摩拉×西林水牛乳化学组成变化的研究

Study on Changes of Chemical Compositions in Murrah × Xilin Buffalo Milk

本实验采用7头1胎的摩拉×西林水牛,分别在产犊后2h、12h、24h、36h、48h、3d、4d、5d、6d、7d、15d、30d、60d、90d、120d、150d、180d、210d采集乳样,称量产乳量,测定乳的物理性质和化学组成。结果表明:摩拉×本地水牛的泌乳高峰出现在产后第三个月(126.56kg),210d总产量805.47kg,平均日产量3.84kg;水牛产犊后2h乳的pH为6.23,乳糖2.33%,之后逐渐上升,15d之后分别在pH6.51～6.55,乳糖4.42%～4.79%之间变化;2h时乳的酸度为36.73°T,之后逐渐下降,15d之后在19.43～23.15°T之间变化;2h时乳密度、蛋白质、固形物分别为1.057、18.23%、31.460%,3d内迅速下降,然后分别在1.028～1.031、4.83%～6.02%、19.12%～20.59%之间变化;脂肪含量在2h为9.73%,之后逐步上升,36h时达到最高值11.57%,之后呈缓慢下降趋势,4d时为9.76%,之后在8.26%～9.06%之间变化;酪蛋白在粗蛋白中的比例逐步上升,2h时为40.15%,5d时达到79.13%,之后在81.07%～83.23%变化。

In this paper, 7 Murrah× Xilin buffaloes which were in their first parturition were chosen in experiment. Milk on 2 h, 12 h, 24 h, 36 h, 48 h, 3 d, 4 d, 5 d, 6 d, 7 d, 15 d, 30 d, 60 d, 90 d, 120 d, 150 d, 180 d and 210 d postpartum respectively were collected. The yield, physical properties and chemical composition of milk were assayed. The results were shown as follows： the apex of yield appeared at the third month is 126.56 kg, total yield of 210 d 805.47 kg, yield per day 3.84 kg; and pH value and lactose 6.23 and 2.33% respectively at 2 h postpartum, increased with lactation, then changed between 6.51-6. 55 and 4.42%-6.02% respectively after 15d. The acidity was 36.73° T at 2 h, decreased with lactation, then changed between 19.43-23.15° T. The dencity, protein and total solid were 1.057, 18.23%, 31.460% at 2 h respectively, changed sharply in 3 d, then varied within 1.028-1.031, 4.83%-6.02%, 19.12%-20.59% respectively. The fat was 9.73% at 2 h, increased to 11.57% at 36 h, then decreased with lactation, was 9.76% at 4 d, then changed within 8.26%-9.06%. Casein/total protein increased with lactation, was 40.15% at 2 h and 79.13% at 5 d, then varied within 81.07%-83.23%.