Beef on Dairy

THIS ARTICLE IS A DRAFT PENDING REVIEW

Beef from dairy herds has traditionally accounted for 16 to 20 percent of the beef supply in the United States, and until recently, this supply was from straight-bred dairy cattle. Market changes and improvements in sexed semen technology have contributed to the transition from dairy to beef breed type semen use in dairies. Using sexed semen in many dairies has led to strategic breeding for creating replacement heifers from the best females and beef semen in lower-performing dairy females. This creates an opportunity to both capture data for use in genetic evaluations and to create the next generation of beef bulls for this specific use.

Beef x dairy performance

Dairy cattle have traditionally contributed to the U.S. Prime Quality Grades but have received discounts for less desirable USDA yield grades and dressing percentages attributed to lighter muscling and smaller ribeye areas Feedlot performance for dairy cattle has lagged compared to beef counterparts due to higher energy requirements and lower average daily gain. Although dairy cattle lacked performance compared to beef cattle, their performance was consistent and predictable. Studies conducted in the U.S. found that beef x dairy cattle were less efficient when compared to beef cattle but demonstrated an advantage for average daily gain compared to straight-bred dairy animals In comparing carcasses for beef, dairy, and beef x dairy cattle, beef x dairy cattle were intermediate in performance compared to straight-bred beef and dairy but beef x dairy crossbreds were not significantly different for quality grade compared to dairy Although beef x dairy cattle performance was intermediate compared to straight-bred, their performance was considerably more variable than straight-bred dairy cattle creating a challenge for cattle feeders. The performance for beef x dairy cattle in the U.S. is limited, and studies on early beef x dairy calf development, health concerns, and feedlot performance are needed.

Data generation and inclusion in genetic evaluations

Including carcass phenotypes from beef x dairy crosses in beef cattle genetic evaluations can significantly expand the number of records used by evaluations, resulting in increased prediction accuracy for more animals. The number of carcass phenotypes included in genetic evaluations is considerably less than other evaluated traits (e.g., weight traits). Incorporating beef x dairy records requires that the evaluation account for dairy breed differences and beef x dairy heterotic effects as fixed effects. The early in life temporary environments experienced by these animals need to be evaluated relative to their impact on the phenotypes used in genetic evaluations to determine if early in life management groups need to be accounted for.

The structure of beef x dairy differs substantially to that of native beef data that currently dominates beef breed genetic evaluations. Given management systems on most dairies, a single beef bull used in such systems could generate thousands of progeny with carcass records. Although this might be most profitable for a given dairy, there is a diminishing rate of return from the perspective of a genetic evaluation in terms of increases in EPD accuracy. Furthermore, using field data to estimate breed differences and the effects of heterosis are complicated given confounding of these effects with the additive effect of the sire. To fit both the needs of dairies and of genetic evaluations, some degree of optimization is needed to ensure management groups (e.g., calving intervals) contain more than one sire and multiple sires are being utilized.

Current breed association genetic evaluations and associated databases have been built to accommodate data originating from seedstock herds. Consequently, the notion of sequential culling, and the potential for culling bias, is routinely built into these evaluation systems. However, for beef x dairy animals (or commercial data more generally) such protection might not be needed and could even be problematic if early in life records are a requirement for inclusion of post-weaning traits. The inclusion of weaning weight as a correlated trait in carcass evaluations can be problematic since beef x dairy calves are not weaned at 5 to 8 months as traditional beef calves routinely are.

The accuracy of a genetic evaluation would depend on the level of connected data across contemporary groups. In the case of beef x dairy calves, the use of beef bulls on dairy females can create a connection between contemporary groups through the pedigree. In order to incorporate the data from beef x dairy calves into a genetic evaluation, the sire must be known, and, at a minimum, the dam breed type. Including dam and maternal grandsire would lead to an increase in the connectivity of data, resulting in better genetic prediction. The recording of sires for beef x dairy calves is often lacking due to dairy producers placing lower importance on recording of terminal animals who would not be used for breeding.

For beef x dairy cattle, data collected on the dairy must remain with the animal through slaughter. Records collected on dairies should include: unique ID, birth date, sire, dam, maternal grandsire, calving difficulty score, disposal record (died, shipped/location). Although sire is assumed known given AI records from the dairy, genotyping to confirm sire would be advantageous. If not on every calf, a sample from dairy-breeding day combinations could give confidence that correct paternity is assigned.

Selection of bulls for use in beef x dairy systems

The decision of genetic merit for beef semen to generate terminal beef x dairy calves is made by dairy producers, but these decisions are driven by on-dairy performance and needs. Breeding objectives for beef x dairy cattle need to consider profitability of the system, improved feedlot performance, carcass merit, and avoiding discounts of straight-breed dairy cattle. However, the vast majority of dairy breeding objectives do not consider the performance of beef x dairy calves post-calving. Profit drivers such as feedlot health, days on feed, and liver abscesses should be considered in beef x dairy indexes, but estimation of genetic parameters for these traits is lacking.

Several semen companies and breed associations in the U.S. have developed indexes for selecting beef bulls for use in dairies. Commonly these indexes are used to sort among bulls that were bred for beef x beef production. Alternatively, bulls could be bred with beef x dairy breeding objectives in mind. Such a strategy would lead to faster improvement in beef x dairy fed cattle. Such objectives may include germplasm that is not favored for native beef production but that could increase muscle, improve yield grade, and increase feed efficiency. Visual characteristics must also be considered. In the U.S., homozygous black and polled bulls are large considerations for beef germplasm use in dairy driven by market demands set by packers.

Recommendations

BIF recommends the following with respect to the genetic evaluation model for beef x dairy carcass evaluation: • include beef x dairy heterosis effects • appropriate pre-weaning contemporary groups should be carefully constructed • multiple beef bulls be represented in the early in life contemporary group • sampling paternity of beef x dairy contemporary groups should be performed to avoid data with high pedigree error rates

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Additional background can be found in the eBeef fact sheet.