不同直/支链淀粉比饲粮对育肥猪粪便中主要微生物数量和臭气物质排放的动态影响

This study aimed to investigate the dynamic effects of diets with different amylose to amylopectin ratios on major microorganism number and odorous substance mission in feces of finishing pigs. Seventy-two healthy Duroc×Landrace×Large White crossbred barrows were randomly divided into tapioca starch group, corn starch group and pea starch group with 8 replicates (pens) per group and 3 pigs per replicate according to the initial body weight of (77. 00±0. 52) kg. The pigs in the three groups were fed diets containing tapioca starch, corn starch and pea starch as the only starch source, and the ratios of amylose to amylopectin in the diets were 0. 11, 0. 25 and 0. 44, respectively. The pre-trial period lasted for 4 days, and the formal trial period lasted for 40 days. The fresh feces of finishing pigs were collected on days 1, 10, 20, 30 and 40 of the formal experiment, and the major microorganism number and odorous substance content in feces were analyzed. The results showed as follows: 1) compared with tapioca starch group, on days 20 and 40, the Clostridium cluster ⅩⅣ number in feces in pea starch group was significantly increased (P < 0. 05); on days 30 and 40, the Bifidobacterium number in feces in pea starch group was significantly increased (P<0. 05); on day 40, the numbers of Lactobacillus and Prevotella in feces in pea starch group were significantly increased (P<0. 05); on days 20, 30, and 40, the Escherichia coli number in feces in pea starch group was significantly decreased (P<0. 05). 2) Compared with tapioca starch group, on days 30 and 40, the contents of lactic acid, acetic acid and total volatile fatty acids in feces in pea starch group were significantly increased (P<0. 05); on days 20, 30 and 40, the butyric acid content in feces in pea starch group was significantly increased (P<0. 05). 3) On days 20, 30 and 40, the pH in feces in pea starch group was significantly lower than that in tapioca starch group (P<0. 05). 4) Compared with tapioca starch group, on days 20, 30 and 40, the contents of total volatile biogenic amines and ammonia nitrogen (NH₃-N) in feces in pea starch group were significantly decreased (P<0. 05); on day 30, the contents of tryptamine and cadaverine in feces in pea starch group were significantly decreased (P<0. 05); on days 20 and 40, the putrescine content in feces in pea starch group was significantly decreased (P<0. 05). 5) Compared with tapioca starch group, on days 10, 20, 30 and 40, the indole content in feces in pea starch group was significantly decreased (P<0. 05); on day 40, the skatole content in feces in pea starch group was significantly decreased (P<0. 05). In conclusion, feeding pea starch diet with high amylose to amylopectin ratio can increase the number of carbon hydration degradation bacteria, and reduce the number of protein degradation bacteria in feces, thus reducing the pH and changing the fermentation pattern of microorganisms in feces, ultimately reduces some odor emission, such as NH₃-N, biogenic amines, indole and skatole. And this above experiment results are realized on day 20 in this experiment.