J. Anim Sci.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J. Anim Sci. 1975. 40:397-408.
© 1975 American Society of Animal Science
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Dickerson, G.E.
Right arrow Articles by Glimp, H.A.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Dickerson, G.E.
Right arrow Articles by Glimp, H.A.

Breed and Age Effects on Lamb Production of Ewes

G.E. Dickerson and H.A. Glimp1

U.S. Department of Agriculture,,2 Clay Center, Nebraska 68933

Abstract

Breed and age effects on fertility for 8,129 ewe matings and on spring lamb crop for 6,726 lambings were examined in seven domestic breeds and two strains of crossbred origin during 4 years. Fertility changed curvilinearly with age at lambing from 45 to 75% at 1 year to 85 to 95% at 4 to 6 years and to 60 to 80% at 9 years, with large breed and year differences in the fertility-age curve. Breed differences in age-adjusted fertility were large within years but rather inconsistent among years. Lambs born per ewe lambing increased curvilinearly with age of ewe, from 100+% at 1 year to 160% at 6 years and back to 135% at 9 years. The influence of age differed importantly among breeds for total and live lambs born but not for live lambs at 4 or 10 weeks of age. Most prolific breeds were Suffolk at 1 to 5 years, Dorset at 6 to 9 years and Targhee; breed differences were highly significant for total born (161 to 140%), barely significant for live lambs born (150 to 135%), but not for lambs weaned (108 to 94%). Based on live lambs born, size and wool production of ewes and boneless cuts from ram lambs, expected relative ewe-efficiency in producing crossbred lambs ranked Dorset (103), Suffolk (100) and Coarse Wool (97), Targhee (95), Corriedale (94), Hampshire (93) and Rambouillet (89). Using lambs weaned, efficiency ranked Coarse Wool (108), Targhee and Dorset (104), Suffolk and Rambouillet (100), Hampshire (98) and Corriedale (96).

Footnotes

1 Present address: 57 14th Street, Wheatland, Wyoming 82201.

2 With cooperation of Nebraska Agricultural Experiment Station, University of Nebraska, Lincoln.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1975 by the American Society of Animal Science.