The Influence of Corpus Luteum Size on the Conception in Embryo Transfer Recipient Cows

Abstract

The aim of study was to investigate the effect of corpus luteums (CL) size that detected before embryo transfer on conception in recipient Holstein cows. The recipient cows utilized had at least one birth and aged 3-8 years old. PGF2α was injected 2 times space 14 days apart to cows and 87 cows which show estrous symptoms were determined as recipient. Fresh embryos were transferred after estrous in 6 th -8 th days. Ovaries were examined by ultrasound before transfer and CL sizes were measured. A scale of '++++' were set as a result of measurements. Recipient cows were into 3 groups. The first group was named as CL2+ (n=25) and consisted of cows with '++' (≥15-20< mm) size CL. The second group was named as CL3+ (n=52) and consisted of cows with '+++' (≥20-25< mm) size CL. The third group was named as CL4+ (n=10) and consisted of cows with '++++' (≥25 mm) size CL. The embryos were transferred to the uterine horn on the side of the CL (ipsilateral). Pregnancy rate was respectively 36%, 46.2% and 40% for groups. No statistically significant difference was found between groups in terms of the effect of CL on conception (P>0.05). As a result, it was concluded that the size of the corpus luteum has no effect on the conception of cows utilized as recipients in embryo transfer.

Assessment of Luteal Function Using Rectal Palpation, B-Mode Ultrasonography, and Progesterone Determination to Improve Recipient Selection in Embryo Transfer Programs

“…Only during the luteal stage of the estrus cycle does the uterine microenvironment provide an adequate medium for the embryos to develop. As a result, the harmonization of the physiological state of the donor and the recipient in ET procedures lays the foundations for its success [ 12 ].…”