METHANE SUPPRESSION BY CALCIUM SOAPS OF STEARIC, OLEIC AND LINOLEIC ACID MIXTURES IN CATTLE

Abstract

Summary Two types of calcium soaps of fatty acids (Ca-FA) were used; Ca-FA-I (C 18:0 17.0%, C18:1 65.0%) and Ca-FA-2 (CI8:0 20.0%, CI8:140.0%, C18:2 35.0%). In Expt 1 four dry cows were fed Italian ryegrass hay and concentrate as basal diet (BD). Treatments were BD, BD + Ca-FA-l (300g), BD + Ca-FA-l (600g) or BD + Ca-FA-2 (600g). In Expt 2 four lactating cows were fed bahiagrass hay and concentrates with or without the Ca-F A-2 supplements (500g). In Expt 1 there were no significant differences in NDF digestibility by feeding Ca-F A. Methane production per dry matter intake (DMI) in dry cows tended to decrease about 7-9% (17-23 litres/day) by feeding Ca-F A but no effects of degree of saturation and amount of Ca-F A fed were observed. In Expt 2 DMI and digestibilities of dry matter (DM) and crude protein (CP) were not affected by feeding Ca-FA. Methane suppression in lactating cows was about 4% (22 litres/day/kg DMI). From the above results, it is concluded that feeding 300-600 g/day of Ca-F A is effective in suppressing methane production without reduction of productivity. Key words: Methane production, calcium soaps, cows, digestibility.