Improving Reproductive Performance of Sheep


Project Title: Improving Reproductive Performance of Sheep

PI: Dr. Dennis Hallford

Funding Source: Agricultural Experiment Station

Objectives of the Project:

Current projects include examining the postpartum/seasonal anestrous period in Rambouillet ewes. If sheep are to produce 2 lamb crops in a single year, they must become pregnant within 30 days after their previous lambing while they are still nursing their current offspring. This is a very difficult research proposition since, in the spring in the US, ewes are often impacted by seasonal and lactational restraints. Other projects are examining the involvement of glucocorticoids in early embryonic survival in sheep. In most females, an estimated 25% of fertilized embryos are lost during the first 25 days after conception. This effect results in large economic losses to producers.

Duration: Through 2015

Selected Publications:

Young, A. M., and D. M. Hallford. 2013. Validation of a fecal glucocorticoid metabolite assay to assess stress in the budgerigar (Melopsittacus undulatus). Zoo Biol. 32: 112-116.

Camacho, L. E., J. M. Benavidez, and D. M. Hallford. 2012. Serum hormone profiles, pregnancy rates, and offspring performance of Rambouillet ewes treated with recombinant bovine somatotropin before breeding. J. Anim. Sci. 90: 2826-2835.

Castanon, B. I., A. D. Stapp, C. A. Gifford, L. J. Spicer, D. M. Hallford, and J. A. Hernandez- Gifford. 2012. Follicle-stimulating hormone regulation of estradiol production: Possible involvement of WNT2 and B-catenin in bovine granulosa cells. J. Anim. Sci. 90: 3789-3797.

Rowe, J. D., L. A. Tell, J. L. Carlson, R. W. Griffith, K. Lee, H. Kieu, S. Wetzlich, and D. M. Hallford. 2010. Progesterone milk residues in goats treated with CIDR-G inserts. J. Vet. Pharmacol. Therap. 33: 605-609.

Yates, D. T., L. J. Yates, R. A. Halalsheh, R. L. Wesley, D. M. Hallford, and T. T. Ross. 2010. Comparison of serum and salivary cortisol in restrained ewe lambs after adrenocorticotropic hormone) ACTH administration. J. Vet. Med. Anim. Health 2: 59-61.