Effect of progesterone-releasing intravaginal device on reproductive performance of cows with cystic ovarian follicles after puerperium.

The aim of the study was to investigate the influence of cystic ovarian follicles (COFs) occurring after puerperium on fertility and the effect of their treatment with progesterone releasing device on reproductive performance in dairy cows. The study was carried out in 3 herds of Polish Holstein-Friesian cows under herd health program. COFs were diagnosed by ultrasound above 60 days p.p. They were defined as follicular structures with a diameter > 2.5 cm in the absence of a corpus luteum at two repeated examinations at the 14-days interval. On the day of COF diagnosis blood samples were collected to measure progesterone (P4) concentration. On the basis of the wall thickness measurement and progesterone concentration at the first examination, the COFs were differentiated into follicular and luteal cysts. The experimental group consisted of 23 animals with COF. The cows were treated with PRID Delta (Ceva Animal Health, Poland), containing 1.55 g of progesterone, for 7 days. The cows without oestrus signs within 14 days after treatment were re-examinated. If COF persisted, the cows were treated again with PRID Delta. The treatment was repeated maximum three times. Fifteen cows with ovarian cysts were left untreated and served as a control group. The cows with COF were matched to healthy cows without COF. The cows with COF had worse fertility performances compared to cows without COF. There were significant (p⟨0.05) differences in conception rates, number of services per conception and days open between these groups. Compared with non-treated cows with COF, in cows with COF treated with PRID Delta conceptions rates and number of services per conception were similar, but the days open were significantly (p⟨0.05) lower in cows treated than in non-treated (183.3 days vs. 277.6 days). There were no differences in reproductive performances between the follicular and luteal cysts in treated and non-treated cows. In conclusion, the results of our study confirm the negative impact of COF after puerperium on fertility in dairy cows. Furthermore the results indicate the usefulness of PRID Delta for the treatment of COF occurring after the puerperium regardless of cysts type.

Prevalence of subclinical endometritis in repeat breeding cows and mRNA expression of tumor necrosis factor alpha and inducible nitric oxide synthase in the endometrium of repeat breeding cows with and without subclinical endometritis.

Information on the prevalence of subclinical endometritis and its mechanism in repeat breeding cows is very limited. The aims of this study were: a) to evaluate the incidence of this disorder with cytobrush cytology b) to analyze mRNA expression of tumor necrosis factor alpha (TNFalpha) and inducible nitric oxide synthase (iNOS) in endometrial biopsy samples collected from repeat breeding cows with and without subclinical endometritis. Two experiments were carried out. In experiment 1,112 (12.4%) repeat breeding cows (inseminated at least 3 times and not pregnant) were selected out of 902 cows from 8 dairy herds. Cytobrush cytology was performed on these cows, using the threshold of 10% PMNs in uterine smears. The results showed that 45 out of the 112 cows (40.2%) were diagnosed as having subclinical endometritis. In experiment 2, uterine biopsy samples were taken from repeat breeding cows with subclinical endometritis (n = 10) and without this disorder (n = 10). Using reverse transcription-PCR, the mRNA expression of TNFalpha and iNOS was determined. A statistically significant increase in expression of both substances was measured in the group of cows with subclinical endometritis (p <0.05). These results provide evidence for a high prevalence of subclinical endometritis in repeat breeding cows as well as the involvement of TNFalpha and iNOS pathways in the regulation of this pathological condition.

Effectiveness of determining the parturition date in bitches using the ultrasonographic fetometry as compared to hormonal and cytological methods.

In clinical practice, the parturition date in bitches is calculated on the basis of the established ovulation date, using determination of the level of LH and P4. Additionally cytological examination of vaginal smears makes it possible to establish the onset of diestrus, from which the delivery occurs after about 57 days. The latest method used in bitches for this purpose is foetal biometry. Measurements of the inner chorionic cavity diameter (ICC) and biparietal diameter (BP) with formulas published by Luvoni and Grioni have been popularized and the most practically useful. In a group of six bitches the effectiveness obtained with the use of ICC was 66.67% with an accuracy of 1 day and 100% with an accuracy of 2 days. BP measurements gave better results, as the accuracy was respectively 83.33% and 100%. The effectiveness of predicting the delivery date on the base of method consisting in determining the LH surge was 66.67% with an accuracy of 1 day and 100% with an accuracy of 2 days. The best effectiveness was obtained while using the method based on P4 level determination (100% both with an accuracy of 1 day, as well as of 2 days). The lowest accuracy was obtained while using the cytological method. Generally, a comparison of the methods used for predicting the date of delivery in bitches confirms practical usefulness of fetometry. Its effectiveness was not lower than traditional methods used so far, while its advantage lies in the ease of performance and the long term of application during gestation. However, full confirmation of the practical usefulness of this method requires further research on a larger number of animals.