Potential of Citrullus colocynthis as herbal feed additive for ruminants

Abstract

To assess the potential of Citrullus colocynthis as herbal feed additive for ruminants, colocynth fruit as a whole, its seeds and peel-pulp were evaluated at various levels (0, 0.5, 1.0, 1.5, 2.0, 2.5, 4.0%) with total mixed ration (roughage to concentrate ratio: 65:35) as substrate in 3×7 factorial design by in vitro gas production technique. Phytochemical analysis revealed significant variation (P<0.01) in total phenols, non-tannin phenols, true tannins, saponins, flavonoids and vitamin C content among different parts of colocynth fruit. Irrespective of the part used, varying level of Citrullus colocynthis had significant effect on net gas production (NGP; ml/24/g), metabolizable energy (ME) availability, methanogenesis, digestibility of neutral detergent fiber (NDF) and true organic matter (TOM) in comparison to control; however the effect was pronounced at 1% level of supplementation. No significant difference in total volatile fatty acids (TVFA) production and acetate production was observed at varying levels of Citrullus colocynthis except at 4% level when total mixed ration (TMR) was used as substrate. Irrespective of its level, supplementation of Citrullus colocynthis fruit as a whole, seeds and peel-pulp significantly improved NGP (P<0.001) and ME (P<0.01) availability in comparison to control group whereas partitioning factor (PF; P>0.578), digestibility of NDF (P>0.905) and true OM (P>0.228) remained unaffected between different test groups. However, TVFA production, acetate, propionate and butyrate concentration was observed lower (P<0.001) in peel-pulp and seed supplemented group. From above results it can be concluded that supplementation of Citrullus colocynthis fruit at 1% level of substrate had potential to improve rumen fermentation characteristics and reduce methanogenesis, however in vivo assessment on ruminants need to be conducted to evaluate the persistency of effects along with health concerns.