Animal Reproductive Biology Group

Billy Day

Fred F. McKenzie Distinguished Professor
Animal Reproduction

Phone: 573-882-7555
Fax: 573-882-6827
E-mail: DayB@missouri.edu
Address: 159 Animal Science Research Center

Education

B.S., West Virginia University
M.S., West Virginia University
Ph.D., Iowa State University

Research Focus

In vitro production of embryos
Estrous synchronization

Research Description

Day's primary research goal is the in vitro production of swine embryos. His research has focused on the development of culture media required for various phases of oocyte maturation, fertilization and early development.

Additionally, Day is developing an improved in vitro fertilization system that will reduce the incidence of polyspermy.

Day is also comparing fertilization parameters in oocytes that are produced by in vitro technology with those that are ovulated and recovered from the reproductive tract as well as mature oocytes still present in ovarian follicles.

More recently Day has used this technology in the development of other biotechnology such as in vitro fertilization to produce gender-selected offspring.

Day also maintains an applied research program involving the whole animal. Recent studies have focused on the synchronization of estrus and ovulation in gilts and sows. A new approach to control of ovarian function is being taken that involves the intravaginal administration of progesterone. Following removal of progesterone impregnated insert, estrus and ovulation have been found to be effectively controlled to a three-to seven-day period. The ability to effectively control the reproductive cycle in animals enhances the application of many other reproductive practices.

Recent Publications

Mao J, Wu GM, Prather RS, Smith MF, Cantley T, Rieke A, Didion BA, Day BN.
Effect of methyl-beta-cyclodextrin treatment of pig spermatozoa on in vitro fertilization and embryo development in the absence or presence of caffeine. Theriogenology. 2005 May 23; PMID: 15919108
Sutovsky P, Manandhar G, Laurincik J, Letko J, Caamano JN, Day BN, Lai L, Prather RS, Sharpe-Timms KL, Zimmer R, Sutovsky M.
Expression and proteasomal degradation of the major vault protein (MVP) in mammalian oocytes and zygotes. Reproduction. 2005 Mar;129(3):269-82. PMID: 15749954
Wu GM, Lai L, Mao J, McCauley TC, Caamano JN, Cantley T, Rieke A, Murphy CN, Prather RS, Didion BA, Day BN.
Birth of piglets by in vitro fertilization of zona-free porcine oocytes. Theriogenology. 2004 Nov;62(8):1544-56. PMID: 15451262
Mao J, Smith MF, Rucker EB, Wu GM, McCauley TC, Cantley TC, Prather RS, Didion BA, Day BN.
Effect of epidermal growth factor and insulin-like growth factor I on porcine preantral follicular growth, antrum formation, and stimulation of granulosal cell proliferation and suppression of apoptosis in vitro. J Anim Sci. 2004 Jul;82(7):1967-75. PMID: 15309943
Sutovsky P, Manandhar G, McCauley TC, Caamano JN, Sutovsky M, Thompson WE, Day BN.
Proteasomal interference prevents zona pellucida penetration and fertilization in mammals. Biol Reprod. 2004 Nov;71(5):1625-37. Epub 2004 Jul 14. PMID: 15253927
Gil MA, Ruiz M, Vazquez JM, Roca J, Day BN, Martinez EA.
Effect of short periods of sperm-oocyte coincubation during in vitro fertilization on embryo development in pigs. Theriogenology. 2004 Aug;62(3-4):544-52. PMID: 15226010
Sutovsky P, Van Leyen K, McCauley T, Day BN, Sutovsky M.
Degradation of paternal mitochondria after fertilization: implications for heteroplasmy, assisted reproductive technologies and mtDNA inheritance. Reprod Biomed Online. 2004 Jan;8(1):24-33. Review. PMID: 14759284
Martinez EA, Caamano JN, Gil MA, Rieke A, McCauley TC, Cantley TC, Vazquez JM, Roca J, Vazquez JL, Didion BA, Murphy CN, Prather RS, Day BN.
Successful nonsurgical deep uterine embryo transfer in pigs. Theriogenology. 2004 Jan 1;61(1):137-46. PMID: 14643868
McCauley TC, Mazza MR, Didion BA, Mao J, Wu G, Coppola G, Coppola GF, Di Berardino D, Day BN.
Chromosomal abnormalities in Day-6, in vitro-produced pig embryos. Theriogenology. 2003 Nov;60(8):1569-80. PMID: 14519476
Gil MA, Abeydeera LR, Day BN, Vazquez JM, Roca J, Martinez EA.
Effect of the volume of medium and number of oocytes during in vitro fertilization on embryo development in pigs. Theriogenology. 2003 Sep 1;60(4):767-76. PMID: 12832024
A complete list of publications for BN Day in PubMed