الفهرس 
Introduction
Physiology of the postpartum periodOnly 14 pages are availabe for public view
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Abstract
Postpartum endometritis caused by persistent bacterial infection has been shown to have a tremendous impact on the fertility of dairy cattle. The most substantial effects of this disease are an increase in the number of days to conception, increased services per conception and an increased risk of culling. Recent scientific publications have distinguished two types of endometritis (subclinical and clinical endometritis). Since only some cows with endometritis display a visible discharge, there has been a concerted effort to develop reliable diagnostic tools and protocols that could be used by both researchers and clinical veterinarians to diagnose and treat subclinical and clinical endometritis.
The current work aimed to investigate whether there is a difference in the endometrial cytology and mRNA gene expression of interleukins (IL8 and IL16) between the uterine body (UB), previously pregnant horn (PPH) and previously non pregnant horn (PNPH). Investigate the therapeutic effect of intrauterine infusion of lactofferin (LF) on subclinical (SE) and clinical endometritis (CE) in pp dairy cows. Investigate the effect of exogenous estradiol benzoate (E2) administration on blood flow of uterine arteries in healthy (HG), subclinical and clinical endometritis cows by transrectal colour Doppler sonography. Investigate whether there are diffreneces in uterine blood flow of healthy, subclinical and clinical endometritis cows by transrectal colour Doppler sonography after E2 adminstration.
In the first study a total of 57 Holstein–Friesian dairy cows belong to governmental dairy farm at Miyazaki city, Japan were used. All cows were assigned for clinical examination on a weekly basis starting from week 2 to week 6 pp. All cows were subjected to be examined firstly by transrectal ultrasonography, vaginal mucous collection device followed by collection of endometrial cytology (EC) by cytobrush from the UB, right uterine horn and left uterine horn, respectively. At the conclusion of the examination, all cows at 3rd week pp diagnosed to have CE or SE were categorized in to 4 groups according to the type of treatment received on the 4th week pp. Group I, CE treated cows (n = 18) and Group II, SE treated cows (n = 14), received an intrauterine infusion of 1.5 gm bovine LF. Group III, CE control cows (n = 13) and Group IV, SE control cows (n=12): kept as control without treatment.
The results of this study showed that there is no difference in PMN% between UB, PPH and PNPH at different pp weeks. In the SE and CE treated groups, the PMN% of UB, PPH and PNPH was significantly lower at weeks 5 and 6 comparing to weeks 2 and 3 pp. Also, the vaginal mucous score (VMS) was significantly lower at weeks 5 and 6 compared to weeks 2 and 3 pp. There was a strong and significant positive correlation between PMN% in the UB and PPH and PNPH. There was no difference in the mean LF concentrations between SEC and CEC groups at the different PP weeks. The expression patterns of IL8 and IL16 mRNA in bovine endometrial samples of CE group were significantly higher at week 4 compared that of SE group. There was a strong positive correlation between IL8 mRNA expression and PMN% in endometrial samples in SE group. On the other hand, there was a strong negative correlation between IL8 mRNA expression and pp weeks in SE group. Also, there was a strong positive correlation between IL8 mRNA and IL16 expression patterns in CE group.
In the second study a total 17 Holstein–Friesian dairy cows belongs to commercial dairy farm at Tano city, Miyazaki prefecture, Miyazaki, Japan were used. All cows were assigned for clinical examination on a daily basis for 10 successive days starting from 4th week PP. All cows were subjected to be examined firstly by vaginal mucous collection device followed by collection of EC by cytobrush on the first day (to diagnose and differentiate cows in to healthy, SE and CE groups). Also, all cows were examined daily by Doppler transrectal ultrasonography using Logic XP ultrasound to quantifiy the blood flow to the uterine arteries ipsilateral and contralateral to the previously pregnant and non pregnant uterine horns. At the 3 rd day of the experiment, all cows (Healthy, SE and CE) were received intramuscular injection of 10 mg of Estradiol benzoate. Blood samples were collected from the cocygeal vein or artery using sterile heparinized Vacutainer tubes, transported on ice to the laboratory, and centrifugated immediately at 3000 rpm for 15 minutes. The harvested plasma was stored at -30 C° until hormonal analysis for E2 concentrations.
The results of this study showed that, in all studied groups, the pulsatility index (PI) and resistance index (RI) values decreased significantly in the ipsilateral and contralateral artereies, for 3-6 days after E2 treatment then start to increase. The time average maximum (TAMAX) velocity, blood flow volume (BFV) and the diameter increased significantly in both the ipsilateral and contralateral uterine arteries for 3-5 days after E2 treatment, and then started to decrease. There was no difference and a high correlation between both the ipsilateral and contralateral uterine arteries in all studied parameters. There was no difference in PI, RI, TAMAX, BFV nor diameter values between the healthy and SE group, SE and CE groups or between healthy and CE groups at different days before or after E2 treatment. There was a strong positive correlation between resistance parameters, the PI and RI and velocity (TAMAX) parameters and volume (BFV) parameters. Also, there was a strong positive correlation between E2 concentrations and TAMAX velocity, BFV and uterine arteries diameter. While, there was a strong negative correlations between E2 concentrations and resistance parameters, the PI and RI.
Based on the scope of this study we can conclude that:
1. Uterine body is the best, easiest and more representative site to collect endometrial cytology for diagnosis of endometritis.
2. The cytobrush technique can provide sufficient uterine cells to perform both cytology and RNA extraction for gene expression analysis with a single sample.
3. The analysis of cytokine gene expression, especially IL-8, showed a strong correlation with endometrial inflammation in terms of PMN%.
4. The high correlation between IL8 and IL-16 gene expression in endometrial cytology in clinical endometritis indicates that their monitoring alone at 4 weeks postpartum may be sufficient to predict uterine inflammation.
5. The inflammatory cytokines are expressed in the bovine endometrium in a time-related manner during the postpartum period with a peak of expression around week 2 pp.
6. Lactofferin is a very effective treatment for subclinical and clinical endometritis in the postpartum dairy cow.
7. Transrectal colour Doppler sonography is a suitable non-invassive tool for measuring changes in uterine perfusion during pueriperium in dairy cows.
8. Administration of estradiol benzoate greatly increased uterine blood flow in postpartum dairy cows.
9. There were no characteristic changes in uterine blood-flow patterns between healthy and endometritis cows, therefore, transrectal Doppler sonography is not suitable tool for diagnosis of endometritis in dairy cows.