The objective of this study is to compare the physical and financial performance of three dairy-beef genetic groups within an efficient grass-based production system.

The groups consisted of male Holstein Friesians (HF) and two Angus (AAX) groups representing the main calf breeds of the dairy herd.

The HF group were the progeny of the top four EBI sires on the active bull list in the previous breeding season. The two AAX groups were the progeny of AA sires that were ranked high for carcase weight and conformation (HIGH AAX), or low for carcase weight and conformation (LOW AAX). Both had similar breeding values for calving ease. All progeny were from HF dams and sired by AI bulls.

Each of the progeny groups were grazed separately, but were managed identically. Each had its own farmlet of 31ac (12.5ha), carrying 40 male calves (0-12 months) and 40 yearlings (12-24 months) over the entire grazing season. An intensive grass-based system of production was implemented, using the best grazing management practices.

The calves were purchased from 33 dairy farms throughout the country

All inputs and outputs from each of the farmlets were measured and used in the animal and financial performance analysis.

In both spring 2018 and 2019, the 120 male calves on the study arrived at Grange at approximately 21 days of age.

The calves were purchased from 33 dairy farms throughout the country, sourced using the ICBF database. The effect of early calf nutrition on lifetime performance was also evaluated, with half of the three groups reared on either 4l or 8l of milk replacer per day.

Each group received 48-hour grass allocations, grazing to a post-grazing sward height of 4cm. Over the finishing period, steers are offered ad-lib silage and 5kg of concentrates per head per day.

Table 1 shows the animal performance for year one of the study, i.e. the calves born in 2018.

There was no difference in the performance of the calves reared on either 4l or 8l of milk replacer/day. The calves on 4l per day consumed 20kg less milk replacer during the rearing phase and consumed 25kg more concentrates during the same period. All calves were castrated in August 2018.

The kill-out was highest for the HIGH AAX

Lifetime concentrate input was 740kg, 640kg and 635kg of concentrate, respectively, for HF, HIGH AAX and LOW AAX animal groups. The ADG of the HF steers was higher in the first grazing season (0.86 versus 0.74kg/day) and finishing period (0.93 versus 0.78kg/day) than the two AAX groups.

Age at slaughter was 19 days greater (the reason for the 100kg additional concentrate usage) for the HF compared to the two AAX groups, but slaughter liveweight was 39kg greater.

The kill-out was highest for the HIGH AAX (52%), lowest for HF (50%) and intermediate for the LOW AAX (51%), resulting in a 8.5kg carcase weight difference between HF and AAX groups, although this was not statistically significant. Carcase conformation was highest for the HIGH AAX (5.0; equating to O=), lowest for the HF (3.5; equating to O-) and intermediate for the LOW AAX (4.6; equating to O=).

Carcase value differences were small. The carcase value for the HIGH AAX was highest (€1,081), lowest for the HF (€1,022) and intermediate for the LOW AAX (€1,047). The finishing period for the HF was greater than for the two AAX groups (20 days), resulting in greater concentrate (100 kg) and silage (150kg DM) requirement per animal.

Earlier-born calves increased carcase yield by 3.5kg every week

Calves born earlier in the spring had a distinct advantage. Earlier-born calves increased carcase yield by 3.5kg every week, because earlier-born calves expressed higher ADG over the first grazing season.

Table 2 shows the financial performance. The purchase price of the calves in 2018 was €120, €295 and €280 for the HF, HIGH AAX and LOW AAX, respectively.

The carcase output per hectare for all three progeny group was 976kg/ha, 960kg/ha and 938kg/ha for the HF, HIGH AAX and LOW AAX groups, respectively. Including calf price, the average cost of production was €3.09, €3.54 and €3.57/kg of carcase for the HF, HIGH AAX and LOW AAX groups, respectively.

Based on a base price of €3.55/kg on the QPS grid, a €0.20/kg quality assurance bonus and a €0.10/kg breed bonus (AAX only), the net margin (€/ha) was €256, €64 and €3 for the HF, HIGH AAX and LOW AAX groups respectively.

If the average calf price paid through livestock marts over the last three years is applied (€60 for HF and €160 for AAX), then the net margin (€/ha) would be €448, €496 and €387 for the HF, HIGH AAX and LOW AAX groups, respectively.

  • Very high animal performance is possible from a predominantly grass-based diet, with the HF being slaughtered at less than 23 months and both the AAX groups slaughtered at 22 months of age.
  • The relative profitability of the three genetic groups is largely dependent on calf purchase price differences.
  • The HIGH AAX had slightly greater carcase weight and kill-out % than the LOW AAX progeny group and the HF group.
  • Earlier born calves have a definite advantage because of their potential to maximise growth during the first grazing season.