Beef cross dairy steers finished off grass under 22 months at the CAFRE Beef and Sheep Centre

December 21, 2021

CAFRE Beef Technologist, Natasha Ferguson provides an update on the performance of a recent group of 21 autumn born beef cross steers originating from the CAFRE Holstein dairy herd. These cattle are part of a project investigating the impact of reducing the age at slaughter from 24 months to under 22 months of age whilst maximising the amount of grass and forage in the diet.

Northern Ireland slaughter data for 2018 shows that of the 56,000 dairy cross steers slaughtered, 39% failed to meet optimal carcase conformation and a further 42% failed to meet desirable carcase fat cover. The data also shows that less than 10,000 head were slaughtered under 22 months of age. These findings indicate that there is great potential for those involved in the dairy beef business to improve efficiencies.

The beef sired calves are reared at the CAFRE Dairy Centre with all calves receiving the same level of colostrum management as replacement heifer calves in the unit. Calves are reared using automatic calf feeders from one week of age with each receiving high quality milk replacer at a rate of 750g of powder per day. This is offered as a daily allocation of up to 6 litres for 49 days, after which milk volume is gradually reduced to day 56. Calves are offered an 18% crude protein calf pellet and are weaned when they are consistently eating 1kg of pellets per day. Following weaning calves are offered high quality grass silage and remain at a rate of 2kg concentrate.

A key element to a profitable dairy calf to beef system is the efficient utilisation of grazed grass. Grazed grass is the cheapest source of energy for ruminants and is capable of supporting high levels of animal performance. The calves were rotationally grazed during their first season at grass, entering paddocks with grass covers of 3,000kg DM/ha and exiting at 1,600kgDM/ha. Calves continued to receive a daily allocation of 1kg concentrate at grass and performance was monitored regularly in conjunction with routine procedures. This concentrate level was increased if grass availability became an issue or if there was continuous rain for a period of time.

This batch of steers had to be housed early in October due to wet weather and poor ground conditions. All steers were then offered high quality grass silage (70 D-value) and 1kg concentrate. Concentrate was withdrawn 6 weeks pre-turnout in order to achieve a compensatory growth response at grass. Steers were turned out early in April to a set stock paddock system. Due to dry conditions during the summer period and low levels of grass growth steers were offered 1kg of home grown barley mix. Silage was also offered for a period from mid-June. All steers were gradually moved up to 5kg of the barley mix from 5^th July until slaughter (group average slaughter date 03/09/2021). Tables 1 and 2 show the lifetime performance and slaughter information of the steers. Overall 71% of beef cross steers were in spec for carcase conformation and 67% were in spec for carcase fat cover.

Table 1: Animal Performance Birth to Slaughter

Performance was ahead of expectation with some animals slaughtered at 19 months of age.  With improving fertility within the CAFRE dairy herd it is expected that beef calves will be available earlier in the autumn calving session which will ensure these animals can get longer at grass or be finished earlier within the grazing season before grass quality starts to dip towards the end of September.

In addition to the beef cross steers a batch of nineteen Holstein steers were sourced from the CAFRE Dairy centre to investigate the suitability of finishing these animals at under 22 months from a grass and grass silage based system. As the data in table 2 shows the Holstein steers are unsuitable for this system and require a later slaughter date. Going forward we will work with the dairy team to demonstrate the use of genetically superior beef bulls on lower PLI cows and reduce the number of Holstein males entering the beef system.

Table 2: Slaughter information for the dairy bred steers