Conversion of Neem fruit biomass for rumen manipulation, meat fatty acid profile improvement of rams

The effect and conversion of diets containing water-washed neem (Azadirachta indica A. Juss) fruit (WN) biomass as substantiable feed resource was determined on rumen microbial population, fermentation, and meat fatty acid profile of fattened West African dwarf rams. One-year old, individually housed rams (N = 25; 12.3 ± 2.0 kg), five per treatment, were allocated in a completely randomized design to one of the five dietary treatments. Each treatment received 0 (WN0), 2.5 (WN2.5), 5 (WN5), 7.5 (WN7.5), and 10 (WN10) % of WN (% dry matter) of complete diet offered for 90 days. Rumen liquor was collected 4 h post feeding for microbial and fermentation assay while Longissimus dorsi muscle was taken after slaughtering the animal for fatty acids (FAs) determination, post feeding trial. Inclusion of WN initially increased but subsequently reduced (P < 0.05) the population of bacteria and fungi but consistently reduced the population of protozoa. The WN decreased NH3-N in WN7.5 and WN10 compared to other treatments. Propionate was higher in WN5 compared to the control. There was increased concentration of meat linolenic, vaccenic, rumenic, oleic, and lauric FAs in WN10 than WN0. Dietary inclusion of WN increased (P < 0.05) the constituent of unsaturated fatty acids, and total desaturase index in WN5 compared to other treatments. Incorporation of water-washed neem fruit beyond 5% reduced rumen microbial population, ammonia nitrogen, and propionate with increased unsaturated fatty acids including rumenic acid, a conjugated linoleic acid known for its health promoting benefits. This imply that at 5% inclusion of water-washed neem fruit biomass there was better substantiable feed resource for stimulation of microbial growth for increased microbial protein production for host’s growth, efficiency in energy use, and the consumption of functional food.