Nutritional status, growth performance and carcass characteristics of Nguni steers supplemented with Acacia karroo leaf-meal

Abstract

The objectives of the current study were to determine the effect of supplementing Acacia karroo leaf-meal on growth performance, blood chemistry and carcass characteristics of Nguni steers. Thirty 19-month old Nguni steers (241.5 ± 14.62 kg) were randomly allotted to three dietary treatments: A. karroo leaf-meal (AK), sunflower cake (SF) and control with no supplement (CN). Steers on the AK and SF diets were offered additional 150 g of protein through A. karroo and sunflower cake per day for 60 days. Serum concentrations of nutritionally-related blood metabolites were measured every fortnight. Steers that were given supplementary diets had higher ( P < 0.05) total protein, urea, non-esterified fatty acids, calcium, phosphorus, magnesium and iron concentrations, and larger eye muscle area than those that received the CN diet. Albumin concentration was higher ( P < 0.05) in steers that received supplementary diets than those that did not. Steers supplemented with the AK and SF diets had lower ( P < 0.05) glucose and cholesterol concentrations than those that received the CN diet. Steers fed on the SF diet had the highest average daily gain, body condition score, slaughter weight, warm carcass weight and cold carcass weight followed by those on the AK diet ( P < 0.05). Steers that were supplemented with AK and SF diets had similar ( P > 0.05) gross margins. It was concluded that A. karroo improves the nutritional status, growth performance, and carcass traits of Nguni steers reared on natural pasture.