A modified technique for flushing ova from the sheep uterus

Abstract

Extract

Sheep ova are normally obtained from the reproductive tract using the flushing techniques described by Hunter et al. (1955) Cumming, I. A. and McDonald, M. F. 1967. The production of ova by New Zealand Romney ewes following hormonal stimulation. N.Z. Jl agric. Res., 10: 226–236. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]. Oviduct flushes, in the writers' experience, give a higher recovery of ova than uterine flushes, but they result in more adhesions of the tract, which can cause infertility. Consequently, the development of satisfactory uterine flushing techniques appears necessary before ova can be recovered repeatedly from superior ewes. This paper describes such a technique.     

超排母牛采卵后预防炎症的必要性及技术要点

目前奶牛场多数奶牛品质较差 ,产量低 ,平均单产奶量仅 40 0 0千克左右 ,同畜牧业发达国家的奶牛相比相差较大。近年来 ,在奶牛的繁育中 ,胚胎工程技术已经走出了实验阶段 ,并开始商品化应用于生产中 ,鲜胚移植受孕率平均65%左右 ,冷冻胚胎的受孕率平均 40 %左右。该技术在奶牛生产中合理应用不仅可以提高繁殖率 ,而且可以加快育种进程 ,对于提高奶牛产奶量和奶牛生产经济效益具有重要意义。然而由于受许多因素影响 ,胚胎移植不能象人工授精那样很快被基层养牛户接受。分析原因 ,除胚胎移植成本较高外 ,另一个主要原因是在牛胚胎移植过程中…     

Ultrasonographic observations of the uterine regression in the ewe under different obstetrical conditions

Involution of the ovine uterus after parturition was studied using real-time B-mode ultrasonography. The diameter of the uterus, the uterine lumen and the caruncles were investigated during the first 30 days post-parturition (p.p.) by transrectal and transabdominal application of the ultrasound probe. Ewes that spontaneously delivered showed a physiological regression of the uterus with a transversal diameter of 4.9 (+/- 0.86) cm on day 1 p.p. which decreased to 1.84 (+/- 0.14) cm until day 30. The course of uterine regression was established on these data and was described by the exponential equation: y = E + A * e(-b*t). 'E' means the final value on day 30 p.p. and 'A' the difference between the initial transversal diameter on day 1 p.p. minus the final value on day 30 p.p. The exponents 'b' and 't' indicate the downward gradient of the regression curve and also the factor time in days. Furthermore, we found that the uterine regression in ewes finishes approximately on day 17 p.p. The uterine involution was delayed in ewes after manual obstetrics and caesarean section, in addition the incidence for retention of foetal membranes was increased. The present study demonstrates that the ultrasonographic technique is a suitable method for the control of the uterine involution and for the diagnosis of pathological aberrations in sheep.     

Hydroureteronephrosis and fetal mummification secondary to uterine torsion in a Merino ewe

A 6 year old pluriparous Merino ewe was presented for investigation of a large intra-abdominal mass. Post-mortem examination revealed a 360° clockwise uterine torsion was present with a mummifying fetus. The torsion involved the left ureter resulting in a severe hydroureteronephrosis. Uterine torsion is uncommon in the ewe, occurring in less than 0.1% of pregnancies in one report (Mahmoud et al. Livest Res Rural Dev 2018;30), but cases are likely to be undiagnosed, particularly under the extensive management conditions typical of Australia. The chronicity of the condition in this ewe would support this statement. To the authors' knowledge this is the first reported case of hydroureteronephrosis secondary to uterine torsion in any species.     

A surgical technique for the long term collection of bile in the pig and measurement of the biliary excretion of copper and zinc

A method is described for surgically modifying the gastrointestinal tract of the pig which enables the long term collection of bile and measurement of bile flow and allows the pig to be kept unrestrained in a large pen. Three surgically prepared gilts grew at an average of 0.79 kg d-1. Bile flow increased with bodyweight from 1.6 ml min-1 at 45 to 50 kg to 3.5 ml min-1 at 124.5 kg bodyweight. Mean output in bile of copper and zinc by the three gilts during the period 08.00 to 12.30 was 161.0 +/- 11.1 and 3.94 +/- 0.41 nmol min-1, respectively. The calculated output during 24 hours represented approximately 5.8 and 0.13 per cent of the daily intake of copper and zinc, respectively.     

Isolation of Mycobacterium paratuberculosis from the uterine flush fluids of cows with clinical paratuberculosis

Mycobacterium paratuberculosis was isolated from the uterine flush fluids obtained from 3 to 4 cows with clinical paratuberculosis. Four cows with clinical paratuberculosis were subjected to uterine lavage, using an established embryo recovery technique, and the recovered fluids were cultured for M paratuberculosis. Mycobacterium paratuberculosis has previously been demonstrated to adhere to bovine ova. Embryos within the uterus of a superovulated cow infected with M paratuberculosis could be exposed to the organism.