The overall chemical composition of sorghum grain is similar to corn, although, it is still a feed ingredient with poor digestibility of proteins and energy for non-ruminant. When sorghum is used as an alternative energy source it would result in surplus N emission from animal manure. Therefore, it is essential to improve its CP or N utilization. New types of coated compound proteases produced by Aspergillus niger, Bacillus subtilis and Bacillus Licheniformis have recently showed improved ileal digestibility of CP in weaned piglets. The objective of this study was to determine the effects of coated compound proteases on performance, apparent total tract digestibility (ATTD) of crude protein (CP), serum urea nitrogen (SUN) content and manure nitrogen (N) output for growing pigs fed sorghum soybean meal based diets. Forty crossbred pigs (Duroc × Landrace × Yorkshire) with initial body weight of 23.4 ± 1.2 kg were allotted to 2 diets with 5 replicate pens per treatment (2 barrows and 2 gilts per pen) in a randomized complete block design. The 2 diets were sorghum soybean meal based diets supplemented with or without 250 mg/kg of coated compound proteases. The experiment (70 d) was divided into 2 stages: phase 1 (d 1–35) and phase 2 (d 36–70).
Proteases had no significant effects on average daily feed intake (ADFI) or average daily gain (ADG), and tended to increase feed conversion efficiency (ADG/ADFI) during phase 1, phase 2 or overall compared with control. The ATTD of dry matter, organic matter and gross energy tended to be greater on d 35, and was greater on d 70 in diets supplemented with proteases than control. Proteases increased the ATTD of CP by more than 8%, and decreased the faecal N excretion per weight gain by more than 10% regardless of the experiment stages. The SUN concentration tended to be reduced by the protease supplementation on d 35 or d 70.
Overall, the coated compound proteases could improve nitrogen utilization efficiency by decreasing manure N excretion to the environment for growing pigs fed sorghum soybean meal based diets.
Pan, L., Shang, Q. H., Ma, X. K., Wu, Y., Long, S. F., Wang, Q. Q., and Piao, X. S. (2017). Coated compound proteases improve nitrogen utilization by decreasing manure nitrogen output for growing pigs fed sorghum soybean meal based diets. Animal Feed Science and Technology, 230, 136-142. https://doi.org/10.1016/j.anifeedsci.2017.05.014