Different approaches of trans-cervical artificial insemination in oestrus synchronized indigenous field ewes using frozen ram semen

Abstract

The study aimed to determine the pregnancy rates of indigenous field sheep following different approaches to transcervical artificial insemination (TCAI). TCAI was performed in oestrus induced ewes using two straws of frozen-thawed semen. In group 1, single-time TCAI was performed on standing heat in traditionally/manually restrained ewes (n=20) and in lab cradle restrained ewes (n=20). In group 2, TCAI was performed in manually restrained ewes single-time after 46-48 h of PGF2a injection (n=20), and double-times at 46-48 h & 52-56 h after PGF2a injection (n=20). In group 3, TCAI was performed in manually restrained ewes single time at 52-56 h after PGF2a injection and 20 minutes after oxytocin injection (n=10), and 20 minutes after oxytocin-estradiol benzoate injection (n=11). The pregnancy rates were 35 % and 45 % in traditional and cradle restrained TCAI, 35 and 55 % in single-time and double-times TCAI, and 50 and 55 % in oxytocin and oxytocin-estradiol cervixtreated TCAI, respectively. Although the pregnancy rates did not differ significantly (p>0.05) by experimental group, the TCAI after cervical treatment and double-time TCAI importantly had more prengnancies than the other approaches to TCAI. Finally, it can be concluded that double-times TCAI would be an effective and acceptable approach for field sheep artificial breeding using frozen semen.

Keywords

• sheep
• oestrus synchronization
• different approaches
• transcervical insemination