Aside from the calves that are exported, the remaining calves (approximately 840,000 calves) are available for beef production.
In general, male dairy calves are managed under bull or steer systems, while beef crossbred heifer calves are either operated in low input production systems, or retained for breeding in the suckler herd.
Currently, male dairy calves represent 41% of dairy calves available for beef production, while 43% are early maturing crossbred calves (26% Aberdeen Angus and 17% Hereford).
Limousin, Belgian Blue, and other crossbred calves make up the remainder (approximately 95,000 calves).
The purpose of this article is to present the optimum production systems for early maturing dairy beef crossbred calves.
Johnstown Castle researchers examined various finishing strategies for early and late spring-born Angus and Hereford dairy crossbred heifers and steers.
Animals were either finished at pasture or indoors during their second winter.
Results from Johnstown Castle have shown that spring-born early-maturing dairy crossbred heifers (February to April born) should be slaughtered before the second winter housing, from 19 to 21 months of age (September to November).
Finishing heifers indoors during their second winter resulted in a greater carcass weight, but winter finishing costs were inevitably incurred, and some heifers were over fat at slaughter.
An economic appraisal of that system highlighted that finishing heifers indoors was less profitable than finishing heifers at pasture.
Early spring-born (January and February), early maturing steers have the potential to be slaughtered at the end of the second grazing season.
Previously, the blueprint for these steers involved a winter finishing period of 80 days.
While both systems were profitable, finishing steers during the second winter was less profitable than pasture finishing.
Alternative finishing strategies were also investigated for late-born steers. Animals were either finished indoors during the second winter, or finished during their third season at pasture at 28 months of age.
Results showed that steers that were finished indoors had a lighter carcass weight and that the system was less profitable than finishing animals during their third season at pasture.
The optimum production systems for early maturing heifers and early and late born, early maturing steers are as follows.
In all of the systems, animals were allocated 2.5kg of concentrates per head daily for 60 days pre-slaughter.
After their first winter, heifers were turned out to pasture in early March and slaughtered off pasture at the end of the second grazing season between September and November (at 19-21 months).
Target carcass weight for this system is 235- 250kg. Carcass conformation for heifer production systems were predominately O=/O+, with carcass fat classes of 3-/=.
Results from Johnstown Castle have shown that all spring-born heifers should be slaughtered before the second winter.
Steers were at pasture for the first grazing season, and ‘stored’ during the first winter on grass silage ad libitum, supplemented with 1.5-2kg of concentrate daily, depending on silage quality.
They were turned out to pasture for the second grazing season, and slaughtered off pasture in November.
Average daily gain during the second season at pasture is 0.8kg.
The target carcass weight in this system is 280kg.
Average carcass conformation score was O=, and carcass fat score was 3-.
Animals were at pasture for the second grazing season and were then housed and offered grass silage only, on an ad libitum basis for the second winter.
During this housing period, average daily gain (ADG) is typically 0.5kg.
Steers are then turned out to pasture in March and slaughtered in June.
ADG during the third season at pasture is 1.3kg.
The target carcass weight is 320kg, with conformation and fat scores of O+ and 3+, respectively.]
This system is particularly well suited to calves born in the late spring (April/May), as winter finishing is avoided, and a heavier carcass weight is achieved under grazing conditions.