Effects of dietary replacement of broiler litter with Melia azedarach foliage on productive performance, fatty acid composition and health-related fatty acid indices in beef fats from Nguni x Brahman steers fed sugarcane tops based diets

Abstract

The study investigated the nutritional value of M. azedarach Linn. (umsilinga; Meliaceae family) leaf meal (MALM) as an alternative protein source for beef cattle. In a completely randomised design (CRD), 18 Nguni x Brahman 18-20 months old steers were randomly offered 3 iso-energetic and iso-nitrogenous dietary treatments with, respectively, 0% (Control), 15% and 30% MALM replacing broiler litter, each with 6 replicate animals, for 90 days. Feed intake (FI), water intake (WI), slaughter weight, body weight gain (BWG), feed conversion efficiency (FCE) and kidney fat depot fatty acid (FA) composition as well as health-related FA totals, ratios and other indices were measured. Results showed MALM contained rather high CP (290.0 g/kg DM), CF (170 g/kg DM), EE (78.1 g/kg DM) and ash (77.5 g/kg DM) contents. Also, dietary supplementation with MALM increased BWG and FCE (P 0.05). Also, it increased kidney fat margaric acid (P 0.05) in kidney fat. Further, dietary MALM supplementation increased kidney fat -linolenic (P 0.05). Furthermore, it increased kidney fat total polyunsaturated fatty acids (PUFAs) (P 0.05). In conclusion, dietary MALM supplementation improved productive performance of beef steers and enhanced their desirable meat fat FA profiles.\n\nImplicationsBroiler litter is widely used as an alternative cheap protein and mineral rich feedstuffs for supplementing poor quality forage based diets for ruminants in Southern Africa and elsewhere. However, its use is limited by the presence of human pathogens, pesticides, drug residues and heavy metals, which pose health hazards to livestock and human consumers. Our study demonstrated MALM as a better and safer alternative source of protein, the use of which in beef cattle diets would improve animal productivity and the desirable FA profile of meat which would potentially enhance the health status of consumers. By improving beef productivity, dietary MALM supplementation thus promises to enhance food and nutrition security and to contribute to poverty alleviation in Eswatini, Africa and beyond.