Sire Effects on Post-Weaning Growth of Beef-Cross-Dairy Cattle: A Case Study in New Zealand

Abstract

Little is known about the growth performance of beef sires used over dairy cows in New Zealand. This experiment aimed to evaluate the growth of Angus and Hereford sires via progeny testing of beef-cross-dairy offspring born to dairy cows and grown on hill country pasture. Live weights at 131, 200, 400, 600 and 800 days were analysed from a dataset of 5208 records from 1101 progeny of 73 sires. The means of the progeny group means for live weight were 118.6 kg at 131 days, 159.1 kg at 200 days, 284.2 kg at 400 days, 427.0 kg at 600 days and 503.6 kg at 800 days, and the overall daily growth rate was 0.58 kg/day from 131 to 800 days. The sire affected (p < 0.05) the live weight of their progeny at all ages. Differences in live weights between the lightest and heaviest progeny group means increased from 19 kg at 131 days to 90 kg at 800 days. Even though growth of calves was likely restricted to 200 days, live weight at 200 days explained 51–56% of the variation in live weights at 400 and 600 days (p < 0.05). Thus, the use of beef sires selected for growth has the potential to increase the live weight of cattle born on dairy farms for meat production.

Optimization of Profit for Pasture-Based Beef Cattle and Sheep Farming Using Linear Programming: Young Beef Cattle Production in New Zealand

“…This would facilitate the need to increase the proportion of selected bull semen to breed with dairy cows to modify the genetic orientation of dairy-origin cattle for beef and to make sure that fast-growing dairy-origin calves are available for young beef production [16,17]. Progeny testing evaluation of Angus and Hereford sires on improving the live weight of dairy-origin cattle by [60] has shown the use of appropriate beef sires has a potential to increase live weight and growth of cattle born on dairy farms.…”

Estimated Breeding Values of Beef Sires Can Predict Performance of Beef-Cross-Dairy Progeny

“…After weaning, the calves in this study went on a pasture-based diet, which was of low quality over the summer [metabolizable energy (ME) of 9.2MJ per kilogram of dry matter (kgDM), CP 12.6 %DM ( Martín et al, 2020 )]. Low-quality pasture likely restricted animal performance, because calves grew at an average of 0.55kg/d from weaning at 81.5–200d, compared with 0.69kg/d pre-weaning (0–81.5d).…”

“…After weaning, calves were weighed on the farm using a weigh crate at a minimum of 2-monthly intervals, as described in Martín et al (2020) . Short-term fluctuations in liveweight were smoothed out by calculating centered moving averages of three liveweight records per animal using the Expand procedure (SAS 9.4, SAS Institute Inc., Cary, NC, United States).…”

“…The animals reported here are a subset of animals for which growth and carcass traits were previously reported (Martín et al, 2020(Martín et al, , 2021Coleman et al, 2021). The animal study was conducted at Limestone Downs, near Port Waikato, New Zealand (37°28'S, 174°45'E).…”

“…Previous studies in New Zealand (Martín et al, 2020(Martín et al, , 2021Coleman et al, 2021) have demonstrated considerable variation in performance among Angus and Hereford sires for birth, growth, and carcass traits. However, it was not explored how the sire performance related to their EBV.…”