Objectives of this study were to investigate the effects of milk replacer (MR) acidification for free- access feeding on pre- and post-weaning performance, morbidity and mortality of calves. Calves were randomly assig...Objectives of this study were to investigate the effects of milk replacer (MR) acidification for free- access feeding on pre- and post-weaning performance, morbidity and mortality of calves. Calves were randomly assigned to free-access feeding of acidified (ACID, n = 31) or non-acidified (NON, n = 31) MR, and weaned at 42 days. ACIDMR was prepared to pH 4.0 - 4.5 using formic acid. Intakes were measured daily and weights weekly. Samples of ACID and NON MR were analyzed for coliform and aerobic bacterial growth. After weaning, calves transitioned to a grain-fed veal diet, weighed every 2 weeks. At slaughter (approximately 6 months of age), lungs were evaluated for gross pathological changes and dressed carcass weights were obtained. Generalized linear mixed models were constructed to examine the effects of MR acidification. Differences by treatment group for pre- and post-weaning morbidity and mortality were tested using Pearson’s χ2 and Fisher’s exact tests. ACID calves consumed less MR than NON (10.6 vs. 11.7 L/d, P = 0.02). Acidification tended to promote earlier onset of starter ration consumption (32.0 vs. 39.5 d, hazard ratio = 1.5, P = 0.07), but did not affect average daily starter ration or water intakes across the pre-weaning period. ACID and NON calves did not differ for BW at weaning, pre- or post-weaning ADG or dressed carcass weight. ACID MR had less coliform (P < 0.001) and aerobic bacterial growth (P < 0.001) than NON MR, but odds of disease treatment and mortality did not differ. ACID calves tended to have lower odds of pulmonary lesions during post-mortem inspection than NON calves (OR = 0.3, P = 0.07). These results indicate that under free-access feeding conditions, acidification limited bacterial growth and MR intake, but there were no long-term impacts of acidification on calf performance or health. In conclusion, acidification to pH 4.0 - 4.5 will significantly reduce bacterial growth in milk fed to calves.展开更多
检测分析奶公犊牛肉的基本营养成分,奶公犊牛肉中蛋白质、粗脂肪、水分、灰分、碳水化合物含量和能量分别达到23.76%、1.38%、77.66%、1.35%、0.85%和469.43 k J/100 g;奶公犊牛肉含有丰富的微量元素,其中奶公犊牛肉中铁元素和铜元素为...检测分析奶公犊牛肉的基本营养成分,奶公犊牛肉中蛋白质、粗脂肪、水分、灰分、碳水化合物含量和能量分别达到23.76%、1.38%、77.66%、1.35%、0.85%和469.43 k J/100 g;奶公犊牛肉含有丰富的微量元素,其中奶公犊牛肉中铁元素和铜元素为成年黄牛肉的10倍之高;奶公犊牛肉中总氨基酸含量略低于成年黄牛肉,风味氨基酸占总氨基酸的比例高于成年黄牛肉。展开更多
文摘Objectives of this study were to investigate the effects of milk replacer (MR) acidification for free- access feeding on pre- and post-weaning performance, morbidity and mortality of calves. Calves were randomly assigned to free-access feeding of acidified (ACID, n = 31) or non-acidified (NON, n = 31) MR, and weaned at 42 days. ACIDMR was prepared to pH 4.0 - 4.5 using formic acid. Intakes were measured daily and weights weekly. Samples of ACID and NON MR were analyzed for coliform and aerobic bacterial growth. After weaning, calves transitioned to a grain-fed veal diet, weighed every 2 weeks. At slaughter (approximately 6 months of age), lungs were evaluated for gross pathological changes and dressed carcass weights were obtained. Generalized linear mixed models were constructed to examine the effects of MR acidification. Differences by treatment group for pre- and post-weaning morbidity and mortality were tested using Pearson’s χ2 and Fisher’s exact tests. ACID calves consumed less MR than NON (10.6 vs. 11.7 L/d, P = 0.02). Acidification tended to promote earlier onset of starter ration consumption (32.0 vs. 39.5 d, hazard ratio = 1.5, P = 0.07), but did not affect average daily starter ration or water intakes across the pre-weaning period. ACID and NON calves did not differ for BW at weaning, pre- or post-weaning ADG or dressed carcass weight. ACID MR had less coliform (P < 0.001) and aerobic bacterial growth (P < 0.001) than NON MR, but odds of disease treatment and mortality did not differ. ACID calves tended to have lower odds of pulmonary lesions during post-mortem inspection than NON calves (OR = 0.3, P = 0.07). These results indicate that under free-access feeding conditions, acidification limited bacterial growth and MR intake, but there were no long-term impacts of acidification on calf performance or health. In conclusion, acidification to pH 4.0 - 4.5 will significantly reduce bacterial growth in milk fed to calves.
文摘检测分析奶公犊牛肉的基本营养成分,奶公犊牛肉中蛋白质、粗脂肪、水分、灰分、碳水化合物含量和能量分别达到23.76%、1.38%、77.66%、1.35%、0.85%和469.43 k J/100 g;奶公犊牛肉含有丰富的微量元素,其中奶公犊牛肉中铁元素和铜元素为成年黄牛肉的10倍之高;奶公犊牛肉中总氨基酸含量略低于成年黄牛肉,风味氨基酸占总氨基酸的比例高于成年黄牛肉。
