HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Davis, M. E. Articles by Hauser, E. R. Search for Related Content PubMed Articles by Davis, M. E. Articles by Hauser, E. R.

Life Cycle Efficiency of Beef Production: I. Cow Efficiency Ratios for Progeny Weaned^1,2,3,

University of Wisconsin, Madison 53706 and and US Department of Agriculture, Clay Center, NE 68933

Abstract

Weights and individual feed consumption collected on 160 beef, dairy and beef x dairy dams and their progeny were used to estimate several measures of lifetime cow efficiency. Dams were fed either a' high or a low energy diet. Efficiency was expressed as the ratio of outputs to inputs. Outputs included progeny weaning weights plus cow salvage weight, and inputs were progeny creep feed consumption plus the dam's lifetime feed consumption. In the first approach, life cycle cow efficiency was estimated by expressing weight output as a ratio to feed inputs when weights and feed consumptions were weighted by their probabilities; probabilities were a function of age distribution and percentage calf crop in a theoretical herd consisting of 100 cows and 20 yearling replacement heifers. In the second approach, actual lifetime cow efficiency was estimated by expressing weight outputs as a ratio to feed inputs when all components were weighted equally. Both approaches included efficiency estimates calculated with and without cow salvage value. Dams receiving low energy diets generally had lifetime efficiencies equal or superior to those fed high energy diets in spite of older ages at calving. Dams on the high energy diet had greater salvage value, but did not wean calves of sufficient additional size to offset their own increased metabolizable energy (ME) intake. Dam breeds and breed crosses of smaller size tended to be more efficient than those of large size, demonstrating the effectiveness of mating small dams to large sire breeds for improving cow efficiency. Breeds calving at later ages were less efficient. Efficiency ratios improved as number of progeny weaned increased.

¹ Dept. of Meat and Anim. Sci. Paper No. 799. Research was supported by the College of Agriculture and Life Sciences, Univ. of Wisconsin, Madison, and the Agr. Res. Service, USDA. Semen was donated by American Breeders Service, DeForest, WI; American Int. Charolais Assoc., Houston, TX; Carnation Genetics, Hughson, CA; Curtiss Breeding Service, Gary, IL; East Central Breeders Coop., Waupun, WI; Midwest Breeders Coop., Shawano, WI; Noba, Inc., Tiffin, OH and Tri State Breeders Coop.,Westby, WI.

² The experiments were contributions to North Central Regional Project NC-1 "The Improvement of Beef Cattle Through Breeding Methods."

³ The authors with to thank Ms. J.Busby and Ms. S. Kading for typing this manuscript and Messrs. E. Hoch, P. Bringle and J. Kane for their excellent technical assistance.

⁴ Present address: Anim. Sci. Dept., The Ohio State Univ. Columbus 43210.

⁵ Dept. of Meat and Anim. Sci., Univ.of Wisconsin, Madison 53706.

⁶ Roman L. Hruska U. S. Meat Animal Research Center, ARS, USDA, Clay Center, NE 68933.

This article has been cited by other articles:

				T. G. Jenkins and C. L. Ferrell Daily dry matter intake to sustain body weight of mature, nonlactating, nonpregnant cows J Anim Sci, July 1, 2007; 85(7): 1787 - 1792. [Abstract] [Full Text] [PDF]