Rapid determination of the content of digestible energy and metabolizable energy in sorghum fed to growing pigs by near-infrared reflectance spectroscopy1

Low-tannin sorghum grain could be used as an alternative to corn in diet for nursery pigs

This study was conducted to test the hypothesis that low-tannin sorghum grain produced in China as a potential substitute for corn in diets could not impair the performance of nursery pigs. A total of 60 pigs (7.2 ± 1.2 kg) were randomly assigned to 2 diets with 5 replicate pens per treatment. Corn-based diet (CBD) included 60% corn grain during the overall experimental period, and sorghum-based diet (SBD) consisted of 30% (d 1 to 14) or 60.55% (d 15 to 28) sorghum grain in partial or total replacement of corn grain. Both diets were formulated to contain the same amount of digestible energy and indispensable amino acids. The results demonstrated no differences in growth performance or apparent digestibility of gross energy between treatments over the whole period. However, the substitution of corn by sorghum reduced (p < 0.05) or tended to reduce (p = 0.09) apparent digestibility of crude protein associated with an increased faecal nitrogen excretion per weight gain (p < 0.05). Pigs fed SBD had higher contents of urea nitrogen, total triglyceride and insulin in serum than those fed CBD (p < 0.05). Visceral organ weights or antioxidant enzyme activities in serum or liver were not different between treatments. Compared with CBD, SBD increased or tended to increase amylase activity in jejunal mucosa (p < 0.05) or trypsin activity in duodenal mucosa (p = 0.08). Replacement of corn by the low-tannin sorghum in diets did not influence the microbiota community based on alpha and beta diversity in caecal and colonal digesta. Overall, the home-grown low-tannin sorghum could be an alternative energy source in diets for pigs without adverse effects on growth performance.