Effect of yeast culture on growth performance, apparent nutrient digestibility and rumen fermentation parameters of beef cattle

The experiment studied the effect of adding yeast culture to feed on growth performance, nutrient digestibility, fermentation parameters and antioxidant function of Simmental hybrid cattle. In the experiment, 80 healthy Simmental crossbred beef cattle with similar body weight were randomly divided into five groups, with eight replicates in each group and two beef cattle in each replicate. The beef cattle in control group were fed with basal diet, and the test groups (A, B, C, D) added 50, 100, 150, 200 g/(head·d) yeast culture into the basal diet. The pre-feeding period was 7 d, and the formal test period was 90 d. The results showed that compared with the control group, the average daily gain of hybrid beef cattle in group C and group D increased by 18.52% and 19.44% (P<0.05), while the feed to gain ratio was lower than that of control group by 14.65% and 14.99% (P<0.05). Compared with the control group, the apparent digestibility of CP for group B, group C, and group D was significantly increased by 5.30%, 7.37% and 6.92% (P<0.05). The apparent digestibility of NDF of group C and group D was significantly increased (P<0.05), and the apparent digestibility of ADF of hybrid cattle in group C and group D was significantly increased by 6.62% and 8.12% (P<0.05). Compared with the control group, the MCP content in the rumen of hybrid cattle in group B, group C and group D was significantly increased by 23.43%, 27.34% and 35.94% (P<0.05). The acetic acid content in the rumen of hybrid beef cattle in group C and group D was significantly increased by 4.06% and 4.21% (P<0.05). Compared with the control group, the serum MDA content of hybrid beef cattle in group B, group C and group D was significantly reduced, and the serum GSH-Px activity was significantly increased (P<0.05). The serum T-AOC of hybrid beef cattle in group C and group D was significantly higher than that in control group (P<0.05), and the serum SOD activity in group C and group D was extremely higher than that in control group (P<0.01). The experiment indicates that yeast culture can improve the

growth performance of Simmental hybrid beef cattle, improve nutrient digestibility and rumen fermentation status, and enhance the bodys antioxidant function. The appropriate dosage is 150 g/(head·d).

Key words: yeast culture; Simmental hybrid beef cattle; growth performance; apparent digestibility of nutrients; rumen fermentation parameters; antioxidant performance