Abstract

Size and milking potential of beef breeding cows affect their productivity and efficiency. This experiment compared the productivity and efficiency of straightbred Angus (AA) (high live weight, low-milk potential), Angus-cross-Holstein Friesian (AF) (high live weight, high-milk potential), Angus-crossKiwicross (AK) (moderate live weight, high-milk potential) and Angus-cross-Jersey (AJ) cows (low live weight, high-milk potential). High-milk lines produced heavier calves at weaning than the low-milkproducing AA. AF and AK cows weaned the heaviest calves at 225 ± 3 kg and 224 ± 4 kg respectively. These calves were heavier than those weaned by AJcows (212 ± 3 kg). All of these three genotypes weaned heavier calves than AA cows (197 ± 3 kg). In turn, all three high-milk lines had greater weaning efficiency ((weaning weight of calf/weight of cow at calf weaning) x100) than AA cows which had an efficiency of 36.7 ± 0.7%. AJ and AK cows were the most efficient at 46.7 ± 0.7% and 46.0 ± 1.0%, respectively. AJ cows were also more efficient than the AF cows (44.0 ± 0.8%). Increased milking potential and decreased live weight of breeding cows increased their efficiency of production.

NL, Law, RE Hickson, N Lopez-Villalobos, PR Kenyon, and ST Morris

Proceedings of the New Zealand Society of Animal Production, Volume 73, Hamilton, 11-16, 2013