Modulation of rumen function and microbiome by purple Napier grass: implications for enhanced growth performance and nutrient utilisation in growing goats

Purple Napier grass (Pennisetum purpureum 'Prince') exhibits purple leaves due to anthocyanins, a class of flavonoids. These compounds possess properties that benefit rumen microorganisms; they have antioxidant properties, thereby enhancing goats' health. In this study, 24 Anglo-Nubian crossbred male goats with an initial body weight of 18.50 ± 2.06 kg were used. The experimental design followed a 2 × 2 factorial arrangement in a completely randomised design (CRD). The first factor was grass species (Napier Pakchong-1 [NP-1] and purple Napier [PN]), and the second factor was forage conditions (fresh and silage). Goats fed fresh PN demonstrated the highest (p < .05) final body weight, weight change, average daily gain (ADG), roughage dry matter intake, total dry matter intake, crude protein intake, anthocyanin intake, organic matter (OM) digestibility, crude protein (CP) digestibility and nitrogen utilisation. Post-feeding, the concentrations of ruminal NH3–N, propionate (C3), total volatile fatty acids (VFA) and blood urea nitrogen (BUN) were significantly higher (p < .05) in goats fed fresh PN, while the acetate-to-propionate (C2/C3) ratio was significantly lower (p < .05) in this group. The abundance of Butyrivibrio fibrisolvens was highest (p < .05) in the rumen of goats fed fresh PN, while methanogenic archaea and protozoa populations were significantly lower (p < .05). Based on the findings of this study, it is concluded that feeding fresh PN improves growth performance, rumen fermentation and microbial population dynamics in the rumen of goats.