Sheep Industry News August 2021

breeders and commercial producers that purchase NSIP breeding animals. Through this effort, GRF will first be established at the USSES, USMARC and Dale Bumpers Small Farms Research Center in Booneville, Ark., and then, collaborating universities with NSIP enrolled sheep flocks. Katahdin, Polypay and Suffolk have been selected as the first GRF breeds as they are common among ARS lo cations – Katahdins are reared at all three, and Polypay and Suffolk are reared at the USSES and USMARC. ARS scientists have started the GRF by first establishing within breed genetic linkages across our locations. The USSES acquired its Katahdin flock from USMARC in 2020 and both have imported Katahdin rams from DBSFRC. The USMARC Polypay flock was augmented in 2019 and 2020 with USSES Polypay ewes and rams. Finally, USSES Suffolk rams were bred to USMARC Suffolk ewes in 2020. In addition to linkages across ARS locations, it will be important to strengthen connectedness to industry NSIP flocks. Rams from pertinent breeds have been and will continue to be pur chased from NSIP flocks at each location and Polypay and Suffolk ewe lambs were purchased from NSIP sources in 2019 and 2020 to establish these breeds at USMARC. These efforts will continue with thoughtful rotation of industry purchased and ARS bred rams across GRF to replicate genetics across diverse production environ ments. The novel trait complexes the GRF will focus on are associated with ewe health and longevity, ewe and ram reproductive efficiency in optimal and suboptimal mating seasons, and lamb survival, feed efficiency and carcass characteristics. Many of these novel traits require specialized technologies to suitably quantify. While the GRF might be able to afford these technologies with grants and

USMARC Katahdin ewes have been milked to quantify intramam mary health and have also been scored for several udder conforma tion traits. Udder conformation can be rapidly and inexpensively measured by NSIP breeders and could be an indicator trait for intramammary health. Similarly, feed efficiency is economically important but requires specialized equipment, which is not feasible for most sheep operations. USMARC is expanding its capabilities to measure individual feed intake on GRF animals and will investigate relationships between it and traits already measured on the farm or ranch (e.g., weaning and post-weaning weight and ultrasound conformation). In addition to quantifying novel traits, the structure of the GRF will provide a means to direct precision animal management through estimating genetic-environment-management system interactions. Moreover, standard and novel traits will be linked to existing and expanding ARS sheep tissue repositories to strengthen molecular genetics studies and accelerate the development of genomic-enhanced EBVs. Finally, as land grant university flocks join this effort, other common NSIP breeds can be included. Genetic reference popula tions are not a new concept, they’ve been successfully implemented in other species and sheep producing countries across the world. This is a major undertaking, and its success will be dependent on collaboration among NSIP breeders, industry groups and university and ARS scientists. ARS looks forward to sharing the progress of this project in fu ture articles and at industry events. If you have NSIP rams that you feel should be represented in the GRF, please contact Tom Murphy at tom.murphy@usda.gov.

internal funding, most industry NSIP flocks cannot. Additionally, it is beneficial if indicator traits – which are genetically related to our novel traits of interest but do not require specialized technolo gies to record – can be identified and incorporated into NSIP. Subclinical mastitis is a good example of a novel trait ARS sci entists are quantifying in maternal breeds. We have found it is as sociated with large reductions in total weight of lamb weaned but quantifying it requires milking many ewes and conducting tests to determine bacterial presence and/or degree of udder inflamma tion. This is obviously not practi cal to do on farm/ranch because it is labor intensive and can be expensive. For the last two years,

Katahdin sheep at the U.S. Meat Animal Research Center in Clay Center, Neb., visit a SuperSmart Feeder, which allows researchers to quantify individual feed intake.

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