Abstract
The use of beef semen in dairy dams is nothing new, but has skyrocketed in popularity in recent years. Beef x dairy is quickly becoming an integral part of both the dairy and beef industries. The reasons for this boom can be regional specific and multifaceted. Due to this increased use of beef semen in dairy operations, 3 studies were conducted to better understand the impact of breeding with beef semen on dairy operations. First, a survey was conducted to gain insight into some of the decisions made on the dairy when deciding to utilize beef semen. Results of this survey indicated 3 main drivers when it came to breeding with beef semen: Reproduction, Herd Management, and Economics. The pregnancy status of a dairy dam was the primary driver of whether she was selected to be bred to beef semen. Additionally, calving ease and semen cost were 2 of the main drivers when picking beef sires. The improved value of the beef x dairy calves was evident and ranged from 1.35 to 5.17 times that of pure dairy calves. Second, a retrospective analysis was done on records from 124, 832 animals representing 104 herds to investigate the influence of service sire type on the dams’ post-calving performance. There was a tendency (p = 0.06) for dams bred to beef service sires to have an increased incidence of fresh cow health events. Also, dams bred to beef services sires had increased calving ease scores on average (p < 0.001) and had higher predicted 305-d milk production (p < 0.001). Finally, an observational study was conducted on a calf ranch to investigate the influence of serum total protein (STP) on the future performance of Angus x Holstein calves from birth till arrival at the feedlot. Calves were enrolled based on their STP measured by a Brix refractometer on the farm and classified into 2 groups: “good” and “Poor”. Serum IgG was measured by radial immunodiffusion. A correlation of 0.69 was found between STP and serum IgG (p < 0.001). There was no significant influence of STP group on morbidity, mortality, body weight, ADG, or the number of times a calf was treated. The STP group tended (p = 0.09) to influence the days to first treatment in the pre-weaning period. Calves in the Good STP group were treated with anti-inflammatory drugs sooner (p < 0.05) compared to calves in the Poor STP group. Likewise, calves in the God STP group were 1.21. times more likely to be treated at any point from birth till arrival at the feedlot compared to calves in the Poor STP group. The results of the studies presented here are a starting point into better understanding beef x dairy from the dairy perspective. Future work is still needed to investigate how the service sire type really impacts the dams’ post-calving performance, especially with the push from the beef industry to larger calves. Similarly, there is much left to understand around how a calf's passive immunity impacts their future performance, but also if it carries over into the feedlot phase. Beef x dairy is not a fad and will become integral to both the future of dairy operations and beef operations alike, and more research is key to making the best decisions regarding these animals.