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ARS Home » Plains Area » Miles City, Montana » Livestock and Range Research Laboratory » Research » Publications at this Location » Publication #185078
Title: DOES DIETARY INTAKE INFLUENCE NUTRIENT UTILIZATION IN DEVELOPING HEIFERS?

Author
item Waterman, Richard
item Grings, Elaine
item Geary, Thomas
item Roberts, Andrew
item Alexander, Leeson
item Macneil, Michael

Submitted to: Research Update for Fort Keogh Livestock and Range Research Laboratory
Publication Type: Other
Publication Acceptance Date: 6/15/2005
Publication Date: 7/15/2005
Citation: Waterman, R.C., Grings, E.E., Geary, T.W., Roberts, A.J., Alexander, L.J., Macneil, M.D. 2005. Does dietary intake influence nutrient utilization in developing heifers? 2005 Research Update for Fort Keogh Livestock and Range Research Laboratory p. 29-30.

Interpretive Summary: One of the major production expenses for cow/calf enterprises is associated with the development of replacement heifers. The present constraints are such that heifers need to obtain 60 to 65% of their mature weight and be pubertal by 14 months of age in order to have their first offspring as 2-year olds. Typically, for cow-calf producers in the Northern Great Plains this requires providing additional feed resources above that provided by native rangelands from weaning to breeding. Low levels of nutrition following weaning can delay the onset of puberty while high levels of nutrition following weaning may reduce life span and limit milking ability of heifers. Therefore, producers encounter the challenge of first obtaining reproductive competency (puberty) in heifers, and secondly, producers must do so in a cost efficient manner (i.e. minimal feed costs). The objective of the present study was to evaluate the efficiency of nutrient utilization between heifers receiving an ad libitum diet to heifers receiving 20% less adjusted to a common body weight (BW) bases. The significance of this initial study suggests that developing heifers with ad- libitum access to a high quality diet may not allow proper or efficient utilization of provided nutrients. On the other hand, by restricting heifers or meeting an optimal level of intake of a high quality diet, restricted heifers become more efficient at utilizing dietary nutrients.

Technical Abstract: One of the major production expenses for cow/calf enterprises is associated with the development of replacement heifers. The present constraints are such that heifers need to obtain 60 to 65% of their mature weight and be pubertal by 14 months of age in order to have their first offspring as 2-year olds. Typically, for cow-calf producers in the Northern Great Plains this requires providing additional feed resources above that provided by native rangelands from weaning to breeding. Low levels of nutrition following weaning can delay the onset of puberty while high levels of nutrition following weaning may reduce life span and limit milking ability of heifers. Therefore, producers encounter the challenge of first obtaining reproductive competency (puberty) in heifers, and secondly, producers must do so in a cost efficient manner (i.e. minimal feed costs). The objective of the present study was to evaluate the efficiency of nutrient utilization between heifers receiving an ad libitum diet to heifers receiving 20% less adjusted to a common body weight (BW) bases. The significance of this initial study suggests that developing heifers with ad- libitum access to a high quality diet may not allow proper or efficient utilization of provided nutrients. On the other hand, by restricting heifers or meeting an optimal level of intake of a high quality diet, restricted heifers become more efficient at utilizing dietary nutrients.