MJAS

Manuscript Details

Examining the Changes in Rumen Bacterial Populations Associated with Improved Rumen Fermentation and Reduced Methane Production in Yankasa Rams Fed Fermented Hibiscus sabdariffa Seed Meal

Mustapha, K.*¹, Ashiru, R. M.², Muhammad, A. I.³, Ubali, S.⁴, Mustapha, Y.⁴, and Ndagi, A. M. ⁴

¹Centre for Innovation and Training in Animal Husbandry, Nigerian Institute of Animal Science (NIAS), Kabo, Kano State, Nigeria.
²Department of Animal Science, Kano University Science Kano State, Nigeria.
³Department of Animal Science, Federal University Dutse, Jigawa State, Nigeria.
⁴Department of Animal Science, Sule Lamido University Kafin Hausa, PMB 048, Kafin Hausa, Jigawa State, Nigeria.

Malaysian J. Anim. Sci. 2025 28(1): 11-25

Click to view the abstract

This study investigated the effects of dietary inclusion of fermented Hibiscus sabdariffa L. (roselle) seed meal (FRSM) on rumen fermentation parameters, methane emission, and microbial populations in Yankasa rams. Sixteen rams with an average body weight of 18.66 ± 2.84 kg were randomly allocated to four treatment groups receiving diets containing 0%, 10%, 20%, and 30% FRSM for 84 days in a randomized complete block design (RCBD). Fermented roselle seed meal was prepared by soaking cleaned seeds in airtight water-filled containers for 72 hours, followed by seven days of sun-drying and coarse grinding. The experimental diets were formulated with standard feed ingredients and analyzed for proximate and fibre fractions using AOAC and Van Soest methods. Rumen fluid was collected at 0 before feeding and 3-hours post-feeding for pH determination, microbial counts, and bacterial identification. Methane production was estimated using the model: CH? (L/day) = 0.34 × BW + 19.7 × DMI + 12. Results showed that dry matter content increased from 92.31% (control) to 94.63% (30% FRSM), and crude protein rose from 11.30% to 19.67% at 20% inclusion. Rumen pH ranged from 6.36 to 6.89, with no significant difference (P>0.05) between treatments or sampling times, maintaining optimal microbial conditions. Estimated methane output ranged from 34.98 to 38.52 L/day, with the 20% FRSM group showing a numerical reduction, though not (P>0.05) statistically significant. Rumen microbial counts increased post-feeding, ranging from 4.3 × 10? to 6.7 × 10? CFU/mL, and dominant bacteria identified included Escherichia coli, Ruminococcus albus, R. flavefaciens, and Salmonella spp. Inclusion of FRSM significantly (P<0.05) improved the nutritional composition of the diets without disrupting rumen fermentation or microbial balance. The study concludes that FRSM can be incorporated up to 30% in Yankasa ram diets, with 20% offering a potential methane mitigation effect while enhancing nutritional intake and supporting microbial stability in the rumen.