BACKGROUND: Previous studies have indicated negative association of anogenital distance (AGD) with fertility in dairy cows; however, the mechanism of inverse relationship is not completely understood. In this regard, post-partum uterine infections and their corresponding risk factors could diminish fertility of cows, yet there has been no research exploring the relationship between AGD and postpartum disorders. OBJECTIVES: The aim of this study was to investigate the relationship between AGD and postpartum reproduc-tive performance in dairy cows. METHODS: AGD of Holstein dairy cows of a commercial dairy herd (n = 290) was measured in millimeter at the first postpartum examination (days 28 to 32 postpartum). The cows were classified into three categories based on the AGD length, including short (20% of cows with lowest values), intermediate (60% of cows with moderate values) and long (20% of cows with highest values) AGDs. Additionally, data of postpartum reproductive variables were retrieved form the herd database. Data was analyzed using SAS software version 9.4. RESULTS: The rate of dystocia, twinning, retention of fetal membranes, puerperal metritis and clinical endome-tritis, calf birth weight, and days to first service did not differ among the various AGD categories (P>0.05). However, proportion of male offspring was lower in the short AGD cows than intermediate and long AGD cows (P<0.05). Furthermore, the first service conception rate was greater in the intermediate anogenital distance group than short and long anogenital distance groups (P<0.05). CONCLUSIONS: In conclusion, the present study showed suboptimal first postpartum conception rate in the cows with minimal and maximal length of anogenital distance and indicated that this inferior fertility was not mediated through alteration in the rate of postpartum reproductive disorders

Background: Phenol is an estrogenic and toxic compound and people are widely exposed to it, in different ways.  OBJECTIVES: The aim of this study was to determine  the  negative effects of phenol on the fertility of male mice, by investigating sperm parameters including viability, motility, fertility rates and daily sperm production (DSP). METHODS: A total of 106 adult NIH mice were divided into four groups, one control and three experimental groups (n=13). The treatment groups were given daily dose of phenol for 35 days through gavage method (30, 75 and 100 mg/kg) while the control group received only normal saline. At day 36, six mice were sacrificed from each group. Gonadosomatic index (GSI), viability, motility and daily sperm production were determined carefully. The remaining 7 mice from each group were used to mate with 2 female mice. On GD10, the female mice were sacrificed and the fertility was verified. RESULTS: Daily sperm production in treatment groups decreased significantly compared to the control group (p≤0.05). Body weight, sperm motility, viability and fertility percentage were significantly decreased in 75 and 100 mg/kg groups in comparison with the control group (p≤0.05). While the testes showed no significant changes in weight in any groups. Gonadosomatic index in the treatment groups compared to the control group, was significantly decreased (p≤0.05). CONCLUSIONS: Pure phenol could reduce fertility rate through decreasing motility, daily sperm production and sperm viability.

BACKGROUND: Early resumption of ovarian activity after parturition could positively influence the fertility of dairy cows. Ovulation of the first postpartum follicular wave and formation of corpus luteum that secretes progesterone can sub-stantially benefit the resumption of ovarian cyclicity in cows. In this regard, the presence of a dominant follicle in the ovary before day 10 postpartum could enhance ovulation rate in the first postpartum follicular wave. Pregnant mare serum gon-adotropin (PMSG) is one of the hormones with the potential to improve the growth of follicles. OBJECTIVES: Accordingly, the present study was conducted to evaluate the effect of PMSG injection six days after parturition on reproductive parameters in dairy cows. METHODS: The subjects were randomly assigned to the two groups of control (N=74) and treatment (N=79). Cows in the control group received no treatment, while animals in the treatment group received 500 IU PMSG on day six postpartum. In both experimental groups, cows were subjected to Presynch-Ovsynch protocol 30-35 days postpartum. The subjects that experienced estrus during the Presynch-Ovsynch protocol were inseminated. On the other hand, the cows that were not in estrus during this period were subjected to fixed-time insemination at the end of the Presynch-Ovsynch protocol. Pregnancy was diagnosed 45 days after artificial insemination using the rectal examination. RESULTS: In the control group, 66.22% of cows were inseminated based on estrus detection and 33.78% of cows were inseminated at fixed times. In the intervention group, 68.35% of cows were inseminated based on estrus detection and 31.65% of cows were inseminated at fixed times. The first-service conception rate (FSCR) was 27.03% and 48.1% in the control and treatment groups, respectively (p =0.01). CONCLUSIONS: The present study showed that the injection of 500 IU PMSG six days after parturition could enhance FSCR in dairy cows.