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Research Interests
Reproductive Physiology
Research Summary
There is evidence that dairy profitability increases as
pregnancy rate (PR) increases; therefore, it is financially
important to address reproductive efficiency in dairy herds.
Consequently, dairy research (and Extension) efforts focus on
increasing 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 pregnancy rate,
as (HDR * CR) = PR.
Specifically, my research interests focus upon increasing the
efficiency of AI in dairy cattle. Recently, together with Dr. Amin
Ahmadzadeh (Associate Professor, University of Idaho), I have
investigated 1) the effect of elapsed time between initial thawing
of multiple .5-mL semen straws and AI on conception rates in dairy
cattle, and 2) conception rates following detection of estrus and
timed AI in dairy cows synchronized using GnRH and PGF2?.
Currently, Dr. Ricardo Chebel, (Assistant Professor, University of
Idaho), and I are investigating the effect of synchronization
protocols on 1) follicular development, and 2) reproductive and
economic performance in dairy heifers.
Research Publications
Dalton, J.C., R. Manzo, A. Ahmadzadeh, B. Shafii, W. J. Price, and J. M. DeJarnette. 2005. Short Communication: Conception rates following detection of estrus and timed AI in dairy cows synchronized using GnRH and PGF2?. J. Dairy Sci. 88:4313-4316.
Dalton, J.C., A. Ahmadzadeh, B. Shafii, W.J.
Price, and J.M. DeJarnette. 2004. Effect of thawing multiple 0.5-ml
semen straws and sequential insemination number on conception rates
in dairy cattle. J. Dairy Sci. 87:972-975.
Dalton JC, Nadir S, Bame JH, Noftsinger M, Nebel RL, Saacke RG. (2001) Effect of time of insemination on number of accessory sperm, fertilization rate, and embryo quality in nonlactating dairy cattle. J Dairy Sci. 84(11):2413-8.
Dalton JC, Nadir S, Bame JH, Noftsinger M, Saacke RG. (2000) The effect of time of artificial insemination on fertilization status and embryo quality in superovulated cows. J. Animal Sci. 78:2081-2085.
Saacke RG, Dalton JC, Nadir S, Nebel RL, Bame JH. (2000) Relationship of seminal traits and insemination time to fertilization rate and embryo quality. Anim Reprod Sci. 60-61:663-77. Review.
Dalton JC, Nadir S, Bame JH, Saacke RG. (1999) Effect of a deep uterine insemination on spermatozoal accessibility to the ovum in cattle: a competitive insemination study. Theriogenology. 51(5):883-90.
Bame JH, Dalton JC, Degelos SD, Good TE, Ireland JL, Jimenez-Krassel F, Sweeney T, Saacke RG, Ireland JJ. (1999) Effect of long-term immunization against inhibin on sperm output in bulls. Biol Reprod. 60(6):1360-6.