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 Nelson, L. D. Articles by Seidel, G. E. Search for Related Content PubMed PubMed Citation Articles by Nelson, L. D. Articles by Seidel, G. E., Jr.

Effect of Heterospermic Insemination on Fertility of Cattle^{1, 2,}

Colorado State University, Fort Collins 80523

Abstract

In 1971, 1972 and 1973 cattle were inseminated with frozen semen from three individual bulls (homospermic) and seminal mixtures from these bulls (heterospermic). Post-thaw spermatozoan motility in heterospermic treatments was not superior to homospermic treatments. The number of motile spermatozoa after thawing ranged from 7.4 to 12.1 x 10⁶ per inseminate but less than 2% of the variability in first-service pregnancy rate was due to spermatozoal numbers. No signiFicant increase in fertility was obtained when insemination with mixtures of semen from two bulls was compared to homospermic insemination. The first-service pregnancy rate of 70.6% for 323 services with the seminal mixtures from three bulls was significantly higher (P < .05) than the 62.7% for 327 homospermic inseminations or 62.2% for 323 services with the seminal mixtures from two bulls. The overall mean pregnancy rate (first and second services combined) for the triple-seminal mixtures was higher than the single and double-seminal mixtures for each group of cattle inseminated. Heterospermic inseminations with frozen semen resulted in a deviation from the expected equal number of progeny per sire.

¹ Supported in part by grants-in-aid from International Beef Breeders, Denver, CO 80229 and Mr. L. W. Bailey, Manter, KS 67862. Portions of these data were presented at the Fifth N.A.A.B. Tech. Conf. A.I. Reprod., Chicago, IL, 1974. Appreciation is expressed to International Beef Breeders, Denver, CO 80229, and Mr. G. P. Schoenfelder, Rainbow's End Ranch, Douglas, AZ 85607, for their generous donation of bull semen used in these studies. Further appreciation is expressed to B. D. Ennen, D. Robinson, O. L. Rodriguez and C. 0. Wilseyfor technical assistance.

² Animal Reproduction Laboratory, Department of Physiology and Biophysics.