Reproduction

The goal of the Reproduction Research Unit (RRU) is to increase reproductive efficiency in cattle and swine by decreasing the number of breeding-age males and females required to produce a given number of offspring. Maintaining animals for breeding is a significant cost in the production of domestic livestock, thus improvements in reproductive efficiency reduce costs, increase profitability and reduce meat prices paid by the U.S. consumer. Reproduction research at the U.S. Meat Animal Research Center includes efforts to improve both male and female components of reproduction, including sperm production, conception rate, embryo-fetal development, the birth process and preweaning survival. The RRU combines traditional endocrine and physiology studies with modern genomic, proteomic and molecular biology techniques to provide an integrated approach to the complex problem of reproductive efficiency in livestock. Physiology research successes include defining the central role of Sertoli cells in the control of testis size and sperm production in boars; characterizing the relationship between fetal red blood cell production, uterine capacity and litter size and increasing the incidence of twinning in beef cattle. Genomics research successes include generating microsatellite and SNP based genetic maps in swine; providing swine EST sequence to help define gene expression in swine tissues; and discovering quantitative trait loci for uterine capacity, testis size (swine), age at puberty, and ovulation rate (swine and cattle; see research summaries for details on these and other projects).  Recent research efforts include defining the role of the farrowing process on stillbirth rate in sows, exploring factors influencing preweaning survival of piglets, defining nutrition/reproduction interactions and physiological indicators of beef cattle fertility, discovering placental factors influencing placental efficiency and litter size in swine, predicting sperm production in boars using ultrasound, and genetic mapping for quantitative trait loci for sow longevity and meat quality traits.

Staff Scientists:

J.L. Vallet, Ph.D., Research Physiologist, Research Leader

R.A. Cushman, Ph.D., Research Physiologist

S.E. Echternkamp, Ph.D., Research Physiologist

J.J. Ford, Ph.D., Research Physiologist

B.A. Freking, PhD, Research Geneticist

J. Miles, Ph.D., Research Physiologist

D.J. Nonneman,PhD, Molecular Biologist

G.A. Rohrer, PhD, Research Geneticist

T.H Wise , Ph.D., Research Physiologist