SELECTED TIMES OF INSEMINATION WITH MICROENCAPSULATED BOVINE SPERMATOZOA AFFECT PREGNANCY RATES OF SYNCHRONIZED HEIFERS

Citation
R. Vishwanath et al., SELECTED TIMES OF INSEMINATION WITH MICROENCAPSULATED BOVINE SPERMATOZOA AFFECT PREGNANCY RATES OF SYNCHRONIZED HEIFERS, Theriogenology, 48(3), 1997, pp. 369-376
Citations number
18
Categorie Soggetti
Veterinary Sciences
Journal title
ISSN journal
0093691X
Volume
48
Issue
3
Year of publication
1997
Pages
369 - 376
Database
ISI
SICI code
0093-691X(1997)48:3<369:STOIWM>2.0.ZU;2-Q
Abstract
This experiment was designed to test whether spermatozoa encapsulated in an alginate poly-l-lysine matrix had an extended fertile life in vi vo after insemination. Estrus was synchronized in 417 primiparous Frie sian and Jersey heifers with a system based on a CIDR-B-(R) intravagin al device before the heifers were inseminated either during proestrus (24 h after device removal) or at estrus (48 h after device removal). Pregnancy rates to first inseminations did not differ between the 24 a nd 48 h inseminations (61 vs 60.6%) with liquid semen diluted in Capro gen((R)) (control) but differed with encapsulated semen (45.1 vs 68.6% ). The difference in pregnancy rates between the 2 types of semen was more pronounced (P < 0.08) in the animals that were visually detected in estrus. The mean survival time of spermatozoa in the female reprodu ctive tract following insemination at the 24-h insemination time was e stimated to be 50 +/- 7.5 h. The increased pregnancy rate with insemin ation of encapsulated spermatozoa at 48 h could have been due to this process predisposing spermatozoa to capacitate soon after insemination . (C) 1997 by Elsevier Science Inc.