The daily food consumption of laying hens in relation to egg formation     

B. A. Morris  T. G. Taylor 《British poultry science》1967,8(4):251-257

The voluntary food consumption of, respectively, 4 and 5 colostomised laying hens was studied in 2 experiments at both normal (20° C.) and high (30° C.) environmental temperatures over a total period of 60 days. Food consumption was greater during 24 hr periods when egg formation was in progress than when no egg was present in the oviduct. At high temperatures food intake was reduced less on egg‐forming than on non‐egg‐forming days.

In a further experiment lasting 24 days 12 normal pullets laying for long sequences with pauses of single days consumed 25 per cent more food in the 19 hr period 14.30–09.30 hr when eggs were being formed than when they were not. During the 5 hr period 09.30–14.30 hr food consumption was significantly greater when albumen was being secreted than when shell formation was in progress.

It is suggested that the requirements of the bird for albumen synthesis may regulate food intake during the period of egg formation.  相似文献   

Deoxyribonucleic acid methylase activity in pea seedlings   总被引：6，自引：0，他引：6  

F Kalousek  N R Morris 《Science (New York, N.Y.)》1969,164(880):721-722

Deoxyribonucleic acid methylase activity has been detected in a preparation of disrupted nuclei prepared from pea seedlings. S-Adenosyl-L-methionine acted as a donor of methyl groups, and the product of the reaction was identified as 5-methylcytosine. The reaction had a sharp temperature optimum at about 30 degrees C and was unusual in that the DNA methylase was able to methylate DNA in the crude extract.  相似文献   

Growth in castrated cattle. Growth, carcase composition and sexual development in bulls, steers and cattle castrated by Baiburtcjan's method     

I S Robertson  J C Wilson  P G Morris 《The Veterinary record》1967,81(4):88-103

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Chemical properties and interactions of rice hemicellulose with trace minerals in vitro     

R R Mod  R L Ory  N M Morris  F L Normand 《Journal of agricultural and food chemistry》1981,29(3):449-454

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Equine tracheobronchial aspirates: correlation of cytologic and microbiologic findings   总被引：1，自引：0，他引：1  

D D Morris 《Journal of the American Veterinary Medical Association》1984,184(3):340-341

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Characteristics of fowl cholera outbreaks in turkeys in Georgia in 1986     

M P Morris  S G Thayer  O J Fletcher 《Avian diseases》1989,33(2):213-218

Information was gathered from 64 cases of fowl cholera (FC) in turkey flocks through diagnostic case records, flock records, and telephone and mail surveys. Forty-five cases came from flocks of commercial turkeys, of which 15 were presented twice, and four came from mature breeder flocks. The prevalence of FC was 18.0% of commercial flocks and 14.7% of breeder flocks at risk. The average age at first diagnosis of FC was 90 days in commercial turkey flocks and 32 weeks 5 days in breeder flocks. Acute mortality was the most common presenting complaint, with a 0.37% average mortality in commercial flocks on the day of first presentation, 0.80% in commercial flocks presented a second time, and 0.43% in breeder flocks. Pasteurella multocida was cultured from 69.8% of the 361 tissue samples submitted from these cases. Novobiocin, penicillin, and chlortetracycline (CTC) had the greatest in vitro activity against isolates. Serotype 3-cross-4 was found in all 18 commercial flocks from which isolates were typed. All breeder flocks and 88.6% of commercial flocks were vaccinated before disease onset. Flocks were treated for an average of 14.3 days, most commonly with high levels of sulfadimethoxine and/or CTC. Body weights of affected birds were comparable to those of birds in unaffected flocks, but mortality and feed efficiency were worse.  相似文献   

Influence of commonly recorded variables on weaning weight of lambs — A necessary consideration before assessing the effects of subclinical disease on production     

Jocelyn Morris  Thomas B. Farver  John S. Glenn  David W. Hird 《Preventive veterinary medicine》1984,3(2):143-149

Data from a commercial sheep enterprise were used to derive correction factors to be applied to 120-day lamb weaning weights. These correction factors made use of information on lamb sex, weaning age, birth and rearing status, and age of dam. The factors obtained were compared with commonly used standard factors, and there was enough difference to justify development of within flock factors.  相似文献   

Partitioning of the response to protein between egg number and egg weight     

T R Morris  R M Gous 《British poultry science》1988,29(1):93-99

1. Data from published trials with laying hens were examined to see whether the concentration of dietary protein needed to achieve maximum egg weight was greater than the amount needed to achieve maximum rate of lay. 2. It is concluded that both rate of lay and egg weight continue to show small responses up to the same level of protein (or limiting amino acid) input. 3. When predicting egg output using asymptotic models, a reasonable assumption is that small increments in dietary protein, close to the optimum, will evoke equal proportional responses in egg size and in rate of lay. 4. When protein supply is severely limiting, the major response is a reduction in rate of lay. Egg weight seldom falls below 0.90 of its maximum value, however inadequate the protein intake may be.  相似文献   

Agricultural ecosystems; Unifying concepts: Lowrance,R., Stinner,B. R. and House,G. J. (Eds). Wiley-Interscience,New York, 1984. x + 233 pp. Price: £40·85     

R.M. Morris 《Agricultural Systems》1985,18(4):252-255

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The incidence of bone lesions in the carpal and tarsal regions and the rate of physeal closure in weanling quarter horses     

J.A. Reynolds BS  E.L. Morris DVM  D.M. Senor MA  K.S. Frey BS  D. Reagan BS  V.A. Weir ARRT  J. Elslander RVT  G.D. Potter PhD 《Journal of Equine Veterinary Science》1992,12(2)

Sixty weanlings were maintained in dry lots without forced exercise and individually fed a diet consisting of 25% Bermudagrass hay and 75% balanced concentrate twice dally. Radiographs of the carpus, metacarpus and first phalanx, and other radiographs of the tarsal region, were taken initially at approximately 180 d of age and at approximately 236, 292 and 348 d of age. The radiographs were evaluated for the presence or absence of subchondral and/or cystic lesions in the carpal and tarsal regions and for closure of physes of the distal third metacarpus and proximal first phalanx. Physeal scores were: 1 = open; 2 -- partially closed; 3 = closed. Only 1.7% of the horses had subehondral lesions in the carpal region at 180 d, and none had those lesions at 236, 292 or 348 d. There was a 3.3% incidence of subchondral lesions of the tarsus at 180, 236 and 292 d, but only 1.7% at 348 d. Cystic lesions of the carpus were evident in 13.3% of the horses at 180 d, 16.7% at 236 d and 18.3% at 292 and 348 d. None of the hrses had cystic lesions oftbe tarsus at 180, 236 or 348 d, but 1.7% had them at 292 d. Physeal closure scores for the distal metacarpus averaged 1.5 and 2.6 at 180 and 236 d, respectively. At 292 and 348 d, all of the distal metacarpi were closed. Physeal closure scores for the proximal first phalanges were 1.5, 2.6 and 2.9 at 180,  相似文献