Nutrient digestibility, nitrogen balance and rumen fermentation parameters of West African dwarf goats offered treated maize stover supplemented with Gmelina arborea

Abstract

A large portion of agricultural crop residues are potential feed resources for ruminants in the tropics. This study therefore, investigated the intake, nutrient digestibility, nitrogen utilisation and rumen fermentation parameters of West African dwarf goats (WAD) fed treated and untreated maize stover supplemented with Gmelina arborea. Twenty male WAD goats (11.50 ± 0.45 kg body weight) were randomly allotted into four treatments with five animals each. Untreated maize stover (MS), urea treated maize stover (UT), molasses treated maize stover (MT) and urea-molasses treated maize stover (UMT) were supplemented with 300 g Gmelina arborea (G) and were offered to each group for three weeks. MS had highest dry matter (DM; 87.1%), neutral detergent fibre (76%), acid detergent fibre (45%) and acid detergent lignin (6%) contents (P<0.05). Crude protein content was high in UT (12.5%) and UMT (13%). Animals fed UMT+G recorded higher DM intake and digestibility, whereas crude protein digestibility was higher in animals on UT+G (72.8%) and UMT+G (76.2%). Nitrogen intake was more in goats fed UMT+G (P<0.05) and least in MS+G fed group. Higher nitrogen was absorbed and retained by goats on UMT+G. The pH of the ruminal fluid was not affected by the dietary treatments. Concentrations of ammonia‑nitrogen and total volatile fatty acids were higher in UMT+G fed animals. Thus, UMT+G is a good option for proper nutritional utilisation of maize stover which can easily be adopted by farmers given the availability of materials (Gmelina arborea, maize stover, urea and molasses) and simplicity of the technology involved in the treatment of the stover.