Effect of Purple Neem Foliage as a Feed Supplement on Nutrient Apparent Digestibility, Nitrogen Utilization, Rumen Fermentation, Microbial Population, Plasma Antioxidants, Meat Quality and Fatty Acid Profile of Goats

Abstract

The purpose of this experiment was to investigate the effect of Purple Neem foliage as a feed supplement on nutrient apparent digestibility, nitrogen utilization, rumen fermentation, microbial population, plasma antioxidants, meat quality and fatty acid profile of goats. Eighteen Boer male goats (approximately 20 ± 2 kg body weight; mean ± standard deviation (SD)) were randomly allocated into three treatments. All goats were fed a 60 d daily feeding with three treatments: (1) control, (2) 3% Purple Neem foliage (PNF) + 3% sunflower oil (SFO) in concentrate, and (3) 6% Purple Neem foliage (PNF) + 3% sunflower oil (SFO) in concentrate. The findings indicate that goat feed containing 6% PNF + 3% SFO in concentrate increased feed consumption, nutrient intake, nutrient apparent digestibility and nitrogen utilization compared to the goat feed at 3% PNF + 3% SFO and the control group. The feeding of goats with 6% PNF + 3% SFO in concentrate resulted in high ammonia nitrogen, BUN, acetic acid, propionic acid, butyric acid, and the total VFA levels were increased at 2 and 4 h after feeding (p < 0.01). The individual microbial population with 6% PNF + 3% SFO had higher (p < 0.01) total bacteria, higher Butyrivibrio fibrisolven, Fibrobacter succinogenes, Ruminococcus albus, Ruminococcus flavefacises, and Streptococcus bovis, decreased protozoa and methanogen levels at 2 and 4 h after feeding. The antioxidant in plasma indices varied, with 6% PNF + 3% SFO having higher total antioxidant (TAC), superoxide dismutase (SOD), glutathione peroxidase (GPX), 2, 2-diphenyl-1-picrylhydrazyl (DPPH), and catalase (CAT) antioxidant activity and lower malondialdehyde (MDA) in plasma at 2 and 4 h after feeding. Additionally, goat fed 6% PNF + 3% SFO can improve meat quality by lowering drip loss, cooking loss, shear force, and saturated fatty acid as well as increase the fatty acid profile (monounsaturated and polyunsaturated fatty acids) in goat meat. Our findings suggest that Purple Neem foliage might be an excellent alternative additive for goat feed.