Division of Animal Sciences, University of Missouri, Columbia, MO 65211, USA.
Department of Animal and Food Sciences, Oklahoma State University, Stillwater, OK 74078, USA.
J Anim Sci. 2023 Jan 3;101. doi: 10.1093/jas/skac399.
To determine effects of dam parity on perinatal nutrient availability in beef cattle, data and samples were collected from 18 primiparous and 35 multiparous spring-calving Sim-Angus dams and their calves. Time to stand was recorded and neonatal vigor assessed. Jugular blood was collected from a subset of calves at 0 (post-standing and pre-suckling) 6, 12, 24, 48, and 72 h of age, and blood chemistry panels were completed. Expelled placentas were dissected, dried, and weighed. Prepartum maternal circulating glucose, non-esterified fatty acids (NEFA), triglycerides, and urea N were analyzed. All statistical models included the fixed effect of dam parity, and calf sex (when P ≤ 0.25) was included for calf and placental variables. Effects of sampling hour, and parity × hour were included for calf metabolites over time using repeated measures. Multiparous dams had greater body weight prepartum (P < 0.001) but similar (P = 0.25) body condition score. Maternal circulating urea N and triglycerides were greater (P ≤ 0.05) in multiparous dams pre-calving. Calves born to primiparous dams weighed 10% less (P ≤ 0.04) at birth with smaller (P ≤ 0.01) heart and abdominal girths. Cotyledonary, intercotyledonary, and total placental masses were less (P ≤ 0.05) for primiparous dams. Dam parity did not affect (P ≥ 0.58) calf time to stand, vigor score at 10 min, or rectal temperature. Serum glucose was greater (P = 0.03) at 0 h but less (P ≤ 0.04) at all other hours in calves from primiparous dams. Calves from primiparous dams had greater (P ≤ 0.02) serum NEFA at 6, 12, and 24 h although plasma triglycerides were greater (P < 0.001) at 6 h. Calves from primiparous dams had greater (P ≤ 0.04) serum urea N at 12 h and creatinine at 12 and 24 h. Plasma insulin was greater (P ≤ 0.04) in calves from multiparous dams at 12, 48, and 72 h, but parity did not affect (P ≥ 0.18) serum total protein or plasma cortisol. Serum aspartate aminotransferase was greater (P ≤ 0.04) at 6 and 24 h, creatine kinase was greater at 24 h, and gamma-glutamyl transpeptidase was less (P ≤ 0.04) at 6, 12, and 24 h, for calves from primiparous dams. Calves born to primiparous dams had greater (P ≤ 0.02) total bilirubin and direct bilirubin at 12 and 24 h. Data indicate that calves born to first-parity heifers had decreased perinatal nutrient availability, resulting in reduced fetal and placental growth, as well as greater energy reserve mobilization and metabolic indicators of stress as neonates.
为了确定胎次对肉牛围产期营养供应的影响，从 18 头初产和 35 头经产春季产 Sim-Angus 母畜及其犊牛中收集了数据和样本。记录了站立时间，并评估了新生牛活力。从部分犊牛中在站立后和吮乳前（0 小时）、6 小时、12 小时、24 小时、48 小时和 72 小时采集颈静脉血，并完成血液化学分析。剖检、干燥和称重排出的胎盘。分析了产前母体循环中的葡萄糖、非酯化脂肪酸（NEFA）、甘油三酯和尿素氮。所有统计模型均包括胎次的固定效应，当 P ≤ 0.25 时，还包括了犊牛和胎盘变量的性别。对于随时间变化的犊牛代谢物，使用重复测量包括了采样时间和胎次×时间的影响。经产母牛产前体重更大（P < 0.001），但体况评分相似（P = 0.25）。产前经产母牛的循环尿素氮和甘油三酯更高（P ≤ 0.05）。初产母牛所产犊牛出生时体重轻 10%（P ≤ 0.04），心脏和腹部周长更小（P ≤ 0.01）。初产母牛的胎衣叶、叶间和总胎盘质量更小（P ≤ 0.05）。胎次对初产犊牛的站立时间、10 分钟活力评分或直肠温度没有影响（P ≥ 0.58）。初产母牛的血清葡萄糖在 0 小时更高（P = 0.03），但在其他所有时间点都更低（P ≤ 0.04）。初产母牛的血清 NEFA 在 6、12 和 24 小时更高（P ≤ 0.02），尽管血浆甘油三酯在 6 小时更高（P < 0.001）。初产母牛的血清尿素氮在 12 小时和肌酐在 12 和 24 小时更高（P ≤ 0.04）。初产母牛的血浆胰岛素在 12、48 和 72 小时更高（P ≤ 0.04），但胎次对血清总蛋白或血浆皮质醇没有影响（P ≥ 0.18）。初产母牛的血清天门冬氨酸氨基转移酶在 6 和 24 小时更高（P ≤ 0.04），肌酸激酶在 24 小时更高，谷氨酰转肽酶在 6、12 和 24 小时更低（P ≤ 0.04）。初产母牛所产犊牛的总胆红素和直接胆红素在 12 和 24 小时更高（P ≤ 0.02）。数据表明，第一胎次小母牛所产犊牛围产期营养供应减少，导致胎儿和胎盘生长减少，以及新生牛能量储备动员和应激代谢指标增加。
