Pasture-based feeding will add cull-cow carcass value
It is possible to dry off and finish feed cull cows at pasture regardless of over-wintering strategy. That was the positive finding of a study to compare days to slaughter, average daily gain, and final live and carcass of cull dairy cows subjected to four over-wintering strategies prior to a pasture based finishing diet.
The work was carried out by a team of research scientists from Teagasc, at Moorpark in Ireland, and University College Dublin and the results were presented to delegates at this year’s British Society of Animal Science annual conference by William Minchin.
“Cull cows comprise about 44% of all cattle slaughtered at Irish meat factories in 2006 – an increase of 6% from 2005. Between September and December 2006, 18% of cull cows failed to achieve P+3 carcass classifications compared with 12% for the remainder of the year,” he said, explaining the rational behind the study.
“There is a large proportion of cows slaughtered in November, which suggests that unfit – both low bodyweight and condition score – cows are being presented for slaughter at the end of lactation without finishing prior to slaughter.”
He added that farmers who are finish feeding cull cows have an interest in alternative feeding regimes, in other words pasture and/or forage use for a more economical beef supply due to increasing concentrate costs: “But present farm practice and culling decisions made by the dairy farmer often excludes this as a real possibility.”
The trial was carried out at Moorepark from 18 December 2006 to 29 June 2007. Fifty-six Holstein-Friesian cull dairy cows were randomised across a four-treatment finishing experiment. They were randomised on age, lactation number, Holstein proportion, liveweight and body condition score.
The treatments were slaughtered on day zero (control), grass silage and straw, ad lib grass silage, ad lib and grass silage plus 6kg of concentrate per day. The finishing criteria applied were a carcass weight of more than 272 kg, fat score 3 and carcass classification P+ or O. Liveweight, body condition score, back fat, milk yield, group intake and carcass characteristics were measured.
“Because the finishing criteria were predetermined, there was no significant effect between the three finishing treatments on slaughter live and cold carcass weight; however there were significant differences between the control treatment and finishing treatments,” said Mr Minchin.
“The ad lib grass silage treatment was the most efficient treatment evaluated – the result of a high average daily weight gain. The grass silage and straw and grass silage and concentrate treatments achieved satisfactory performance, but over-winter feed restriction and milk production created prolonged finishing periods for both treatments,” he added.
“So we concluded that pasture-based strategies will significantly add to cull-cow carcass value.”
Presented to the British Society of Animal Science Annual Meeting, March 31 to April 2, 2008, Scarborough, UK.
Full details: Minchin W, O’Donovan M, Kenny D, Monahan F, Shalloo L and Buckley F: “The effect of over wintering strategies on performance and carcass characteristics for cull dairy cows on a subsequent grass based finishing strategy.”
summary (pdf) Presentation_116minchin (pdf)
For further information visit http://www.bsas.org.uk/Publications/Annual_Conference_Proceedings/or contact BSAS on 0131 445 4508 or bsas@sac.ac.uk
