Abstract: The purpose of this experiment was to study the effects of feeding rape silage on the rumen fermentation parameters and rumen flora composition of goats. Twenty-four Yichang white goats of about 3 months old [average weight (14.83±0.32) kg, 12 male and 12 female] were randomly divided into two groups. The experimental group was fed a total mixed ration containing ensiled forage, and the control group was fed a total mixed ration containing ensiled whole maize. There was a pre-test period of 7 days and a feeding period of 90 days. At the end of the experiment, 6 goats were slaughtered in each group, and the rumen fluid was used to measure pH, ammonia nitrogen, rumen liquid bacterial protein, volatile fatty acids and other indicators. High-throughput sequencing (16S) method was used to analyze the bacterial population structure in the rumen. There was no significant difference in average daily gain, dry matter intake or feed ratio between the experimental group and the control group (P>0.05). There was no significant difference in rumen fluid pH and ammonia nitrogen between goats in the two groups (P>0.05). The contents of bacterial protein and isobutyric acid in rumen fluid of goats fed ensiled forage rape were significantly higher than those of the control group (P<0.05), and differences in levels of other volatile fatty acids did not significantly (P>0.05) between the two groups. There were 15 bacterial taxa with relative abundance greater than 0.1% identified in the experimental group and 14 in the control group. The most taxa common to both experimental and control groups were Bacteroides, Firmicutes, Proteobacteria, Spirochaetae and Saccharibacteria. At the genus level, the most abundant taxon was Prevotella.Compared to the control group, the only significant differences in bacterial abundance observed in the experimental group were a reduction in Prevotella_1 from 21.10% to 16.66% abundance and an increase in ambiguous taxa (for which reads could not be assigned to a species) from 1.95% to 3.19% abundance. For all other taxa, there was no significant difference between the control and experimental groups in the species abundance in the rumen flora. In summary, in this experiment feeding of silage rape maintained the rumen environment and microbial community structure of Yichang white goats without disruption to normal rumen fermentation.

Key words: silage feeding rape, Yichang white goat, rumen, microbial diversity