Czech Journal of Animal Science (Mar 2009)
The effect of feeding diets markedly differing in the proportion of grass and maize silages on bovine milk fat composition
Abstract
Ten Czech Pied cows in the mid-lactation stage were fed diets based on grass silage and maize silage. The composition of milk fats differed. The proportions of even-chain saturated fatty acids (SFAs) up to C14:0 were insignificant and the content of C16:0 was significantly higher (P < 0.05) when feeding a diet based on maize silage, while the proportions of the individual polyunsaturated fatty acids (PUFAs) were significantly (except for C18:2) higher when feeding a diet based on grass silage. The total SFA proportions were 67.60 and 62.93% (P < 0.05) of maize and grass silages, respectively, while an opposite relation was observed for the sum of PUFAs (3.56 and 4.74%; P < 0.001). Feeding of grass silage resulted in a significantly lower proportion of hypercholesterolaemic fatty acids C12:0, C14:0 and C16:0 (49.38 and 44.98%, respectively; P < 0.05) and in lower values of the atherogenic index (3.03 and 2.44; P < 0.05). Thus, the results could be used for the improvement of milk fat composition.
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