EFFECT OF FEEDS AND FEED ADDITIVES ON IN VITRO METHANE EMISSION OF CROSSBRED DAIRY COW

Abstract

Two in vitro experiments were conducted at Livestock Production and Management Laboratory, Sylhet Agricultural University, Sylhet from 3rd April to 28th April 2016 to estimate the methane emission from 10 feed ingredients grouped according to their nutrient composition where rice straw (Oryza sativa), napier grass( Pennisetum purpureum) and german grass (Echinochloa polystachya) were grouped as roughages, rice polish (Oryza sativa), wheat bran (Triticum aestivum) and broken rice (Oryza sativa) as energy rich concentrates and red lentil (Lens culinaris), grass pea (Lathyrus sativus), mung bean (Vigna radiata) and mustard oil cake (Brassica nigra) as protein rich concentrates to estimate the methane emission from them by in vitro gas production techniques. In addition 3 feed additives cumin (Cuminum cyminum), coriander (Coriandum sativeum) and turmeric (Curcuma longa) were added to evaluate their effect on methane production from german grass and wheat bran by this technique. Complete randomize design were followed to assess the in vitro degradability after 72h incubation, gas production at 0, 3, 6, 12, 24, 36, 48, 72h and methane emission at 24, 48 and 72h of incubation. Among the roughages methane emission was highest in german grass (92.56ml/g DM) followed by napier (63.89ml/g DM) and rice straw (21ml/g DM). Methane emission among the energy rich concentrates were 76.33, 61.00 and 23.56ml/g DM for broken rice, wheat bran and rice polish. Methane emission from protein rich concentrates group was 63.67, 54.44 54.11 and 49.78ml/g DM respectively in rass pea, mung bean, red lentil and mustard oil cake. Methane emission was negatively correlated with the level of cured protein and ether extract and was positively correlated with the level of nitrogen-free extract. Addition of feed additives had no significant effect on in vitro degradability but significantly (p<0.01) reduced the gas production and methane emission from german grass and wheat bran. Cumin was most effective to reduce the gas production from both feed but turmeric was most effective for german grass and cumin was most effective for wheat bran in term of methane emission. So turmeric and cumin are most effective to reduce methane emission from dairy cows.