Effects of Replacing Maize Silage with Silage Sweet Sorghum on Milk Production and Blood Biochemical Indexes of Dairy Cows.

In order to study the effects of replacing different proportions of silage maize with silage sweet sorghum treated by different fermentation methods on the production performance and blood biochemical indexes of dairy cows, 25 Chinese Holstein lactating cows were randomly divided into 5 groups, 5 in each group. The control check(CK) was fed the basal diet; for the experimental group 1 and the experimental group 2, 50% of the silage maize in the basal diet was replaced with the additive silage sweet sorghum and the conventional silage sweet sorghum, respectively; and as to the experimental group 3 and the experimental group 4, all the silage maize in the basal diet was replaced with additive silage sweet sorghum and conventional silage sweet sorghum, respectively. The preliminary trial period was 7 d, and the trial period was 35 d. The results showed that the experimental group 1 and the experimental group 3 had the dry matter intake significantly higher than that of the experimental group 2, the experimental group 4 and the CK(P<.05). The daily milk yields of the experimental group 1 and the experimental group 2 were significantly lower than that of the CK(P<.05), and the experimental group 3 and the experimental group 4 were significantly lower than the experimental group 1 and the experimental group 2(P<.05). The milk protein percentage of the experimental group 2 was extremely significantly higher than that of the experimental group 4(P<.01). The experimental group 1, the experimental group 2 and the experimental group 3 showed the blood glucose levels extremely significantly higher than that in the CK(P<.01). The blood urea nitrogen contents in the experimental group 2 and the experimental group 4 were significantly higher than those in the experimental group 1 and the CK(P<.01). There were no significant differences in other blood biochemical indexes between various groups(P<.05). It is feasible to use silage sweet sorghum to feed dairy cows, but the proportion should not be too large, and attention should be paid to the energy and nitrogen balance of the diet. [ABSTRACT FROM AUTHOR]