Department of Animal Science
Date of this Version
December 2007
Abstract
Historically, considerable efforts have been made to understand how nutrition impacts health and productivity during the postnatal period. While maternal nutrition during pregnancy plays an essential role in proper fetal and placental development, less is known about how maternal nutrition impacts the health and productivity of the offspring. Indeed, the prenatal growth trajectory is sensitive to the direct and indirect effects of maternal dietary intake from the earliest stages of embryonic life when the nutrient requirements for conceptus growth are negligible (Robinson et al., 1977). Not only is neonatal health compromised, but the subsequent health may be “programmed” as offspring from undernourished dams have been shown to exhibit poor growth and productivity and also to develop significant diseases later in life (Barker et al., 1993; Godfrey and Barker, 2000).
Fetal, or developmental programming, defined as the concept that a maternal stimulus or insult at a critical period in fetal development has long term impacts on the offspring, was originally coined by Dr. David Barker, at Southampton University in England (Barker et al., 1993; Godfrey and Barker, 2000). Barker and his colleagues studied birth records in the United Kingdom and Europe, and related different maternal stresses to infant weight and physical characteristics at birth and to subsequent health status in later life. Of interest was that they determined that maternal undernutrition in the first half of gestation, followed by adequate nutrition from mid-gestation to term, resulted in infants of normal birth weight, which were proportionally longer and thinner than normal. This early fetal undernutrition resulted in an increased incidence of health problems experienced by these individuals as adults, including obesity, diabetes, and cardiovascular disease. In livestock production settings, undernutrition can often occur during gestation, particularly during the first two trimesters. This results from either low feed reserves and(or) management practices that result in cows losing weight during late fall and early winter (Sletmoen-Olsen et al., 2000a,b). However, current data indicate that health and growth of offspring born from undernourished mothers are diminished (Godfrey and Barker, 2000; Vonnahme et al., 2003). This theory of developmental programming has been experimentally challenged and verified using several animal models. While variations in the duration and severity of maternal undernutrition do not always result in a reduced birth weight, physiologic alterations such as glucose intolerance, skewed growth patterns and even alterations in carcass characteristics have been reported. Therefore, birth weight in and of itself may not be the best predictor for calf survival and productivity.
The objective of this paper is to review the literature on bovine fetal and placental development and how maternal nutrition impacts fetal, neonatal and postnatal health and performance of the offspring. While this work will concentrate on beef cattle, examples from other species will be added when appropriate.
Comments
Published for the Proceedings, The Range Beef Cow Symposium XX December 11, 12 and 13, 2007 - Fort Collins, Colorado.