What children know     

Bretherton I 《Science (New York, N.Y.)》1991,254(5030):446

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Influence of stocking density and layer age on production traits and egg quality in Japanese quail     

S. Nagarajan  D. Narahari  I. Alfred Jayaprasad  D. Thyagarajan 《British poultry science》1991,32(2):243-248

1. Japanese quail hens were housed from 6 to 26 weeks of age in cages providing areas of 150, 180, 210 and 240 cm²/bird.

2. Body weight gain, age at 50% egg production, mortality, hen‐day egg production and food conversion values showed significant improvement with proportionate increase in cage space per layer.

3. Egg weight gradually increased with age but shell thickness was influenced neither by age of the hen nor by stocking density.

4. Yolk index and colour were superior in the lowest stocking density (more cage space) group; other egg quality traits and egg weight were not influenced by stocking density.

5. The albumen index, internal quality unit, yolk index and yolk colour values increased with age.  相似文献   

Polymers     

Brauman JI 《Science (New York, N.Y.)》1991,251(4996):853

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Three cases of disputed paternity in dogs resolved by the use of DNA fingerprinting     

Hermans IF  Atkinson J  Hamilton JF  Chambers GK 《New Zealand veterinary journal》1991,39(2):61-64

DNA fingerprinting with the probes 33.15 and alpha-globin 3'HVR has been used to resolve three cases of disputed paternity in dogs. For each pedigree it was necessary to establish which bands in the DNA fingerprints of the offspring were of paternal origin, and then establish which putative sire carried all these bands. In the first case, a litter of Rhodesian Ridgebacks, twelve DNA bands were informative in establishing paternity. In the second case, a litter of Afghan hounds, five DNA bands established paternity, Lastly, in a litter of Border collies, five DNA bands established paternity. In each case a single dog only sired the entire litter.  相似文献   

A case-control study of Nocardia mastitis in Nova Scotia dairy herds   总被引：1，自引：0，他引：1       下载免费PDF全文

Ferns L  Dohoo I  Donald A 《The Canadian veterinary journal. La revue veterinaire canadienne》1991,32(11):673-677

A case-control study was conducted to identify herd production, housing, and hygienic and therapeutic factors associated with a diagnosis of Nocardia mastitis in dairy herds in Nova Scotia. The data were collected by on-farm interviews with owners of 54 case and 54 control herds.

Logistic regression was used to study risk factors. The use of dry cow products containing neomycin, including two specific dry cow products, was strongly associated with a diagnosis of Nocardia mastitis in a herd. Other factors which increased the risk of Nocardia mastitis were higher levels of production, larger herd size, and a large percentage of cows treated with dry cow products. These results are compared to results from a similar study carried out in Ontario.

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Field evaluation of melatonin implants to advance the breeding season in 1-year-old farmed red deer hinds     

Wilson PR  Walker IH  Bond DB  Middleberg A  Staples LD 《New Zealand veterinary journal》1991,39(1):23-28

The efficacy of controlled-release melatonin implants to advance the onset of the breeding season was assessed in 1-year-old red deer hinds on five commercial deer farms in various localities in the North Island of New Zealand. Between 44 and 60 hinds in each of six herds were equally divided among treatment and control groups at each site. Melatonin treatment commenced between 27 November and 16 December and was achieved by the subcutaneous administration of two 18 mg melatonin implants. Three doses were given at about 30 day intervals. Two adult stags for each hind group were treated with three 18 mg melatonin implants concurrently on either two or three occasions. On each property, treated and control hinds were joined as one herd to treated stags commencing 30 January-10 February and concluding 15 May-2 June. The hinds in the four experimental herds underwent rectal ultrasound examination May-June to estimate conception rate and foetal age. Calving dates, hind and calf mortalities, weaning weights, and the antler growth cycle and harvesting data were recorded. Overall, treatment with melatonin resulted in an average advance of the median calving date of 22 days (range 12-36 days) when compared with untreated controls in the same herds. Pregnancy rates were 91.3-100% in treated hinds and 63.6-100% in untreated hinds. There were no differences in calf mortality or calf sex ratio between treated and untreated groups. No hind deaths could be attributed to melatonin treatment. The weaning weights of calves were 5.68 kg and 4.43 kg heavier for the male and female offspring of treated hinds respectively, compared with those of control hinds. Treated stags commenced rutting behaviour earlier than normal and the antler casting and growth cycle was advanced. Treatment resulted in advancement of the seasonal pattern of coat changes in hinds and stags, but no untoward side effects of the melatonin treatments were observed.  相似文献   

Meat inspection in New Zealand: prospects for change     

Hathaway SC  McKenzie AI 《New Zealand veterinary journal》1991,39(1):1-7

Regulatory authorities are facing increasing challenges with respect to the newly-recognised public health risks associated with meat products. Meat inspection resources should be allocated according to their maximum ability to reduce food-borne hazards, rather than according to the classical rules of meat inspection. Scientific evaluation of routine post-mortem inspection procedures for each class of livestock, introduction of the Hazard Analysis Critical Control Point approach to process control, on-line testing for microbiological hazards and residues, and effective management of production, processing and inspection data are central to this process. The meat inspection system that has evolved in New Zealand reflects a response to non-scientific forces such as market requirements and industrial practices rather than scientific discipline. In the future, the daily routine of meat inspectors will be extended well beyond their current slaughterfloor responsibilities, and veterinarians will require specialist skills. Science should be the basis for international food regulation and policy concepts such as equivalence or mutual acceptance are achievable on this basis.  相似文献   

Standards of practice          下载免费PDF全文

Fleming BI 《The Canadian veterinary journal. La revue veterinaire canadienne》1991,32(5):265

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Induction of lactogenic immunity to transmissible gastroenteritis virus of swine using an attenuated coronavirus mutant able to survive in the physicochemical environment of the digestive tract.     

J M Aynaud  S Bernard  E Bottreau  I Lantier  H Salmon  P Vannier 《Veterinary microbiology》1991,26(3):227-239

A transmissible gastroenteritis (TGE) coronavirus mutant (188-SG), selected as attenuated and resistant to acidity and proteases of the digestive tract of adult pigs, was used as vaccine ("Nouzilly strain") in sows to protect suckling piglets against a challenge exposure carried out with a highly virulent TGEV strain. The pregnant sows were immunized once (42-49 days before farrowing) or twice (42-49 and 7-15 days before farrowing) by the oral, intramuscular or conjunctival route with the 188-SG strain. Sows exposed to virulent TGEV in the field and experimentally infected sows (two oral inoculations during pregnancy) were used as positive controls leading to high protection. The neutralizing antibody response to vaccination and/or infection was studied in serum and milk. No protection against mortality was observed in the litters of (1) the nine seronegative, susceptible sows, with piglet mortality of 65/70, (2) the seven once orally vaccinated sows, with mortality of 44/54, (3) the seven sows vaccinated twice by the conjunctival route, with mortality of 55/76. Moderate protection was observed in (1) the eight sows vaccinated intramuscularly twice with piglet mortality of 36/90, (2) the seven orally and intramuscularly vaccinated sows with piglet mortality of 31/51. In of 3 contrast, improved protection was observed in (1) the 10 sows vaccinated twice orally, with piglet mortality of 23/95, (2) the four naturally infected sows with piglet mortality of 6/41, (3) the six sows experimentally infected with virulent TGEV with piglet mortality of 1/59. No correlation was found between neutralizing antibodies titers in serum and milk and protection rate of the piglets. The results indicate that relative protective lactogenic immunity against TGEV is induced only by repeated ingestion of the attenuated 188-SG strain of TGEV.  相似文献   

Comparative studies of BHV-1 variants by in vivo--in vitro tests.     

A C Bratanich  S I Sardi  E N Smitsaart  A A Schudel 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1991,38(1):41-48

The new encephalitogenic BHV-1.3 and previously characterized BHV-1 strains were studied with reference to their immunogenic and protective potency and their antigenic relationships using "in vitro" and "in vivo" tests. The "in vitro" results obtained by neutralization kinetics showed that the Los Angeles (LA) strain (BHV-1.1) and a vaginal isolate L-114 strain (BHV-1.2) had antigenic similarities. Conversely, the behavior of the encephalitogenic strain A-663 (BHV-1.3), was significantly distinct. The "in vivo" protection test was carried out in calves using LA and A-663 strains. Post-vaccination antibodies and challenge with A-663 strain showed that the immunogenic behavior and protective capacities of both strains were similar. Neutralization kinetics differences between BHV-1.1 and BHV-1.3 did not alter the "in vivo" protection against BHV-1.3 challenge.  相似文献