The objective of this study was to find the correlation between the pregnancy rate of Holstein recipient heifers and their corpus luteum type, diameter, and its secretary competence at the day of embryo transfer. A total of (92) recipients were selected after estrus synchronization by prostaglandin. Fresh embryos were collected from (12) donors. Corpus luteum type and diameter were determined at transfer date using trans-rectal ultrasound. Serum samples were collected at transfer day (7th day post heat/luteal phase) for progesterone and Estradiol-17ß assessment. Current study revealed non-significant difference between pregnant and non-pregnant recipients concerning CL diameters; regardless CL type either compact (24±0.83 and 24±0.58mm, respectively) or cavitary (26±1.1 and 27±1.4mm, respectively); however, there was significant difference (P |
