The detection and treatment of post insemination progesterone insufficiency in dairy cows

Abstract

An analysis on the outcome of 124 inseminations monitored using daily milk progesterone concentration data revealed that those cows in which pregnancy did not occur experienced a 1.7day delay in post-ovulatory luteal progesterone rise when compared to the pregnant group (P<0.001). This suggests that luteal progesterone secretion needs to be initiated prior to day 5 post-ovulation. A comparison between the milk progesterone concentration on day 5 post-ovulation and the pregnancy rate for 1451 inseminations showed the maximum pregnancy rate to occur when the milk progesterone concentration was between 3-9ng/ml. Pregnancy rate fell significantly (P<0.01) when progesterone concentrations were below 3ng/ml, identifying cows that may benefit from progesterone supplementation. The supplementation of progesterone in cows with a day 5 milk progesterone concentration of less than 3ng/ml, using an intra-vaginal progesterone releasing device, only provided benefit for those cows with a day 5 progesterone concentration of between 1-2ng/ml, resulting in a doubling of the pregnancy rate. This data shows that a delay in post-ovulatory progesterone secretion has a detrimental effect on pregnancy but that not all cows with a deficient progesterone concentration benefit from progesterone supplementation.

Identification of inadequate maternal progesterone concentrations in nulliparous dairy heifers and treatment with human chorionic gonadotrophin

“…The positive correlation identified between plasma progesterone concentration and PR in the early luteal phase is in agreement with previous studies in different classes of cattle: dairy cows (Starbuck and others 2001), beef heifers (Diskin and others 2002) and dairy heifers (Parr and others 2012). Combining all progesterone values from animals sampled on day 4, 5 or 6 after insemination and analysing as one group compensated for daily fluctuations in peripheral progesterone concentration, and has been previously shown to be correlated with embryo survival and development (Mann and Lamming 2001).…”

“…This correlates with previous studies in lactating cows using milk progesterone concentrations; Starbuck and others (2001) and McNeill and others (2006), both finding the lowest PR in groups <2 ng/ml. The present study did not reveal a decrease in embryo survival at the highest concentrations of progesterone, contrary to previous studies in dairy heifers (Parr and others 2012) and lactating cows (Starbuck and others 2001, Stronge and others 2005) possibly because there were very few mistimed inseminations in the synchronised groups in the present study. The reasons for a decrease at higher concentrations is thought to be due to an excess of progesterone causing embryo loss but may also result from mistimed insemination, leading to sampling of heifers at a ­different luteal stage than predicted.…”

“…Luteal progesterone secretion should have commenced by day 5 after insemination for a successful pregnancy, but even a one day delay can reduce the embryo survival rate (Mann and Lamming 2001, Starbuck and others 2001). Peripheral blood progesterone concentrations have been correlated with embryo survival from as early as day 5 after insemination in lactating cows (Butler and others 1996), and day 7 in beef heifers (Diskin and others 2002).…”

“…Supplementation with progesterone in early pregnancy can advance embryo development and could be used as a potential treatment to mimic the relationship between increased endogenous progesterone and embryo survival (Robinson and others 1989, Macmillan and others 1991, Starbuck and others 2001, Mann and others 2006, Larson and others 2007, Carter and others 2008). However, it appears that the timing of such supplementation is important; if started four to five days after insemination, embryo survival rates increase more consistently compared with later supplementation (Mann and Lamming 1999).…”

Progesterone and pregnancy status of buffaloes treated with a GNRH agonist

“…The reasons for higher embryonic mortality in buffaloes during increasing daylight length or photoperiod are not fully understood, but it would appear as if it can be attributed, at least in part, to a decrease in progesterone secretion by the corpus luteum (CL) during early pregnancy (Campanile et al, 2005). The importance of adequate progesterone secretion for early embryonic development, including embryonic secretion of interferon-tau which prevents the regression of the CL, has been previously clearly demonstrated in cattle (Starbuck et al, 1999;Mann, 2002). The administration of GnRH and GnRH agonists induces an acute release of gonadotropins in cattle (Martinez et al, 2003) and buffaloes (Rastegarnia et al, 2004).…”