Enhancing Rumen Fermentation Characteristic and Methane Mitigation Using Phytonutrient Pellet in Beef Cattle

Abstract

The objective of this experiment was to assess the effects of chaya (Cnidoscolus aconitifolius) leaf and rambutan (Nephelium lappaceum L.) fruit peel pellet (CRP) supplementation on rumen fermentation, feed intake, nutrient digestibility, and nitrogen balance in crossbred beef cattle. Four beef cattle crossbred bulls (Brahman 75% × Thai native 25%), with 250 ± 15 kg of liveweight at 18 months old, were randomly selected to receive four dietary treatment groups: no supplementation (control) and the supplementation of CRP at 2, 4 and 6% of dry matter intake (DMI) by using a 4 × 4 Latin square design. The cattle were fed a concentrate at 2 kg/day, and rice straw was offered ad libitum. The results showed that rumen pH at 4 h and average post-feeding values were in the normal range, though they were slightly reduced with CRP supplementation at 4 and 6% DMI (p < 0.05). Rumen temperature, ammonia nitrogen level, and total volatile fatty acid (VFA), acetate (C2), and butyrate (C4) production were similar among treatments. Nevertheless, propionate (C3) concentration was significantly increased (p < 0.05) in the CRP groups at 2 and 4% DMI. In addition, the C2/C3 ratio and CH4 production were significantly reduced in the CRP groups, especially at 2 and 4% DMI. Rice straw intake and total feed intake in terms of %BW were significantly higher in the groups with CRP at 2 and 4% DMI (p < 0.05). The apparent nutrient digestibilities were not affected by the treatments. Nitrogen intake, nitrogen absorption, and nitrogen retention were significantly enhanced by the CRP supplementation (p < 0.05). Moreover, feces and total nitrogen excretion were not different among treatments (p > 0.05). Ultimately, the supplementation of CRP at 2 and 4% DMI significantly improved the C3 concentration, reduced the C2/C3 ratio, mitigated methane production, and enhanced feed intake and nitrogen utilization efficiency. Therefore, CRP supplementation shows promise as a rumen dietary enhancer.