摘要
Milk replacers (MR) formulated to contain more lactose than whole milk could potentially reduce insulin sensitivity in dairy calves. This study evaluated how partially replacing lactose in MR with fat on a weight/weight basis affects glucose–insulin kinetics in neonatal dairy calves fed high quantities of MR. Thirty-four Holstein bull calves were blocked by dam parity (1.6 ± 0.3) and randomly assigned to 1 of 2 treatments (n = 17): a high-lactose MR (HL; 46.1% lactose, 18.0% crude fat, and 23.9% crude protein on a dry matter basis) or a high fat MR (HF; 39.9% lactose, 24.6% crude fat, and 24.0% crude protein on a dry matter basis). Calves were individually housed and fed pooled colostrum at 1.5 h and 12 h postnatal at 18 and 9% of metabolic body weight (BW0.75), respectively. From 24 h postnatal until the end of the study (d 7), calves were transitioned to MR (prepared at 150 g/L) at 18% of BW0.75 twice daily at 0700 and 1900 h. On d 4, an insulin-modified intravenous glucose tolerance test was conducted 8 h after the morning meal by intravenous infusion of glucose (0.54 g/kg of BW0.75, min 0) and insulin (3.9 μg/kg of BW0.75, min 20). During postprandial sampling on d 6, abomasal emptying was assessed by dosing acetaminophen (0.13 g/kg of BW0.75) with MR and measuring its appearance within plasma. Sequential blood samples were collected and analyzed for plasma glucose, insulin, and acetaminophen concentrations. Calves were killed on d 7 and liver and pancreatic tissues were collected for histomorphological analysis. Partially replacing lactose in MR with fat increased body weight gain (679.6 vs. 462.0 ± 69.68 g/d) and gain:metabolizable energy intake (186.6 vs. 120.5 ± 20.21 g of body weight/Mcal) compared with feeding HL MR. Furthermore, abomasal emptying rate was reduced in calves fed HF MR. Calculated variables based on postprandial glucose and insulin concentrations, such as maximum concentration or area under the curve, were or tended to be lower in HF than in HL calves. Postprandial insulin sensitivity tended to be reduced in HL compared with HF, although insulin sensitivity estimated from the insulin-modified intravenous glucose tolerance test was not different. Calves fed HF MR showed enhanced glucose-stimulated insulin secretion. In conclusion, partially replacing lactose in MR with fat resulted in smaller fluctuations in postprandial glucose and insulin concentrations and tended to increase postprandial but not fasting insulin sensitivity in neonatal dairy calves.
摘要译文
配制的牛奶替代品（MR）含有比全牛奶更多的乳糖可能会降低乳制品犊牛的胰岛素敏感性。该研究评估了在重量/重量的脂肪中的部分替代乳糖是如何影响新生儿乳制品犊牛的葡萄糖 - 胰岛素动力学。坝奇偶校验（1.6±0.3）阻塞了三十四个孔牛犊，并随机分配给2个处理中的1个（n = 17）：高乳糖MR（HL; 46.1％乳糖，18.0％粗脂肪和23.9％的粗蛋白质在干物质的基础上或高脂肪MR（HF; 39.9％乳糖，24.6％粗脂肪和24.0％粗蛋白质的干物质）。单独容纳犊牛并在1.5小时和12小时以18和9％的代谢体重（BW 0.75 ）分别在1.5小时和12小时内喂入汇集的初乳。从24小时后，直到研究结束（D 7），犊牛在每天在0700和1900小时的每天28％的BW 0.75 / sop>的18％转变为Mr（以150g / L）的MR（制备）。在D 4中，通过静脉内输注葡萄糖（0.54g / kg Bw 0.75 ，min 0）和胰岛素（0.54g / kg 0.75）和胰岛素（3.9μg/ kg bw 0.75 ，min 20）。在D 6上的后施加期间，通过将乙酰氨基酚（0.13g / kg 0.75 0.75 ）用MR和测量其在血浆内的外观来评估rabomas排空。收集顺序血液样品并分析血浆葡萄糖，胰岛素和乙酰氨基酚浓度。在D 7上杀死犊牛，并收集肝脏和胰腺组织以进行组织形态分析。与喂养HL MR相比，部分替代脂肪MR中的乳糖（679.6对462.0±69.68g / d）和增益：代谢能量摄入量（186.6与120.5±20.5±20.5±20.21g）。此外，饲喂HF MR的小腿中的脱毛排放率降低。基于餐后葡萄糖和胰岛素浓度的计算变量，例如曲线下的最大浓度或区域，或者往低于HL犊牛。与HF相比，HL的后胰岛素敏感性趋于降低，尽管从胰岛素改性的静脉内葡萄糖耐量试验估计的胰岛素敏感性并不不同。饲喂HF MR显示出增强的葡萄糖刺激的胰岛素分泌。结论是，部分替代脂肪MR中的乳糖导致餐后葡萄糖和胰岛素浓度的较小波动，并倾向于增加餐后，但在新生儿乳制品犊牛中没有禁食胰岛素敏感性。
A.C.Welboren[1];B.Hatew[2];O.López-Campos[3];J.P.Cant[1];L.N.Leal[4];J.Martín-Tereso[4];M.A.Steele[1][2];. Effects of energy source in milk replacer on glucose metabolism of neonatal dairy calves - ScienceDirect[J]. Journal of Dairy Science, 2021,104(4): 5009-5020