Abstract A 2×2 factorial design experiment was conducted to investigate effects of cow genotype and concentrate supplementation (CS) on milk composition and processability. Four treatment groups (n = 12) were: (i) lower milk genotype (LM) offered no CS; (ii) LM + 2.7 kg dry matter (DM) CS; (iii) higher milk genotype (HM) offered no CS; and (iv) HM + 2.7 kg DM CS. Cows were +208 d in milk, grazed full time, and were offered 17 kg DM pasture cow-1 d-1. Increased milk yield resulted from HM cows and offering CS. The HM cows had decreased fat, protein and casein concentrations, while offering CS also decreased fat, protein and casein concentrations. Milk from cows offered CS had increased ethanol stability compared with cows offered pasture-only. In conclusion, HM cows and offering CS increased milk yield at the expense of components, but offering CS increased milk colloidal stability.

中文翻译：

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基因型和浓缩物添加对晚泌乳春季产犊放牧奶牛牛奶成分和选定牛奶加工参数的影响

摘要 进行了一项 2×2 因子设计实验，以研究奶牛基因型和浓缩物添加 (CS) 对牛奶成分和可加工性的影响。四个治疗组 (n = 12) 是： (i) 较低的牛奶基因型 (LM) 不提供 CS；(ii) LM + 2.7 kg 干物质 (DM) CS；(iii) 较高的牛奶基因型 (HM) 不提供 CS；(iv) HM + 2.7 kg DM CS。奶牛在牛奶中 +208 天，全天放牧，并提供 17 公斤 DM 牧场奶牛 - 1 天 - 1。HM 奶牛和提供 CS 导致产奶量增加。HM 奶牛的脂肪、蛋白质和酪蛋白浓度降低，而 CS 也降低了脂肪、蛋白质和酪蛋白的浓度。与仅提供牧场的奶牛相比，来自提供 CS 的奶牛的牛奶具有更高的乙醇稳定性。总之，HM 奶牛和提供 CS 以牺牲组件为代价增加了产奶量，