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Abstract.— Two experiments were designed to improve upon existing methods for cryopreserving striped bass Morone saxatilis , semen. In the first experiment, two extenders, two cryoprotectant concentrations, and two freezing rates were evaluated on the basis of post-thaw semen motility after 1, 7, and 30 d of storage at −196 C. Semen samples cryopreserved at a freezing rate of −40 C/m resulted in a significantly higher percentage of motile sperm ( P < 0.001) and longer duration of spermatozoa motility ( P < 0.001) than samples cryopreserved at a freezing rate of -30 Chin. Also, the cryoprotectant dimethyl-sulfoxide yielded a significantly higher percentage of motile sperm ( P < 0.001) and longer duration of spermatozoa motility ( P < 0.001) when a 5% concentration was used instead of 7.5%. In the second experiment, the two extenders from Experiment I were re-evaluated and a new extender, which was a modified version of Extender 1, was tested. The samples were cryopreserved at -40 C/min with 5% DMSO and thawed in a 25 C water bath. Spermatozoa motility and fertilization ability were evaluated, and semen cryopreserved in Extender 2 yielded the longest duration of spermatozoa motility ( P < 0.001). the highest percentage of motile sperm ( P < 0.001). and the highest percentage of fertilized eggs ( P < 0.002) in comparison to Extenders I and 3.  相似文献   
74.
Fifteen cows among a herd of 50 suckler cows and calves rapidly lost body condition and became dull and anorexic after grazing pasture containing bog asphodel (Narthecium ossifragum) during the summer of 1989. The affected cows had evidence of kidney damage characterised by elevated plasma urea and creatinine concentrations. Eleven cows died and diffuse renal tubular necrosis was present in three cows which were examined post mortem. Similar renal lesions were reproduced experimentally by feeding bog asphodel to a healthy calf.  相似文献   
75.
Embryo transfers from mares in athletic competition   总被引:1,自引:0,他引:1  
The objective of this project was to produce multiple pregnant recipient mares during one year from each of four mares which were in athletic training and competition. Twenty-six embryos were recovered from the four mares in 38 collection attempts. Each embryo was surgically transferred to one of 20 recipient mares. Nine of 10 recipient mares which were transferred to on one occasion were detected pregnant at the one week post transfer pregnancy examination and six of eight mares which were transferred to on two occasions were detected pregnant at one of the one-week post transfer pregnancy examinations. Three of the 15 pregnant recipient mares lost their pregnancies by day 150. The 12 resulting pregnant recipient mares from the four competing donor mares demonstrated that donor mares can remain in athletic competition and at the same time provide viable embryos for embryo transfer.  相似文献   
76.
Lumpy skin disease—A review   总被引:1,自引:0,他引:1  
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77.
Four horses were stabled and fed a diet of hay ad libitum, and 2 kg oats per animal per day, for a month. The basic diet was then supplemented with molybdenum, at a rate of 20 mg/kg dry matter for 4.5 months. For one month of this period the diet was supplemented also with sulphur at a rate of 1.2 g/kg dry matter. Analyses of jugular blood samples, obtained at intervals varying between two and 20 days, showed no evidence of a decline in total plasma copper or of an increased proportion of trichloroacetic acid (TCA) insoluble copper in plasma over this period. In separate studies, two other horses were given 99molybdenum (molybdate, 20 to 28 mg Mo, 4 mCi per animal) per os, initially while being fed the basic diet and later while maintained on the molybdenum supplemented diet. 99Molybdenum appeared rapidly in plasma, but the radioactivity was then quickly cleared (half-life 7 to 10 h). The 99molybdenum present was identified as (99Mo)-molybdate. There was no evidence of the persistent, protein-bound (99Mo)thiomolybdates which appear in ruminants. These studies indicate that increased dietary molybdenum is unlikely to interfere with copper metabolism in horses.  相似文献   
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An in vitro leukocyte-aggregation assay was developed to detect the exposure of swine to transmissible gastroenteritis virus. Leukocytes in heparinized blood samples aggregated when mixed with test antigen prepared from transmissible gastroenteritis-infected swine testicle cell cultures. Twenty-two of 23 swine exposed 3 days or more were positive or suspects in the assay; 6 nonexposed swine were negative. Aggregation was shown as early as 3 days postexposure in 1 sow and persisted for as long as 14 months in another. Persistence of the assay was proved by repeated evaluations on 2 experimentally exposed swine.  相似文献   
80.
Cross-protection studies between the feline infectious peritonitis (FIP) and the porcine transmissible gastroenteritis (TGE) viruses were conducted in cats, pigs and pregnant gilts. Cats vaccinated with TGE virus developed neutralizing antibodies against TGE virus and low titer antibody against FIP virus detected by an indirect fluorescent antibody technique but were not protected against a virulent FIP virus challenge. Baby pigs and pregnant gilts vaccinated with FIP virus did not develop detectable antibodies to TGE virus. Nevertheless, it appeared that vaccination of swine with FIP virus conferred some immunity against TGE virus infection. Seventeen-day-old pigs vaccinated with two doses of FIP virus had a 67% survival rate following a virulent TGE virus challenge, and 75% of the 3-day-old pigs suckling either FIP or TGE-virus-vaccinated gilts survived virulent TGE virus infection in contrast to 0% survival of baby pigs suckling unvaccinated gilts.  相似文献   
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