Effect of lucerne fodder (first cut) supplementation on in vitro methane production, fermentation pattern and protozoal counts

Abstract

The study was carried out to ascertain the effect of various levels of lucerne fodder (first cut) supplementation at 0 (T0), 15 (T1), 30 (T2) and 45 (T3) % to wheat straw and concentrate based diet on in vitro methane production, IVDMD, TVFA, molar proportion of VFA,s and protozoal counts. The roughage to concentrate ratio was maintained as 60: 40 irrespective of the diet. Highest total gas production was recorded in treatment T3 followed by T2 and T1, however, the lowest cumulative total gas production was recorded in control treatment (T0). Cumulative gas production in treatment T3 was significantly higher than that recorded in T0. Total gas production from slowly fermentable fraction ‘b’ ranged between 118.80 (T0) and 139.70 (T3) litre/kg, DM in different treatments. The reduction in methane production was 15 and 18% in treatment T2 and T3, respectively. The DMD in treatments T2 and T3 was significantly higher than that recorded in treatment T0. Total volatile fatty acid (TVFA) recorded as 105.58 and 107.93 Mm/litre in treatment T2 and T3, was significantly higher than that recorded in control treatment (101.43 Mm/litre). The acetate proportion was significantly lower in treatment T3 as compared to the control and reverse trend was observed for the propionate production. Protozoal numbers (log cfu/ml) decreased significantly by the supplementation of first cut lucerne fodder at 30 and 45% level. Saponins containing feed may serve the purpose of methane mitigation from ruminants without giving any additional input as the farmers grow leguminous fodder traditionally. Thus, there is urgent need to explore the new feed resources containing saponin and fix the safe level of their inclusion in ration for achieving the goal.