Dairy calf to beef systems research update Teagasc Grange
The current research focus is to compare the performance of three DAIRY-BEEF genetic groups. These groups consist of male Holstein Friesian (HF) and two Angus (AAX) groups. Researcher Nicky Byrne gives an update on the herd and some recent performance figures.
Three DAIRY-BEEF genetic groups are being used in the research. These groups consist of male Holstein Friesian (HF) and two Angus (AAX) groups. The HF group are the progeny of the top 4 EBI sires, while the two AAX groups are the progeny of AA sires divergent in genetic merit for carcass weight and conformation.
Steers were housed for finishing and to reduce grass demand at the end of September, and are currently on a diet of high quality silage (78 DMD) and 5 kg of concentrate/day. Overall dry matter intake has been high over the first month of the finishing period, with each genotype consuming 2.2% of their body weight on a DM basis. High performance has been achieved over the first month of the finishing period, with an ADG of 1.7 kg across genotypes, while BCS has improved by 0.34, giving an average BCS of 3.25. Cattle will be drafted for slaughter once a BCS of ≥ 3.75 is achieved.
Table 1. Steer performance for the finishing period to date (1st month)
| Genotype |
Live weight performance (kg) |
Dry matter intake (kg DM/hd/day) | |||||
|---|---|---|---|---|---|---|---|
| 29 September | 29 October | ADG | Silage | Concentrate | Total | % BW consumed | |
| HF | 500 | 547 | 1.60 | 7.1 | 4.2 | 11.3 | 2.2 |
| HIGH | 500 | 553 | 1.84 | 7.4 | 4.2 | 11.6 | 2.3 |
| LOW | 501 | 550 | 1.71 | 7.5 | 4.2 | 11.7 | 2.2 |
Over the second grazing season steers were offered a grass only diet, grazing covers of 1300-1600 kg DM/ha to a residual height of 4 cm. This management lead each group to exceed their minimum ADG target of 0.9 kg. The HIGH carcass merit AA group achieved the highest growth, gaining 1.1 kg per day while LOW carcass merit AA and HF groups achieved an ADG of 1.0 kg.
Animal performance declined from late summer, when poor ground conditions combined with low grass DM limited performance. Over the grazing season each group had to be supplemented with high quality surplus bale silage for a total of 16 days to bridge deficits in grass supply. Across the three farmlets, DM production for the year to date has been 12.4 t DM/ha, 1.4 t DM/ha behind the same period last year.
By housing steers, calves will have sufficient grass to continue grazing up to December. Over their 1st grazing season, 2020 born calves achieved an ADG of 0.82 kg and currently weigh 233 kg. These calves form a new study investigating the effects of genotype and feed management on age at slaughter.
Table 2. First grazing season calf performance per feed management group year to date
*Grass only calves received no concentrate from 3 weeks post-turnout until the reintroduction of 1 kg from 15 September; all other groups received 1kg throughout the grazing season.