Effects of corn replacement by sorghum in diets on performance, nutrient utilization, blood parameters, antioxidant status, and meat colour stability in lambs

Abstract

The aim of this research was to compare growth performance, nutrient utilization, rumen fermentation, blood parameters, antioxidant status, and meat colour stability of lambs fed diets that partially or completely substituted corn with sorghum. Twenty-four male German merino weaned lambs (16.19 ± 2.05 kg body weight) were divided into four treatments in a completely randomized design. The diets for four treatments contained 450 g kg−1 of ground corn (C), 300 + 150 g kg−1 of ground corn and sorghum (CSM1), 150 + 300 g kg−1 of ground corn and sorghum (CSM2) and 450 g kg−1 ground sorghum (S); all diets consisted of 70% concentrated feed and 30% Leymus chinensis hay. The lambs were fed the experimental diets for 56 d. Inclusion of sorghum tended to increase average daily weight gain and total gain (P = 0.06), and lower feed conversion ratio (P = 0.10). Significant increase in nitrogen (N) intake and fecal N excretion was observed after substitution of corn with sorghum, and the apparent digestibility of crude protein was significantly reduced. Concentrations of ammonia N in rumen fluid were affected by treatment (P = 0.01) and an interaction (P < 0.01) between treatment and sampling time. No significant effects were found on blood parameters among treatments. Replacement of corn with sorghum significantly decreased b* (yellowness) values of meat during storage. Sorghum instead of corn is feasible in lamb diets, and it has positive effects on the lamb growth and meat quality.