CAFRE beef technologist Natasha Ferguson provides an update on slaughtering a group of 21 autumn-born dairy-beef steers.
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.
A further 42% failed to meet desirable carcase fat cover. The data also shows that less than 10,000 head slaughtered under 22 months of age.
These findings indicate great potential for those involved in the dairy beef business to improve efficiencies.
We rear beef-sired calves at the CAFRE Dairy Centre, with all calves receiving the same level of colostrum management as replacement heifer calves in the unit.
We rear calves using automatic calf feeders from one week of age. Each receive high-quality milk replacer at a rate of 750g of powder per day.
We offer this as a daily allocation of up to 6 litres for 49 days, after which milk volume is gradually reduced to day 56.
Also, we offer calves an 18% crude protein calf pellet and wean them when they are consistently eating 1kg of pellets per day.
Following weaning, we offer them high-quality grass silage and remain at a rate of 1kg 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 can support high levels of animal performance.
We rotationally graze calves 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. We monitored performance regularly in conjunction with routine procedures.
We increased this concentrate level if grass availability became an issue or if there was continuous rain for a period of time.
We housed this batch of steers early in October due to wet weather and poor ground conditions.
Also, we offered all steers high-quality grass silage (70 D-value) and 1kg of concentrates.
Then, we withdrew concentrates 6 weeks pre-turnout to achieve a compensatory growth response at grass.
We turned out steers in early April to a set stock paddock system. Due to dry conditions during the summer period and low grass growth levels, we offered steers 1kg of homegrown barley mix.
Also, we offered silage for a period from mid-June. All steers were gradually moved up to 5kg of the barley mix from July 5th until slaughter (group average slaughter date 03/09/2021).
Slaughtering dairy-beef steers
Tables 1 and 2 show the steers’ lifetime performance and slaughter information.
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
|Number of Animals||Av. Date of Birth||Birth Weight (kg)||Weaning Weight (kg)||Turnout 1 Weight (kg)||Housing Weight (kg)||Turnout 2 Weight (kg)||Slaughter Weight (kg)||DLWG from Birth to Slaughter (kg)|
|Beef X Steers||21||03/01/2019||47||97||206||308||524||653||0.99|
Performance was ahead of expectation, with some animals slaughtered at 19 months.
With improving fertility within the CAFRE dairy herd, we expect that beef calves will be available earlier in the autumn calving session.
This 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.
19 Holstein steers
In addition to the beef–cross steers, a batch of nineteen Holstein steers were sourced from the CAFRE Dairy centre.
The purpose was 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 (averages)
|Slaughter Weight (kg)||Carcase Weight (kg)||Kill Out %||Conformation Grade||Fat Grade||Age of Slaughter|
|Beef X Steers||653||333||51||O=||3=||612days|
Other reading from CAFRE: