Dietary influences on lutein pigments and carcass fat quality in wethers of different maturity types

01 Sep 2020

The aim of this research was to study the effect of high-maize diets and pelleting on the accumulation of lutein pigments and appearance of the subcutaneous fat in Dorper and SA Mutton Merino wethers. High and medium energy maize diets were fed to Dorper and SA Mutton Merino wethers from an initial live weight of ca. 21 kg to a target weight of 43 kg. Fat colour and firmness were evaluated subjectively on a 5-point scale. Samples of the subcutaneous fat and feed were collected for fatty acid and lutein analyses. Loin samples (L1-L6) were oven-roasted and fat characteristics evaluated by a trained sensory panel. The concentrations of lutein pigments and total long-chain fatty acids were influenced mainly by the fattening period (p<0.05) and pelleting of the diets (p<0.05). Lutein concentrations increased during longer fattening periods and resulted in lower colour scores for subcutaneous fat. Neither breed nor the maize content of the diet significantly affected the concentration of lutein in the subcutaneous fat. Lutein concentrations resulted in lower subjective colour scores (p<0.05) and improved the aroma of lamb during carving (p<0.05). The present results suggest that the 'unacceptable' lutein pigments contribute to the typical aroma of lamb.