Most cross-bred beef-dairy calves display heartier constitutions than purebreds
Many modern dairy farm operations have developed an additional revenue stream by breeding dairy cows with Black Angus beef bulls using artificial insemination to produce crossbred calves, which typically have improved meat quality and higher market value compared to purebred dairy calves. However, these valuable hybrid calves often face the challenge of pneumonia, which was believed to impact their growth performance after recovery. A new study led by Penn State researchers has discovered that by the age of eight months on average, hybrid calves that recovered fr om pneumonia achieved similar average daily growth to calves that never had pneumonia.
The findings were published in the Journal of Dairy Science, showcasing the research led by Ingrid Fernandes, a graduate assistant in the Department of Animal Science, and her team. This research is anticipated to aid dairies under financial strain, according to study author Melissa Cantor, Penn State assistant professor of precision dairy science.
"We've had really high inflation across the United States, especially affecting the dairy industry wh ere the cost of raising purebred dairy replacements has grown astronomically," Cantor stated. "Adding the beef-on-dairy hybrid sideline has helped, but financial constraints necessitate careful selection of animals. It needs to be economically viable for them."
During the study, researchers noted that pneumonia only inhibited growth for three weeks before the calves started bouncing back, exhibiting compensatory growth akin to their healthy peers, highlighting that the illness was just a temporary setback.
For the first study of its kind to observe the long-term impact of pneumonia on beef-on-dairy cattle growth, 143 crossbred dairy calves were monitored, focusing on growth performance related to signs of pneumonia at weaning. The study assessed calf weights shortly after birth, at weaning, post-weaning, and at approximately eight months.
The study crucially found that lung pathogens were not associated with growth performance, with average daily growth being similar among all calves by about eight months of age. Notably, these calves recovered without antibiotics, a finding with potential implications for the organic dairy industry and the reduction of antimicrobial resistance in cattle.
"This study aimed to understand pneumonia's effects on growth and self-healing potential in calves," stated Cantor. "Our findings indicate that beef-on-dairy crosses often recover fr om pneumonia without antibiotics, a testament to hybrid vigor — a phenomenon wh ere progeny exhibit superior traits such as growth rate and productivity compared to their parents."
Contributions to the research also came from Tara Felix, Allison Welk, David Renaud, and Donald Sockett. The U.S. Department of Agriculture supported the research through its National Institute of Food and Agriculture.
