The Effect Of Starch Sources On Nutrient Digestion In Growing-finishing Pigs

By revealing the relationship between the composition and content of amylase and amylopectin in the diet and digestion and absorption of nutrients in growing-finishing pigs, the study uses fifteen PIC growing-finishing pigs(initial baby weight was 75.59±1.19 kg, final baby weight was 100.20±4.29 kg), were randomly assigned to 3 treatment groups and fed with 100% corn, 50% corn and 50% potato, 100% sticky as starch sources, respectively. Egesta of anterior jejunum, posterior jejunum, anterior ileum and posterior ileum were collected using the slaughter technique to determine the digestibility of starch, dry matter, protein, Ca, P and the viscosity and p H of Chyme.The results showed:1. The amylose content in corn starch, potato starch and sticky starch were 28.42%, 20.34% and 0.2% respectively, the proportion of amylose and amylopectin were respectively 0.40,0.26 and 0.02.2. The starch digestibility of sticky starch group(100% sticky starch) in anterior jejunum, posterior jejunum, anterior ileum and posterior ileum were 97.92%, 98.63%, 98.66%, 98.66% respectively, when compared with the corn starch group(100% corn starch)(99.12%, 99.39%, 99.44%, 99.54%) and the potato starch group(50% corn starch and 50% potato starch)(99.27%, 99.58%, 99.33%, 99.36%),there were significant differences(P < 0.05).3. Digestion of nutrients in each segment of the small intestine differs with the sources of starch.(1) On dry matter digestibility, the digestibility of sticky starch group in front jejunum, posterior jejunum, anterior ileum and posterior ileum were 72.97%, 82.12%, 83.01% and 84.27%, all of which were less than the corn starch group and the potato starch group, and the difference was significant(P < 0.05); there was no significant digestibility difference between the corn starch group and the potato starch group in posterior jejunum, anterior ileum and posterior ileum(P > 0.05).(2) On crude protein digestibility, the digestibility of the corn starch group in anterior jejunum, anterior ileum and posterior ileum were 84.83%, 85.13%, 90.48%,which were the maximum; sticky starch group in anterior jejunum, anterior ileum and posterior ileum were 50.80%, 81.58%, 84.32%, which were the minimum. Compared with the previous two treatment groups, there were significant differences(P < 0.05).(3) On calcium digestibility, the digestibility of sticky group in the anterior jejunum, posterior jejunum, anterior ileum and posterior ileum were 56.57%, 57.16%, 59.85% and 59.54%, less than that of the corn starch group and the potato starch group and was significantly different from the corn starch group in posterior jejunum, anterior ileum and posterior ileum(P < 0.05); potato starch group in the anterior jejunum, posterior jejunum and anterior ileum were less than the corn starch group, but the difference was not significant(P > 0.05).(4) On the total phosphorus digestibility, the digestibility of the corn starch group in the anterior jejunum, posterior jejunum, anterior ileum, posterior ileum were the maximum(66.14%, 67.10%, 69.20%, 71.23%), while that of the sticky starch group(54.06%, 59.08%, 65.37%, 67.96%) were minimal; the total phosphorus digestibility of potato starch group were less than that of the corn starch group, but there was no significant difference(P > 0.05) between them. There was significant difference among sticky starch group, the corn starch group and the potato starch group(P < 0.05).4. Among the intestinal p H of the three treatment groups, sticky starch group was the highest, potato starch group the second and the corn starch group the lowest, but the difference between the three groups was not significant(P > 0.05).the digestion index of sticky starch group was significantly higher than that of the other two groups(P < 0.05).In conclusion, starches from different sources are different in structure properties, which determine the nutrient digestion of the growing-finishing pigs. The amylopectin content in sticky starch were 98%. The nutrient digestibility of sticky starch group in small intestine were minimal, all of which were less than the corn starch group and the potato starch group. The digestion index of sticky starch group was significantly higher than that of the other two groups.