In-vitro and in-vivo evaluation of dietary cerium supplementation on ruminal fermentation, growth performance and immune status of Murrah buffaloes

The study objective was to evaluate different levels of organic and inorganic cerium (Ce) supplementation on rumen fermentation patterns and nutrient digestibility in-vitro and in-vivo. A basal diet (300 g/kg dry matter (DM) concentrate and 700 g/kg DM roughage) as a substrate was incubated without additives (control) and with cerium oxide (100, 200, 300, 400, and 800 mg/kg DM) or cerium acetate (100, 200, 300, 400, and 800 mg/kg DM) for 24 hours to evaluate their effect on gas production, ruminal fermentation and nutrients degradability using in-vitro gas production technique (IVGPT). The most effective inclusion rate obtained from in-vitro trials was evaluated in-vivo using 18 intact vaccinated Murrah male buffaloes (296 +/- 7.4 kg body weight) as a feed additive for 90 days. The animals were assigned randomly to three dietary treatments (n = 6 animals per treatment); 1) control (basal diet without any supplementations), 2) CO-300 (basal diet supplemented with 300 mg cerium oxide/kg of DM) and 3) CA-300 (basal diet supplemented with 300 mg cerium acetate/kg of DM). Rumen fermentation characteristics, nutrient digestibility and growth performance of individual animals were measured. The in-vitro results revealed that supplementation of cerium oxide and acetate linearly (P < 0.05) increased total gas production (GV(24) h; mL/g DM), in-vitro dry matter (IVTDMD) and organic matter (IVTOMD) digestibility as well as production of volatile fatty acids (VFA). The most significant effects on rumen fermentation characteristics were achieved at 300 mg/kg DM inclusion of cerium oxide and acetate. Results of the in-vivo trial showed that the DM intake, nutrients digestibility and growth performance remained at par among all the groups. Cerium oxide and acetate supplementation enhanced the relative proportion of propionate to total VFA production with a consequent decrease in methane production in the rumen. Further, cerium oxide supplementation (P < 0.05) enhances skin thickness as compared to both control and CA-300 groups. These results suggest that cerium oxide supplementation favorably modified the rumen fermentation and improved the immune status of Murrah male animals while cerium acetate vs. cerium oxide had no further beneficial effects.