|Department:||Animal & Veterinary Science, UI|
|Credentials:||1999~PhD., Virginia Polytechnic Institute and State University-Animal Science|
|Office:||Caldwell R&E Center|
Caldwell Research and Extension Center
Research InterestsReproductive Physiology
Dairy research (and Extension) efforts focus on increasing pregnancy rate (PR) through the development of, and (or) dissemination of information regarding scientifically sound, labor-efficient management practices aimed at optimizing conception rate (CR) and heat detection rate (HDR), which are components of PR. Specifically, my research is focused upon increasing the efficiency of AI in dairy cattle. I am currently investigating 1) heat detection accuracy of professional AI technicians and herdsman-inseminators working with cows and heifers, and 2) temperatures in the neck of semen storage tanks with varying levels of liquid nitrogen. I am also a member of a multi-institution (Washington State University-University of Idaho-University of Florida) team attempting to 1) identify genomic loci associated with fertility in dairy heifers and cows, and 2) transfer technology regarding novel approaches for improving fertility using genetic selection tools.
Johnson, C.R., M.W. Ayers, A. Ahmadzadeh, B. Shafii, S. Etter, R.C. Chebel, and J.C. Dalton, Short Communication: Characterization of early postpartum estrous behavior and ovulation in lactating dairy cows using radiotelemetry. J Dairy Sci, 2012. 95: p. 5085-88.
Dalton, J.C., L. Deragon, J.L.M. Vasconcelos, C.N. Lopes, R.F.G. Peres, and A. Ahmadzadeh, Fertility-associated antigen on Nelore bull sperm and reproductive outcomes following first-service fixed-time AI of Nelore cows and heifers. Theriogenology, 2012. 77: p. 389–94.
Dalton, J.C. Strategies for success in heat detection and artificial insemination. In: WCDS Advances in Dairy Technology, 2011, 23: p. 215-29.
Dalton, J.C., and A. Ahmadzadeh. 2010. AI technician management. In: Proc. Dairy Cattle Reproduction Council Annual Meeting, Minneapolis, MN, pp. 35-43.
Dalton, J.C., and A. Ahmadzadeh, Heat detection accuracy and AI technician evaluation. In: Proc. 9th Western Dairy Management Conference, Reno, NV, 2009, pp. 117-29.
Ahmadzadeh, A., F. Frago, B. Shafii, J.C. Dalton, W.J. Price, and M.A. McGuire, Effect of clinical mastitis and other diseases on reproductive performance of Holstein cows. Anim Reprod Sci, 2009. 112(3-4): p. 273-82.
Stevenson, J.L., J.A. Rodrigues, F.A. Braga, S. Bitente, J.C. Dalton, J.E.P. Santos, and R.C. Chebel, Effect of reproductive protocols and reproductive tract score on reproductive performance of dairy heifers and economic outcome of breeding programs. J Dairy Sci, 2009. 91: p. 3424–38.
Johnson, C.R., A. Ahmadzadeh, K.S. Jensen, S. Etter, R. Wilson, N. Dalton, and J.C. Dalton, Effect of duration of intravaginal progesterone insert (CIDR) treatment on pregnancy rate per AI in dairy heifers using a timed-AI protocol. In: Proceedings of the Western Section of the American Society of Animal Science, Laramie, WY, J Anim Sci, 2008, 59: p. 33-36.
Stevenson, J.L., J.C. Dalton, J.E. Santos, R. Sartori, A. Ahmadzadeh, and R.C. Chebel, Effect of synchronization protocols on follicular development and estradiol and progesterone concentrations of dairy heifers. J Dairy Sci, 2008. 91(8): p. 3045-56.
Chebel, R.C., F.A. Braga, and J.C. Dalton, Factors affecting reproductive performance of Holstein heifers. Anim Reprod Sci, 2007. 101(3-4): p. 208-24.
Howard, J.M., R. Manzo, J.C. Dalton, F. Frago, and A. Ahmadzadeh, Conception rates and serum progesterone concentration in dairy cattle administered gonadotropin releasing hormone 5 days after artificial insemination. Anim Reprod Sci, 2006. 95(3-4): p. 224-33.
Sellars, C.B., J.C. Dalton, R. Manzo, J. Day, and A. Ahmadzadeh, Time and incidence of ovulation and conception rates after incorporating estradiol cypionate into a timed artificial insemination protocol. J Dairy Sci, 2006. 89(2): p. 620-6.
Dalton, J.C., R. Manzo, A. Ahmadzadeh, B. Shafii, W.J. Price, and J.M. DeJarnette, Short communication: Conception rates following detection of estrus and timed AI in dairy cows synchronized using GnRH and PGF2alpha. J Dairy Sci, 2005. 88(12): p. 4313-6.
Dalton, J.C., A. Ahmadzadeh, B. Shafii, W.J. Price, and J.M. DeJarnette, Effect of simultaneous thawing of multiple 0.5-mL straws of semen and sequence of insemination on conception rate in dairy cattle. J Dairy Sci, 2004. 87(4): p. 972-5.