Lambing rate as a function of artificial insemination depth in ewe lambs, primiparous and multiparous ewes

Abstract

The objective of this study was to survey the depth of penetration of a helicoid type catheter for cervico-uterinal insemination in breeding season.
This study evaluated:
− the differences in the penetration depths of the catheter in ewe lambs, primiparous and multiparous ewes.
− the differences in the penetration depths between the morning and afternoon inseminations.
− the differences in the penetration depths between the ewes that lambed and ewes that failed to lamb after AI.
− relationship between the depth of semen deposit with this catheter and the lambing rate.
Lacaune ewe lambs (n=204), primiparous ewes (n=215) and multiparous ewes (n=227) were artificially inseminated with 2 to 4ºC cooled, diluted, short-time preserved ram semen. Depth of penetration examinations was conducted with modified Milovanov catheter. Depth of penetration of the catheter into the cervix was different (P<0.01) in ewe lambs, primiparous and multiparous ewes. Penetration depth differed significantly (P<0.01) between ewes that lambed and failed to lamb. There was a statistically significant positive correlation between insemination depth and lambing rate. Nevertheless, there were no significant differences in penetration depth between the morning and afternoon inseminations. Analysis of the data indicated that adequate fertility results could be obtained with deep cervical deposit of 2 to 4ºC cooled, diluted ram semen.