Steven Zinn

Department Head & Professor

Department of Animal Science

Dr. Steven Zinn’s research interests are tissue-specific expression of growth factors during development in livestock and physiological mechanisms involved in efficiency of animal production.  Currently, this work focuses on the effects of poor maternal during gestation on the offspring, also known as maternal programming.  This research primarily uses sheep as a model.

Variations in feed and forage quality and availability can result in periods of sub-optimal nutrition for livestock species. This is problematic as poor maternal nutrition during gestation has immediate and long-lasting consequences on production efficiency and health of offspring including reductions in birth weight, pre-weaning survival, postnatal growth rate, feed utilization, carcass quality and lifespan. Maternal programming is defined as alterations to the intrauterine environment that affect the growth and development of the fetus resulting in changes in offspring growth, metabolism and organogenesis. Organogenesis primarily occurs during gestation making it especially vulnerable to the effects poor maternal nutrition. As a result, multiple organ systems can potentially be affected; thus, predisposing offspring to metabolic and endocrine disorders.

We have shown that both restricted- or over-feeding during gestation can alter lamb growth rates, muscle and adipose composition, and organ size at 1 day of age and 3 months of age. That is, poor maternal nutrition can reduce growth rate and muscle size, increase adipose development, and cause changes in heart and other vital organs. Since these changes are apparent at birth, our current focus is to identify mechanisms at the molecular and cellular level during gestation, including alterations in genetic pathways, hormone secretion, muscle and mesenchymal stem cell function, and the inflammatory response with the overall goal to identify treatments to alleviate the negative impacts of poor maternal nutrition on the offspring.