Bull R C, Everson D O, Olson D P, Kelley K W, Curtis S, Tzou G
Dept. of Anim. Sci., University of Idaho, Moscow 83843.
J Anim Sci. 1991 Feb;69(2):853-63. doi: 10.2527/1991.692853x.
A study with neonatal calves was conducted to determine the effects of maternal crude protein (CP) and(or) metabolizable energy (ME) malnutrition, cold stress (0 or 21 degrees C), and age on concentrations of selected serum constituents. For each of 2 yr, 60 artificially bred Angus heifers were assigned randomly to a 2 x 2 factorial nutritional plan 150 d before predicted parturition. The diets provided each heifer with either .32 or .96 kg/d of CP and 8.7 or 12.6 Mcal/d of ME. Blood samples were obtained from heifers at parturition and from their calves at birth and at 12, 24, 36, 48, and 72 h of age. Sera were analyzed for concentrations of blood urea nitrogen (BUN), creatinine (Creat), iron, total protein (TProt), alkaline phosphatase (AlkPhos), total bilirubin (TBil), and cholesterol (Chol). Mean correlations of these constituents in calf sera between 12-h adjacency intervals were high, but those between longer times (48 or 60 h) were low. Simple correlations of serum constituents between cows and calves at birth were low except for BUN (r = .578 and .295 for yr 1 and 2, respectively). There were significant main treatment effects for maternal CP consumption on BUN levels, for environmental temperature on BUN, Creat, and TBil levels, and for years on BUN, Creat, iron, and AlkPhos levels in calves. Significant polynomial relationships were found over hours of age for all variables. Blood urea N decreased in normal calves but remained relatively constant at a low level in deficient calves. Year x hour of age interactions occurred for iron, TProt, AlkPhos, TBil, and Chol. Protein x year x hour of age interactions were found for iron and Chol. These results suggest that random sampling times are not useful for decision making during the first 72 h after birth. Consideration must be given to multiple samples taken at specific calf ages, to environmental temperatures, and to maternal protein nutritional levels when interpreting calf blood sera data.
开展了一项针对新生犊牛的研究，以确定母体粗蛋白（CP）和（或）代谢能（ME）营养不良、冷应激（0或21摄氏度）以及年龄对选定血清成分浓度的影响。在连续2年的时间里，在预计分娩前150天，将60头人工饲养的安格斯小母牛随机分配到一个2×2析因营养方案中。这些日粮分别为每头小母牛提供0.32或0.96千克/天的CP以及8.7或12.6兆卡/天的ME。在分娩时从小母牛采集血样，并在出生时以及出生后12、24、36、48和72小时从它们的犊牛采集血样。分析血清中的血尿素氮（BUN）、肌酐（Creat）、铁、总蛋白（TProt）、碱性磷酸酶（AlkPhos）、总胆红素（TBil）和胆固醇（Chol）浓度。犊牛血清中这些成分在相邻12小时间隔之间的平均相关性较高，但在较长时间（48或60小时）之间的相关性较低。除了BUN外，出生时母牛和犊牛血清成分之间的简单相关性较低（第1年和第2年的r分别为0.578和0.295）。母体CP摄入量对犊牛BUN水平、环境温度对BUN、Creat和TBil水平以及年份对犊牛BUN、Creat、铁和AlkPhos水平均有显著的主要处理效应。所有变量在犊牛年龄小时数上均发现了显著的多项式关系。正常犊牛的血尿素氮下降，但营养缺乏的犊牛在低水平上保持相对恒定。铁、TProt、AlkPhos、TBil和Chol出现了年份×年龄小时数的交互作用。铁和Chol发现了蛋白质×年份×年龄小时数的交互作用。这些结果表明，在出生后的前72小时内，随机采样时间对决策没有用处。在解释犊牛血清数据时，必须考虑在特定犊牛年龄采集的多个样本、环境温度以及母体蛋白质营养水平。
