Relationships between the daily intake of unsaturated plant lipids and the contents of major milk fatty acids in dairy goats

A meta-regression of the effects of the amount of plant lipids consumed by dairy goats on the contents of some milk fat fatty acids (FA) was carried out. Fourteen peer-reviewed published papers reporting 17 experiments were used in the study. Those experiments compared control diets without added fat with diets that included plant lipids rich in unsaturated FA, summing up to 64 treatments. The results showed that increasing daily intake of plant lipids linearly reduced the contents of all medium chain saturated FA in milk fat. Moreover, it was observed that the longer the chain of the milk saturated FA, the greater the negative effect of the plant lipid intake on their contents. On the other hand, the contents of stearic acid and the sum of oleic, linoleic and alpha-linolenic acids in milk fat linearly increased as daily plant lipid intake rose. The results obtained corroborate previous reports on the effects of feeding dairy goats with increasing amounts of unsaturated plant lipids on milk FA profile.