A comparative analysis of the potential protein value of some agro-industrial by-products for ruminant animals

Abstract

This study evaluated the chemical composition, buffer N solubility and in vitro ruminal N degradability of three agro-industrial by-products; coconut (Cocos nucifera L.) seed meal (CSM), poultry by-product meal (PBPM), and moringa (Moringa oleifera Lam) seed meal (MSM). Soybean meal (SBM) was included for comparative purposes. Poultry by-product meal had the highest N (85.0g/kg DM) content while CSM had the least (39.9 g/kg DM). Calcium (0.87 g/kg DM) was highest in PBPM while P content did not differ among by-product feedstuffs. Soybean meal was the richest by-product in terms of both K and Mg. The highest concentration of lipids was observed in PBPM. Moringa seed meal had the highest N solubility index (49.7%) while SBM had the least solubility index (14.8%). In vitro ruminal N degradability revealed that MSM had the most degradable N (983.9 g/kg DM) after 36 hours of incubation followed by CSM (812.0 g/kg DM). Soybean meal had the highest soluble N fraction (a) and the lowest insoluble N fraction (b) whereas CSM had the lowest (496.1 g/kg DM) soluble N fraction (a) and the highest insoluble N fraction (b). The rate of degradation of the insoluble N fraction (b) was highest in MSM (16.5%/hour) followed by SBM (13.3%/hour), PBPM (7.3%/hour), and CSM with the lowest rate (4.9%/hour). It was concluded that CSM can be used as a source of rumen by-pass protein while MSM has the potential to support rumen microbial activity due to its rapidly degradable N in the rumen.