day growth trial. Pigs were alloted by weight, sex, ancestry, and assigned to body weight (BW) blocks. Within BW blocks, sex ratios were constant in each pen. Pen was the experimental unit and growth performance was analyzed using BW, ADG, ADFI, and G:F. There were 7 pigs/pen and 6 pens/treatment. Treatments were: 1) a negative diet (NC); 2) positive control (PC; Carbadox, 55 ppm); 3) NC+300 ppm Cordyceps mushroom powder (NC+MP); 4) PC +300 ppm mushroom(PC+MP); 5) supplemental copper sulfate (125 ppm) and zinc oxide (3000 ppm d 0-7, 2000 ppm d 7-35), CuZn. Dietary treatments were fed in a four-phase feeding program (d0-7, d7-14, d14-21, and d21-33). There were no interactions between MP and Carbadox at any time point (P > 0.10). Pigs fed the PC, PC+MP and CuZn treatment had increased BW (P < 0.05), ADG (P < 0.05), ADFI (P < 0.10) and G:F (P < 0.05) over the NC at the end of phases 1, 2, and 3, with no main effect of MP treatment. During Phase 4, pigs fed MP, PC, and CuZn diets all had increased ADG (P < 0.05; 431, 477, 455, 505, 486 g/d, diet 1-5, respectively) and ADFI (P < 0.05) over the NC fed pigs. Overall, d0-33, PC diets and CuZn supplemented pigs had increased ADG (P < 0.05) and ADFI (P < 0.05), with pigs fed MP tending to have increased ADFI (P < 0.08) over NC fed pigs. Feeding nursery pigs pharmacological levels of Cu+Zn and carbadox have economical value to increase nursery pig performance with MP may increase pig ADFI and final BW through potentially complimentary modes of action.

Including dietary fiber and resistant starch to increase satiety and reduce aggression in gestating sows

Aggression during mixing of pregnant sows impacts sow welfare and productivity. The aim of this study was to increase satiety and reduce aggression by including dietary fiber and fermentable carbohydrates. Sows were housed in individual stalls 7 to 14 d after breeding (moving day was considered d 0 of treatment) and were fed (at 0700 h) with a CONTROL (corn-soybean meal based with no additional fiber sources), RSTARCH (10.8% resistant starch), BEETPULP (27.2% sugar beet pulp), SOYHULLS (19.1% soybean hulls), or INCSOY (14.05% soybean hulls) for 21 d (5 sows/diet × 5 diets × 8 replications = 200 sows). The CONTROL diet was targeted to contain 185 g(d∙sow) NDF and the other diets were targeted to contain 350 g(d∙sow) NDF. The INCSOY diet was fed at 2.2 kg/(d∙sow) and the other diets were fed at 2 kg(d∙sow). On d 22, sows were mixed in groups of 5 (at 1200 h). Behaviors in stalls (on d 1, 7, 14, and 21) and after mixing (d 22 and 23), heart rate (on d 1, 7, 14, and 21), blood metabolites (on d 2, 8, 15, 22, and 25), and the effects of diets on production were collected and analyzed. Sows stood more ( < 0.01) and rested less ( < 0.001) over time irrespective of the diet. Sows on BEETPULP stood more ( < 0.01) and sows on SOYHULLS rested more ( < 0.01). Sham chewing increased over days irrespective of the diet. Chewing behavior (bar and feeder) increased with days on diet ( < 0.001) and was lowest in sows on the SOYHULLS diet ( = 0.045). When mixed, biting frequency in the first hour was highest for sows on the CONTROL diet (236.5 ± 62.6) and lowest for sows on the RSTARCH diet (90.5 ± 30.5). Skin lesions increased ( < 0.001) 24 h after mixing sows irrespective of diet. Blood urea nitrogen (BUN) concentration was lowest in sows fed BEETPULP and SOYHULLS ( < 0.001). Serum glucose concentration was highest in sows fed RSTARCH and BEETPULP ( = 0.04), but there was no day effect ( = 0.62) or diet × day interaction ( = 0.60). The NEFA was greatest in sows fed RSTARCH, BEETPULP, and SOYHULLS ( < 0.001). Lactate ( < 0.001) and BUN concentrations were greatest on d 2 but dropped and remained constant after d 8. Average heart rate was lowest for sows on SOYHULLS and INCSOY compared with sows on the other diets ( = 0.03). Number of piglets born and average weaning weight were not affected by diets ( > 0.05). Average birth weight was lowest in the INCSOY diet ( = 0.02). This study demonstrates that RSTARCH and SOYHULLS can improve the welfare of sows by reducing aggression and increasing satiety in limit-fed pregnant sows without affecting production.

Repeated intranasal oxytocin administration in early life dysregulates the HPA axis and alters social behavior

Agonistic interactions are a powerful stressor. Conversely, positive social interactions can reduce the adverse effects of social stress. This possibly occurs through the action of oxytocin (OT), a neuropeptide able to reduce activation of the hypothalamo-pituitary-adrenal (HPA) axis. We hypothesized that repeated OT intranasal administration to neonatal pigs could provide long-lasting protective effects against social stress. In each of six litters, two pigs per litter received 0.5 mL of saline containing 24 IU (or 50 μg) of OT intranasally and two control littermates received 0.5 mL of saline as a control at 1, 2 and 3 days of age. Contrary to our predictions, when socially mixed after weaning at 17 days of age, neonatally OT-administered pigs received more aggressive interactions and performed more aggressive interactions in return, showed greater locomotion, spent less time in social contact, and had greater cortisol concentrations than control pigs. When this social mixing was repeated at 8 weeks of age, OT pigs still performed more aggressive interactions and had greater adrenocorticotropic hormone concentrations than control pigs. A dexamethasone suppression test and corticotropic releasing hormone administration challenge at 11 weeks of age revealed that OT pigs were less responsive to dexamethasone than control pigs, suggesting a deficient HPA axis' negative feedback control. Postnatal repeated OT administration altered social behavior and resulted in a long-term dysregulation of the HPA axis. These findings highlight the complex, fine-tuning of the neurobiological mechanisms regulating the development of social behavior and suggest caution in the application of neonatal peptide treatments during early development.

Behavioral changes in neonatal swine after an 8-hour rest during prolonged transportation

Long distance transportation of weaned piglets (Sus scrofa) is increasingly common in the united states and may result in delayed eating, drinking, or normal social behaviors. A potential solution is a mid-journey rest (lairage). The objective of this study was to determine if a lairage altered behavior after a 16-h transport. Pigs that weighed approximately 18 kg each (n = 894) were housed in 16 pens with 8 pens per treatment. Lairaged pigs were transported for 8 h and given an 8-h rest with food and water, whereas control pigs were transported continuously for 16 h. The heaviest, the lightest, and 2 average-BW pigs relative to the average weight of the pen were observed by video recording for 24 h immediately before and after transport, and during d 6 and 13 after transport. Postures (lying, sitting, and standing) were recorded using 10-min-interval scan sampling, and behavioral categories included inactivity, activities (eating, drinking, alert, manipulating pen, rooting, and walking) and social interactions (aggression, belly nosing, playing, tail biting, and positive social behaviors). In both treatments, sitting occurred most before transport (P < 0.01) than at other times, but did not differ between treatments. Standing increased (time effect; P < 0.01) for both treatments immediately after transport through d 6, but returned to pre-transport values by d 13. In contrast, lying decreased (time effect; P < 0.01) after transport, but returned to above pre-transport values by d 13. Time effects were evident for activity (P < 0.01), pen manipulation (P = 0.05), rooting (P < 0.01), initiation of belly-nosing (P = 0.01), and receiving belly-nosing (P = 0.03); however, initiation of aggression did not differ for day (P = 0.19) or treatment (P = 0.56). Lairaged pigs initiated more (P = 0.05) play than continuously transported pigs, but no differences (P = 0.84) were seen in receipt of play behavior. Pigs that were to be transported for 16 h continuously walked less pre-transport, walked more post-transport (treatment × time interaction; P = 0.02), and drank less pre-transport, but drank more on all days post-transport compared with the lairage group (treatment × time interaction; P = 0.001). This study indicated that extended transport without lairage alters some swine behaviors relevant to production (water consumption) and demonstrated that a long-duration transport, regardless of the mid-journey lairage treatment, affects a number of behaviors up to 13 d after transportation.

The effects of R-salbutamol on growth, carcass measures, and health of finishing pigs

A pure form of salbutamol has the potential to deliver positive production benefits to the swine industry. The aim of this experiment was to determine the effects of salbutamol on growth, carcass measures, and health of finishing pigs. The study used 192 pigs (89 ± 1 kg BW) housed in groups of 6 in 32 pens and assigned to 1 of 4 treatments: 1) control (CTL), 0 mg/kg salbutamol; 2) 2R, control diet with 2 mg/kg of the pure R-enantiomer of salbutamol; 3) 4R, control diet with 4 mg/kg of pure R-salbutamol; or 4) 8RS, control diet with 8 mg/kg of a 50:50 mixture of the R- and S-enantiomers. All diets were offered ad libitum for 4 wk. All pigs were weighed and pen feed intakes were recorded weekly. At slaughter, individual HCW and measurements of the 10th-rib loin muscle area (LMA), color, marbling, firmness, and back fat, last lumbar, and midline back fat depths were collected. Data were analyzed using Proc GLM of SAS, with pen as the experimental unit. Overall, 2R and 4R pigs had greater ADG than CTL pigs (P < 0.05) and, at slaughter, were heavier than CTL pigs (P < 0.01). Overall, 8RS pigs had decreased ADFI (P < 0.05), and CTL pigs had poorer G:F (P < 0.001) than the other 3 treatments. All salbutamol-fed pigs had 5 to 6 kg greater HCW (P < 0.001), 2% to 3% increased carcass yield (P < 0.001), 5.6 cm(2) larger LMA (P < 0.01), 3 to 4 mm less 10th-rib back fat (P < 0.01), and 2 mm less lumbar back fat (P < 0.05) than CTL pigs. However, control pigs had greater loin muscle color scores (P < 0.05) and marbling scores (P < 0.001) than all salbutamol-treated pigs. Taken together, these data indicate that as little as 2 mg/kg R-salbutamol has a positive effect on pig growth and carcass composition. However, the effects of salbutamol on meat quality require further research.

Controlling Salmonella infection in weanling pigs through water delivery of direct-fed microbials or organic acids: Part II. Effects on intestinal histology and active nutrient transport

The objective of this study was to evaluate the effects of water-delivered, direct-fed microbials (DFM) or organic acids on intestinal morphology and active nutrient absorption in weanling pigs after deliberate Salmonella infection. Pigs (n = 88) were weaned at 19 ± 2 d of age and assigned to 1 of the following treatments, which were administered for 14 d: 1) control diet; 2) control diet + DFM (Enterococcus faecium, Bacillus subtilis, and Bacillus licheniformis) in drinking water at 10(9) cfu/L for each strain of bacteria; 3) control diet + organic acid-based blend (predominantly propionic, acetic, and benzoic acids) in drinking water at 2.58 mL/L; and 4) control diet + 55 mg/kg carbadox. Pigs were challenged with 10(10) cfu Salmonella enterica var Typhimurium 6 d after commencement of treatments. Pigs (n = 22/d) were harvested before Salmonella challenge and on d 2, 4, and 8 after challenge. Duodenal, jejunal, and ileal mucosal tissues were sampled for measurement of villus height and crypt depth. Jejunal tissue was sampled for determination of active nutrient absorption in modified Ussing chambers. Duodenal villus height was greater in pigs fed in-feed antibiotic before infection (P < 0.05). Jejunal crypts were deeper in DFM- and acid-treated pigs on d 4 after infection compared with all other treatments (P < 0.05). Salmonella infection resulted in a linear decrease in phosphorus (P < 0.001) and glucose (P < 0.05) active transport, and an increase (P < 0.001) in glutamine uptake immediately after challenge. Salmonella infection reduced basal short-circuit current (I(sc)); however, water-delivered DFM or organic acid treatments caused greater basal I(sc) on d 2 after challenge than did carbadox. Carbachol-induced chloride ion secretion was greatest in negative control pigs before infection (P < 0.01) and DFM-treated pigs (P < 0.05) after infection. In conclusion, both the DFM and acidification treatments induced increases in basal active ion movement and jejunal crypt depth, which could be interpreted as responses consistent with increased Salmonella pathology, but none of the additives markedly affected intestinal absorptive and secretory function in response to Salmonella challenge.

Controlling Salmonella infection in weanling pigs through water delivery of direct-fed microbials or organic acids. Part I: effects on growth performance, microbial populations, and immune status

Pigs (n = 88) weaned at 19 ± 2 d of age were used in a 14-d study to evaluate the effects of water-delivered direct-fed microbials (DFM) or organic acids on growth, immune status, Salmonella infection and shedding, and intestinal microbial populations after intranasal inoculation of Salmonella Typhimurium (10(10) cfu/pig). Pigs were challenged with Salmonella 6 d after commencement of water treatments. Treatments were 1) control diet; 2) control diet + DFM (Enterococcus faecium, Bacillus subtilis, and Bacillus licheniformis) in drinking water at 10(9) cfu/L for each strain of bacteria; 3) control diet + an organic acid-based blend (predominantly propionic, acetic, and benzoic acid) in drinking water at 2.58 mL/L; and 4) control diet + 55 mg/kg of carbadox. Serum samples were taken on d 6, 8, 10, and 14 for determination of tumor necrosis factor α (TNFα) concentrations. Fecal samples were taken on d 0, 5, 7, and 11 for determination of Salmonella shedding and enumeration of coliforms. Pigs were euthanized on d 6, 8, 10, and 14. Intestinal and cecal tissue and digesta and mesenteric lymph nodes were sampled and analyzed for Salmonella. Duodenal, jejunal, and ileal mucosal scrapings were sampled for measurement of mucosal TNFα concentrations. Water delivery of DFM prevented a decline in ADG on d 2 to 6 postchallenge compared with the negative control (P < 0.05). Coliform counts tended to be greater (P = 0.09) in the cecum of the DFM treatment group on d 2 postinfection compared with the negative control and acid treatment groups. However, Salmonella prevalence in the feces, gastrointestinal tract, or lymph nodes was not affected by water delivery of acids or DFM. Serum and mucosal TNFα concentrations were not affected by treatment throughout the study with the exception of ileal concentrations on d 4 postchallenge, which were greater in the negative control group compared with all other treatments (P < 0.05). The in-feed antibiotic was the only treatment that reduced Salmonella prevalence and this was localized to the cecum on d 8 postinfection. In conclusion, the DFM and organic acid treatments used in this study offered little or no benefits to pigs infected with Salmonella and should not be considered under the constraints of this study as viable alternatives to in-feed antibiotics in a pathogen challenge situation.