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 ±â€…31 kg) and body condition score (BCS; 6.0 ±â€…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 ±â€…4 d prepartum to 104 ±â€…4 d postpartum). Calves were weaned on day 242 (96 ±â€…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.

Direct-fed microbials (DFM), such as Bacillus spp., have been shown to produce a wide variety of enzymes related to nutrient digestion and to support gastrointestinal tract immune function and integrity, leading to increased nutrient digestibility and cattle performance. Nutritional management of beef cows during gestation and early lactation has been associated with enhanced future offspring growth performance and immune response following birth. The present study combined the use of Bacillus-based DFM for pregnant heifers during critical production stages (late gestation and early lactation) to promote the overall performance of heifers and their offspring. Heifers offered Bacillus-based DFM had greater body condition score at calving and postpartum plasma concentration of glucose, whereas their offspring had similar body weight at birth, but greater growth performance when fed relatively high amounts of protein and energy in drylot compared to cohorts born from heifers that did not receive Bacillus-based DFM supplementation.

Removing maternal heat stress abatement during gestation modulated postnatal physiology and improved performance of Bos indicus-influenced beef offspring.

This study evaluated the growth and immune response of beef calves born from Bos indicus-influenced beef heifers provided pre- and postpartum heat abatement on pasture. On 83 ±â€…4 d prepartum (day 0), 64 Brangus crossbred beef heifers (~» B. indicus) were stratified by body weight (BW; 454 ±â€…37 kg) and body condition score (BCS; 6.3 ±â€…0.28; scale 1 to 9), and then allocated into 1 of 16 bahiagrass pastures (1 ha and 4 heifers per pasture). Treatments were randomly assigned to pastures (8 pastures per treatment) and consisted of heifers provided (SH) or not (NSH) access to artificial shade (4.5 m2 of shade area per heifer) from 83 d prepartum to 50 d postpartum (days 0 to 133). Heifers and calves were managed similarly from day 133 until the start of the breeding season (day 203). Calves were weaned on day 203 (at 119 ±â€…19 d of age), limit-fed the same drylot diet at 3.5% of BW (DM basis) days 209 to 268 (3 to 4 calves per pen; 8 pens per treatment) and vaccinated against respiratory disease pathogens on days 222 and 236. Heifer intravaginal temperatures from days 35 to 42 were lower (P ≤ 0.03) for NSH vs. SH heifers from 0000 to 0800 hours but greater (P ≤ 0.05) for NSH vs. SH heifers from 1100 to 1800 hours. Heifer intravaginal temperature from days 126 to 132 did not differ (P = 0.99) between NSH and SH heifers. Heifers assigned to NSH had greater respiration rates from days 20 to 96 (P ≤ 0.0007), greater plasma concentration of cortisol on days 35 (P = 0.07) and 55 (P = 0.02), less plasma concentration of insulin-like growth factor 1 (IGF-1) on days 35 (P = 0.10), 55, and 133 (P ≤ 0.05), and less BCS from days 55 to 203 (P ≤ 0.01) compared to SH heifers. Calves born from NSH heifers had less birth BW (P = 0.05), greater overall plasma haptoglobin concentrations (P = 0.05), greater seroconversion against bovine respiratory syncytial virus on day 222 (P = 0.02), tended to have greater ADG from days 209 to 268 (P = 0.07), and had greater BW on day 268 (P = 0.05) compared to SH offspring. Plasma concentrations of cortisol and serum titers against other respiratory disease pathogens did not differ (P ≥ 0.15) between NSH and SH offspring. Hence, removing maternal access to artificial shade: (1) increased prepartum intravaginal temperature and plasma concentrations of cortisol but reduced prepartum BCS and plasma concentrations of IGF-1 in grazing B. indicus-influenced beef heifers; and (2) increased post-weaning BW gain and had positive effects on humoral immune response of their offspring.

In dairy cattle, heat stress during late gestation negatively impacted offspring postnatal growth and immune function. The use of artificial shade is a management strategy that alleviates heat stress in environments with high temperatures and humidity. The effects of maternal access to artificial shade and its impacts on offspring performance have not been reported for Bos indicus influenced-beef cattle and were the main objective of the present study. From 83 d prepartum until 50 d postpartum, heifers had access or not to an artificial shade structure located centrally on their pastures. Overall, removing maternal access to artificial shade increased maternal internal body temperature and respiration rates, and reduced maternal body condition score from calving until the start of the breeding season and calf body weight at birth. However, calves born from heifers with no access to shade were remarkably heavier at the end of the drylot period and had lower plasma indicators of inflammatory response and positive effects to humoral immune response to vaccination.

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 ±â€…65 kg) and body condition score (BCS, 5.5 ±â€…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 ±â€…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.

This study evaluated the effect of bakery waste supplementation during the last trimester of gestation in Bos indicus-influenced beef cows and the subsequent impact on their offspring. Brangus cows were allocated to one of three prepartum treatments consisting of no prepartum supplementation, 1 kg/d of bakery waste with low or high concentration of crude fat. Prepartum supplementation of bakery waste, regardless of crude fat concentration, increased maternal plasma concentrations of ω-6 fatty acids during gestation and body condition score at calving. Offspring birth weights were not affected but offspring born to cows that received prepartum supplementation of bakery waste, regardless of crude fat concentration, were heavier at weaning compared to no prepartum supplementation. However, the greatest improvements to weaning weights were observed for offspring born to cows fed low-fat vs. high-fat bakery waste. In contrast, high-fat bakery waste supplementation during late gestation alleviated physiological stress and improved humoral immune response to vaccination during preconditioning compared to low-fat bakery waste supplementation. Thus, altering the crude fat concentration of bakery waste provided to Bos indicus-influenced beef cows during the third trimester of gestation can be implemented to modulate offspring preweaning growth or postweaning immune function.