Effect of levels of concentrate on rumen fermentation and methane production In vitro and in weaner Barbari kids Mamata, Dutta T.K., Tripathi M.K.* Division of Nutrition Feed Resources and Product Technology, Central Institute for Research on Goats, Makhdoom, Farah- 281 122, Uttar Pradesh *E-mail address: mktripathi@gmail.com
Online published on 5 March, 2014. Abstract An experiment assessed the effect of varying concentrate levels in diet on in vitro fermentation characteristics and methane production and in vivo rumen fermentation characteristics in kids. Four composite feed mixtures (CFM) were prepared with 0 (T1), 20 (T2), 40 (T3) and 60% (T4) concentrate. The CFM contained roughage gram straw and cowpea fodder in 60:40, 50:30, 38:22 and 25:15 ratios in T1, T2, T3 and T4 respectively In vitro experiment studied dry matter digestibility (IVDMD), fermentation characteristics and methane production?, while rumen fermentation characteristics (pH, N and VFA fractions) were studied in kids. The microbial inoculums for in vitro study was collected from kids fed respective diets at 89 (P1) and 166 (P2) days of kid feeding. In vitro experiment revealed that increasing concentrate levels improved (P<0.05) IVDMD of diet, which ranged from 60.8 to 65.6% and was the highest in T4. Total gas production did not change by concentrate levels while methane production was reduced (P<0.05) with increasing levels of concentrate in the diets. Methane production varied from 46.1 to 39.63 ml and 76.0 to 62.6 ml, respectively on each g DM incubated and on each g DM fermented. Methane production was 76.0, 69.3, 63.2 and 62.3 ml per g DM fermented respectively at 0, 20, 40 and 60% concentrate levels, which accounted a reduction of 9.7, 20.3 and 221.5% methane at respective concentrate levels. The pH of fermentation medium reduced (P<0.05), whereas total N, NH3 -N, TCA-ppt-N and TVFA increased (P<0.05) by increasing concentrate levels in the diet. The fractional VFA and A/P ration was similar among four treatments. In vitro observation was not affected by the microbial inoculums used from kids between the two periods. Rumen fermentation characteristics of kids viz., pH, total N, TCA-ppt-N and TVFA followed the trend of in vitro fermentation. The NH3 -N of rumen fluid was not different among kids fed four diets, while propionate production increased (P<0.05) and A/P ratio reduced (P<0.05) with increasing concentrate level in diet. It is concluded that increasing concentrate level in the diet of kids from 0 to 60% increased dry matter digestibility, promotedrumen fermentation andreducedmethaneproduction. Top Keywords Barbari kids, Concentrate, Methane, Rumen fermentation. Top |