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.

Productive and physiological responses of feedlot cattle receiving different sources of Ca salts of fatty acids in the finishing diet.

This study evaluated productive and physiological responses in feedlot cattle receiving a finishing diet that included Ca salts of palm oil (CSPALM), or a blend of Ca salts of palm, cottonseed, and soybean oils (CSMIX). Ninety yearling steers were housed in 15 pens equipped with Calan-gate feeders (6 steers/pen). Steers within each pen were stratified by shrunk body weight (BW; 410 ±â€…3.3 kg across pens) on d 0 and assigned to receive a total-mixed ration (TMR) containing (dry matter basis) 2.2% of CSPALM (n = 30), 2.2% of CSMIX (n = 30), or no supplemental fat (CON; n = 30). Individual TMR intake was evaluated weekly. Blood samples were collected on d 0, 28, 56, 91, 119, and 147. Samples of the Longissimus muscle (LM) were collected on d 84 via biopsy. Upon slaughter on d 148, hot carcass weight (HCW) was recorded to estimate final BW (63% dressing), and one LM steak sample (2.54 cm thickness) was removed from the right side of each carcass. Steer ADG was greater (P = 0.02) for CSMIX compared with CSPALM and tended to be greater (P = 0.09) for CSMIX compared with CON. The gain:feed ratio was greater (P ≤ 0.05) for CSMIX compared with CSPALM and CON, and carcass LM area was less (P = 0.01) for CSPALM compared with CSMIX and CON. No treatment effects were detected (P ≥ 0.21) for TMR intake, final BW, and other carcass merit traits including marbling. Mean plasma cholesterol concentrations were greater (P < 0.01) in CSMIX and CSPALM compared with CON, and mRNA expression of adipocyte fatty acid binding protein in the LM on d 84 was greater (P ≤ 0.04) in CSPALM compared with CSMIX and CON. No treatment effects were detected (P ≥ 0.15) for plasma concentrations of glucose, insulin, insulin-like growth factor I, and leptin, nor for other LM genes associated with marbling and muscle growth. Concentrations of total fatty acids (FA) in plasma and LM steak samples were greater (P < 0.01) in CSMIX compared with CSPALM and CON, and greater (P < 0.01) in the LM samples of CSPALM compared with CON. Steers receiving CSMIX had greater (P < 0.01) concentrations of polyunsaturated and ω-6 FA in plasma and LM steak samples compared with CSPALM and CON. Supplementing CSMIX improved gain efficiency and FA profile in the LM of feedlot steers compared with the CON diet, but the same responses were not observed when CSPALM was offered. Perhaps the advantages from CSMIX supplementation resulted from increasing the supply of polyunsaturated and ω-6 FA to the finishing diet.

Supplemental fat has been provided to feedlot cattle to increase energy density of their diets, and may yield nutraceutical advantages if includes polyunsaturated fatty acids (FA). Alternatively, carcass quality can be improved when the fat supplement is based on saturated and monounsaturated FA. Hence, this experiment evaluated a blend of saturated, monounsaturated, and polyunsaturated FA to improve both performance and carcass merit in feedlot cattle. Steers received a finishing diet that included this blend (CSMIX), a source of saturated and monounsaturated FA (CSPALM), or no supplemental fat (CON). Growth rate and gain efficiency were improved in steers that received CSMIX compared with CSPALM and CON, and these traits did not differ between the latter treatments. Inclusion of CSMIX increased FA concentrations in the circulation of steers throughout the 147-day study and in Longissimus muscle (LM) samples collected after slaughter. This increase in FA concentrations was associated with greater accumulation of polyunsaturated and ω-6 FA, suggesting that CSMIX resulted in LM with FA profile deemed more beneficial for human consumption. Collectively, supplementing CSMIX to feedlot steers improved gain efficiency and FA composition in the LM, and these advantages may be associated with increased supply of polyunsaturated ω-6 FA to the finishing diet.