PSVI-12 Effects of protease supplementation on growth performance, meat quality, serum biochemical parameters and apparent ileal amino acid digestibility in growing pigs fed diets containing different levels of sorghum

Sorghum has been increasingly used as animal feed ingredients due to low cost and high energy. However, anti-nutritional factors in sorghum negatively affect the availability of nutrients. This study aimed to mitigate the adverse impacts of sorghum on the growth performance of growing pigs by protease supplementation. Forty-two crossbred pigs (Duroc × Landrace) were randomly assigned into seven treatment groups: A (0% sorghum + 0% protease); B (20% sorghum + 0% protease); C (20% sorghum + 0.015% protease); D (50% sorghum + 0% protease); E (50% sorghum + 0.015% protease); F (80% sorghum + 0% protease); and G (80% sorghum + 0.015% protease). Growth performance, meat quality, serum biochemical parameters, and apparent ileal amino acids digestibility were measured. Results showed that average daily feed intake (ADFI) significantly increased in the group with 50% sorghum, and ADFI and average daily gain (ADG) increased in the group with 80% sorghum (P < 0.05). Precaval vein, mesenteric vein and portal vein serum concentration of histidine decreased (P < 0.05). The apparent ileal threonine digestibility increased with 20% sorghum and the apparent ileal lysine digestibility increased with 50% sorghum (P < 0.05). The apparent ileal digestibility of other amino acids decreased or remained stable with 80% sorghum. Protease supplementation improved feed conversion ratio (FCR) with 20% sorghum (P < 0.05) when compared to 20% sorghum without protease. The FCR, ADG, ADFI and meat quality of growing pigs with 50–80% dietary sorghum and protease supplementation were comparable to the control (P > 0.05). The apparent ileal digestibility of amino acids decreased in the group with an 80% sorghum amount except for lysine and valine. Sorghum could be a substitution for corn with a proper proportion (between 20% and 80%) of dietary feed. In conclusion, the supplementation of protease improved feed efficiency at 20% sorghum inclusion.