Movement of broiler chickens reared in commercial conditions

1. Bird movement was studied at various ages in two flocks of 18,200 broiler chickens. 2. One-d-old chicks placed in corners of a 29 x 14 m brooding area dispersed evenly over the whole area in a period of 48 h. 3. At 15 d of age, when released from the brooding area, birds which were among the first to move to the far end of the house did not necessarily remain in that area of the house. 4. Starting at 4 and 5 weeks of age, birds marked individually were variable in their movement throughout the house during a 16- and 9-d period respectively. Even the least mobile individual covered an area of the house containing several thousand birds. 5. Closer scrutiny of movement by individual birds showed that some moved over areas of 20 m2 in an hour. Birds moved further than was necessary simply to reach food and water. No agonistic interactions were observed and there was no evidence that crowding was a physical restraint on bird movement. 6. Results indicated that birds were not generally attached to a particular site in the shed and that social factors did not restrict movement. Some implications of bird movement are discussed with regard to performance, welfare and leg abnormalities.     

Bilateral eyelid swelling attributable to lymphosarcoma in a horse

Bilateral swelling of upper and lower eyelids was caused by lymphocytic infiltration in an 8-year-old Thoroughbred mare. The condition worsened with pregnancy and became associated with subcutaneous dissemination of lymphosarcoma at distant sites.     

Immunotherapy in ocular equine sarcoid.

A modified Bacillus Calmette-Guerin (BCG) preparation was used successfully in the treatment of 7 cases of equine sarcoid. The BCG preparation was injected into the lesions. The longest period of remission has been 24 months, and the shortest period of remission has been 9 months, with no signs of recurrence of the tumor in any of the presented cases.     

The effects of androgens and gonadotropins on testicular development in the prepubertal rat.

Treatment of male rat pups from five to 34 days of age with dihydrotestosterone or 5 alpha-androstane-3 alpha, 17 beta-diol, resulted in reduced testicular size at 35 days of age. This appeared to be due to decreased tubular diameters and reduced spermatocyte numbers, especially late pachytene cells in stages X to XIII. In rat pups treated with dihydrotestosterone or 5 alpha-androstane-3 alpha, 17 beta-diol, treatment with luteinizing hormone resulted in some restoration of tubular diameter and spermatocyte numbers. In 5 alpha-androstane-3 alpha, 17 beta-diol treated rat pups partial restoration of testes size resulted from follicle-stimulating hormone treatment, but tubular diameter and spermatocyte numbers were depressed. Single serum samples collected at 35 days of age were analysed for luteinizing and follicle-stimulating hormone concentrations. These data indicated that the effects of administered androgens were due primarily to depression of circulating gonadotropin concentrations but a direct inhibition at the level of the testis could not be ruled out.     

Determination of brodifacoum and bromadiolone residues in rodent and canine liver

A method to determine residue concentrations of anti-coagulant rodenticides, brodifacoum (BF) and bromadiolone (BD) in liver was developed, using gas chromatography/mass spectrometry. Nine dogs were given 1.1 mg of BF/kg of body weight, PO, in polyethylene glycol 400, one time. Rats were fed BF or BD (via commercial baits) in amounts from 0.28 to 11.25 mg/kg over 1- to 4-day periods. Fresh liver samples were collected at necropsy from all rats and 3 dogs, ground with Na2SO4, and extracted with CHCl3:MeOH (9:1). After evaporation and silica cartridge purification were performed, residues were oxidized with a 0.16M chromic acid solution, and an oxidation product (4-bromobenzoic acid) was partitioned into CHCl3. The methylated derivative (port derivatization with trimethylanilinium hydroxide) was assayed, using gas chromatography/mass spectrometry. Bromadiolone was detected in livers from rats given greater than 6 mg of BD/kg of body weight, but not in livers of rats given 1.25 mg of BD/kg. In contrast, BF was detected (with one exception) in livers from dogs (given 1.1 mg of BF/kg) and from rats given high (11.25 mg of BF/kg) and low (0.28 mg of BF/kg) doses. This protocol, which does not differentiate between BF and BD because of the formation of a common product after chromic acid oxidation, was used to diagnose anticoagulant toxicosis in 3 dogs, 1 human being and 1 llama naturally poisoned.     

Carbon dioxide exchange and growth of a pine plantation

The exchange of materials between the atmosphere and terrestrial ecosystems is important to an understanding of the cycling of essential elements, the deposition of materials from the atmosphere and the entrance of pollutants into the forest ecosystems. This paper reports the results of measurements of carbon dioxide exchange in a vigorously growing pine plantation. Measurement data were incorporated into a model used to estimate annual carbon dioxide exchange. The measured annual biomass accumulation in the same plantation was used to determine a carbon dioxide to biomass conversion efficiency. Carbon dioxide exchange was 10.5 t/ha and biomass accumulation was 4.5 t/ha. The conversion efficiency of carbon dioxide to biomass is about 25% less than the theoretical chemical conversion efficiency. Considering the possible errors in both the estimates, this is very good agreement.     

Whole-blood and plasma cholinesterase levels in normal koi (Cyprinus carpio).

Organophosphate and carbamate insecticides produce their toxic effects by binding with cholinesterase enzymes, resulting in the inhibition of acetylcholine catabolism. Excessive acetylcholine levels cause excessive synaptic neurotransmitter activity. In most animal species, whole blood is the preferred sample for evaluation of cholinesterase activity. Previous reports of cholinesterase activity in carp have involved sampling of serum, plasma, brain, liver, muscle, and heart. Whole-blood samples were obtained from 12 healthy koi (Cyprinus carpio). Whole-blood cholinesterase activity was measured in all 12 samples. Plasma cholinesterase activity was also measured in 4 samples. The overall average of the whole-blood cholinesterases was 0.08 micromol/ml/minute (SD = 0.024). The results for the plasma cholinesterases were similar, with an average of 0.08 micromol/ml/minute (SD = 0.012). Because these reference values are below the minimum detection limit for the method of analysis used, results from blood samples from koi suspected to be suffering from anticholinesterase toxicosis may be uninterpretable.