Cows with heifer calves produce more milk than those calving bulls

US study suggests extra milk output associated with having a heifer at first calving can also carry through to the second lactation.

John Shirley

4 February 2015

Cows with heifer calves produce more milk than those calving bulls

Pictured at the presentation of the RDS Champion of Champion awards for 2014/15 are the winners of the cattle and sheep awards along with the owners of the top EBI (David Kerr) and Maternal Index (Ernest Mackay) animals and the top young stock persons in 2014. Picture includes Dr Austin Mescal RDS, stock persons Conor Craig, and Shannon Kinahan, Cattle winners Albert de Cogan, David Pearson, Martin Clyne, Padraig Farrell, David Boyd, William Smith, Garrett Behan along with sheep breeders Eddie O

Cows that give birth to heifer calves give more milk in their subsequent lactation than their counterparts that have bull calves, according to recent research in the US. This phenomenon has been measured over and above the increase in milk output that could be expected from the lesser calving difficulty associated with calving heifers.

Cows that give birth to heifer calves give more milk in their subsequent lactation than their counterparts that have bull calves, according to recent research in the US.

This phenomenon has been measured over and above the increase in milk output that could be expected from the lesser calving difficulty associated with calving heifers.

The survey evidence indicates that the extra milk output associated with having a heifer at first calving can also carry through to the second lactation. One estimate put this cumulative two-lactation advantage at an extra 445kg in US Holstein heifers and cows.

There is also a suggestion that cows carrying heifer calves can have slightly higher milk yield compared to those carrying bull calves.

A study of 2.39m lactation records from 1.49m dairy animals in the US in the 1990s, pre-BST (Bovine Somatrophin) largely confirmed the milk advantage trends linked to heifer calves.

Their estimate indicated that heifers carrying heifer calves give 140kg extra milk in 305 days compared to heifers which have calved bulls. In US Holstein heifers, this represents an advantage of about 1.5%, but over such a population even this small difference is statistically significant.

The milk yield advantage in the cow linked to carrying heifers versus bulls was smaller and put at about 30kg in this study.

The study showed that the milk yield gap between heifer and bull calvings was less when the cows were treated with BST, but that BST in its own right boosted milk output by 12% across all cows.

Another statistic uncovered in this large cow population study was that 28% of cows had bull/bull calves in their first two calvings versus 23% with heifer/heifer calvings.

In the US, companies involved in sexing semen are using this research result as conferring an extra economic response to the use of sexed semen.

Further information, go to www.plosone.org and search for ‘Holsteins favor heifers’ to download a PDF of the research article by authors Katie Hinde et al.

A home-bred eight-year-old cow owned by Michael Stephens, Corofin, Co Galway, took top prize in the Irish Limousin Society carcase competition operated in conjunction with Ashbourne Meats.

The Limousin cross Blonde cow won the non-pedigree section and then was judged overall winner. She killed out 550kg carcaseweight and graded U+4-. This was deemed an ideal fat cover by French judge Henry Hoffman.

Offaly breeder Garrett Behan took first prize in the pedigree section with a carcase grading E-4+.

Overall, the competition had an entry of over 300 Limousin and Limousin cross cows which were slaughtered in Ashbourne Meats Roscrea over the past week.

Fourteen of the top carcases were selected for special mention and from these the overall winners were selected.

According to the Limousin Society website, E, U and R grade cows are priced at 390, 385 and 375 c/kg, with an extra 10c/kg payable for cows accompanied with a pedigree cert.

Show and sale

Spring 2015 pedigree bull Show and Sale season gets underway next Saturday Feb 7 in Carrick-on-Shannon where the Midland and Western Livestock improvement Society has an entry of 74 Charolais and 12 Limousin bulls. The following week this traditional venue sees an entry of 89 Angus, four Shorthorn and six Hereford bulls.

Cows clearance

Buyers from county Meath dominated at last week’s sale of the entire winter section of the Carrigeen Hall herd held at the Cork Marts Corrin Centre Fermoy. There was a complete clearance of 80 cows with a top of €1,420. Some of the older cows milking since October sold under €800.

Belted Galloway

The Belted Galloway Club of Ireland AGM will be held on Saturday 7 February in the Crowne Plaza Hotel, Dundalk, at 12.45pm.