JDS
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Journal of Dairy Science Vol. 41 No. 7 987-993
© 1958 by American Dairy Science Association ®
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 Fryer, H. C.
Right arrow Articles by Farmer, E. L.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Fryer, H. C.
Right arrow Articles by Farmer, E. L.

Nonreturn Rate of Artificially Inseminated Dairy Cows as Affected by Age of Semen, Breed of Bull, and Season1

H. C. Fryer, G. B. Marion and E. L. Farmer

Department of Dairy Husbandry and Statistical Laboratory, Kansas Agricultural Experiment Station, Manhattan

ABSTRACT

Records from 71,098 first services involving 60 bulls from six dairy breeds were obtained during 1951 and 1953. The breed of bull, age of semen, date of service, and collection number were recorded in the field on IBM mark-sense cards. Records of repeat services included the code number of the bull previously used, and the collection number, so that unsuccessful first services could be identified. It was found that: (a) Nonreturn rate decreases from five to 11 percentage units (depending on breed) for each additional day of storage of the semen. (b) Breeds, as represented in this study, have different potential nonreturn rates, and these rates are differentially affected by storage of the semen. (c) Seasonal effects on the percentage of nonreturns depend, somewhat erratically, upon the age of the semen. (d) Although the decline in fertility of stored semen is least rapid in the winter months of December, January, and February—as might be expected—it is no greater in the summer than in the spring and fall seasons. However, it may be that apparent seasonal effects are partially confounded with dairy husbandry practices associated with recommended time between calving and first service, milk pricing systems, and types of milk marketing.

FOOTNOTES

1 The data for this study were provided by the Kansas Artificial Breeding Service Unit.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1958 by the American Dairy Science Association ®.