Effect of sulphur and calcium nitrate on methane production by goats fed a basal diet of molasses supplemented with Mimosa ('Mimosa pigra') foliage

Four weaned crossbred goats (Bach thao x local female), with an initial body weight of 10.5± 2.5 kg and 4-5 months of age, were assigned to a 2*2 factorial design in a 4*4 Latin square to compare the effect on rumen methane emissions, digestibility and nitrogen balance on a basal diet of molasses and Mimosa ('Mimosa pigra') foliage, supplemented with NPN from calcium nitrate or urea, and sulphur (0.8%) from sodium sulphate. Supplementing the basal diet with calcium nitrate led to a reduction in the methane/carbon dioxide ratio in the eructed breath of the goats compared with control animals supplemented with urea. The addition of sodium sulphate to the diet also reduced the methane/carbon dioxide ratio, with the two supplements having additive effects. Added sulphate increased both digestibility of crude protein and N retention. These criteria were not affected by the NPN source.