Monensin effect on rumen metabolic profile, methane production and protozoal population in buffalo-heifers

ABSTRACT

Thirteen propuberal buffalo-heifers aged 10-14 months were kept on the experimental farm on National Research Center, to investigate the effects of monensin on rumen metabolic profile, mithane production and protozoal population. The experimental animals were radomly allotted into two groups control group of 5 heifers fed a pelleted concentrate and monensin group of 8 heifers which received the same concentrate after milling and mixing with 100 mg monensin head daily. Rumen samples were taken from buffalo-heifers of both groups 8 and 10 months after the beginning of treatment, before and 2 hours post-feeding. The rumen juice was subjected for determination of pH value, ammonia production, total and individual volatile fatty acids. Methane was also calculated and derect smears from the whole rumen contents were made for detection of protozoal density. pH values were not affected by neither feeding nor monensin and ammonia production was increased significantly by feeding, while monensin administration lowered the amonia production. The values of total volalille fotty avds [TVFAS] were elevated significantly by control feeding regime while monensin had no significant effects on the TVFAS concentrations. The production of acetic acid decreased in the rumen of monensin treated heifers. Monensin supplementation resulted in increasing the propionic acid production. The concentration of butyric acid was not affected by adding monensin. The molar prportions of acitic propionic butyric acids were 53.82 26.3419.75 under feeding of basal diet, and 41.82 38.64 19.53 on monensin administration. Monensin lowered the production of mentane in the rumen. Moreover, the density of protozoal population decreased in the rumen liquor of buffalo-heifers receiving monensin. In conclusion, monensin acts as a propionate enhancer and methane inhibitor. Thus, use of monensin as a feed additive may be profitable and incentive in buffalo production