Evaluation of Forages in Terms of Carbohydrate, Nitrogen Fractions and Methane Production.

To develop database on Indian feeds as per Cornell net carbohydrate and protein (CNCP) system for developing precise feeding to ruminants and also to determine the methane production, 18 feed samples were collected in triplicate from different sources and analyzed for cell wall constituents. The choice of green fodders in descending order to mitigate methane release was chikori, mustard, leuceana, white clover, Chinese cabbage and lucerne. Among dry roughages, sorghum stover, maize stover and paddy straw could be preferred for lower methane production. The results of present study suggest that the characteristic of a feed in terms of methane production is unique, thus selection of a feedstuff (genus/species/varieties) on the basis of methane production appears to be logical proposition worth further exploring, and exploiting. Contents of cell wall constituents were the highest in dry roughages followed by non legumes, legumes and other greens. NDF; varied significantly (P0.01) and ranged from 50.8 in Oat (OS-6) to 67.2; in maize. Lignin ; of NDF ranged from 3.3; in Oat (OS-6) and barley to 4.3; in wheat. Legume and other greens had higher concentration of lignin than non legumes, but lower than dry roughages. CP; of DM varied significantly (P0.01) amongst the non-legume green fodders and ranged from 7.8; in maize to 28.8; in wheat. SP; of CP was maximum in berseem (60.3;) and minimum in fenugreek (16.4;). ADFIP; of CP ranged from 3.1; in lucerne to 14.2; in fenugreek. In forages, the highest percentage of PB3 which may largely be bypass protein was in non legumes. In non legume and legume green fodders, average C fraction which is indigestible fraction of CP was around 8; against highest 21; in dry roughages. Among dry roughages, sorghum stover had the highest lignin bound carbohydrate (1/3rd) and sugarcane tops (1/6th) had the lowest values. The total CHO ; in maize was 72.4; which was the highest and 62.8; in oat (OS-6) which was the lowest among non legumes. Non structural carbohydrates ratio was the highest in legume and related forages. The C fraction (indigestible fibre fraction) was the highest in wheat (9.2;) and lowest in barley (6.4;) in this category of forages. The data indicated that wheat and barley produce less methane than oat and maize. Similarly among legumes the least methane was recorded with chicory and mustard. It can be concluded that methane production is unique to a given forage/feed and there appears ample opportunity of selection of a genus/species to mitigate methane release from ruminants. Top Keywords Green forages, Dry roughages, CNCPs, Methane, Cell wall constituents. Top