Effect of Early Postpartum Ovulation on Fertility in Dairy Cows

Abstract

Our objectives were to determine the effects of early ovulation on fertility and uterine health of dairy cows. Four hundred and forty-five Holstein cows (185 primiparous and 260 multiparous) from five herds were used. Blood samples were collected at 21, 35 and 49 days in milk (DIM) and cows were considered to be cyclic at 21 DIM (Cyc21) if serum progesterone (P4) concentration was above 1 ng/ml, cyclic by 49 DIM (Cyc49) if P4 concentration was above 1 ng/ml at 35 or 49 DIM, or not cyclic (NotCyc) if P4 concentration was below 1 ng/ml at all sample times. Endometrial cytology for diagnosis of subclinical endometritis was examined at 49 DIM in a subset of 414 cows. Cows in the group Cyc21 had increased hazard of insemination, for the first service, compared with cows in Cyc49 [hazard ratio (HR) = 1.40; 95% CI = 1.10-1.79; p = 0.006] and NotCyc (HR = 2.07; 95% CI = 1.52-2.82; p < 0.001). Cows in the Cyc49 group also had increased hazard of insemination compared with cows in the NotCyc group (HR = 1.47; 95% CI = 1.13-1.93; p = 0.005). Median days to insemination were, respectively, 71, 76 and 96 for cows in Cyc21, Cyc49 and NotCyc groups. Cows in Cyc21 had greater first service pregnancy per AI than Cyc49 [38.6 vs 28.1%; adjusted odds ratio (AOR) = 1.67; 95% CI = 1.01-2.75; p = 0.04] and NotCyc (38.6 vs 23.6%; AOR = 2.08; 95% CI = 1.08-4.00; p = 0.03). Pregnancy per AI was similar in Cyc49 and NotCyc cows (28.1 vs 23.6%; AOR = 1.25; 95% CI = 0.70-2.24; p = 0.45). Cows in Cyc21 had increased hazard of pregnancy up to 300 DIM compared with Cyc49 (HR = 1.52; 95% CI = 1.17-1.96; p = 0.002) and NotCyc (HR = 1.98; 95% CI = 1.41-2.78; p < 0.001). Cows in Cyc49 tended to have increased hazard of pregnancy compared with NotCyc (HR = 1.31; 95% CI = 0.96-1.77; p = 0.09). Median days to pregnancy were, respectively, 103, 147 and 173 for cows in Cyc21, Cyc49 and NotCyc groups. Cows in the Cyc21 group had decreased prevalence of subclinical endometritis compared with cows in the NotCyc group (29.9 vs 43.7%; AOR = 0.53; 95% CI = 0.29-0.97; p = 0.04); however, the prevalence did not differ from the Cyc49 group (29.9 vs 39.1%; AOR = 0.68; 95% CI = 0.41-1.14; p = 0.15). Cyc49 cows had similar prevalence of subclinical endometritis compared with NotCyc cows (AOR = 0.77; 95% CI = 0.46-1.29; p = 0.32). Early postpartum ovulation was associated with improved uterine health and fertility.

Ovarian follicle growth dynamics during the postpartum period in Holstein cows and effects of contemporary cyst occurrence

“…(Table 2). Galvao et al (2010) published a study on the positive role of the earlier 1 st ovulation on subsequent fertility, which was also found in our experiment. Animals ovulating follicles from the 1 st follicular wave (G1 group) got pregnant earlier (mean DO for G1, G2, and G3 were 84, 113, and 164 days, respectively; P = 0.07) and after a voluntary waiting period they were not hormonally treated as often as cows ovulating later pp (frequency of hormonal treatment was 1, 8, and 5 animals for G1, G2, and G3, respectively; P = 0.008).…”

“…In the context of the onset of ovarian activity pp, authors have focused mainly on indicators such as dynamics and metabolic/hormonal profiles of the first follicular wave (Kawashima et al, 2007), days of the first ovulation (Galvao et al, 2010), the first onset of luteal activity (Hayashi et al, 2008), links to uterine involution (Sheldon and Dobson, 2004) or to the first insemination term (Hommeida et al, 2005). It has been determined that the first follicular growth wave emerges soon after delivery and is independent of the EB of the animal (Butler, 2003).…”

Prepartum and postpartum nutritional management to optimize fertility in high-yielding dairy cows in confined TMR systems

“…In general, fertility is greater in cows that ovulate sooner after parturition (Butler, 2003;Bossaert et al, 2008;Galvão et al, 2010b). During early postpartum NEB, the pulse frequency of LH release, the size and development rate of follicles, concentrations of estrogen and progesterone, and size of the CL all are decreased (Jorritsma et al, 2003;Garnsworthy et al, 2008).…”

“…Although studies have demonstrated a weak and variable relationship between the degree of NEB and impaired fertility, the time to NEB nadir and the direction and/or rate of change in NEB appear to be stronger indicators (Whitaker et al, 1993;Butler, 2003;Reist et al, 2003). Possible mechanisms for detrimental effects of NEB on reproduction include (1) delayed resumption of ovarian cyclicity, through effects on hypothalamic, pituitary and ovarian function, (2) impacts on oocyte or corpus luteum (CL) 'quality', viability, or function, sometimes referred to as 'follicular memory' and (3) development of fatty liver (hepatic lipidosis).In general, fertility is greater in cows that ovulate sooner after parturition (Butler, 2003;Bossaert et al, 2008;Galvão et al, 2010b). During early postpartum NEB, the pulse frequency of LH release, the size and development rate of follicles, concentrations of estrogen and progesterone, and size of the CL all are decreased (Jorritsma et al, 2003;Garnsworthy et al, 2008).…”

Recent advances in the immunology and uterine microbiology of healthy cows and cows that develop uterine disease

“…Cows that developed metritis had decreased (P ≤ 0.05) TNFα gene expression at 0, 7, and 14 days after calving, and decreased IL-1β and IL-6 at 7 and 14 days after calving compared to cows that had endometritis and control cows. Adapted from Galvão et al (105).…”