Animal Reproductive Biology Group

Robert S. Youngquist

Professor
Veterinary Medicine and Surgery

Phone: 573-882-7821
E-mail: YoungquistR@missouri.edu
Address: E379 Clydesdale Hall

Education

D.V.M., Iowa State University
Residency, University of Missouri
Diplomat, American College of Theriogenologists

Research Focus

Clinical reproduction
Bovine reproductive efficiency

Research Description

Youngquist's research interests focus on clinical reproduction in domestic animals, primarily reproductive efficiency of cattle.

Youngquist has developed a model for cystic ovarian disease in cattle that has served as the basis for several studies that have contributed to the elucidation of the mechanism by which that condition develops.

Recently, his efforts have been directed toward normal ovarian function, specifically the mechanism(s) by which ovarian follicles are selected for development and ovulation.

Youngquist is also studying the control of venereal trichomoniasis in beef cattle, the quality of frozen/thawed canine semen, and fescue-induced agalactia in mares.

Recent Publications

Hampton JH, Bader JF, Lamberson WR, Smith MF, Youngquist RS, Garverick HA.
Gonadotropin requirements for dominant follicle selection in GnRH agonist-treated cows. Reproduction. 2004 Jun;127(6):695-703. PMID: 15175506
Kieborz-Loos KR, Garverick HA, Keisler DH, Hamilton SA, Salfen BE, Youngquist RS, Smith MF.
Oxytocin-induced secretion of prostaglandin F2alpha in postpartum beef cows: effects of progesterone and estradiol-17beta treatment. J Anim Sci. 2003 Jul;81(7):1830-6. PMID: 12854821
Belyea RL, Curry RD, Mesyats GA, Filatov AL, Clevenger TE, Miller MA, Youngquist RS.
Short communication: effects of X-rays on growth and germinal tissue of calves. J Dairy Sci. 2001 Dec;84(12):2777-81. PMID: 11814034
Manikkam M, Calder MD, Salfen BE, Youngquist RS, Keisler DH, Garverick HA.
Concentrations of steroids and expression of messenger RNA for steroidogenic enzymes and gonadotropin receptors in bovine ovarian follicles of first and second waves and changes in second wave follicles after pulsatile LH infusion. Anim Reprod Sci. 2001 Sep 15;67(3-4):189-203. Erratum in: Anim Reprod Sci 2001 Oct 31;68(1-2):133. PMID: 11530265
Manikkam M, Bao B, Rosenfeld CS, Yuan X, Salfen BE, Calder MD, Youngquist RS, Keisler DH, Lubahn DB, Garverick HA.
Expression of the bovine oestrogen receptor-beta (bERbeta) messenger ribonucleic acid (mRNA) during the first ovarian follicular wave and lack of change in the expression of bERbeta mRNA of second wave follicles after LH infusion into cows. Anim Reprod Sci. 2001 Sep 15;67(3-4):159-69. PMID: 11530262
Calder MD, Manikkam M, Salfen BE, Youngquist RS, Lubahn DB, Lamberson WR, Garverick HA.
Dominant bovine ovarian follicular cysts express increased levels of messenger RNAs for luteinizing hormone receptor and 3 beta-hydroxysteroid dehydrogenase delta(4),delta(5) isomerase compared to normal dominant follicles. Biol Reprod. 2001 Aug;65(2):471-6. PMID: 11466215
Bilby CR, Bader JF, Salfen BE, Youngquist RS, Murphy CN, Garverick HA, Crooker BA, Lucy MC.
Plasma GH, IGF-I, and conception rate in cattle treated with low doses of recombinant bovine GH. Theriogenology. 1999 May;51(7):1285-96. PMID: 10729092
Calder MD, Salfen BE, Bao B, Youngquist RS, Garverick HA.
Administration of progesterone to cows with ovarian follicular cysts results in a reduction in mean LH and LH pulse frequency and initiates ovulatory follicular growth. J Anim Sci. 1999 Nov;77(11):3037-42. PMID: 10568475
Evans TJ, Miller MA, Ganjam VK, Niswender KD, Ellersieck MR, Krause WJ, Youngquist RS.
Morphometric analysis of endometrial periglandular fibrosis in mares. Am J Vet Res. 1998 Oct;59(10):1209-14. PMID: 9781449
Bao B, Calder MD, Xie S, Smith MF, Salfen BE, Youngquist RS, Garverick HA.
Expression of steroidogenic acute regulatory protein messenger ribonucleic acid is limited to theca of healthy bovine follicles collected during recruitment, selection, and dominance of follicles of the first follicular wave. Biol Reprod. 1998 Oct;59(4):953-9. PMID: 9746748
A complete list of publications for RS Youngquist in PubMed