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1.
Uterine tube abnormalities as a cause of bovine infertility 总被引：2，自引：0，他引：2
A total of 2000 bovine reproductive tracts (1000 parous and 1000 nulliparous) from freshly slaughtered animals were examined for uterine tube abnormalities and lesions. Tubal lesions were recorded in 180 tracts (9.0 per cent). More parous tracts (6.4 per cent) had tubal lesions than nulliparous tracts (2.6 per cent). The most frequently identified lesion was ovarobursal adhesions which comprised 80 per cent of all abnormalities and were identified in 6.85 per cent of all the genital tracts examined. The uterine tubes were insufflated with carbon dioxide gas to a maximum pressure of 300 mm Hg; 22 were found to be occluded even though they were macroscopically normal. 相似文献
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The effects of oestrogen and progesterone, injected alone or during successive periods, were studied in mature ovariectomised ewes on sodium intakes ranging from 1 to 4 mmol kg-1 d-1. Progesterone had no effect on fluid and electrolyte balance. Oestrogen (17 beta oestradiol) inhibited drinking but had little effect on water excretion whereas it reduced both food intake and urinary potassium concentration. Since the resulting changes in potassium intake and excretion were very similar, oestrogen had little net effect on potassium balance; neither change lasted beyond the treatment period. Oestrogen had a biphasic effect on urinary and faecal sodium excretion, an initial enhancement of salt loss being followed by sodium retention. Faecal sodium retention and the biphasic effect on renal sodium excretion were independent of changes in food intake. These observations are discussed in relation to the pattern of change of electrolyte balance during the reproductive cycle and the influence of changes in food intake and factors affecting sodium preference. The fact that a variety of responses is involved in a coordinated change of sodium balance is emphasised and its possible importance is considered. 相似文献
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Laboratory studies were conducted to test the ability of brook charr (Salvelinus fontinalis) alevins, the earliest free-swimming life stage of the species, to detect and avoid toxic levels of H+ and inorganic Al. Alevins were tested in steep gradient choice tanks using a range of H+ (pH 4.0 to 5.5) and Al (0 to 500 μg L?1) concentrations in low Ca (2.0 mg L?1) water. The young brook charr actively avoided acidic water with a pH < 5.0. Aluminum additions of 500 μg L?l increased the avoidance response. The observed behavioral response of alevins to low pH and elevated levels of Al, may be of significant adaptive advantage in systems undergoing acidification. 相似文献
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Bacterial flora of the uterus of cows after calving on two hygienically contrasting farms. 总被引：1，自引：0，他引：1
Intrauterine swabs were obtained from cows after calving on two commercial dairy herds with contrasting hygienic environments and incidence of leucorrhea, and cultured aerobically and anaerobically. Of 26 cows with a normal calving and puerperium, eight of 14 (57 per cent) were sterile on farm B where hygiene was poor, compared with five of 12 (42 per cent) on farm A where hygiene was better. Two cows on farm B retained their placentas and subsequently developed metritis/endometritis. Actinomyces pyogenes was the commonest bacterial isolate and Fusobacterium nucleatum, Proteus mirabilis and Bacteroides melaninogenicus were also frequently observed. Similar isolates were obtained from cows on farm B with parturient or puerperal disorders. The contrasting hygienic environments had no influence on either the quantitative or qualitative uterine bacterial flora. Thus, the difference in the incidence of endometritis must have been due to factors other than hygiene. 相似文献
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Uterine and cervical involution after calving was measured sequentially in 25 parous commercial Friesian cows by using electronic calipers and real-time ultrasound imaging, transrectally. Ovarian activity was monitored by using real-time ultrasound imaging and by the assay of milk progesterone concentrations. Peripheral plasma prostaglandin F2 alpha metabolite concentrations were assayed during this period. Five groups of five cows were treated intramuscularly, approximately 48 hours after calving, with either 100 mg progesterone in oil, 25 mg dinoprost tromethamine, 5 mg oestradiol benzoate, 1.2 mg of the long-acting oxytocin analogue carbetocin or 5 ml sterile water. There were no statistically significant differences between the intervals from calving to the completion of involution or between the intervals from calving to the first ovulation for the cows in the different groups. The mean PGFM concentrations in the peripheral circulation were significantly higher in the carbetocin-treated group, presumably owing to the stimulation of endogenous prostaglandin F2 alpha secretion. This study provides no evidence that a single treatment with any of the four hormones significantly affected the reproductive function of the cows after calving. 相似文献
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本实验监测8头围产期奶牛外周血浆中胶原蛋白和肌浆球蛋白的代谢产物——羟基脯氨酸(HP)和3甲基组氨酸(3MH)的含量,借以找出这两种蛋白质的代谢规律和子宫复旧的关系。结果表明:荷兰黑白花牛和娟珊牛血浆中HP的含量和子宫角直径分别呈显著及极显著正相关(r=0.41,P<0.05和r=0.57 P<0.01),而3MH分别呈极显著和显著正相关(r=0.52 P<0.01和r=0.39(P<0.05)。此外,黑白花牛血浆中3MH的含量极显著高于娟珊牛(P<0.001)。两个品种牛子宫复旧的平均时间,黑白花牛为37.4±3.1天,娟珊牛32.3±2.1天。结果说明牛产后子宫体积的缩小与子宫肌肉的胶原蛋白和肌浆球蛋白降解成氨基酸排出体外有关,子宫复旧的速度可能决定于这两种蛋白质的降解速度。 相似文献
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