High-concentrate diets with fibrous by-products for feedlot Nellore heifers

Abstract

The objective of this study was to evaluate high-concentrate diets and two energy sources on intake, performance and meat quality parameters of feedlot Nellore heifers. Twenty-eight heifers (200 ± 22.5 kg BW) were randomly assigned to four treatments in a 2×2 factorial arrangement: two concentrate levels (70 and 80%) and two energy sources (corn and corn germ meal). At the end of day 112, heifers were slaughtered. There was no interaction (P>0.05) of concentrate levels and energy sources for dry matter intake, unlike crude protein (CP) and neutral detergent fi ber (NDF) intakes.The concentrate level of 80% and corn, allowed the highest CP (1.17 kg/day) and NDF (4.05 kg/day) intakes. Final BW (P<0.05) and daily gain (P<0.01) were infl uenced just by energy source. The carcass composition represented by muscle and fat was affected by concentrate level (P<0.05). Treatments affected (P<0.01) carcass fat deposition, global preference and texture of Longissimus muscle (P<0.05). It was concluded thathigh proportions of concentrate containing corn as energy source provided the best performance in heifers, and that the total replacement of corn with corn germ meal in high-concentrate diets is not recommended for performance Nellore heifers, but provided good sensory quality to the meat.