Reproduction during lactation of dairy cattle: Integrating nutritional aspects of reproductive control in a systems research approach

Abstract

Reproduction in mammals is a highly complex system that is affected by many genetic and environmental components. There is no simple way to describe control of reproduction, such as “increased body fat improves fertility”; there are too many variables. A systems research approach involving cooperative and integrated study design, hypothesis setting, data sharing, and mathematical modeling can speed improvement in reproductive success Reproduction in dairy cattle is a multivariate process that is under control of heritable and constitutive genetic traits, nutrient profiles and intake, season, housing, and climate. To more rapidly improve practical reproduction such as pregnancy rate, a fully systems biology approach to research and application must be taken. We have improved management, housing, nutrition, and breeding, but we must now fully integrate our efforts to identify those primary genetic and nutritional controls. A bio-mathematical systems model that can contribute to this task is proposed.