Effect of plane of milk replacer intake and age on glucose and insulin kinetics and abomasal emptying in female Holstein Friesian dairy calves fed twice daily
Effect of plane of milk replacer intake and age on glucose and insulin kinetics and abomasal emptying in female Holstein Friesian dairy calves fed twice daily
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DOI：
10.3168/jds.2015-10826
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发表时间：
2016-10-01
影响因子：
3.5
通讯作者：
Steele, M. A.
中科院分区：
文献类型：
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作者：
MacPherson, J. A. R.;Berends, H.;Steele, M. A.
本研究的目的是调查断奶前代乳粉摄入量和日龄如何影响每天饲喂两次的奶牛犊的胰岛素和葡萄糖动力学以及皱胃排空率。总共 12 头雌性荷斯坦弗里斯兰犊牛按母牛胎次分组，按初乳来源配对，并随机分配到高营养平面（8 L/天，1.2 kg 代乳粉/天；n = 6）或低营养平面（4 L/d，0.6 kg 代乳粉/天；n = 6）。所有犊牛在两餐中（出生后 1 小时和 6 小时）接受 4 L 初乳，然后直接转移到指定的喂养计划，直到在第 7 周期间将牛奶减少 50%，并在第 8 周断奶。以 150 g/L 的浓度每天两次（0700 和 1700 小时）饲喂代乳粉（24% 粗蛋白，18% 粗脂肪），所有犊牛都可以随意摄入颗粒状犊牛发酵剂、切碎的麦秆和水。所有犊牛在 4、7 和 10 周龄时均置入颈静脉导管。然后，确定餐后对血浆葡萄糖、胰岛素和对乙酰氨基酚（随餐提供）的反应，以测量皱胃排空。第二天，通过颈静脉导管注入葡萄糖进行葡萄糖耐量试验。在第 4 周和第 7 周时，高位犊牛的真胃排空速率常数 (%/h) 较低（第 4 周为 0.21 +/- 0.02；第 7 周为 0.27 +/- 0.02），而低位犊牛（第 4 周为 0.34 +/- 0.02；第 7 周为 0.47 +/- 0.02）。与低体重犊牛相比，高体重犊牛在 420 分钟内的餐后血浆胰岛素曲线下面积更大（18,443 +/- 7,329；低体重 = 5,834 +/- 739 mu U/mL）。我们发现 4、7 或 10 周龄高奶牛犊和低奶牛犊之间的葡萄糖耐量测试动力学没有差异。这项研究的结果表明，每天用两餐代乳粉喂养奶牛犊，提高营养水平并不会降低胰岛素敏感性。
The objective of this study was to investigate how preweaning plane of milk replacer intake and age can affect insulin and glucose kinetics as well as abomasal emptying rate in dairy calves fed twice a day. A total of 12 female Holstein Friesian calves were blocked by cow parity, paired by colostrum origin, and were randomly assigned to a high plane of milk replacer intake (8 L/d, 1.2 kg of milk replacer/d; n = 6) or a low plane of nutrition (4 L/d, 0.6 kg of milk replacer/d; n = 6). All calves received 4 L of colostrum over 2 meals (1 and 6 h after birth) and were then directly transferred to their assigned feeding plans until they were stepped-down from milk by 50% during wk 7 and weaned on wk 8. Milk replacer (24% crude protein, 18% crude fat) was fed at 150 g/L twice daily (0700 and 1700 h) and all calves had ad libitum access to pelleted calf starter, chopped wheat straw, and water. Jugular catheters were placed in all calves at 4, 7, and 10 wk of age. Then, postprandial response to plasma glucose, insulin, and acetaminophen (supplied with the meal) were determined to measure abomasal emptying. The next day, a glucose tolerance test was conducted by infusing glucose via the jugular catheter. At 4 and 7 wk of age, the rate constant (%/h) for abomasal emptying of the meal was lower in high calves (0.21 +/- 0.02 in wk 4; 0.27 +/- 0.02 in wk 7) compared with low (0.34 +/- 0.02 in wk 4; 0.47 +/- 0.02 in wk 7). The postprandial plasma insulin area under the curve over 420 min was greater in high calves (18,443 +/- 7,329; low = 5,834 +/- 739 mu U/mL) compared with low. We found no differences in glucose tolerance test kinetics between the high and low dairy calves at 4, 7, or 10 wk of age. The findings from this study suggest that feeding dairy calves an elevated plane of nutrition in 2 meals of milk replacer per day does not decrease insulin sensitivity.