PSIII-2 Late-Breaking: Collaboration to Demonstrate the Potential Use and Value of Electronic Identification and DNA Testing in the Sheep Industry
Authors: Brown Austin R , Finzel Julie , Busch Rosie , Doran Morgan , Harper John , Macon Dan , Ozeran Rebecca , Van Eenennaam Alison L 
Published: October 2022

The dearth of individual performance records derived from an extensively driven production system coupled with the impracticality of utilizing reproductive technologies makes commercial genetic improvement challenging in small ruminants. We collaborated with five producers throughout California to assess how electronic ID (EID) and genetic testing could inform ram selection. Our objective was to determine how the data collected from these technologies could augment genetic improvement on commercial ranches. Familiarity and use of EID tags on ranches at the start of the research varied; thus, allowing for a qualitative reflection on the participant's perceptions of the usefulness of this technology. Ear notch samples were collected and EID ear tags were placed in 2,963 sheep; 305 rams, and 2,658 of their potential progeny. We partnered with Superior Farms (Dixon, CA) to genotype the animals using their Flock54 single nucleotide polymorphism panel which contains 956 markers for assigning parentage, and includes markers linked to quantitative trait loci and/or known single gene causative markers to aid in disease management. SNP data was used to assign paternity and determine sire prolificacy. A total of 524 carcass samples from ram lambs from two of the ranches were processed at Superior Farms' plant and assessed with a USDA-approved camera grading system (e+v, Oranienburg, Germany) that matches EID’s to carcass data. Progeny contemporary group deviations were calculated for hot carcass weight, yield grade, and ovine cutability calculation (OCC) which predicts the yield of edible product on the carcass. The average number of lambs per sire born at each ranch and the mean OCC of the progeny for each sire were compared using a one-way analysis of variance. There was a significant ranch effect on the average progeny number per ram (P &lt; 0.05). The ranch with the lowest ram to ewe ratio (1:10) also has the lowest average progeny per ram and the ranch with the greatest ratio (1:50) has the most progeny per ram. There was a large range in the number of lambs per sire (0-135) within each ranch. There was a significant sire effect (P &lt; 0.05) on average OCC within each progeny contemporary group, meaning some sires were producing offspring with significantly more marketable meat. The use of EIDs in combination with genetic testing, allowed for the collection of individual progeny performance data. This provided insight into sire performance and identified prolific sires that were also producing lambs with superior carcass merit. Producers could use this information to select for high-performing rams; however, there is an unavoidable delay between ram turnout and the collection of progeny carcass data. This limits the practical utility of these data and reinforces the value of having estimated breeding values available at ram purchase to select genetically superior rams.