Effect of forage sweet sorghum silage on the metabolic parameters in the rumen of small-tailed han sheep

This study was conducted to (1) investigate the mechanism of the effects of sweet sorghum (Sorghum bicolor) on the rumen metabolism of the meat sheep and (2) provide technical support for the scientific utilization of sweet sorghum. Eight small-tailed han sheep body weight=(26.61.1) kg were randomly divided into two groups and were fed sweet sorghum silage (HG) and maize (Zea mays) silage (HY), respectively. The concentrate and alfalfa pellet (Medicago sativa) were fed at 1% and 0.5% of animal weight. The rumen fluid was collected on days 1 (D1), 7 (D7), and 30 (D30) of the study period. Subsequently, the pH, concentration of ammonia nitrogen (NH3-N), and volatile fatty acid (VFA) were determined. The results showed that the feed intake of corn silage (520 gd-1) was higher than that of the sweet sorghum silage (310 gd-1). There was no effect of the treatment, period, and interaction (P0.05) on the rumen pH in the two groups. However, the concentration of ammonia nitrogen (NH3-N) was affected by the treatment, period, and interaction (P0.05), and the concentration of NH3-N was the highest in D7 and lowest in D1. Furthermore, the concentration of NH3-N in HG group was significantly higher than that in HY group on D30. The content of branched fatty acids (isobutyric and isovaleric acids) were affected by the feed treatment (P0.05), the content of fatty acids of HG group was significantly higher than those of HY group on D7 and D30. The ratio of acetic acid/propionic acid (A/P) was effected by the interaction effects of feed treatment and period (P0.05), A/P of HG group was higher than that of HY group on D7; however, on D30, the result was contrary. These results suggest that there are differences in the adaptability of different silage diets in the rumen of small-tailed han sheep.