Minimum physically effective Neutral Detergent Fiber (peNDF) requirement for feedlot cattle fed high-concentrate diets

Abstract

In the present project, four studies will be proposed. The objective of the Study 1 will be to evaluate the effect of genetics and physically effective neutral detergent fiber (peNDF). Six ruminal cannulated cattle, three Angus and three Nellore will be conducted as a 3×3 Latin square with 2×3 factorial arrangement of treatments. Factors will include genetics (Angus vs. Nellore) and peNDF inclusion (10%; 14% and 18% of dietary dry matter [DM]). The objective of Study 2 will be to evaluate the effect of peNDF on feedlot performance, particle sorting, carcass characteristics, rumen and cecum morphometric. The experiment will be a completely randomized block design, in which 72 Nellore bulls will be fed according to peNDF inclusion (10%; 14% and 18% of dietary DM). The objective of the Study 3 will be to evaluate the effect of the roughage inclusion and peNDF inclusion. Eight ruminal cannulated Nellore cattle will be conducted as a 4×4 Latin square with 2×2 factorial arrangement of treatments. Factors will include roughage inclusion (10% vs. 15% of dietary DM) and peNDF inclusion (peNDF inclusion will be based on Study 1 and will be divided by low and high peNDF). The objective of the Study 4 will be to evaluate the effect of the starch inclusion and peNDF inclusion. Eight ruminal cannulated Nellore cattle will be conducted as a 4×4 Latin square with 2×2 factorial arrangement of treatments. Factors will include starch inclusion (22.5% vs. 45% of dietary DM) and peNDF inclusion (low vs. high peNDF). Studies 1, 3, and 4 will be evaluated eating behavior, particle sorting, ruminal motility, ruminal fermentation, ruminal pool size, NDF turnover rate, ruminal bacterial community composition and apparent total tract digestibility. Study 2 will be evaluated feedlot performance, carcass characteristics, rumen and cecum morphometric. (AU)