Implications of nutritional management for beef cow/calf systems

Authors: FUNSTON, R - University Of Nebraska; SUMMERS, A - University Of Nebraska; Roberts, Andrew

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/19/2011
Publication Date: 6/1/2012
Citation: Funston, R.N., Summers, A.F., Roberts, A.J. 2012. Implications of nutritional management for beef cow/calf systems. Journal of Animal Science 90:2301-2307.

Interpretive Summary: The beef cattle industry relies on utilization of high forage diets to maintain the cow herd, develop replacement females, and stocker operations. Depending on class and stage of production, a grazed forage diet may not always meet nutritional requirements resulting in low gain or weight loss if supplemental nutrients are not provided. Producers are then faced with the question of how much supplemental feed they should provide to offset any negative effects of nutritional deficiency. However, periods of limited or insufficient nutrient availability can actually result in compensatory gain once dietary conditions improve and may provide producers with opportunities to enhance efficiency. Maternal nutrition during fetal development can having long term implications for the offspring, a concept referred to as fetal programming. Depending on timing, magnitude, and duration of nutrient limitation or supplementation, it is possible that early measures in life, such as calf birth weight may be unaffected while measures later in life such as weaning weight, carcass characteristics and/or reproductive traits may be influenced. Thus much of the old research evaluating negative nutrition or supplemental feeding during pregnancy now needs to be revisited to determine what effects these conditions my have on lifetime productivity of the progeny.

Technical Abstract: The beef cattle industry relies on utilization of high forage diets to maintain the cow herd, develop replacement females, and stocker operations. Forage quantity and quality fluctuate with season and environmental conditions. Depending on class and physiological state of the animal, a grazed forage diet may not always meet nutritional requirements resulting in low ADG or weight loss if supplemental nutrients are not provided. It is important to understand the consequences of such weight loss and the economics of providing supplementation to the beef production system. Periods of limited or insufficient nutrient availability can actually result in compensatory gain once dietary conditions improve and may be of less impact in breeding animals where actual weight is not as important as animals destined for the feedlot provided reproductive efficiency is not compromised. A rapidly evolving body of literature is also demonstrating that nutritional status of cows during pregnancy can affect subsequent offspring development and production characteristics later in life. Maternal stimuli or an insult during a critical period of fetal development having long term implications for the offspring is the concept of fetal programming. Depending on timing, magnitude, and duration of nutrient limitation or supplementation, it is possible that early measures in life, such as calf birth weight may be unaffected while measures later in life such as weaning weight, carcass characteristics and/or reproductive traits may be influenced. This body of research provides compelling evidence of a fetal programming response to maternal nutrition in beef cattle. Future competitiveness of the beef industry will continue to be dependent on the utilization of high forage diets to meet the majority of nutrient requirements. Consequences of nutrient restriction or supplementation must be considered not only on individual animal performance but also the developing fetus and its subsequent performance throughout life.