Rumen fermentation pattern as affected by incorporation of high glucosinolate rapeseed-mustard (Brassica sp.) meal as a protein supplement in sheep

Rumen fistulated adult: ewes (2) in switch-over design were fed 300g concen trate/day/head with ail lib. ground siris (Albezia lebbeck) pods and baru. (Sorghum helipence) hay in 50:50 ratio. Basal 300 g concentrate provided 11 7 g mustard seed-meal (MSM)which was raised to 160, 200, 250, 300 and 350 g with the addition of pure MSM to study the effect of varying levels of MSM supplementation on rumen fermentation characteristics and thiocyanate (SCN ) production. MSM as such contained 5.7% glucosinates. The pH of strained r umen liquor (SRL) ranged from 5.74 to 6.50, averaging 6.12 from 0 to 24 hr post feeding. There was no defined trend in pH changes, whereas, it was hig her (P<0.01) at from 0 to 24 hr post feeding. SCN concentration increased l inearly (P<0.01) from 0 to 6 hr past feeding, averaging 40.89 mu g/ml SRL. Total nitrogen was significantly (P<0.05) higher at 2 hr followed by and si milar at 4, 6, 8 and 12 hr post feeding, whereas, it was lower in 0 and 24 hr SRC samples. Ammonia nitrogen (NH3-N), TCA precipitable protein and tota l volatile fatty acids (TVFA) linearly increased from 0 to 8 hr past feedin g followed by declining trends. SCN did not exhibit significant correlation with any of the rumea parameters studied. Whereas it linearly increased wi th increasing supplementation of MSM (r = 0.87). It is concluded that progr essive increase in MSM feeding linearly increased the SCN content in SRL, h owever, its effect on rumen fermentation characteristics was not evident.