Suspected chlorpyrifos toxicosis in a llama, and plasma pseudocholinesterase activity in llamas given chlorpyrifos

Five days after treatment with chlorpyrifos, a 1.5-year-old male llama was unable to stand, had saliva flowing from its mouth, and had constricted pupils, hyperglycemia, a metabolic acidosis, and a plasma pseudocholinesterase activity of 111 IU/L. Mean (+/- 1 SD) plasma pseudocholinesterase activity of 29 healthy llamas was 233.76 +/- 51.55 IU/L. Five to 8 days after topical application of chlorpyrifos (25 mg/kg of body weight) to 3 healthy llamas, the pseudocholinesterase activity decreased to 38% to 62% of pretreatment (base-line) activity and returned to within 90% of base-line activity by the 36th to 48th day after treatment.     

Ruminal evacuation's effect on microbial activity and ruminal function

The influence of evacuating, mixing and returning ruminal contents on microbial populations, volatile fatty acid (VFA) concentrations and liquid flow rate was investigated with four ruminal-cannulated Hereford steers (247 kg avg wt). Ruminoreticular contents were sampled, then completely removed, mixed for 5 min and returned to the rumen. Subsequent samples were taken immediately, 1 h and 4 h later. Non-evacuated steers were sampled at identical time intervals either 1 d before or after evacuation. Averaged over time, there was no significant difference between evacuated and non-evacuated steers in total anaerobic, cellulolytic and facultative bacteria, protozoa, oxidation-reduction potential, VFA concentrations, and liquid flow rates. There were no treatment X time interactions and, except for holotrich protozoa and VFA, no differences from time of sampling. Ruminal evacuation does not appear disruptive to anaerobiosis or detrimental to ruminal microorganisms and digestive processes.     

Effect of electroimmobilisation on ovine plasma concentrations of beta-endorphin/beta-lipotrophin, cortisol and prolactin

The effect of electroimmobilisation on the plasma concentrations of beta-endorphin/beta-lipotrophin (beta-EP/beta-LPH), cortisol and prolactin (PRL) has been assessed in sheep. Serial blood samples were collected from control and electroimmobilised animals during the first and fourth of a series of four repeated treatments over two days. After electroimmobilisation the mean (+/- SEM) plasma concentrations of beta-EP/beta-LPH increased significantly from 132 +/- 19 pg ml-1 to 545 +/- 111 pg ml-1; the plasma concentrations of cortisol also increased significantly from 22.3 +/- 3.5 ng ml-1 to 108.0 +/- 12.9 ng ml-1. There was no significant change in plasma PRL concentrations after electroimmobilisation and also no significant difference between the plasma concentrations of PRL in the control and electroimmobilised animals. There was no significant difference between the effects of the first and fourth exposure to electroimmobilisation on the plasma concentrations of beta-EP/beta-LPH, cortisol and PRL. These results suggest that the endocrine response to electroimmobilisation may be specific to the pituitary-adrenal axis.     

Surface proteins of Breda virus

The serotypes 1 and 2 of Breda virus from feces of experimentally infected gnotobiotic calves were studied with respect to their sedimentation and density properties in sucrose gradients and their structural polypeptides; Berne virus, the proposed prototype of the new family Toroviridae, was included for comparison. After Breda-1 virus had been stored at 4 C for a prolonged period, it showed a heterogeneous sedimentation behavior (480 to 520 Svedberg units [S]) and density (1.18 to 1.21 g/ml) indicative of its poor state of preservation. In contrast, freshly prepared Breda-2 virus sedimented at 350 S and showed a buoyant density of 1.18 g/ml; these values compare well with those of Berne virus (400 S and 1.16 g/ml, respectively). Efficient purification of the Breda viruses could be achieved by a 2-step method, involving pelleting by ultracentrifugation followed by isokinetic and isopyknic sucrose gradient centrifugation. Radioiodinated purified virus showed polypeptides with apparent molecular weights of 105,000, 85,000 37,000, and 20,000; another labeled protein of 65,000 D is of doubtful virus specificity. Mouse immune serum raised against Breda-2 virus recognized the polypeptides of the homologous virus and the 2 highest molecular weight proteins of Breda 1 virus in radioimmune precipitation. The same serum inhibited hemagglutination of the heterologous serotype to a low, but significant, degree and efficiently neutralized the infectivity of Berne virus. These observations are taken as indications that the 105,000- and 85,000-D polypeptides represent surface structures of torovirions, probably peplomeric proteins.     

An inquiry into the causes of liver damage in lambs

The lamb slaughter records of a large private abattoir showed that a small minority of farms had a lamb liver rejection rate exceeding 40 per cent. Small sheep farms were most likely to have high rejection rates and farms producing both lambs and pigs had relatively high lamb liver rejection rates. In a farm survey statistical analysis showed that the spreading of pig slurry, access to the grazing land by hunts and the infrequent use of dog cestocides were factors significantly linked to high lamb liver rejection rates. A survey of 4000 lambs' livers confirmed the importance of Cysticercus tenuicollis as a cause of rejection. Fifty-two per cent of the livers had lesions which could not be identified but showed histological similarities to ascarid lesions.     

Icterus and amaurosis caused by lead poisoning in a cynomolgus monkey (Macaca fascicularis)

The diagnosis and treatment of a case of lead poisoning in a cynomolgus monkey (Macaca fascicularis) are described. The clinical signs were jaundice and amaurosis. Clinicopathological findings suggested cholestasis. A tentative diagnosis of lead poisoning was made when basophilic stippling of erythrocytes was observed in a peripheral blood smear. The diagnosis was confirmed by finding a lead concentration of 2280 micrograms/litre in a venous blood sample. Cage bars painted with red lead appeared to be the source of the poison. The lead was chelated by the intramuscular administration of 2,3 dimercapto-1-propanol (BAL) and calcium disodium edetate for seven days, followed by oral D-penicillamine for five weeks. The encephalopathy was treated with dexamethasone sodium phosphate. Recovery from the blindness was noted after 10 days and marked improvement of the general well being of the animal was observed after one month.     

Observations on the egg output resulting from continuous low level infections with Ostertagia circumcincta in lambs

Faecal egg counts were determined twice weekly for two groups of four-month-old worm free cross Suffolk lambs experimentally infected with 100 and 320 Ostertagia circumcincta larvae, five times per week for 20 weeks. The group mean egg count in both groups rose to a maximum of approximately 500 eggs per gram during weeks 12 to 14 and had fallen to less than half of that value at slaughter. There was no statistical difference in egg output between these two groups or between them and a comparable group of lambs receiving 4000 Ostertagia circumcincta larvae per day. No significant changes in live weight gain or serum pepsinogen levels were observed in the lambs given 100 and 320 larvae per day.     

Effects of food intake regulation on the energy metabolism of hens and cockerels of a layer strain

1. Indirect calorimetry was used to study the effects on the energy metabolism of cockerels and hens after peak lay of a hybrid layer strain of regulating food or energy intake to 80% of ad libitum for an extended period of time. 2. Regulation of food intake decreased fasting and fed heat productions per bird and per unit metabolic body weight (kg0.75). 3. Maintenance energy requirements (per kg0.75) of both sexes were reduced about 20% by regulation; maintenance requirements of cockerels were about 30% lower per kg0.75 than hens on the same treatments. 4. Reducing the intake of all nutrients by 20% had the same effect on the energy metabolism of cockerels as restricting energy alone by the same amount. 5. Gross efficiency of egg production, in terms of both mass and energy, was higher when intake was regulated. During weeks 21 to 52 of restriction, daily egg mass output was significantly higher in hens fed ad libitum. 6. After 52 weeks of food regulation, restricted hens weighed 20% less and their total carcass energy was 36% less than hens fed ad libitum; similar effects were found in the cockerels.