The effect of 6‐ and 8‐hour light‐dark cycles on egg production and pattern of ovipositions     

Y. Nys  P. Mongin 《British poultry science》1981,22(4):391-397

1. Two flocks of 60 laying hens were transferred from 14 h light (L): 10 h dark (D), to repeated 3L:3Dor4L:4D lighting schedules at 37 weeks of age. Egg production decreased slightly but egg weight and shell quality improved.

2. The intake of low‐calcium diet and of oyster shell were similar for each light period of each lighting regimen.

3. Ovipositions were distributed virtually at random throughout the day and the mean interval between successive eggs within a clutch was increased.

4. Reducing the total daily photoperiod from 12 to 6 h decreased daily food consumption.  相似文献   

Some factors affecting urinary and Faecal nitrogen loss by chickens fed on a protein‐free diet     

J. Okumura  Y. Isshikp  Y. Nakahiro 《British poultry science》1981,22(1):1-7

1. In adult colostomised cockerels, the rates of urinary and faecal nitrogen loss were measured when feeding low‐ and high‐energy, protein‐free diets after a preliminary period during which diets of differing energy and protein contents had been fed.

2. Urinary nitrogen excretion increased with increasing protein and decreasing energy in the preliminary diet.

3. Urinary nitrogen excretion was high during the first 3 d of feeding a high‐energy, protein‐free diet, decreased rapidly during the next 3 d and thereafter become relatively constant. However, in the case of a low‐energy, protein‐free diet, urinary nitrogen excretion gradually declined throughout the trial period of 15 d, resulting in increased urinary nitrogen excretion.

4. After a 3‐d period of adjustment faecal nitrogen loss from birds fed on a protein‐free diet was relatively constant under the conditions examined.  相似文献   

Origin and mechanism of large-scale climatic oscillations     

Sergin VY 《Science (New York, N.Y.)》1980,209(4464):1477-1482

Numerical experiments with a simplified thermodynamic model of the glacier-ocean-atmosphere global system have been performed. Characteristic regimes of the system are auto-oscillations with periods varying between 20,000 and 80,000 years. The longer climatic waves are generated by the influence of variations of the earth's orbital parameters. Computed changes of glacial area, temperature, sea level, and other climate characteristics have values within expected ranges. The transition from a relatively warm epoch (when continental ice sheets are absent) to conditions characteristic of the Pleistocene is modeled. The calculated curves show how weak temperature fluctuations have been followed by large-scale oscillations.  相似文献   

Detection of antibody against transmissible gastroenteritis virus of pigs by indirect immunoperoxidase antibody test     

Y Kodama  M Ogata  Y Shimizu 《American journal of veterinary research》1980,41(1):133-135

Immunoperoxidase intibody (IPA) test was developed for detecting antibody against transmissible gastroenteritis (TGE) virus of pigs. The IPA antibody titers in sera collected in the field from 82 pigs were approximately seven times higher than those obtained in a serum-neutralization test. The correlation between the TGE antibody concentrations in the IPA and serum neutralization tests was positive (r = +0.74). The IPA tests appears to have the potential for routine laboratory use for serologic diagnosis of TGE.  相似文献   

Polychlorinated biphenyl contamination of areas surrounding two transformer salvage companies, Colman, South Dakota--September 1977     

Y A Greichus  B A Dohman 《Pesticides monitoring journal》1980,14(1):26-30

Soil, corn plants, and foliage from areas surrounding two electrical salvage companies involved in reconditioning old transformers had unusually high levels of polychlorinated biphenyls (PCBs). Levels decreased as distance from the factories increased. PCBs were dispersed into the air through incineration of waste oils; water and soil contamination was caused by runoff from the factories. PCBs found in the contaminated areas closely resembled Aroclor 1260 as did the PCBs in the waste oil, whereas PCBs in other areas were more similar to Aroclor 1254. PCBs on surface soils taken from an unplowed pasture near the factories also resembled Aroclor 1260, whereas samples taken from depths of 2-4 inches showed degradation of some PCB isomers. PCB concentrations in corn cobs and kernels were < 0.05 ppm, whereas leaves contained PCB levels of up to 2.2 ppm. PCB levels in earthworms and small rodents collected near the factories were considerably higher than levels in the same types of animals collected from other areas.  相似文献   

Information dissemination: whatever happened to the weinberg report?     

Johnson IY 《Science (New York, N.Y.)》1978,200(4337):6

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Bovine antibody against Streptococcus agalactiae, type Ia, produced by preparturient intramammary and systemic vaccination.     

Y Yokomizo  N L Norcross 《American journal of veterinary research》1978,39(3):511-516

Four pregnant heifers were immunized by the intramammary route with killed or live Streptococcus agalactiae vaccine, and a 5th heifer was vaccinated by the intramuscular route with killed vaccine. Antibody in the colostrum from vaccinated and non-vaccinated glands was compared. Antibacterial glands was compared. Antibacterial antibody titers of the 4 immunoglobulin classes were determined by indirect fluorescent antibody assay. Although the content of immunoglobulin G1 (IgG1), IgG2, and IgM in the colostrum from the vaccinated glands was not substantially different from the nonvaccinated glands, IgA content was considerably greater in the former. Antibody specific to S agalactiae was isolated from all colostrum samples. The mouse passive protection test and Ouchterlony analysis were used to demonstrate the presence of type-specific antibody to Ia strain used for vaccination. The passive mouse protection test also was useful to compare the protective capacity of specific S agalactiae, type Ia, antibodies of immunoglobulin classes IgG, IgM, and IgA. Increased protective capacity of IgM and IgA over IgG1, on a weight basis, was demonstrated. The present study indicates that S agalactiae preparations, when introduced into the mammary gland, can give rise to local antibody synthesis in the vaccinated glands.  相似文献   

Necrotizing enteritis in suckling pigs (Clostridium perfringens type C enterotoxemia). II. Toxin formation, heat and drug resistance of Clostridium perfringens strains isolated from suckling pigs and broilers with necrotizing enteritis]     

B K?hler 《Archiv fuer experimentelle veterinaermedizin》1978,32(6):841-853

Nineteen Clostridium perfringens Type C strains and ten foreign control strains of subtypes C1, C3, and C4 were tested for their toxin formation and spore resistance to heat. The 19 Type C strains had been isolated from unweaned piglets in the context of necrotising enteritis outbreaks in the GDR. The Clostridium perfringens Type C strains formed beta-toxin, but they failed to form epsilon-toxin or gamma-toxin, alpha-toxin was successfully recorded from 15 of the 19 strains tested from unweaned piglets. The minor-lethal toxin fractions were also tested, with delta-toxin being recorded from all strains, non-alpha-delta-theta-toxin from six, theta-toxin from five, and K-toxin from one. Tests for delta-toxin, lambda-toxin, and mu-toxin were negative. The Clostridium perfringens Type C strains isolated in the GDR from unweaned piglets with necrotising enteritis were, basically, identical with those described in Denmark by von Hogh (1967) with regard to toxin formation. Clostridium perfringens strains cultured in broilers with necrotising enteritis were characterised by regular toxin production in the context of alpha, theta, delta as well as non-alpha-delta-theta. They failed to form beta, epsilon, gamma and lambda, while mu-toxin was formed by them quite irregularly. They, consequently, are Type A strains. Resistance to chloramphenicol and/or oxytetracycline was exhibited by 78.5 per cent of 237 tested Clostridium perfringens strains which had been isolated from unweaned piglets and broilers with necrotosing enteritis. Multiple resistance was recorded from 33.9 per cent. All strains were susceptible to penicillin, nitrofurantoin, and erythromycin.  相似文献   

Brief communication: replication of feline infectious peritonitis virus in organ cultures of feline tissue.     

Y Hoshino  F W Scott 《The Cornell veterinarian》1978,68(3):411-417

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Serological identification of animal species of meat using species-specific anti-serum albumin antibodies obtained by immunoadsorbent chromatography.     

T Kamiyama  Y Katsube  K Imaizumi 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1978,40(6):663-669

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