Breeding Angus cattle that naturally emit less methane

Abstract

The aim of this experiment is to investigate and demonstrate genetic variation in daily methane production (MP; g/d), methane intensity (MI; MP per unit bodyweight; g/kg) and methane yield (MY; MP per unit feed intake; g/kg). Angus cows in pedigree- and performance-recorded research herds at Industry & Investment NSW research centres at Grafton and Trangie NSW were mated in 2007 to Angus bulls that had previously been recorded for MY. Bulls that had been identified as either phenotypically high or low for MY were used as sires in the Grafton herd; unselected sires were used in the Trangie herd. In 2010 the near 2-year-old bull progeny from Trangie and heifer progeny from Grafton were measured for MP, MI and MY. There were 8 sires with progeny represented in the Trangie bull data (n=63 progeny). A wide range in least-squares (LS) sire means was observed for MP (191g/d to 233g/d), MI (0.26g/kg to 0.63g/kg) and MY (24.3g/kg to 30.2g/kg). There were 6 sires with progeny represented in the Grafton heifer data (n=79 progeny). A wide range in LS sire means was observed for MP (133g/d to 165g/d), MP (0.15g/kg to 0.55g/kg) and MY (21.5g/kg to 27.0g/kg). The differences between sires for these traits that indicate that there may be genetic variation present and provide preliminary evidence that selection on a methane production trait may be possible.