2007 Annual Report 1a.Objectives (from AD-416) Improve economically important production traits of sheep without compromising reproductive efficiency. 1b.Approach (from AD-416) To improve economically important production traits of sheep without compromising reproductive efficiency, we will develop and validate nonsurgical, transcervical artificial insemination procedures for sheep; determine whether manipulating uterine immune functions will reduce the incidence of uterine bacterial contamination and prevent subsequent reductions in pregnancy and lambing rates; evaluate different biological types of sheep for reproductive efficiency, rate and efficiency of growth, carcass composition, meat quality, and mature size; determine whether strategic nutrient intervention will mitigate the negative effects of production stressors on growth, health, and reproductive processes and on skeletal muscle nutrient composition; and develop and validate methods for characterizing sexual performance of rams and reproductive efficiency of their daughters. 4.Accomplishments Evaluation of western white-faced breeds of sheep: Breed comparisons, when made in experimental settings, allow producers to identify the breed best suited for their production objectives. Scientists at the U.S. Sheep Experiment Station, Dubois, Idaho, characterized purebred Columbia, Polypay, Rambouillet, and Targhee ewes for maternal performance and production trends in an extensive western production system. Production data from 28 years were used for this study, and all breeds were managed as contemporaries. Polypay ewes had the lightest body and fleece weights, produced the largest litters at birth and weaning, and produced the smallest lambs at birth and weaning; Columbia ewes had the heaviest body and fleece weights, produced the smallest litters at birth and weaning, and produced the heaviest lambs at birth and weaning. Litter weight at weaning was heaviest for Columbia ewes, intermediate for Polypay ewes, and lightest for Rambouillet and Targhee ewes. In general, in the time period studied, ewes of these breeds increased in body weight, produced larger and heavier litters, and produced lighter fleece weights. This research contributes to NP 101, Food Animal Production, Component 1: Understanding, Improving, and Effectively Using Animal Genetic and Genomic Resources: Problem Statement 1C, Preserve and Curate Livestock and Poultry Genetic Resources; and Problem Statement 1D, Develop and Implement Genome-Enabled Genetic Improvement Programs. Analysis of historical lamb survivability: Poor lamb survivability reduces ewe productivity and flock profitability, and survivability may be enhanced through genetic and management approaches. Faculty and graduate students at Virginia Polytechnic Institute and State University, and scientists at the U.S. Sheep Experiment Station, Dubois, Idaho, have collaborated to evaluate genetic and environmental factors that affect lamb survival from birth to weaning. Data from more than 20,000 USSES Polypay lambs were used for this survival analysis. The greatest risk of death was associated with lambs born to young ewes, lambs born to litters larger than two, or lambs with low birth weights. Heritability estimates for lamb survivability were low (no more than 0.01); thus, direct selection for this trait is likely to have only limited benefit. However, because larger lambs at birth are more likely to survive, and because birth weight is heritable, selecting for larger lambs at birth may improve survivability. This research contributes to NP 101, Food Animal Production, Component 1: Understanding, Improving, and Effectively Using Animal Genetic and Genomic Resources: Problem Statement 1C, Preserve and Curate Livestock and Poultry Genetic Resources; and Problem Statement 1D, Develop and Implement Genome-Enabled Genetic Improvement Programs. Ultrasound for estimating carcass measures: Measures of carcass fatness and muscling have traditionally been made only after the animal was harvested. Accurate estimates of these measures in the live animal will enable the producer to make better breeding and marketing decisions. Scientists at the U.S. Sheep Experiment Station, Dubois, Idaho, used noninvasive ultrasound to estimate carcass measures of fatness and muscling in live sheep. Multiple ultrasound scans were performed to evaluate the repeatability of these estimates, and direct carcass measures of fatness and muscling were used to evaluate the accuracy of the estimates. The data suggest that live-animal ultrasound estimates of carcass measures are reasonably repeatable and accurate, and thus can be used to reliably rank animals for these traits. In addition, these ultrasound estimates improve our ability to predict weights of high-value subprimal cuts in the live animal. This research contributes to NP 101, Food Animal Production, Component 1: Understanding, Improving, and Effectively Using Animal Genetic and Genomic Resources: Problem Statement 1C, Preserve and Curate Livestock and Poultry Genetic Resources; and Problem Statement 1D, Develop and Implement Genome-Enabled Genetic Improvement Programs. Terminal sire breed evaluation: At the U.S. Sheep Experiment Station, Dubois, Idaho, a terminal sire breed evaluation is being conducted to identify breeds/composites that excel at survival, growth, and carcass composition for incorporation into a newly developed white-face terminal sire composite line. The first production cycle of lambs for the terminal sire breed evaluation were born in 2006. These lambs were characterized for survival, growth, carcass composition and meat quality in collaboration with scientists at Virginia Polytechnic Institute and State University and Ohio State University. Industry terminal sire rams were purchased and mated to produce lambs to evaluate in 2007. Lambs born spring of 2007 are currently being monitored for survival and growth from birth to weaning. This research contributes to NP 101, Food Animal Production, Component 1: Understanding, Improving, and Effectively Using Animal Genetic and Genomic Resources: Problem Statement 1B, Identify Functional Genes and Their Interactions; Problem Statement 1C, Preserve and Curate Livestock and Poultry Genetic Resources; and Problem Statement 1D, Develop and Implement Genome-Enabled Genetic Improvement Programs. Composite sire development: In anticipation of developing a white-faced composite terminal sire line of sheep that excels at survival, growth, and carcass composition, matings of Suffolk x Columbia, Texel x Columbia and Texel X Suffolk were conducted at the U.S. Sheep Experiment Station, Dubois, Idaho, in 2006 and 2007 to estimate breed complimentarity and heterotic effects. Lambs born in 2006 were evaluated for survival and growth, and ultrasound was used to estimate carcass composition. Lambs produced in 2007 will be weaned in August and evaluated in a similar fashion. This research contributes to NP 101, Food Animal Production, Component 1: Understanding, Improving, and Effectively Using Animal Genetic and Genomic Resources: Problem Statement 1C, Preserve and Curate Livestock and Poultry Genetic Resources; and Problem Statement 1D, Develop and Implement Genome-Enabled Genetic Improvement Programs. Enhancing long-term selenium status: Providing supplemental selenium to ewes grazing selenium-deficient rangelands is difficult and sometimes impossible. Scientists at the U.S. Sheep Experiment Station, Dubois, Idaho, developed strategic supplementation protocols with a naturally high source of organic selenium that enhanced long-term selenium status in lambs (up to 160 days of age). This research contributes to NP 101, Food Animal Production, Component 2: Enhancing Animal Adaptation, Well-Being and Efficiency in Diverse Production Systems: Problem Statement 2B, Reducing Reproductive Losses; and Problem Statement 2C, Improving Efficiency of Nutrient Utilization and Conversion to Animal Products. Identifying unique sources of selenium: Unique feed sources, with naturally high organic selenium content, are needed to rapidly enhance muscle selenium for muscle food enrichment and to counter selenium deficiency in livestock. Scientists at the U.S. Sheep Experiment Station, Dubois, Idaho, identified unique flour-milling coproducts that have are enriched with organic selenium. These coproducts will be used in short-duration feeding programs to strategically enhance selenium content of muscle tissue. This research contributes to NP 101, Food Animal Production, Component 2: Enhancing Animal Adaptation, Well-Being and Efficiency in Diverse Production Systems: Problem Statement 2B, Reducing Reproductive Losses; and Problem Statement 2C, Improving Efficiency of Nutrient Utilization and Conversion to Animal Products. Winter weight loss in early pregnant ewes: Depending on severity of climatic conditions, early-pregnant ewes may lose body weight while grazing winter range; however, the impact of this body weight loss on subsequent productivity is not known. Scientists at the U.S. Sheep Experiment Station, Dubois, Idaho, characterized lambing performance of four major western white-faced breeds in which significant body weight was lost during early pregnancy while ewes were grazing winter range. This information allows producers to develop, objectively, nutrient and health solutions for managing ewes on winter range. This research contributes to NP 101, Food Animal Production, Component 2: Enhancing Animal Adaptation, Well-Being and Efficiency in Diverse Production Systems: Problem Statement 2B, Reducing Reproductive Losses; and and Problem Statement 2C, Improving Efficiency of Nutrient Utilization and Conversion to Animal Products. High and low sexual-performance rams in single-sire breeding environments with high and low breeding requirements: Scientists at the U.S. Sheep Experiment Station, Dubois, Idaho, determined that rams with serving capacity test scores above the average scores (high rams) bred more ewes and sired more lambs than low rams when they were challenged to individually breed 9-12 ewes daily. In contrast, when the same rams only needed to service 1 or 2 ewes daily, the low rams bred an equivalent number of ewes and sired an equivalent number of lambs as the high rams. Previous research at the U.S. Sheep Experiment Station indicated that high sexual-performance rams will mate with approximately twice as many ewes and sire approximately twice as many lambs as low sexual-performance rams when they were in direct competition for 10 to 12 estrual ewes daily. Thus, low sexual-performance rams reduce the overall flock reproductive efficiency when a high number of ewes need to be bred daily in a competitive breeding environment. The more recent results indicate that low-sexual performance rams also reduce the overall reproductive efficiency when they were challenged to breed a high number of ewes daily, but not when they only need to breed a small number of ewes daily in a single–sire breeding environment. Combined results indicate that high sexual-performance rams will reduce the cost of producing lambs where a large number of ewes need to be bred daily in single- and multiple-sire breeding environments, whereas low sexual-performance rams provide adequate performance when a minimal number of ewes need to be bred daily. This research contributes to NP 101, Food Animal Production, Component 2: Enhancing Animal Adaptation, Well-Being and Efficiency in Diverse Production Systems: Problem Statement 2B, Reducing Reproductive Losses. High and low sexual-performance rams in a highly competitive breeding environment: Scientists at the U.S. Sheep Experiment Station, Dubois, Idaho, determined that rams with serving capacity test scores above the average scores (high rams) bred more ewes and sired more lambs than low rams when they were in direct competition for only 1 or 2 estrual ewes daily. This was true for rams isolated from estrual ewes just before they reached puberty until time of testing as adults and when single 3-ram cohort serving capacity test was given before 9 individual tests. Thus, lack of exposure to estrual ewes before the single cohort test reduced the breeding efficiency of the low sexual-performance rams compared to the high sexual-performance rams with the same treatment combination. Previous research results at the U.S. Sheep Experiment Station, Dubois, Idaho, indicated that exposure of 6- to 7-mo-old rams to estrual ewes for 17 days increased sexual performance in serving capacity tests. The results from the more recent research reemphasize the importance of exposure of ram lambs to estrual ewes for improving ram sexual performance in serving capacity tests and indicate that this also improves performance in the breeding environment, which is important for improving overall reproductive efficiency of the flock. This research contributes to NP 101, Food Animal Production, Component 2: Enhancing Animal Adaptation, Well-Being and Efficiency in Diverse Production Systems: Problem Statement 2B, Reducing Reproductive Losses. 5.Significant Activities that Support Special Target Populations None. 6.Technology Transfer Number of web sites managed 1 Number of non-peer reviewed presentations and proceedings 27 Number of newspaper articles and other presentations for non-science audiences 8 Review Publications Stellflug, J.N., Lewis, G.S. 2007. Effect of early and late exposure to estrual ewes on ram sexual performance classifications. Animal Reproduction Sciences. 97:295-302. Kunkle, R.A., Miller, J.M., Alt, D.P., Cutlip, R.C., Cockett, N.E., Wang, S., Richt, J.A., Thomsen, B.V., Hall, S.M. 2006. Determination of sheep prion gene polymorphisms from paraffin-embedded tissue. Journal of Veterinary Diagnostic Investigation. 18(5):443-447. Mousel, M.R., Nonneman, D.J., Rohrer, G.A. 2006. Rearranged gene order between pig and human in a quantitative trait loci region on SSC3. Animal Genetics. 37:403-406 Taus, N.S., Herndon, D.R., Traul, D., Stewart, J.P., Ackermann, M., Li, H., Knowles Jr, D.P., Lewis, G.S., Brayton, K.A. 2007. Comparison of ovine herpesvirus 2 genomes isolated from domestic sheep (Ovis aries) and a clinically affected cow (Bos bovis). Journal of General Virology. 88(1):40-45. Barraza, M.L., Strickland, J.R., Zepada, H., Taylor, J.B., Krehbiel, C.R., Bell, G.S. 2006. Gross and histopathological observations of long term catheterized vessels in experimental sheep. Journal of Veterinary Medicine. 53:230-238 (2006). Leytem, A.B., Taylor, J.B., Raboy, V., Plumstead, P.W. 2007. Dietary low-phytate mutant-M 955 barley grain alters phytate degradation and mineral digestion in sheep fed high-grain diets. Animal Feed Science and Technology. 138:13-28. Stellflug, J.N., Cockett, N.E., Lewis, G.S. 2007.The influence of breeding intensity on above- and below-average sexual performance rams in single- and multiple-sire breeding environments. Animal Reproduction Sciences. doi:10.1016/j.anireprosci.2007.02.017 Reed, J.J., Ward, M.A., Vonnahme, K.A., Neville, T.L., Julius, S.L., Borowicz, P.P., Taylor, J.B., Redmer, D.A., Reynold, L.P., Caton, J.S. 2007. Effects of selenium supply and dietary restriction on maternal and fetal body weight, visceral organ mass, cellularity estimates, and jejeunal vascularity in pregnant ewe lambs.. Journal of Animal Science. doi:10.2527/jas.2006-785