山羊传染性胸膜肺炎支原体和绵羊肺炎支原体对抗菌药物敏感性的研究

测定了环丙沙星、氧氟沙星、单诺沙星、红霉素、罗红霉素、泰乐菌素、泰妙菌素、四环素等8种药物对羊肺炎支原体两个标准株Y-98和Y-goat的体外抑菌浓度以及红霉素与氧氟沙星、泰乐菌素对Y-goat和四环素与氧氟沙星、泰乐菌素对Y-98的联合药敏作用.结果表明,这8种抗菌药物对Y-goat和Y-98的MIC(μg/mL)分别为:环丙沙星0.223、0.002 23,氧氟沙星0.281、0.014 0,单诺沙星0.136、0.014 0,红霉素0.021 8、无效,罗红霉素0.032 7、无效,泰乐菌素0.042 2、0.039 0,泰妙菌素0.021 7、0.052 0,四环素0.195、0.052 0.红霉素与氧氟沙星的联合药敏指数为1,是相加作用;红霉素与泰乐菌素对Y-goat的联合药敏指数为1.5,是无关作用;四环素与氧氟沙星、泰乐菌素对Y-98的联合药敏试验指数均为0.375,是协同作用.     

In vitro studies of Norwegian Red bovine semen immobilized and cryopreserved in alginate solid gel network

Development of new semen cryopreservation techniques improving sperm survival and ensuring availability of viable spermatozoa for a prolonged time‐period after AI is promising tools to reduce sensitivity of timing of AI and enhance overall fertility. The SpermVital^® technology utilizes immobilization of bull spermatozoa in a solid network of alginate gel prior to freezing, which will provide a gradual release of spermatozoa after AI. The objective of this study was to compare post‐thaw sperm quality and in vitro sperm survival over time of Norwegian Red bull semen processed by the SpermVital^® (SV) technology, the first commercialized production line of SpermVital^® (C) and by conventional procedure applying Biladyl^® extender (B). Post‐thaw sperm motility was not significantly different between SV, C and B semen (p > .05). However, sperm viability and acrosome intactness were higher for SV than C and B semen (p < .05). Small differences in DNA quality were observed (p < .05). Sperm viability after storage in uterus ex vivo was higher for SV than for C semen (p < .05). Furthermore, sperm survival in vitro over time at physiological temperature was significantly higher for SV semen than C semen as well as B semen during the incubation period of 48 hr (p < .05). In conclusion, the SpermVital^® technology is improved and is more efficient in conserving post‐thaw sperm quality and results in higher sperm viability over time in vitro for SV than for C and B semen.     

Cardiac evaluation of anesthetized Grevy's zebras (Equus grevyi)

OBJECTIVE: To determine ECG and echocardiographic measurements in healthy anesthetized Grevy's zebras (Equus grevyi). ANIMALS: 20 healthy zebras. PROCEDURES: Auscultation, base-apex ECG, and echocardiography were performed on anesthetized zebras. RESULTS: Low-grade systolic murmurs were detected in the left basilar region in 4 of 20 zebras. Evaluation of ECGs from 19 zebras revealed sinus rhythm with a predominantly negative QRS complex and a mean +/- SD heart rate of 67 +/- 10 beats/min. Echocardiograms of sufficient image quality were obtained for 16 zebras. Interventricular septal thickness in diastole, left ventricular chamber in diastole and systole, left atrial diameter, and left ventricular mass were significantly and moderately correlated with estimated body weight (r values ranged from 0.650 to 0.884). Detectable swirling of blood in the right and sometimes the left ventricles was detected in 9 of 16 zebras, whereas physiologic regurgitation of blood was detected for the aortic valve in 3 zebras, pulmonary valve in 2 zebras, mitral valve in 2 zebras, and tricuspid valve in 1 zebra. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study provide reference information for use in the cardiac evaluation of anesthetized Grevy's zebras.     

Pericardial lipoma in a geriatric dog with an incidentally discovered thoracic mass

An intrathoracic mass was discovered as an incidental finding in a 14-year-old, spayed, female Rottweiler cross during evaluation of urinary incontinence. Computed tomography suggested a pericardial or pleural location and high adipose content of the mass. The mass was removed via lateral thoracotomy with partial pericardectomy and was diagnosed as a pericardial lipoma. The dog recovered well, and there was no evidence of recurrence approximately one year later. Adipose tumours of the heart and its associated structures are rare in dogs and have been associated with both successful and fatal outcomes.     

Pregnancy Rate in Zebu Cows with Two Different Postpartum Intervals Exposed to a Two-Bull Rotational System

In order to evaluate the reproductive effect of a rotational breeding system, the pregnancy rate of 69 Zebu cows was assessed, 32 late postpartum (211±93 days postpartum, LP) and 37 early postpartum (averaging 63±8 days after calving, EP). In the LP group, 60% (19/32) were cycling before exposure to the bulls but only 38% (14/37) in the EP group. The two groups were dissimilar from the start (p<0.05). The cows were exposed in a rotational breeding system, with six Brahman bulls with previous sexual experience paired off in three groups (A–B, C–D and E–F). The cows were exposed to each pair of bulls for a period of 3 weeks, with one week in between each period, when the females were without the presence of a male. In the LP group, the pair of bulls A–B obtained a pregnancy rate of 72% (23/32), whereas for bulls C–D the pregnancy rate was 33% (3/9) and for bulls E–F the pregnancy rate was 67% (4/6). In contrast, for the EP cows, bulls A–B obtained a pregnancy rate of 32% (12/37), bulls C–D a pregnancy rate of 67% (12/18) and for bulls E–F a pregnancy rate of 55% (6/11). The percentage pregnancy obtained using the pair of bulls A–B differed (p<0.05) between LP and EP, whereas for bulls C–D and E–F it was similar. The pregnancy rate was different (p<0.05) in the first 3 weeks of mating for the LP group, the highest number of cows becoming pregnant during the first 3 weeks of the study. In contrast, the highest number of pregnancies in EP occurred evenly during the last 6 weeks. This study suggests that the reproductive performance of pairs of bulls in a 9-week rotational programme with the overall pregnancy rate is similar (94% in the LP and 81% in the EP). However, the time taken for the females to become pregnant, and hence the performance of the bulls, is related to the average number of days postpartum for the cows.     

Epidemiology of viral haemorrhagic disease and myxomatosis in a free-living population of wild rabbits

From January 1993 to June 1996, the epidemiology of myxomatosis and viral haemorrhagic disease (VHD) was studied in a free-living population of wild rabbits (Oryctolagus cuniculus) in Spain by means of serological surveys and radiotracking. Myxomatosis was endemic and associated with the breeding period. Its serological pattern was characterised by a 100 per cent prevalence of antibodies in adult rabbits and a rapid increase in antibodies in young rabbits in their first year. No mortality from myxomatosis was detected in adults, and mortality in young rabbits could not be estimated because of interference by predators and scavengers and the deaths of many radiotagged rabbits inside their burrows. VHD was also an endemic disease associated with the breeding period. Adults had a higher prevalence of antibodies against VHD than young rabbits, reaching values of 80 to 90 per cent. During the study, there was an increase in rabbit numbers as a result of a decrease in mortality from predation which was associated with an increase in mortality due to VHD and in the prevalence of antibodies to VHD. Mortality from VHD was lower in rabbits with VHD antibodies than in seronegative rabbits, but some mortality from the disease was also detected in seropositive rabbits. The annual mean mortality rate due to VHD in adult rabbits was estimated to be 21.8 per cent.