Evaluation of a novel phytase derived from Citrobacter braakii and expressed in Aspergillis oryzae on growth performance and bone mineralization indicators in nursery pigs

A total of 297 pigs (DNA 241 × 600; initially 8.64 ± 0.181 kg) were used in a 21-d trial to determine the efficacy of a novel phytase derived from Citrobacter braakii and expressed in Aspergillis oryzae (HiPhorius; DSM Nutritional Products, Animal Nutrition & Health, Parsippany, NJ) on pig growth and bone mineralization indicators. Pens of pigs were assigned to 1 of 5 dietary treatments in a randomized complete block design with 5 pigs per pen and 12 pens per treatment. The trial was initiated 14-d after weaning. The first three treatments were formulated to contain 0.09% aP; without added phytase (control), or the control diet with 600 or 1,000 FYT/kg of added phytase (considering a release of 0.15% or 0.18% aP, respectively). The remaining two treatments were formulated to contain 0.27% aP, one without added phytase and the other with 1,000 FYT/kg. From days 0 to 21, pigs fed increasing phytase in diets containing 0.09% aP had increased (linear, P ≤ 0.002) ADG, ADFI, and G:F, but added phytase in the 0.27% aP diet did not impact growth performance. Increasing phytase in diets containing 0.09% aP increased percentage bone ash in metacarpals and 10th ribs (linear, P < 0.001; quadratic, P = 0.004, respectively), and increased grams of Ca and P in metacarpals, 10th ribs, and fibulas (linear, P ≤ 0.027). Adding 1,000 FYT/kg phytase in diets with 0.27% aP increased (P ≤ 0.05) percentage bone ash and grams of Ca and P in fibulas and 10th ribs compared with pigs fed 0.27% aP without added phytase. Increasing aP from 0.09% to 0.27% in diets without added phytase increased (P < 0.001) ADG, ADFI, and G:F. Increasing aP from 0.09% to 0.27% in diets without added phytase increased bone density (P ≤ 0.002) in fibulas and metacarpals, percentage bone ash in all bones (P ≤ 0.074), and increased (P < 0.05) grams of Ca and P in fibulas and 10th ribs. Pigs fed diets containing 0.09 or 0.27% aP, both with 1,000 FYT added phytase, had increased (P < 0.05) bone density in fibulas and metacarpals, percentage bone ash in all bones, and increased grams of Ca and P in fibulas and 10th ribs. For growth performance (average of ADG and G:F), aP release was calculated to be 0.170% for 600 FYT/kg and 0.206% for 1,000 FYT/kg. For the average of all bone measurements (average of 3 bones for both bone density and percentage bone ash), aP release was calculated to be 0.120% and 0.125% for 600 and 1,000 FYT/kg, respectively.

Impacts of a post-transport/pre-processing rest period on the growth performance, anthelmintic efficacy, and serum metabolite changes in cattle entering a feed yard

A total of 80 crossbred, high-risk heifers (initially 250 ± 4.2 kg BW), were transported from an Oklahoma City, Oklahoma sale barn to the Kansas State University Beef Cattle Research Center. Cattle were unloaded and randomly placed into one of four receiving pens and provided ad libitum hay and water. Each pen was randomly assigned to one of the four rest times before processing: (1) immediately upon arrival (0); (2) after a 6-h rest period (6); (3) after a 24-h rest period (24); and (4) after a 48-h rest period (48). After all cattle were processed, heifers were allotted into individual pens with ad libitum access to a receiving ration and water. Heifers were weighed individually on d 0, 7, 14, 21, 28, and 35 to calculate average daily gain (ADG). Feed added and refusals were measured daily to determine dry matter intake (DMI). A fecal egg count reduction test and analysis of blood serum metabolites were also conducted. All data were analyzed using the GLIMMIX procedure of SAS (v. 9.4, Cary, NC) with individual animal as the experimental unit. Processing time did not impact (P > 0.05) heifer BW or ADG. From d 0 to 35, DMI decreased linearly (P = 0.027) as rest time increased. The number of days for heifers to reach a DMI of 2.5% BW was linearly increased (P = 0.023) as rest time increased. There was no evidence of differences (P ≥ 0.703) among rest times for feed efficiency. While morbidity did not differ between treatments (P > 0.10), mortality increased linearly (P = 0.026) as the time of rest increased. A significant processing time × day interaction (P < 0.0001) was observed for the prevalence of fecal parasites, where the percentage of positive samples was significantly lower 14-d after anthelmintic treatment, regardless of the processing time. Serum IBR titer for heifers processed at either 0 or 6-h upon arrival was significantly higher (P < 0.01) on d 35 compared to d 0. Heifers processed after a 48-h rest period had significantly higher glucose values (P < 0.01) on d 0 compared to heifers processed at 0, 6, or 24-h. In summary, rest time prior to processing did not impact receiving calf growth performance. A 6-h rest period upon arrival appeared to be most beneficial to DMI. Anthelmintic treatment at processing reduced the parasitic load in heifers processed at all times. Vaccine titer did not increase after initial processing in heifers processed 24- or 48-h after arrival, indicating the seroconversion of IBR antibodies during the longer rest period.

151 Impact of Feed Allotment During the Wean-To-Estrus Interval on Sow Reproductive Performance

Pork producers have recently inquired whether the allotment of feed should be greater during the wean-to-estrus interval to optimize sow performance. The objective of this experiment was to validate the amount of feed allotted to sows during the wean-to-estrus interval to optimize feed costs and farrowing performance. A total of 257 PIC 1050 (PIC, Inc., Hendersonville, TN) weaned sows were blocked to 3 body condition categories (thin, ideal, or heavy, respectively) and then randomly allotted to 1 of 2 feed quantity treatments (2.7 or 5.4 kg, respectively) on d 0. The sows used in this experiment were housed under commercial conditions and had an average parity of 3.15. One day prior to weaning, each sow was calipered to determine body condition and feed boxes were validated to determine that the desired amount of feed was actually allocated during the experimental period. Sows were fed their allotted amount of feed (2.7 or 5.4 kg, respectively) from d 0 till the sows were serviced or if the sows had not been detected in estrus until d 8. Sows were tracked through their subsequent wean to detect any downstream differences. Data were analyzed using Proc MIXED (SAS 9.4; Cary, NC) with sow as the experimental unit, treatment as the main effect, and caliper score as the block criteria. These data indicate that allocating 5.4 kg of feed did not improve wean-to-first service interval (2.7 kg = 4.4 d vs. 5.4 kg = 4.4 d; P = 0.99), farrowing rate (2.7 kg = 91.5% vs. 5.4 kg = 90.6%; P = 0.81), or total born (2.7 kg = 15.9 vs. 5.4 kg = 15.4 pigs/litter; P = 0.31). In summary, feeding greater than 2.7 kg of feed from wean-to-estrus does not improve sow performance, but does increase feed costs.

Tamegrass Forage Options for Growing Heifers During the Summer

Developing methods to provide high quality forage through a majority of the year is important for cattle operations. The purpose of this study was to determine forage management options to off-set the summer “slump” with fescue. Four grass pasture treatments (10 pastures total; 1.67 ha each) were used in a completely randomized design and stocked with growing heifers (initial wt 190 ± 9.1 kg). Pasture treatments consisted of fescue (FES; n = 2 pastures with 4 head/pasture), crabgrass (CRAB; n = 3 pastures with 4 head/pasture), bermudagrass (BERM; n = 3 pastures with 5 head/pasture), and sorghum-sudan interseeded into fescue (SS-FES; n = 2 pastures with 6 head/pasture from April to July, then 4 head/pasture from July to November). Heifers were weighed in April, May, July, September, and November. Heifers assigned to FES/SS-FES pastures grazed from April to November (213 d) and for CRAB and BERM treatments, May through September (131 d). Heifers on FES grazed continuously, while other grass treatments were rotationally grazed. Heifers remained in treatment pasture through the entire grazing period. Data were analyzed using mixed procedures of SAS with pasture as experimental unit. Average daily gain for the entire grazing period was greater for heifers on SS-FES as compared to all other grass treatments (P = 0.001). Between April and May, FES heifers had greater ADG than SS-FES (P = 0.001); yet, heavier stocking rate in SS-FES resulted in similar BW gain/ha (P = 0.16). May to July ADG and BW gain/ha was greatest for BERM, then CRAB, with FES and SS-FES having the lowest gains (P &lt; 0.001). From July through September, ADG was greater for SS-FES and CRAB as compared to FES, with BERM intermediate (P = 0.03); and BW gain/ha tended to be lower for FES compared to other treatments (P = 0.10). Average daily gain and BW gain/ha were greater for SS-FES than FES (P = 0.001) from late September to November. As a summer grazing option, warm season grass alternatives, either as the sole source of pasture or interseeded into fescue, are better options for gain as compared to fescue alone.

PSI-2 Spices in Free-choice Mineral Offer Gain Advantages to Cattle on Tallgrass Native Range and Promise as Fly Control

This study aims to evaluate effectiveness of two operational management systems for steer gains and fly control. The first strategy evaluated was pasture burn date of March (MAR) or April (APR). The second management strategy was fly control through feeding free-choice mineral with spices (SPICE) or without spices (CON). Eight pastures (n = 281 steers; initial weight 277.7 ± 25.2 kg) were used in a 2 x 2 factorial treatment structure. Steers were weighed individually, randomly assigned to treatment, and grazed for 85 days. Weekly 33% of steers per pasture were photographed and fly numbers counted. ADG was impacted by both burn date and mineral type (P = 0.01). Cattle on the APR-SPICE treatment had a greater ADG than MAR-SPICE and APR-CON with MAR-CON intermediate. Cattle on SPICE gained 4.5 kg (P = 0.12) more than cattle consuming CON mineral. Flies per steer were impacted by burn x mineral x week (P &lt; 0.001). In general, APR-SPICE steers had a greater number of flies weeks 8, 10, and 11 (P &lt; 0.05), corresponding to a time when mineral intake averaged 72% of the formulated intake. The MAR-SPICE steers consumed on average the formulated amount of mineral and through the entire grazing period had lower number of flies than APR-SPICE steers (P &lt; 0.05). The second largest ADG observed with the MAR-CON treatment may be attributed to lower fly numbers as this treatment had one extra week below economic threshold for horn flies. These results are somewhat inconclusive on pasture burn date, but show that the addition of spices to a free-choice complete mineral shows promise as a cost-effective method to increase gains in stocker steers on tallgrass native range. As a fly control method, the spices utilized in this study may be effective if intake is at formulated level.