Megalac – methane

Addition of Megalac to a diet has been proven to reduce production of methane gas by dairy cows. Up to 12% of the energy intake of a dairy cow may be lost as methane produced in the rumen, so methods of reducing methane production can improve feed efficiency and reduce undesirable environmental emissions of this greenhouse gas.

Work by Andrew et al. (1991) used respiration chambers to determine the methane production of lactating dairy cows when fermentable corn was removed from the diet and replaced with Megalac rumen-protected fat. As presented in Table 1, the addition of Megalac increased milk yield by 2.1 kg/d and reduced the total volume of methane produced, resulting in a reduction in methane production of 13.3% per litre of milk.

Table 1      Milk and methane production when corn was replaced by Megalac in dairy cow diets

Control  Megalac  P
Milk yield (kg/d) 32.2  34.3  <0.01
Methane (litres/day)  539  498 <0.05
Litres methane/litre milk 16.7 14.5  13.3% reduction

Andrew et al., 1991. Net energy for lactation of calcium salts of long-chain fatty acids for cows fed silage-based diets. J. Dairy Sci. 74, 2588-2600.