Relation of reproductive performances and rectal palpation for luteum function of heifers 7days after estrus

• Published in: Animal science journal Vol. 83; no. 3; p. 207
• Main Authors: YOSHIDA, Tatsuyuki, SEKI, Makoto, WATANABE, Norio, FURUTA, Hiroki, YOSHIMURA, Itaru, OSADA, Masahiro, CHIBA, Koji, OKADA, Konosuke, KAWASUMI, Koh, USHIJIMA, Hitoshi
• Format: Journal Article
• Language: English
• Published: Tokyo Blackwell Publishing Ltd 01-03-2012
• Subjects: Animal reproduction; Animal sciences; Cattle; Medical diagnosis; Reproductive technologies
• ISSN: 1344-3941; 1740-0929
• DOI: 10.1111/j.1740-0929.2011.00935.x

Diagnosis of corpus luteum (CL) function by rectal palpation (RP) has been widely used for recipient selection of embryo transfer (ET), a technology essential for genetic improvements in cattle. To examine the accuracy of RP diagnosis method, the relationship between RP-based CL function and reproductive performance was compared in this study. In Experiment 1, CL of Holstein heifers on day 7 after estrus was classified into functional or hypoplastic by RP, and the results were compared with ultrasonographic (US) images and plasma progesterone (P4) levels. As a result, heifers with functional CL judged by RP had a mean maximum CL diameter of 20.1±3.1mm on US and a mean P4 concentration of 8.1±2.3ng/mL. These values were significantly greater than those of heifers with hypoplastic CL (12.4±5.4mm, 4.0±2.8ng/mL) (P<0.001). In Experiment 2, the length of the estrus cycle was examined between functional CL and hypoplastic CL. The rate of heifers with a normal estrus cycle length with 18-25days was significantly lower with hypoplastic CL than with functional CL (16/24 vs. 43/46, P<0.01). In Experiment 3, 543 inseminated heifers were similarly classified by CL function by RP 7days after estrus. The heifers with functional CL showed higher pregnancy rate compared with the heifers with hypoplastic CL (75.2 vs. 47.9%, P<0.0001). Finally, the CL function of 66 heifers was examined by RP on day 7 post-estrus, and ET was performed in 49 (74.2%) heifers with functional CL. As a result, 27 (55.1%) of them became pregnant. Taken together, these results reconfirm that RP on day 7 after estrus is useful for selection of heifers with functional CL. [PUBLICATION ABSTRACT]