摘要
The optimization of milk production includes a rational use of forages, respect for the environment and offers the best quality to consumers. Milk production based on grass and forages produces healthier milk and it is widely spread throughout the Atlantic arc to maximize milk yield per hectare. However, the mode of offering the grass can have a major influence on milk composition. The aim of this study was to evaluate the effect of grass supply mode (grazing, zero-grazing or ensiling) on dairy cows’ performance, with particular reference to fatty acids and fat-soluble antioxidants concentration. A three by three Latin square experiment was performed with 18 dairy cows. Experimental treatments consisted of exclusive feeding with grass silage and zero-grazing, both offered ad libitum indoors, or grazing for 24 h. The results showed that grazing cows had a higher dry matter intake and greater milk yield than cows feeding on grass silage and zero-grazing, as well as higher concentrations of protein, lactose, nonfat-solids and urea in milk than housed cows. Milk fat from grazing cows had a higher proportion of unsaturated fatty acids than from cows feeding on grass silage and zero-grazing, with significant differences in the proportion of vaccenic and rumenic acids. The 18:1 trans-11 to 18:1 trans-10 ratio is proposed as biomarker to identify the milk produced from the management system of grazing cattle. Milk from grazing cows had a greater proportion of lutein than cows eating grass silage, with the zero-grazing system having intermediate values. In conclusion, the mode of grass supply affects fatty acid and antioxidant profiles of milk.
摘要译文
牛奶产量的优化包括合理利用牧草，对环境的尊重，并提供最佳的质量给消费者。基于草和饲料生产牛奶生产更健康的牛奶，它是整个大西洋弧广泛传播最大化每公顷产乳量。然而，提供草的模式可以对牛奶成分有重大影响。本研究的目的是评估的草供应模式（放牧，零放牧或青贮）上奶牛的性能，特别是关于脂肪酸和脂溶性抗氧化剂的浓度的影响。三乘三拉丁方实验用18头奶牛进行。实验处理由草青贮和零放牧，既随意提供室内或放牧24小时专属喂养。结果表明，放牧牛有牛奶比容纳奶牛较高干物质采食量和更高的产奶量超过奶牛青贮草和零放牧馈送，以及蛋白质，乳糖，脱脂固体的更高的浓度和尿素。放牧牛乳脂具有不饱和脂肪酸的比从奶牛青贮草和零放牧，具有在异油酸和rumenic酸的比例显著差异供给比例较高。在18：1的反式11〜18：1反-10比率被提议作为生物标志物，以确定从放牧牛管理系统产生的乳汁。放牧牛乳具有比叶黄素奶牛吃草青贮的更大比例，用具有中间值的零放牧系统。总之，草供给的模式影响脂肪酸和牛奶的抗氧化剂分布。
Senén De La Torre-Santos[ 1]; Luis J. Royo[ 1]; Adela Martínez-Fernández[ 1]; Cristina Chocarro[ 2];Fernando Vicente[ 1;[*]. The Mode of Grass Supply to Dairy Cows Impacts on Fatty Acid and Antioxidant Profile of Milk[J]. Foods, 2020,9(9): 1256