Maternal pre- and postpartum supplementation of a Bacillus-based DFM enhanced cow and calf performance

This study evaluated the effects of maternal supplementation of a Bacillus-based direct-fed microbial (DFM) on the physiology and growth performance of Bos indicus-influenced cow-calf pairs. On day 0 (~139 d before expected calving date), 72 fall-calving, Brangus crossbred beef heifers (20 to 22 mo of age) pregnant with first offspring were stratified by their initial body weight (BW; 431 ± 31 kg) and body condition score (BCS; 6.0 ± 0.36; scale 1 to 9), and randomly allocated into 1 of 12 bahiagrass pastures (1 ha and six heifers per pasture). Treatments were randomly assigned to pastures (six pastures per treatment) and consisted of heifers supplemented with 1 kg/d of soybean hulls (dry matter, DM) that was added (BAC) or not (CON) with DFM containing Bacillus subtilis and B. licheniformis (Bovacillus; Chr. Hansen A/S, Hørsholm, Denmark). Treatments were provided from days 0 to 242 (139 ± 4 d prepartum to 104 ± 4 d postpartum). Calves were weaned on day 242 (96 ± 30 d of age) and then allocated into 1 of 16 drylot pens and fed the same concentrate at 3.25% of BW (DM) until day 319. Maternal treatment effects were not detected (P ≥ 0.29) for herbage allowance and forage chemical composition. Heifer BCS on days 39 and 63 tended (P ≤ 0.09) to be greater for BAC vs. CON heifers, whereas heifer BCS on day 91 was greater (P = 0.01) for BAC vs. CON heifers. Heifer BCS did not differ (P ≥ 0.20) between treatments on days 179 and 242. Plasma glucose concentration did not differ from days 0 to 63 (P ≥ 0.14) but were greater (P < 0.01) on day 179 and tended (P = 0.09) to be greater on day 242 for BAC vs. CON heifers. Calf BW at birth, ADG from birth to weaning, and BW at weaning did not differ (P ≥ 0.19) between treatments, but calf BW at drylot exit (day 319) was greater (P = 0.05) for BAC vs. CON calves. Maternal treatment effects were not detected (P ≥ 0.42) for calf serum concentration of IgG at birth and postvaccination plasma concentrations of glucose, cortisol, and haptoglobin. Serum titers against bovine respiratory syncytial virus (BRSV) were greater (P = 0.04) for BAC vs. CON calves on day 287, whereas seroconversion against parainfluenza-3 virus (PI-3) was greater (P < 0.01) for BAC vs. CON calves on day 271. Thus, maternal supplementation of a Bacillus-based DFM increased prepartum BCS gain and postpartum plasma glucose concentration of heifers and led to positive carryover effects on postweaning BW gain and humoral immune response in their offspring.

Bakery waste supplementation to late gestating Bos indicus-influenced beef cows successfully impacted offspring postnatal performance

This study evaluated the growth and immune function of beef calves born to cows supplemented with bakery waste containing two concentrations of crude fat. On day 0 (~90 d before calving), 108 multiparous Brangus crossbred cows were stratified by body weight (BW; 551 ± 65 kg) and body condition score (BCS, 5.5 ± 0.9) and randomly allocated into 1 of 18 bahiagrass (Paspalum notatum) pastures (6 cows and 4.3 ha per pasture). Treatments were randomly assigned to pastures (6 pastures per treatment) and consisted of no prepartum supplementation (NOSUP) and isocaloric and isonitrogenous supplementation of low-fat (LFAT; 6.4% crude fat) or high-fat (HFAT; 10.7% crude fat) bakery waste from days 0 to 70 (1 kg DM per cow per day). Calves were weaned on day 292 (201 ± 17 d of age). Then, 15 heifers per treatment were randomly selected and assigned to drylot pens from days 300 to 345 and vaccinated against respiratory pathogens on days 300 and 315. Cow BCS near calving (day 70) was the least (P ≤ 0.05) for NOSUP cows and did not differ (P = 0.12) between LFAT and HFAT cows. Cow BCS at the start of the breeding season (day 140) was greater (P = 0.05) for HFAT vs. NOSUP cows and intermediate (P ≥ 0.35) for LFAT cows. Plasma concentrations of total polyunsaturated fatty acids in HFAT cows did not differ (P ≥ 0.76) compared with LFAT cows but were greater (P ≤ 0.05) compared to NOSUP cows on day 70. Final pregnancy percentage did not differ (P ≥ 0.26) among treatments, but a greater percentage of HFAT cows calved (P ≤ 0.05) their second offspring during the first 21 d of the calving season compared to NOSUP and LFAT cows (bred by natural service). Weaning BW was the greatest (P ≤ 0.05) for LFAT and least for NOSUP calves. Maternal treatments did not impact (P ≥ 0.11) postweaning growth and total DM intake of calves. Average plasma cortisol concentrations were greater (P = 0.03) for NOSUP vs. HFAT calves and intermediate for LFAT calves (P ≥ 0.26). Serum titers against infectious bovine rhinotracheitis and bovine respiratory syncytial virus were greater or tended to be greater (P ≤ 0.08) for HFAT vs. LFAT calves and intermediate (P ≥ 0.27) for NOSUP calves at the end of preconditioning. Thus, supplemental fat concentration fed to late-gestating beef cows had variable effects on calf performance. Low-fat bakery waste led to the greatest calf preweaning growth, whereas high-fat bakery waste enhanced maternal reproduction and had minor benefits to calf humoral immune function.

36 Inclusion of Different Sources of Ca Salts of Fatty Acids on Productive Responses of Finishing Cattle

This experiment (d -9 to d 148) evaluated productive responses of feedlot cattle consuming or not different sources of fatty acids (Nutricorp, Araras, SP, Brazil) during the finishing period. Bos taurus-influenced steers (n = 120) were ranked by initial body weight (BW; 410 ± 6 kg) on d -9 and allocated to 1 of 20 pens (6 steers/pen) equipped with Calan gate feeders (American Calan, Northwood, NH) for individual feed delivery. Steers within each pen were randomly assigned to receive a corn-based finishing diet containing or not (CON; n = 30) Ca salts of palm oil (PALM, n = 30), Ca salts of soybean oil (SB, n = 30), or a mixture of Ca salts of palm, soybean, and cottonseed oils (MIX, n = 30) at 2% of the diet (as-fed basis). Within each treatment, 12 steers were shipped to a packing plant on d 93 of the experiment, and the remaining steers on d 148 of the experiment. Steer shrunk BW was recorded on d -9 (initial), and final BW calculated as 63% of hot carcass weight. Initial and final BW were used to calculate average daily gain (ADG). Individual dry matter intake was calculated by measuring dietary weekly offer and refusals. Feed efficiency was measured using steer total body weight gain and total dry matter intake during the experiment. No differences were detected for initial BW (P = 0.99). Final BW, BW gain, and dry matter intake were all greater (P ≤ 0.05) for MIX, PALM and CON compared with SB. Feed efficiency was greater (P ≤ 0.05) for MIX and PALM compared with SB, and also greater (P ≤ 0.05) for MIX compared with CON. Longissimus muscle area was greater (P ≤ 0.05) for MIX and CON compared with PALM. Collectively, inclusion of MIX into a finishing diet increased performance and feed efficiency of feedlot cattle, whereas inclusion of SB was detrimental to these responses.

33 Dietary Impacts on Rumen, Vaginal, and Uterine Microbiota in Beef Heifers

This experiment investigated the effects of diet composition on rumen, vaginal, and uterine microbiota of beef heifers. Fifteen rumen-cannulated, pubertal Angus-influenced heifers were used in a replicated 3 x 3 Latin square design (28-d periods and 21-d washout intervals). Dietary treatments included diets based on (as-fed) 100% grass hay (HF), 61% grass hay + 39% corn-based concentrate (INT), or 25% grass hay + 75% corn-based concentrate (HG). Treatments were offered individually to heifers once daily at 2% BW. Heifers also received 280 g/d of a mineral mix containing melengestrol acetate. Rumen, vaginal, and uterine samples were collected on d 0 and 28 of each period for bacterial profiling of the 16S rRNA gene and pH measurement. Data were analyzed using the MIXED procedure of SAS using results from d 0 as independent covariates, and heifer as the experimental unit. Ruminal pH on d 28 was greater (P &lt; 0.01) in HF compared with INT and HG, and greater (P &lt; 0.01) in INT compared with HG. Uterine and vaginal pH on d 28 did not differ among treatments (P &gt; 0.10). In the rumen, Bacteriodetes was the most abundant phylum with the relative abundance being significantly greater (P &lt; 0.01) in HF and INT (64.9 and 62.6%, respectively) when compared with HG (53.9%). Prevotella was the most abundant genus of bacteria within the rumen but did not differ (P &gt; 0.10) by dietary treatment. While there were no significant differences (P &gt; 0.10) for bacterial phyla in vaginal samples, Prevotella was the most abundant genus with the relative abundance being significantly greater (P &lt; 0.01) for the HG (18.62%) when compared with HF and INT (7.78 and 10.35%, respectively). There were no significant differences (P &gt; 0.10) for bacterial phyla in uterine samples, and while Prevotella was the most abundant, it was unaffected (P &gt; 0.10) by diet. Therefore, diet impacted rumen microbiota and appears to have an influence on vaginal microbiota of beef heifers.

37 Performance, Health, and Physiological Responses of Feedlot Cattle Supplemented with Pre- and Probiotic Ingredients

This experiment compared performance and health responses of feedlot cattle receiving a ymbiotic supplement, which replaced or was fed in conjunction with feed-grade antimicrobials. Angus-influenced steers (n = 192) from 4 different sources were weaned and immediately transported for 800 km. Steers arrived at the experimental feedlot on d 0, and a shrunk body weight (BW) was immediately recorded. Steers were ranked by source and shrunk BW, and allocated to 1 of 24 drylot pens (8 steers/pen). Pens received a free-choice diet containing: 1) monensin and tylosin (RT; 360 mg/steer daily from Rumensin and 90 mg/steer daily from Tylan; Elanco Animal Health, Greenfield, IN), 2) yeast-derived ingredient and B. subtilis probiotic (CC; 18 g/steer daily of Celmanax and 28 g/steer daily of Certillus; Church and Dwight Co., Inc., Princeton, NJ), or 3) combination of RT and CC (RTCC). Cattle were slaughtered according to BW, and slaughter groups were balanced by treatments (33 steers on d 200, 33 steers on d 230, 63 steers on d 257, and 63 head on d 285). Feed intake during the experimental period (d 0 to slaughter) was greater (P &lt; 0.01) in CC compared to RT and RTCC, although feed efficiency was lower in CC (P = 0.02). No treatment effects were observed for BW gain (P = 0.61), final BW (P = 0.67), or morbidity (P = 0.15). Upon slaughter, CC had higher marbling scores compared to RT (P = 0.04). Both CC and RTCC had larger Longissimus muscle area (P = 0.07) and more carcasses grading choice or better (P &lt; 0.01) than RT. Liver abscesses tended (P ≤ 0.09) to be greater in CC compared to RTCC and RT. Hot carcass weight, dressing percentage, backfat thickness, and yield grade did not differ among treatments (P ≥ 0.20). Collectively, replacing RT with CC improved feed intake and certain carcass measures despite decreased feed efficiency, whereas combining CC with RT did not yield additional performance and health benefits.

PSVIII-28 Dietary impacts on rumen, vaginal, and uterine environments in beef heifers

This experiment examined the effects of diet composition on rumen, vaginal, and uterine environments in beef heifers. Fifteen rumen-cannulated, pubertal Angus-influenced heifers were used in a replicated 3 x 3 Latin square design (28-d periods and 21-d washout intervals). Dietary treatments included (as-fed) diets based on 100% grass hay (HF), 61% grass hay + 39% corn-based concentrate (INT), or 25% grass hay + 75% corn-based concentrate (HG). Treatments were offered individually to heifers once daily at 2% of their body weight. Heifers also received 280 g/d of a mineral mix containing melengestrol acetate. Rumen, vaginal, and uterine fluid samples were collected on d 0 and 28 of each period for pH measurement. Data were analyzed using the MIXED procedure of SAS (SAS Inst. Inc., Cary, NC) using results from d 0 as independent covariates, and heifer as the experimental unit. Rumen pH on d 0 did not differ (P = 0.97) among treatments (7.197, 7.194, and 7.188 for HF, INT, and HG, respectively; SEM = 0.038). Ruminal pH on d 28 was greater (P ≤ 0.01) in HF compared with INT and HG (6.805, 6.628, and 6.380, respectively; SEM = 0.049), and greater (P &lt; 0.01) in INT compared with HG. Vaginal and uterine pH on d 0 did not differ (P ≥ 0.24) among HF, INT, and HG (6.914, 6.965, 6.780 of vaginal pH, respectively, SEM = 0.082; 6.644, 6.760, 6,592 of uterine pH, respectively, SEM = 0.079). Uterine and vaginal pH on d 28 also did not differ (P ≥ 0.64) among HF, INT, and HG heifers (6.926, 6.937, 6.918 of vaginal pH, respectively, SEM = 0.051; 6.567, 6.507, and 6.457 of uterine pH, respectively, SEM = 0.084). Therefore, dietary composition impacted rumen pH of beef heifers as expected, but without consequences to their vaginal and uterine pH.

PSXV-26 Performance and health responses of feedlot receiving cattle supplemented with pre- and probiotic ingredients

This experiment compared performance and health responses of feedlot cattle receiving a synbiotic supplement (yeast-derived prebiotic + Bacillus subtilis probiotic), which replaced or were fed in conjunction with feed-grade antimicrobials (monensin and tylosin) during a 56-d receiving period. Angus-influenced steers (n = 192) from 4 different sources were transported for 800 km, and arrived on the experimental feedlot on d 0 when shrunk body weight (BW) was recorded. Steers were ranked by source and shrunk BW, and were allocated to 1 of 24 drylot pens. Pens were assigned to receive a free-choice diet containing: 1) monensin and tylosin (RT; 360 mg/steer daily from Rumensin and 90 mg/steer daily from Tylan; Elanco Animal Health, Greenfield, IN), 2) yeast-derived ingredient and B. subtilis probiotic (CC; 18 g/steer daily of Celmanax and 28 g/steer daily of Certillus; Church and Dwight Co., Inc., Princeton, NJ), or 3) monensin and tylosin combined with yeast-derived and B. subtilis ingredients (RTCC) as in RT and CC. Feed intake was greater (P &lt; 0.01) in CC compared with RT and RTCC cattle (7.34, 6.15, 6.22 kg of dry matter/head daily, respectively; SEM = 0.29). Average daily gain tended (P ≤ 0.10) to be greater in CC compared with RT and RTCC cattle (1.23, 1.16, 1.16 kg/d, respectively; SEM = 0.03). Feed efficiency was less in CC compared with RT and RTCC cattle (0.160, 0.173, 0.171 kg/kg, respectively; SEM = 0.003). Incidence of bovine respiratory disease did not differ (P = 0.37) between treatments (25.9, 20.2, and 15.5% for CC, RT, and RTCC, respectively; SEM = 5.2) during the 56-d receiving period. Collectively, replacing RT with CC improved feed intake and BW gain during a 56-d receiving period, despite reducing feed efficiency. Combining RT and CC ingredients, however, did not yield additional productive and health benefits to receiving cattle.

172 Effect of energy and lasalocid supplementation on stocker cattle performance grazing winter-wheat pasture

Wheat pasture is unique to the Southern Plains where income can be reaped from the grazed forage followed by a grain harvest. The performance by cattle grazing is excellent, but nitrogen intake is excessive, resulting in inefficient use. Highly digestible supplements that are low in protein have been shown to augment ADG and improve nitrogen utilization. At the Southern Plain Experimental Range near Fort Supply, OK, an experiment was conducted to examine a supplement high in digestible fiber at multiple level of intake with or without 66 g of lasalocid/tonne. Sixty-five steers (324 ± 0.52 kg) grazed 41-ha of irrigated wheat pasture for 64 d. The supplement (4-Square Stocker/Grower 14; 14% CP; Purina Animal Nutrition, Shoreview, MN) was placed in 1 of 2 SmartFeed Plus feeders (C-Lock, Inc., Rapid City, SD); 1 feeder with the control feed and the other contained lasalocid. Each feeder was programmed to allow maximum intakes of 1.2, 2.0, and 3.2 kg/d for 8 or 9 steers at each level. So, there were 24 non-supplemented, 21 energy supplemented, and 21 energy supplemented steers with lasalocid. Because steers had liberty to consume supplement at will and only limited by a maximum, actual supplement intakes were calculated for the grazing period and steer performances were regressed on supplement intakes. Each kilogram of supplement increased (P = 0.04) ADG by 73 g/d; however, lasalocid did not increase (P = 0.73) ADG (avg ADG = 1.7 kg). Total BW gain by each steer (kg) was increased (P = 0.04) 4.7 kg for each kilogram of supplement fed daily and again, lasalocid did not increase (P = 0.73) performance (avg total BW gain = 109 kg). Supplementation with a moderate CP feed increased the ADG of steers grazing winter-wheat pasture, but the addition of lasalocid showed no benefit in this experiment.