Collaboration to demonstrate the potential use and value of electronic identification and DNA testing in the sheep industry

The first phase of test results from Flock 54 were received in August 2019. Most producers in the study cull rams in April/May before the breeding season starts (mid-May for most) and to make room for new rams purchased at ram sales that spring (April-ish). The results were received too late for a producer to use them to make decisions for the next breeding season. Parentage information needs to be returned within a window that facilitates selection for next lamb crop. Similar to results from studies completed in commercial beef cow/calf herds, the economics of genetic testing is not sustainable on a large scale. We expect genetic testing to be an important tool for purebred producers (primarily rams). Further the Flock 54 program is not the appropriate test  for determining genetic markers to support the development of Estimated Breeding Values (EBV's). The National Sheep Improvement Program (NSIP) or Sheep Genetics USA would be more appropriate programs.

The presentation given at the American Sheep Industry conference in San Diego, CA in January 2022 is available at the link below. The presentation includes numerous figures summarizing the data analysis and results.

ASI2022_DataDrivenDecisions

The parentage results for Ranch C (Macon) , D (Indart) and E (Iturriria) (Figure E) followed common trends seen in similar beef cattle studies where a small number of sires produce a large percentage of the lamb crop. Ranches A and B had a lower ram:ewe ratio (Figure A) which resulted in some dilution of this effect (Figure F). One potential explanation for this is the increased competition among rams during breeding season. Ranch E had the greatest number of rams for which parentage was not identified. We believe this was caused by the use of some clean-up rams later in the breeding season that were not tissue sampled for Flock 54.

Figure E - Number of lambs per sire for Ranch C (Indart)

Figure F - Number of lambs per sire for Ranch A (Irwin)

A Principle Component Analysis (PCA) plot was completed for each ranch and between ranches. Slide 12 illustrates some of the genetic variation within flocks from Ranches A, B, and D. Of interest, Ranch B produces Rambouillets, a wool breed, while Ranches A and D focus more on meat breeds. Despite the genetic difference in lambs from Ranch A and Ranch B, when their carcass traits are considered, the final consumable product is quite similar. Figure G.

Figure G - Results from carcass measurements of lambs from Ranches A (Irwin) and B (Emigh). Ranch C (Macon) sold his lambs to Superior Farms, but carcass measurements were not collected at the plant. Ranches D and E (Indart and Iturriria, respectively) did not sell their lambs to Superior Farms and as a result no carcass measurements were collected.

Before the project there were varying levels of EID use among the producers on this project. The producer summary in Figure A provides a snapshot. Ranch A had been using EID’s, but wasn’t using the EID’s to collect data on their flock. Ranch B successfully used EID technology to reduce footrot and the overall health of their flock, along with increasing their lambing percentage 30%. Ranch C, a small flock producer, saved time and money by switching to EID’s and away from a system that required 3 types of ear tags and working the lambs twice at weaning (see link below). Ranch D was interested in the technology, but had not yet invested. Ranch E used only scrapie tags on a small portion of their flock; all flock production was tracked with paint brands or ear marks.

Ranch C cost study of switching to EID's - https://ucanr.edu/sites/Livestock/files/294788.pdf 

Citing the experience of both Ranch B and Ranch C, the value of EIDs is seen when the individual animal performance data is used to make better-informed management decisions towards clear goals. In the case of Ranch B, when they first started using EIDs they identified a number of traits they felt it was important to track. After they started processing lambs, they realized the data collection was taking up to 5 minutes per lamb. This level of data collection was not practical for their operation. In response, Ranch B chose three traits to focus on: footrot, twinning rate, and wool microns. This system created a significant reduction in foot rot and, as previously stated, a 30% increase in lamb crop. For Ranch C, switching to EIDs cost slightly less than the previous system of three types of ear tags. Ranch C was already tracking individual animal performance data on their flock and had seen progress towards their identified goals, but switching to EIDs also saved them time and has proved to be a more efficient and practical system for their small flock operation.

One of the common challenges cited when discussing the use of EIDs with large flock producers is the potential cost of the equipment and labor versus the financial benefit to the business. For example, if placing an EID in the ear of each lamb requires 5 seconds per lamb, for a 3,000 ewe flock with 100% lamb crop that could mean an additional 4 hours of labor. Given the cost of the tags ($1.00/EID at the time we purchased the tags), the reader ($2,200), and the labor, producers want to know they are making an investment that will not only pay for itself, but also bring a positive return to the business.

 Another common challenge cited by producers is the logistics of using EID systems in the field. In speaking with one producer, he voiced the concern that producers are already short on time. If they think a new practice will require more work or more time, they will often choose to keep management unchanged rather than make some changes that might take more time, but would increase their income. This is a fundamental issue we need to address when working with producers and we are just beginning to discuss potential solutions. However, sheep producers are skilled at finding creative ways to resolve issues. Each producer would need to find the best fit for their operation. Once the EIDs are in the ears of the lambs and the rest of the flock, the next questions are: what is the best way to collect data on the flock and what data should be collected? We spoke with one producer that stated cost of the reader was prohibitive because on their operation each herder would need a tag reader to track flock data. In other words, they would need at least five tag readers and maybe more.

Perhaps one of the most inciteful comments that described a lack of adoption of EID's among producers was that producers need to want to change. If producers are satisfied with the status of their flock, there is little motivation to implement a new practice to improve the flock. Further, the influence of less objective decision making factors bears discussion.  In many instances there are factors impacting decisions about flock management unrelated to flock production traits. These may include family dynamics, emotional attachment to specific animals, resistance to follow culling recommendations and more. For example, one producer stated he had fool-proof way to track twins. He used a hole punch to put a hole in the middle of the ear of all twin lambs at birth. However, at weaning, when it was time to identify replacement ewes and ship the remainder of the ewe lambs and all wether lambs he had trouble following his own guidelines. Specifically, he stated, "When that beautiful 130 pound single ewe lamb comes down the chute, I can't get rid of her." When considered objectively, one 130 pound ewe lamb produces less pounds of lamb per ewe exposed than two 90 pound lambs, however, something about that large singe ewe lamb caused that producer to change his mind. While the term might not be completely accurate, for the sake of discussion, let's call these 'right brain decisions'. Individuals are making decisions based on a gut reaction outside of objective information. It's part of being human. What might be helpful in these situations is to plan ahead and decide that for every 1,000 lambs, 10 'right-brain' decisions to keep or sell can be made (and then find a way to keep a count and resist the urge to deviate from the well-thought out plan).

In the rearview mirror...

This project showed producers, who had never used or seen EID's, how to use them and provided an introduction to what the tag readers look like and how they work. We hope to follow up with a hands-on workshop on how to use a reader. Some of the difficulties we encountered (outside of Covid factors) included scheduling tail collection with producers. Some of our producers were hesitant to have us on site when tails were docked. Instead of tail collection we would collect ear notches, which required processing the sheep an extra time. This added labor and time. Further, it took longer to collect the ear notches than we anticipated. Timing and method of tissue sampling need to be worked into opportunities when sheep are already being processed. This applies to EID placement as well.

This project was a first-step in a series of research projects designed to foster interest and use of EID's in commercial sheep flocks and consider their use in conjunction with genetic testing. There is still work to be done to find practical ways for commercial producers to utilize EID's to support individual animal management. However, tracking individual animal performance has been shown to be effective at moving the entire herd (or flock) towards identified breeding goals in other livestock species (dairy, beef, pork). We know it works, the challenge is finding a way to make it feasible and economical for sheep producers.