Effect of protease supplementation on apparent ileal crude protein and amino acid digestibility of over-processed soybean meals in broilers  

作　　者：Sergio Salazar-Villanea Maikol Astúa-Ureña Allison Masís-Montoya Juan I.Herrera-Muñoz Catalina Salas-Durán 

机构地区：[1]Escuela de Zootecnia,Universidad de Costa Rica,San José,Costa Rica [2]Centro de Investigación en Nutrición Animal,Universidad de Costa Rica,San José,Costa Rica

出　　处：《Journal of Animal Science and Biotechnology》2022年第6期1810-1817,共8页畜牧与生物技术杂志（英文版）

基　　金：funded by Consejo Nacional para Investigaciones Científicas y Tecnológicas(CONICIT),Costa Rica,grant number RE-006-17.

摘　　要：Background: Nutritional value of proteins in feed ingredients can be negatively affected by hydrothermal processing, which causes large variation in the bioavailability of amino acids(AA) and negatively affects animal productive performance. Supplementation of exogenous proteases could increase the rate of digestion of damaged proteins, thereby increasing overall AA digestibility and bioavailability. The aim was to determine the effect of exogenous protease supplementation on the apparent ileal digestibility(AID) of crude protein(CP) and AA of soybean meals(SBM) with different degrees of hydrothermal processing in broilers.Methods: The experiment involved a 3 × 2 factorial arrangement, with SBM processing time(commercial SBM or autoclaved for 30 or 60 min at 120 ℃) and protease supplementation(not supplemented and supplemented) as factors. Protease was included at three times the recommended dose(0.06%) and the experimental diets were fed from 15 to 21 d.Results: The interaction between the effects of SBM processing and protease supplementation was significant for the AID of CP(P = 0.01), Trp(P = 0.01), Gly(P = 0.03) and Pro(P = 0.03), and also for the average daily gain(P = 0.01)and feed conversion ratio(P = 0.04). Increasing the processing time of SBM decreased(P < 0.0001) the AID of all amino acids, whilst the effect of protease supplementation was only significant for the AID of Phe(P = 0.02) and Tyr(P = 0.01).Conclusions: Exogenous protease supplementation at three times the commercial dose does not seem to offset the negative effects of hydrothermal processing of SBM on the apparent ileal digestibility of CP and amino acids or performance of broilers. Whilst positive numerical improvements of digestibility and performance(ADG and FCR)were noticed with protease supplementation at relatively mild processing levels, negative results were obtained with the harsh-processed meals.

关 键 词：Amino acids Apparent ileal digestibility BROILERS Exogenous protease 

分 类 号：S831.5[农业科学—畜牧学]