June 13, 2024

 

Crossbreeding boosts dairy farmers' revenue without harming cow health, US study finds

A study by researchers from Pennsylvania State University, US, analysing nearly 40,000 cattle has found that the practice of dairy farmers increasingly crossbreeding their Holstein cows with beef breed bulls to enhance the value of surplus calves generally does not negatively affect the health of dairy cattle.

 

The research, published in the Journal of Dairy Science, examined records from 39,249 Holstein cattle across 10 dairy herds in the Northeast and Midwest from 2010 to 2023. These cattle had calves sired by either Holstein or beef breed bulls.

 

According to the study, calves sired by beef bulls had similar birth survival rates to those sired by Holstein bulls, except for those sired by crossbred beef bulls. The likelihood of cattle experiencing dystocia, or difficult births, did not vary based on the sire breed of their calves. Furthermore, the rates of clinical health issues post-calving and early lactation cessation were similar between cattle with Holstein-sired and beef-sired calves.

 

The study also found that cattle carrying beef-sired calves had longer gestation periods compared to those carrying Holstein-sired calves. Gestation for calves sired by Angus bulls was extended by one day, while those sired by Limousin and Wagyu bulls extended gestation by five and eight days, respectively.

 

"Understanding the impact of different beef sire breeds on gestation length allows dairy farmers to plan for longer pregnancies and adjust their operations accordingly," said Bailey Basiel, the study's lead author and recent doctoral graduate in animal science.

 

Notably, cows carrying beef-sired calves showed no difference in milk, milk fat, or milk protein yields compared to those with Holstein-sired calves. Tara Felix, the study's team leader and associate professor in the Department of Animal Science at Penn State, emphasised that the results suggest current beef-dairy sire selection practices in the US do not negatively impact dairy cattle.

 

The study indicates that Holstein cattle can handle carrying and birthing beef crossbred calves due to their large frames. Basiel said they did not see any ill effects in these herds using Holstein cattle, which is reflective of the US dairy population that primarily milks Holsteins. But further research is needed to determine if Jersey cattle, which are smaller, can safely produce beef crossbreds without health and milk-yield issues.

 

A significant aspect of the study was that the Holstein cattle involved were all multiparous, meaning they had given birth at least once before. Basiel pointed out that first-time calving is more likely to result in traumatic experiences because the cow is smaller and inexperienced. However, the study found no differences in calving ease or stillbirth rates among these older cows.

 

Adrian Barragan, associate research professor in animal science and extension veterinarian, and Chad Dechow, associate professor of dairy cattle genetics, also contributed to the research. The US Department of Agriculture's National Institute of Food and Agriculture supported this work through a predoctoral fellowship award.

 

-      Pennsylvania State University