Antagonism of medetomidine sedation by atipamezole in pigs.

The efficacy of atipamezole as a medetomidine antagonist was evaluated in pigs. The atipamezole doses (intramuscularly) were 80, 160, 320 and 480 micrograms/kg of body weight, which were one, two, four and six times higher than the preceding medetomidine dose (80 micrograms/kg, intramuscularly). Atipamezole effectively reversed medetomidine-induced sedation, and the optimal action was seen at doses of 160 and 320 micrograms/kg. Recovery from sedation was quick and smooth, and adverse effects such as hyperactivity or tachycardia were minimal with either dose.     

Cross protection studies on Bordetella bronchiseptica in mice using an intracerebral challenge model.

Protective activities of heat-inactivated (60 degrees C for 30 min) merthiolate preserved Bordetella bronchiseptica and B. pertussis bacterins were compared in intraperitoneally immunized mice challenged intracerebrally (i.p./i.c.) or intraperitoneally (i.p./i.p.). In the i.p./i.c. assay (Kendrick test), a B. pertussis bacterin protected mice against challenge with B. pertussis 18-323, as well as against phase I cytotoxic and non-cytotoxic strains of B. bronchiseptica. A B. bronchiseptica bacterin, prepared from a phase I cytotoxic strain, gave protection against two phase I B. bronchiseptica strains, irrespective of their cytotoxin-production. A non-cytotoxic phase I strain of B. bronchiseptica elicited protection against the homologous strain only. Neither cytotoxic nor non-cytotoxic B. bronchiseptica strains protected mice challenged with B. pertussis 18-323. Vaccines prepared from phase III strains of B. bronchiseptica were not protective at all against any of the challenge strains. No such differences in the protective activities of the bacterins could be detected by the i.p./i.p. method. They seem to cross-protect equally well. The results indicate that the Kendrick test may be useful in testing potency of different B. bronchiseptica bacterins.     

Synchronization of estrus in dairy goats given norgestomet and estradiol valerate at various stages of the estrous cycle.

Dairy goats were given subcutaneous implants with 3 mg of norgestomet (NOR) and IM injections of 0.625 mg of estradiol valerate and 0.375 mg of norgestomet on day 0 of the estrous cycle (estrus; NOR 0, n = 18), on postestrus day 4 (NOR 4, n = 18), or on postestrus day 11 (NOR 11, n = 15). Ear implants were removed after 9 days. Mean (+/- SE) hours from removal of ear implants to onset of estrus and proportion of goats responding were 36 +/- 3.8 and 83%, 33 +/- 4.0 and 61%, and 36 +/- 2.7 and 93% for groups NOR 0, NOR 4, and NOR 11, respectively. There were no significant differences between treatment groups in time to onset of estrus. The percentage of goats in group NOR 11 that had signs of estrus was significantly greater than the percentage of goats in group NOR 4. Of the goats in groups NOR 0, NOR 4, and NOR 11 that had signs of estrus, 53, 55, and 86%, respectively, had onset of behavioral estrus between 24 and 48 hours after implant removal. All goats that had signs of estrus had onset of behavioral estrus between 12 and 72 hours after implant removal. Mean (+/- SE) hours from removal of ear implants to time of peak concentrations of luteinizing hormone (LH) were 49 +/- 4.1, 49 +/- 3.8, and 49 +/- 4.0 for groups NOR 0, NOR 4, NOR 11, respectively (not different). The percentage of goats in group NOR 11 that had LH peaks was significantly greater than the percentage of goats in group NOR 4.(ABSTRACT TRUNCATED AT 250 WORDS)     

Seroepidemiological survey of Corynebacterium pseudotuberculosis infection in sheep in Japan using enzyme-linked immunosorbent assay and immunodiffusion

Sera from 1186 apparently healthy sheep in Hokkaido were examined by enzyme-linked immunosorbent assay (ELISA) and immunodiffusion (ID) for the presence of antibodies against Corynebacterium pseudotuberculosis. ELISA-positives were 466 (39.3%) while ID-positives were 330 (27.8%). Spread of caseous lymphadenitis in sheep in Hokkaido was thus clarified. Although ID was less sensitive than ELISA in detecting the antibodies against C. pseudotuberculosis it did not give any non-specific reaction. From the results and in view of the simplicity of the test procedure, ID was found to be of practical diagnostic value. Distribution by age group of anti-C. pseudotuberculosis antibodies in 758 sheep in a herd detected by both tests showed that the ratio of positives was low in sheep aged less than 1 year, and the ratio increased significantly in those aged 1 year and continued to increase with age until it reached a plateau at the age of 4-5 years.     

The diagnostic significance of different blood parameters and liver biopsy in chronic copper poisoning of sheep

In a flock of sheep to which food with excess copper (= Cu) had been fed for some months 39 animals died of chronic copper toxicosis. In 5 sheep of this flock the plasma concentrations of the enzymes glutamate dehydrogenase (GLDH), sorbitol dehydrogenase (SDH), aspartate-amino-transferase (ASAT) and copper were measured several times over a period of 100 days. At day 23, 58 and 97 needle biopsies of the liver were taken. The biopsies were used for histological examination and Cu-analysis. After 100 days the sheep were slaughtered and chronic copper poisoning was diagnosed by raised Cu concentration and typical histological alterations in the liver. The activities of GLDH and SDH in the plasma of the 5 sheep were consistently above normal, ASAT activity and the plasma Cu level were raised only occasionally. The results of Cu determination in biopsy samples were of little predictive value compared with post mortem Cu analysis of the liver.     

Experience with Cyclosporin-A After Renal Allografting in Two Dogs Research Note

After renal allografting, cyclosporin-A was administered to one partially nonmatched dog that was followed for 79 days. Cyclosporin-A and prednisolone were administered to one nonmatched dog that was followed for 805 days. Side effects encountered with cyclosporin-A included lymphocytic dermatitis, papillomatosis, bacterial and fungal infections, and B lymphocyte hyperplasia.     

Response of Mustard to Ethrel Spray and Basal and Foliar Application of Nitrogen

In a field trial conducted during 1992–93 and 1993–94, the effect of basal (B) nitrogen (N) (45 and 60 kg N ha⁻¹) and foliar application (F) of water (W) or 10 kg N ha⁻¹ and 400 or 600 ppm ethrel (E) (2-Chloro ethyl phosphonic acid) at 70 days after sowing was studied on leaf area index and dry mass at 90 days and pod number per plant, seeds per pod, 1000 seed weight, seed yield, oil content and oil vield at harvest of mustard ( Brassica juncea L. Czern & Coss.) cv. T-59. Recommended basal (B) application of 90 kg N ha (BN₉₀) was used as control. On the basis of 2 year data it was found that basal application of 60 kg N and foliar spray of 10 kg N ha ⁻¹ and 600 ppm ethrel gave higher values for growth and yield characteristics and enhanced seed yield and oil yield by 12.5 and 14.8%, respectively over control BN_90.     

Selectivity estimates for Amblygaster sirm (Clupeidae) in the small-meshed gill net fishery on the west coast of Sri Lanka

Selectivity of Amblygaster sirm by gill nets of seven mesh sizes ranging from 2.3 to 3.8 cm stretched mesh was studied for a period of 12 months in the coastal waters off Negombo on the west coast of Sri Lanka. The size range of fish caught was 9.0–22.0 cm. Selection by mesh sizes smaller than 3.0 cm was towards the lower end of the selection curve.

Estimated values for selection factors ranged from 5.11 to 6.03 and those for optimum selection lengths varied from 12.9 to 19.7 cm. The highest selection factor was observed for 2.9 cm mesh, probably due to wedging of larger individuals in this mesh.     

Effect of Integration of Fertilizer and Green Manure Nitrogen on Yield Attributes, Nitrogen Uptake and Yield of Lowland Rice (Oryza sativa L.)

Field experiments were conducted at Tamil Nadu Rice Research Institute, Aduthurai, India, during the wet seasons of 1992 and 1993 to study the effect of full and partial substitution of fertiliser N with green manure N (Sesbania rostrata) on nitrogen uptake, yield attributes and yield of rice. The experiment consisted of eight treatments with two levels of N (100 and 200 kg ha⁻¹) and three sources of N application viz., fertilizer, integrated (1:1 fertilizer and green manure N) and green manure N compared to the recommended practice (150 kg fertilizer plus 6.25 t ha⁻¹ (72 kg N) green manure) and a no N control. Nitrogen application markedly increased the N uptake. Combined use of the two N sources at 200 and 222 kg N ha⁻¹ and of single fertilizer N at 200 kg N ha⁻¹ recorded the maximum N uptake, increased the yield attributes such as number of panicles per unit area, weight per panicle, number of total and filled grains per panicle and test weight. At 200 kg N ha⁻¹ full substitution of N by green manure reduced the grain yield but only partial substitution of N by green manure resulted in almost similar yield as single fertilizer N. Thus 200 kg N ha⁻¹ applied in equal proportions of fertilizer and green manure N can be recommended for medium duration rice cultivars.     

In vitro viability of cryopreserved equine embryos following different freezing protocols.

The main objective of this study was to evaluate two freezing protocols and the effect of agar embedding on survival of day 6.5 equine embryos. A total of 133 embryos were used, in one group (n = 51), embryos were first embedded in agar before the freezing protocol was started. A freezing protocol to -30 degrees C or -33 degrees C was used before plunging embryos into liquid nitrogen (LN2). The embryos were thawed in water at 37 degrees C, evaluated and placed in culture. After 24 h culture, the embryos were evaluated for their morphology and development. No differences were observed between embryos plunged at -30 degrees or at -33 degrees C in LN2. The analysis of the morphology and development after thawing showed that the diameter and developmental stage at freezing correlated with embryo survival. Morula and early blastocyst stages of development were associated with better quality after freezing and thawing and had a better potential to survive after in vitro culture (p < 0.05) compared to more advanced stages. The agar failed to protect embryos from zona pellucida damage, but a tendency to prevent rupture was observed in larger embedded embryos.