Surgical Repair of an Intrathoracic Esophageal Pulsion Diverticulum in a Horse

An intrathoracic esophageal pulsion diverticulum causing repeated episodes of esophageal obstruction in a Morgan weanling colt was diagnosed by endoscopy, positive contrast radiography, and pleuroscopy. Surgical excision of the diverticulum alleviated clinical signs, and the horse was able to resume a normal diet by day 6. After 9 months the colt remains asymptomatic.     

Modulation of Ovarian Function in Female Dogs Immunized with Bovine Luteinizing Hormone Receptor

Adult female dogs were immunized with 0.5 mg bovine luteinizing hormone receptor (LH-R) encapsulated in a silastic subdermal implant and subsequently with four intramuscular booster injections of 0.1 mg LH-R each. Circulating LH-R antibody was detected in the sera 3 weeks post-implant. The appearance of LH-R antibody was associated with a decline in the serum progesterone concentrations to a range of 0–0.5 ng/ml until day 365 in the immunized dogs in comparison with a range of 5–10 ng in the control animals, suggesting a lack of ovulation and corpus luteum function in immunized dogs. The immunized dogs did not show signs of `standing heat' and failed to ovulate when induced by LH-RH challenge. Serum oestradiol levels, however, remained in the range of 30–40 pg/ml in both the immunized and the control dogs. With the decline in the antibody titres, the hormonal profile and vaginal cytology returned to a fertile state and the dogs exhibited signs of `standing heat', as well as vaginal bleeding. Dogs immunized with LH-R did not show any serious metabolic, local or systemic adverse effects. The hypothalamic–pituitary gonadal axis remained intact as indicated by little difference in pituitary LH levels between control and immunized animals, and by the release of LH by LH-RH challenge. These studies demonstrate that active immunization of female dogs with LH-R could immunomodulate ovarian function to cause a reversible state of infertility. It may be postulated that, due to extensive interspecies homology, a recombinant LH receptor-based immunocontraceptive vaccine may also be effective in other vertebrates.     

Immunolocalization of Melatonin and Follicle‐Stimulating Hormone Receptors in Caprine Ovaries and their Effects During in vitro Development of Isolated Pre‐Antral Follicles

The expression of melatonin type 1 (MT1) and FSH (FSHR) receptors in caprine ovaries and the effects of these hormones on the in vitro development of isolated pre‐antral follicles were evaluated. Follicles (≤200 μm) were cultured for 12 days in α‐MEM (control) or melatonin (100 or 1000 pg/ml) or sequential melatonin medium (100 pg/ml: from day 0 to day 6; 1000 pg/ml: from day 6 to day 12; experiment 1) and in control or sequential FSH (100 ng/ml from day 0 to day 6; 500 ng/ml from day 6 to day 12) or sequential melatonin or this latter plus sequential FSH (experiment 2). MT1 and FSHR expressions were observed in granulosa cells from secondary and antral follicles. The oocytes from primordial and primary follicles also express FSHR. Sequential melatonin increased the percentage of normal follicles and oocyte recovery compared with the control or melatonin (1000 pg/ml) at day 12. In experiment 2, all the treatments increased the normal follicles and growth compared with the control. In conclusion, this study demonstrated the presence of MT1 and FSHR in caprine ovaries. The addition of increased concentrations of melatonin (sequential medium) or FSH can be used to promote the in vitro development of caprine pre‐antral follicles.     

Animal production evaluation of herbage varieties.

Perennial ryegrass/white clover (Lolium perennel Trifolium repens) pastures of three white clover varieties were compared at UK lowland (Plas Gogerddan, PG) and upland (Bronydd Mawr, BM) sites over three harvest years (1989–91) under continuous variable stocking (ewes and lambs until weaning and lambs thereafter). Mean annual lamb output from small-leaved S 184 (1179 kg ha^?1) was 29% greater than that from prostrate small-leaved AberEndura at PG with medium-leaved Huia also giving 19% more output than AberEndura. At BM, output from S 184 (863 kg ha^?1) was 19 and 14% greater than that from AberEndura and Huia respectively. The differences in lamb output between the small-leaved varieties owed to a combined effect of higher individual lamb growth rates and greater stock-carrying capacity, both of which were more pronounced in the post-weaning period. The higher output from S 184 relative to Huia at BM was attributed to higher stocking rate, particularly after weaning. Clover productivity and persistence were also studied under three cutting-only managements at PG. Performance under a treatment cut at 2–3 cm every 10 d (T1), which is synonymous with assessment of persistence in UK National List testing, was poor with clover growing point number of only 498 m^?2 compared with 4906 m^?2 on the grazed sward in autumn 1991. Although productivity and clover content under T3 (cut at 3–4 cm every 42 d — similar to National List yield regime) gave the same varietal ranking as lamb production, there was an under-estimation of the small-leaved varieties, particularly AberEndura, relative to Huia. An intermediate treatment (T2), cut at 3–4 cm every 21 d, also over-estimated the performance of the medium-leaved variety. Herbage data from ground level sampling every 21 d using exclosure cages on the grazed swards were also poorly related to lamb performance. These results highlight the effect of clover variety on lamb production, which appeared to be independent of leaf size, and also confirm the existing problems associated with assessment of white clover varieties using a cutting regime.     

Potential use of activated carbon as a protectant against pre-emergence herbicides in direct-seeded processing tomatoes

Activated carbon protected direct-seeded tomato (Lycopersicon esculentum Mill., cv. UC 82B) against pre-emergence applications of metribuzin and metolachlor, but not of oxyfluorfen or oxadiazon. Accurate placement of activated carbon on the soil surface directly above the seed was necessary for protection of tomato seedlings. Displacement of the carbon by overhead watering reduced its protective properties. A major disadvantage of the technique is that weed seeds under the activated carbon are also protected. Also, of the chemicals examined here, those against which it did provide protection did not control Solanum nigrum L. Utilisation potentielle du charbon actif comme phytoprotecteur des tomates conduites en semis direct contre les herbicides de prelevee Le carbone actif a protege des tomates en semis direct (Lycopersicon esculentum Mill., cv UC 82 B) contre des applications de prelevee de metribuzine et de metolachlor mais pas d'oxy-fluorfen ou oxadiazon. Une locahsation précise du charbon actif sur la surface du sol directe-ment au dessus de la graine est necessaire pour la protection des plantules de tomate. Le déplacement du charbon par arrosage réduit ses propriétés de protection. Un inconvénient important de la technique est que les graines d'adventices sous le charbon actif sont égale-ment protégées. En outre, les produits chimiques examinés ici qui assurent une protection, ne sont pas actifs contre Solanum nigrum L. Aktivkohle als Schutzmittel gegen Vorauflauf-Herbizide in gesdten Tomaten Mit Aktivkohle konnten gesate Tomaten (Lycopersicon esculentum Mill., ‘UC 82B’) gegen die Vorauflauf-Anwendungen von Metribuzin und Metolachlor geschutzt werden, jedoch nicht gegen Oxyfluorfen oder Oxadiazon. Fur den Schutz der Tomaten-Keimpflanzen mußte die Aktivkohle ganz genau uber den Samen auf die Bodenoberflache ausgebracht werden. Ver-schwammen der Kohle durch Beregnung reduzierte ihre Schutzwirkung. Ein großer Nachteil dieser Methode liegt darin, daß keimende Unkrauter unter der Aktivkohle ebenso geschutzt werden. Auch konnte mit den hier untersuchten Herbiziden Solanum nigrum L. nicht bekampft werden.     

Comparison of the Johne''s absorbed EIA and the complement-fixation test for the diagnosis of Johne''s disease in cattle

A commercially available absorbed ELISA for the diagnosis of Johne's disease (JD) (paratuberculosis) in cattle, the Johne's Absorbed EIA, was compared with the conventional complement-fixation test (CFT) used in Australia. Stored plasma from 3 Victorian dairy herds with a history of JD, sera from specimens submitted from animals showing clinical signs of JD and sera from the US National Repository for Paratuberculosis Specimens were used to determine the sensitivity of each test. The EIA detected 48.8% of 43 Australian animals with subclinical JD, while the CFT detected only 12 (21.4%) of 56 subclinically affected cattle. Of 150 subclinically infected US cattle, the EIA detected 47.3% and the CFT detected 52.0%. The EIA detected 59.7% of animals which at the time of sampling were shedding Mycobacterium paratuberculosis in their faeces, but showed no clinical signs of JD, while the CFT detected 57.3%. The EIA correctly identified 88.2% of 136 histologically confirmed clinical cases, and the CFT detected 83.4%. The specificity of each test was determined by testing sera collected at slaughter from animals residing in a known JD-free area of Australia, and from samples from the US National Repository of Paratuberculosis Specimens collected from certified-free herds in Wisconsin. The EIA was found to have a specificity of 99.8% when 998 Australian animals were used as the test population, and 99.0% when 196 US animals were used. The specificity of the CFT using Australian samples was 96.9% and 95.2% using American samples.     

Variation in spring temperatures, grass production and response to nitrogen over twenty years in the uplands

Large between-year variation was observed in spring air and soil temperatures at Pant-y-dwr Hill Centre (305 m altitude) from 1967 to 1984 and at Bronydd Mawr Research Centre (330 m) from 1985 to 1986 in Powys. The mean date of attaining T-sum 200°C accumulated air temperature was 13 March (range 9 February to 23 April) and that of soil temperature at 100 mm depth permanently above 5 5°C was 9 April (range 7 March to 4 May). Net herbage accumulation and response to applied N from Aberystwyth S23 perennial ryegrass (Lolium perenne L.) swards during April were also highly variable and were correlated with the date of reaching target soil temperatures of above 5 5°C for 5 consecutive days ( r =−0·68, P < 0·001 for net herbage accumulation and r =−0·70, P < 0·001 for response to N).
The use of early flowering varieties of perennial ryegrass gave a significant increase of herbage growth in spring compared with late varieties. From 1979 to 1980 net herbage accumulation during April from the early variety Frances was 94% more than from Perma (late) and 55% more than from Talbot (intermediate) varieties. Under conservation management more winter hardy and persistent varieties of Italian and hybrid ryegrasses ( L. multiflorum L. and L. multiflorum X L. perenne ) gave higher quantities of firstcut silage crops in early June than RvP Italian ryegrass.
After the severe winters of 1978–79 and 1985–86, subsequent spring production from a wide range of ryegrasses was shown to be affected by sward survival, highlighting the value of winter hardy varieties when resowing in the uplands     

A LUMBOSACRAL TRANSITIONAL VERTEBRA IN THE DOG PREDISPOSES TO CAUDA EQUINA SYNDROME

The association between the occurrence of a lumbosacral transitional vertebra (LTV) and the cauda equina syndrome (CES) in dogs was investigated. In 4000 control dogs without signs of CES, 3.5% had an LTV, while in 92 dogs with CES, 16.3% had an LTV. The lesion causing CES always occurred between the last true lumbar vertebra and the LTV. Dogs with an LTV were eight times more likely to develop CES than dogs without an LTV. German Shepherd dogs were eight times more likely to develop CES compared with other breeds. Male dogs were twice as likely to develop CES than females. Dogs with an LTV develop CES 1-2 years earlier than dogs without an LTV.