Cervical artificial insemination in sheep

Results are reported from a fresh semen cervical artificial insemination trial in April 1989 at the Lincoln College Research Farm. One hundred and ninety Coopworth ewes were inseminated over 5 days. Semen was collected twice daily from four Dorset Down rams using an artifical vagina (A.V.). Fixed-time insemination versus on-oestrus insemination and 'synchronised on-oestrus' versus 'natural on-oestrus' were compared. 'On-time' ewes (TI) were inseminated at 50-51 hours after CIDR withdrawl. On-oestrus treatments (T2 and T3) were drafted twice daily and inseminated on average 15-22 hours after the onset of oestrus. Oestrus was detected by two vasectomised rams and five testosterone treated wethers, harnessed with crayons. Fifty-seven (97%) T1 ewes were marked within 50 hours after CIDR withdrawal. Submission rates were 100% for T2 and T3 (not including 5 (3%) ewes that lost CIDR's). Sixty-four (97%) T3 ewes were inseminated over three days on their second cycle after synchronisation using CIDR's. Two (1%) ewes lambed to A.I with no significant difference between treatments or across insemination days. The low lambing percentage appears to be due to an error in semen handling post collection/dilution, but results may have been compounded by low dose rates (96-232 x 10⁶ spermatozoa/inseminate) and marginal semen quality (motility) prior to insemination. Seventy-seven (41%) ewes were inseminated intrauterine via the cervix (including the two ewes that lambed to A.I). Ejaculate volume and motility varied significantly between collections and between rams - average ejaculate volume was 0.6 ml (0.2 - 2.0 ml), and average motility was 3+ (range 1-4).

Grantor dc:publisher

Lincoln College, University of Canterbury

Year dc:date

1989

Author dc:creator

• Lawson, H. S.

• artificial insemination
• fixed-time
• on-oestrus
• synchronisation
• lambing percentage
• semen quality
• ANZSRC::070201 Animal Breeding
• ANZSRC::070206 Animal Reproduction

Statement dc:rights

• Digital thesis can be viewed by current staff and students of Lincoln University only. If you are the author of this item, please contact us if you wish to discuss making the full text publicly available.

Licence

• https://researcharchive.lincoln.ac.nz/pages/rights

Language dc:language

en

Identifier

Q112847526

OAI identifier oai:identifier

oai:researcharchive.lincoln.ac.nz:10182/4790