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 Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Bereskin, B. Articles by Steele, N. C. Search for Related Content PubMed PubMed Citation Articles by Bereskin, B. Articles by Steele, N. C.

Performance of Duroc and Yorkshire Boars and Gilts and Reciprocal Breed Crosses¹

U.S. Department of Agriculture^,3, Beltsville, MD 20705

Abstract

Analyses of variance were computed for records on growth and body composition traits made in 1983 by 255 boars and gilts in selected and control lines of Durocs and Yorkshires and their reciprocal crossbreds. Previous selection over a period of several generations was mainly on an index of sow productivity including preweaning litter sizes and weight. Animals in the select lines were selected for high index values; animals in the control lines were selected to average near the mean index values of that year and line. Breeding animals in all four lines during that period were basically randomly selected with regard to growth rate or body composition traits. The same boars sired both purebred and crossbred litters in 1983. Traits analyzed were average daily gain (ADG) during a standard test period from 56 d of age to 90.7 kg and average backfat thickness (ABF) and longissimus muscle area (LMA) from ultrasonic scans at 90.7 kg. Crossbred pigs had greater (P<.01) ADG than purebred pigs, but did not differ (P>.05) in ABF or LMA. Heterosis was 8.2% for ADG. Crossbreds with Yorkshire dams had thinner (P<.01) ABF and larger (P<.01) LMA than crossbreds with Duroc dams. Boars had greater (P<.05) ADG, thinner (P<.01) ABF and smaller (P<.01) LMA than gilts. Correlations between 38 half-sib family averages of purebred and crossbred pigs of the same sex and the same sires were .07, .37 and .24 for ADG, ABF and LMA, respectively. Implications of the above and additional findings for swine breeding strategies are discussed.

¹ The authors acknowledge with appreciation the contributions of D. L. Parsons, Animal Caretaker Leader, for managing the swine herd and collecting and recording the necessary data; the cooperation of W. H. Peters, Head, Animal Operations; and the contributions of Bonnie Morgan, Statistical Assistant.

² USDA, Agr. Res. Serv., Beltsville Agr. Res. Center, Anim. Sci. Inst., Nonruminant Anim. Nutr. Lab., Beltsville, MD 20705.

³ Mention of trade names, proprietary product or vendor does not constitute a guarantee or warranty of the product by USDA or imply its approval to the exclusion of other products or vendors that may also be suitable.