水牛初乳和常乳主要组分的动态变化

试验旨在研究水牛初乳和常乳主要组分的动态变化规律。采用乳品分析仪对摩本杂水牛(摩拉水牛×德宏水牛)初乳和常乳中乳脂、乳糖、乳蛋白、总固形物(TS)和非脂固形物(SNF)等含量进行测定,用SDS-PAGE对乳蛋白各组分进行分离,并利用凝胶成像系统进行扫描定量。结果表明,初乳中乳糖含量随泌乳天数的增加逐渐升高;乳蛋白、总固形物(TS)和非脂固形物(SNF)含量呈下降趋势;初乳中乳脂含量变化不规则,出现小幅波动;蛋白质各组分中乳铁蛋白(LF)、血清白蛋白(SA)、免疫球蛋白(Igs)含量第1天最高,以后开始下降;酪蛋白(CN)在乳蛋白百分比含量中占优势,随着泌乳天数的增加逐渐升高;β-乳球蛋白(β-LG)第1天含量低,第5 和7天达到最高值;α-乳白蛋白(α-LA)第1天最低,第2天急剧上升,以后变化平稳。常乳中大部分组分含量比较稳定,有时有波动,但各天数之间差异不显著。研究结果显示,水牛乳中大部分组分的含量在初乳中变化较大,初乳的营养价值高于常乳。

Dynamic Changes of Main Components in Colostrum and Milk of Buffalo

The aim of this study was to investigate the dynamic changes of main components in colostrum and milk of buffalo. The percentage of milk fat, lactose, protein, TS and SNF from buffalo (Murrah×Dehong) colostrum and milk were assayed by instrument. In addition, the compositions of protein were separated by SDS-PAGE and scanned using gel imaging-forming system. As a result, the concentration of lactose in colostrum seemed to increase by day. The percentages of protein, TS and SNF tended to decrease. Fat content in colostrum changed irregularly and appeared small-scope fluctuation. The content of LF, SA and Igs were the highest on 1 d, then declined in subsequent days. The percentage of CN dominated in milk protein and increased with lactation. The content of β-LG was the lowest at 1 d and had the peak at 5 d and 7 d. The content of α-LA was the lowest on 1 d, but it rose sharply on 2 d and varied smoothly in the other days. Most of the components in milk were stable, sometimes had volatility, but there was no significant difference between each day. The results indicated that the content of main components in colostrum changed greatly, the colostrum was nutritionally superior to milk.