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971.
1. The sulphur amino acid requirements of White Leghorn‐type laying hens were determined in two 52‐week experiments using diets based on maize and soyabean meal providing from 5.0 to 6.5 g sulphur amino acids/kg, 12.35 MJ ME/kg and 8.6 to 8.8 g lysine/kg. There were six replicates of 15 individually‐caged hens each per treatment.

2. A requirement of approximately 775 to 800 mg sulphur amino acids /hen d, of which about 390 to 440 mg was methionine, was found for a maximum of 80 to 83 eggs/100 hen d. There were indications that the requirement for maximum egg production was less than that for maximum efficiency of food utilisation.

3. Diets containing 138 g protein/kg supplemented with methionine and lysine supported production and food utilisation as effectively as a diet containing 167 g protein/kg.  相似文献   

972.
1. Blackening of the skin in factory processed cooked hens has been associated with elevated copper levels.

2. The degree of blackening was not directly related to copper content although the latter level was always higher than in control hens.

3. Simulated factory procedures, using scald water at 53 °C or 60 °C containing 50 mg Cu2+/1 and 50 mg C12/1, produced blackened skins of varying intensity on cooking.

4. It is suggested that the problem arose from a malfunction of the chlorination plant which produced excessive levels of chlorine and low pH, followed by erosion of copper from water pipes and subsequent interaction of copper and chlorine with the chicken skin.  相似文献   

973.
1. The electrophoretic patterns of water‐soluble proteins of avian muscle showed differences due both to species and to muscle type.

2. Each muscle pattern within a species showed a unique protein band which distinguished that species from other species.  相似文献   

974.
975.
An outbreak of S. typhimurium gastroenteritis and septicemia is described in young cats admitted to a veterinary hospital for routine medical and surgical reasons. A morbidity of 32% and a mortality of 61% was observed in the outbreak. Affected cats exhibited oral shedding of the organism and contaminated feed and water dishes may have been the vehicle of spread of infection. Possible detrimental effects of incorrect choice of antibiotic therapy are discussed. Attempts to reproduce the disease in a group of laboratory cats were unsuccessful. Antibody production was poorly correlated with infection in these cats.  相似文献   
976.
977.
After oral administration of sublethal doses of thallium (lower than 10 mg/kg) to dogs, 75.5 +/- 3.9 per cent of the dose was eliminated from the body--47 per cent faecal and 28 per cent urinary. Cumulative excretion reached 50 and 70 per cent after 10 and 25 days respectively, and was almost complete after 75 days. This was slightly lower at higher doses. The total body-burden of thallium, calculated from the cumulative excretion, decreased exponentially for at least the first 40 days with a half-time (T 1/2) of 6.5 days. Oral doses of Prussian blue after 10 days resulted in an acceleration of the thallium elimination from the body (T 1/2 2.5 days), an increase of the faecal (49 per cent) and a decrease of the urinary excretion (18 per cent). Nevertheless, the cumulative faecal and urinary thallium excretion was not influenced. Minor transitory influences of Prussian blue on the faecal thallium excretion could be observed up to day 26. After 40 days, Prussian blue could no longer influence the faecal thallium excretion. At no time did sodium-ethylenediaminetetraacetic (Na2EDTA) acid significantly change faecal or urinary thallium excretion.  相似文献   
978.
The ability of nine strains of avian infectious bronchitis virus (IBV) to induce chicken interferon has been investigated using Semliki Forest virus for the tests. The Beaudette, H120 and Connecticut 46 strains induced interferon in the allantoic fluids of embryonated hens' eggs, the highest titre (1 : 30) being associated with Beaudette; but these as well as the Massachusetts M-41 and H52 strains failed to yield interferon in primary monolayer cultures of chick kidney cells as did all nine strains in organ cultures of chick embryo trachea. None of six strains of IBV investigated was susceptible to the inhibitory effects of chicken interferon.  相似文献   
979.
Extracts of erythroblastosis affected livers from which much of the structural protein had been removed were prepared by acid denaturation. These extracts contained complement fixing "soluble" antigen in a form which was not associated with viral or subviral particles. Ultracentrifugation can be of assistance in separating complement fixation activity from contaminating material in these extracts.  相似文献   
980.
Sediment samples were collected from a subarctic salt marsh on James Bay, Ontario in May 1976. Of 15 organochlorine compounds analyzed, trace amounts mainly of p,p-DDE and polychlorinated biphenyls (PCBs) were detected, but could not be quantitated.  相似文献   
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