DIAGNOSIS OF COMMON CONGENITAL HEART ANOMALIES IN THE DOG USING SURVEY AND NONSELECTIVE CONTRAST RADIOGRAPHY

The most common canine congenital heart anomalies include patient ductus arteriosus, ventricular septal defects, tetralogy of Fallot, pulmonic stenosis, and aortic stenosis. Survey radiography and nonselective (venous) angiography can allow the practicing veterinarian to confirm the diagnosis in many of these patients. Typical radiographic findings using these diagnostic procedures are reviewed. Nonselective angiocardiography is a relatively easy, rapid, and noninvasive procedure which can be performed using conventional equipment. The major disadvantage of this special procedure is that the superimposition of opacified structures can make the identification of some left-to-right shunts difficult. Dilution of contrast medium can occur if a rapid bolus injection is not made.     

血清、精清中锌和睾酮含量与种公牛精液品质的关系

对9头种公牛连续测定5次血清、精清中锌和睾酮的浓度,研究了锌、睾酮和精液品质的相互关系。结果表明,血、精清中的锌和睾酮含量呈正相关(P<0.01),血、精清锌与精液 冻后活力和顶体完整率呈正相关(P<0.01),与精子畸形率呈弱负相关(P<0.05)。精液品质与血、精清中睾酮浓度呈正相关。     

THE ISOLATION OF SALMONELLA FROM JEJUNAL AND CAECAL LYMPH NODES OF SLAUGHTERED ANIMALS

One jejunal and one caecal lymph node were sampled from each of 50 cows, 40 yearling cattle, 25 sheep, 20 lambs and 45 pigs after slaughter. Salmonella, Clostridium perfringens and Staphylococcus aureus , all organisms which cause food poisoning in man, were sought by direct plating methods. The samples were also enriched and cultured for Salmonella. Organisms were cultured from 208 (58%) of the 360 lymph nodes; aerobic plate counts yielded up to 25,000 organisms per gram of tissue, although from most infected samples less than 1000 organisms per gram were cultured. Salmonella was isolated directly from 5% of samples, with counts up to 1,500 per gram. After enrichment Salmonella was isolated from nodes taken from 15 cows, 2 yearling cattle, one sheep and 8 pigs. Cl. perfringens was isolated from the caecal nodes of 2 yearling cattle and 2 pigs; S. aureus was not isolated from any sample. It was concluded that mesenteric lymph nodes may be a significant reservoir of Salmonella for transfer to meat and meat products.     

THE RELATIONSHIP BETWEEN A SERVING CAPACITY TEST AND FERTILITY OF BEEF BULLS

SUMMARY In a trial using Bos indicus and Bos taurus bulls in a tropical environment the serving capacity, defined as the number of complete services achieved during a 40-minute yard test, failed to predict the fertility of the bulls after 3 or after 7 weeks of mating. The numbers of services achieved during the yard test were much lower than those reported from a temperate region using Bos taurus bulls.     

对牦牛和普通牛种间杂种公牛精子生成水平的研究

本文对牦牛和普通牛种间杂种公牛睾丸组织及电刺激所采精液进行了观测。结果表明,种间杂种公牛随代数增加,睾丸逐渐恢复产生精子的机能。种间杂种3代公牛有的可产生形态正常的精子。种间杂种3代是可育或不育(不能产生精子)的临界代。     

屠宰母牛卵巢卵母细胞体外受精与发育的研究

将从屠宰母牛卵巢采得的卵母细胞用含有LH或hCG的M199培养24～26小时,然后用经钙离子载体Ionophore A23187诱导获能的牛新鲜或冷冻精子进行授精处理。授精6～7小时后再用含有乳酸钠和EDTA的M199培养至48～60小时后观察受精及受精卵的发育情况。结果表明,卵子的受精率及受精卵的发育率与卵母细胞成熟用培养基、授精用精子(新鲜或冷冻)以及供卵牛的品种均有关系。将用含有hCG的M199培养成熟的卵子,以获能处理过的新鲜精子授精后,其受精率和受精卵子中单精子受精并发育为2～8细胞期胚的比率在蒙古牛为91.4％(265/200)和19.6％(52/265),在黑白花奶牛为69.7％(62/89)和4.8％(3/62)。     

砷的发育毒性和致癌性

本文对砷的发育毒性和致癌性的最新研究进展进行了综述。据此，作者建议应尽早禁用砷制剂作为饲料添加剂使用。     

THE INFLUENCE OF AGE ON THE SUSCEPTIBILITY OF BULLS TO CAMPYLOBACTER FETUS SUBSP VENEREALIS

Observations were carried out on 22 Hereford bulls to determine the age at which they bacame carriers of C. fetus. During preliminary investigations, 5 bulbs were repeatedly exposed to the organism by artificial or natural means from the age of 18 months. All animals became longterm carriers on reaching an age of between 40 and 70 months. Prior to this, a temporary carrier state lasting from 4 to 29 days was produced in 4 bulls. In a subsequent experiment, 17 bulls of 3 different age groups were artificially exposed to C. fetus on 5 occasions over a 2-year period. Thirteen bulls became long-term carriers, including 9 (53%) when less than 4 years old. A transient carrier state occurred in 4 bulls, 2 of which subsequently became long-term carriers. It usually lasted 1-2 weeks, although in 1 animal the organism persisted for 11 weeks. These results are discussed in relation to the findings of other workers and it is concluded that the use of young bulls to limit the spread of C. fetus in infected herds is of dubious value.     

MASCULINISATION OF THE EXTERNAL GENITALIA IN EWES WITH CLOVER DISEASE

Prolonged exposure of ewes to oestrogenic pasture resulted in partial fusion of the labia of the vulva and hypertrophy of the clitoris. Partial fusion of the labia was also seen in ewes which had grazed oestrogenic pastures on normal commercial properties, and was related to the amount of histological change in the cervix. This lesion may be useful as a screening test for previous exposure to oestrogenic pasture.     

BREED DIFFERENCES IN ABNORMALITIES OF THE REPRODUCTIVE ORGANS OF YOUNG BEEF BULLS

SUMMARY A total of 702 examinations were conducted on young (16 to 31 months) beef bulls of 3 breeds and 3 breed crosses (Brahman cross — 100; Africander cross — 93; Shorthorn cross — 109; Brahman — 81; Africander — 89, and Hereford — 230). A high occurrence of both increased size (overall 11.7%) and consistency (overall 40.2%) of seminal vesicles was observed. The Hereford breed had most enlarged (19.1%, P.01) and firm (20.9%, P.01) seminal vesicles. The significance of these findings is discussed. Testicular hypoplasia was diagnosed in 2.7% of examinations. The Brahman breed had most testicular hypoplasia (8.6%, P.01). The implications of this finding are discussed and the need is stressed for a wider investigation of gonad development in the Brahman breed in Australia. Other findings included: small seminal vesicles in 1.6% of examinations (Brahman breed highest with 8.6%, P.001), enlarged ampullae, 1.9%, ‘soft’ testicles, 3.4% and small testicles, 7.5%. Abnormal carriage of the testicles was detected in 0.3% of examinations. Ulceration of the prepuce was observed in 6.8% of examinations. The highest occurrences were in the SH (13.8%, P.01) and Africander (13.5%, P.05) breed groups. Varying degrees of preputial eversion or prolapse were seen in 0.7% of examinations with the Bx breed group having highest representation (3.0%, P.05).     

BREED DIFFERENCES IN THE RESPONSE OF YOUNG BEEF BULLS TO ELECTRO-EJACULATION

SUMMARY A total of 702 electro-ejaculation attempts are recorded on young (16 to 31 months) beef bulls of 3 breeds and 3 breed crosses (Brahman cross 100, Africander cross 93, Shorthorn cross 109, Brahman 81, Africander 89, and Hereford 230. Four hundred and forty of these attempts were conducted on bulls of the first 5 of these breeds which had been reared under similar conditions on the same property. The machine employed was a Watson Transtimulator, powered by a 12-volt automobile battery, and connected to a 6.25 cm diameter bipolar ring electrode probe, 37.5 cm in length. The voltages at which the sperm free (sample A) and sperm rich (sample B) samples were initiated were 4.8 ± .2 and 7.7 ± .2 volts respectively. No breed differences occurred. Breed differences occurred in the proportion of bulls showing a severe reaction to the electricity (P < 0.001) with the Africander (32.6% P < 0.001) and Ax (28.0% P < 0.01) having the highest proportions of severe reactions. These 2 breed groups also had the highest proportions of electro-ejaculation failures (respectively, 23.6% P < 0.05 and 19.4% n.s.). Overall, bulls of Bos indicus derivation did not differ from those of Bos taurus derivation in electro-ejaculation failures. During stimulation, erection was achieved by 19.8% of bulls and failure to collect an assessable ejaculate occurred in 15%. No breed differences occurred in either category. Collapse during stimulation occurred in 5.3% of electro-ejaculation attempts (overall P < 0.05) with the SH breed group having highest representation (12.8% P < 0.001).