British Poultry Science

Hughes, B. O.; McNab, J. M.

doi: 10.1080/00071668908417119pmid: N/A

Siegel, Paul B.

doi: 10.1080/00071668908417120pmid: 2663115

Abstract 1. Marked changes have occurred in poultry production practices and in stocks bred for the production of meat and eggs. 2. Of behaviour patterns that originally favoured domestication, positive responses to humans and adaptability to environments are now most important. 3. Development of specific strains for production of meat or eggs resulted in correlated responses in behavioural traits. Compared with egg strains, meat strains are docile and have excessive appetites, poor immunoresponsiveness and reduced motor ability. 4. Genotype by environment interactions for behaviour limit inferences concerning responses of stocks across environments. 5. Innate behaviour patterns and habituation processes can prevent some stimuli from causing physiological manifestations observed in general responses to stressors. 6. Husbandry procedures should optimise phenotypic expressions of genetic potential to enhance well‐being.

Herremans, M.; Decuypere, E.; Siau, O.

doi: 10.1080/00071668908417121pmid: 2743169

Abstract 1. Heat production, which accounts for 0.6 of gross energy intake, is insufficiently represented in predictions of food intake. Especially when heat production is elevated (for example by lower temperature or poor feathering) the classical predictions based on body weight, body‐weight change and egg mass are inadequate. 2. Heat production was reliably estimated as [35.5‐environmental temperature (°C)] × [Defeathering (=%IBPW) + 21]. Including this term (PHP: predicted heat production) in equations predicting food intake significantly increased accuracy of prediction, especially under suboptimal conditions. 3. Within the range of body weights tested (from 1–1 kg in brown layers to 2'8 kg in dwarf broiler breeders), body weight as an independent variable contributed little to the prediction of food intake; especially within strains its effect was better included in the intercept. 4. Significantly reduced absolute values of residual food consumption were obtained over a wide range of conditions by using predictions of food intake based on body‐weight change, egg mass, predicted heat production (PHP) and an intercept, instead of body weight, body‐weight change, egg mass and an intercept.

Madelin, Theresa M.; Wathes, C. M.

doi: 10.1080/00071668908417122pmid: 2743174

Abstract 1. Deep litter and raised netting flooring systems in broiler houses were compared for their effects on air quality and bird health during an 8‐week growing period. 2. Weekly measurements were taken of respirable dust, numbers of airborne microorganisms and concentrations of gaseous pollutants. Airborne fungi and bacteria were identified to species. 3. At the end of the experimental period, randomly sampled bird lungs were examined for the presence of viable microorganisms and for pathological changes. Bird health and performance were monitored throughout the 8 weeks. 4. Respirable dust concentrations and numbers of airborne microorganisms were significantly higher in the litter rooms. The type of floor had no effect on concentrations of gaseous ammonia. 5. Floor type had no significant effect on bird mortality but birds on litter had a slightly better gain: food ratio. However, birds on litter were observed to have a higher incidence of lung damage and more of the birds on litter had viable microorganisms present in the lungs at necropsy.

Bumstead, N.; Huggins, M. B.; Cook, J. K. A.

doi: 10.1080/00071668908417123pmid: 2545316

Abstract Two‐week‐old chickens of 9 inbred and partially inbred lines of chickens were challenged intranasally with a mixed infection consisting of a pool of virulent strains of infectious bronchitis virus and a pool of pathogenic strains of Escherichia coli. 2. Wide differences in mortality were observed in the different lines, ranging from 3% in a Brown Leghorn line to 87% in White Leghorn line 72. 3. Experiments involving challenge with E. coli alone or virus alone suggested that this variation reflected resistance to the virus rather than to E. coli. 4. Reciprocal F1 matings suggested these differences in mortality were not attributable to maternal effects and indicated that the inheritance of resistance was fully dominant. 5. The pattern of mortality in F2 and backcross progeny of matings was compatible with the inheritance of a dominant autosomal resistance gene and showed no evidence of association with the major histocompatibility complex.

Naito, M.; Nirasawa, K.; Oishi, T.; Komiyama, T.

doi: 10.1080/00071668908417124pmid: 2743175

Abstract 1. A selection experiment was conducted for increased rate of lay under 23‐h (23HS line) and 24‐h (24HS line) light‐dark cycles over 5 generations. 2. In generation 5, rate of lay was higher in the 23HS line than in the 24HS line, and the proportion of hens with mean intra‐sequence intervals of less than 24 h in the 23HS line increased to 88% in generation 5 from 15% in the base generation. 3. The realised heritability for rate of lay was 0.25 ± 0.04 in the 23HS line and 0.15±0.05 in the 24HS line. 4. Egg weight and shell weight decreased in both lines, and the decrease in the proportion of shell was larger in the 23HS line than in the 24HS line. 5. It is suggested that a regimen of 23 h light and dark may be an effective environment for selection to improve the laying performance of a population approaching a plateau for egg production.

Howlider, M. A. R.; Rose, S. P.

doi: 10.1080/00071668908417125pmid: N/A

Abstract 1. One hundred and twenty (60 male and 60 female) 21‐d‐old Ross 1 broiler chicks were reared in cages in rooms kept at 21°C or 31°C and were killed at body weights of 1.0, 1.5, 2.0, 2.5 or 3.0 kg. 2. Birds reared at either of the two temperatures ate similar quantities of food to reach their slaughter weight although at 31°C they took longer to reach it. 3. The meat yields of the birds at each slaughter weight were similar at both rearing temperatures, but at body weights greater than 2.0 kg, the broilers reared at 21 °C had more breast meat than those reared at 31°C. 4. Females ate more food than males to reach each of the slaughter weights. The females deposited more fat and had a greater skin weight than the males and, although they had a similar amount of total meat, they had more breast meat.

Sosnicki, A.; Cassens, R. G.; McIntyre, D. R.; Vimini, R. J.; Greaser, M. L.

doi: 10.1080/00071668908417126pmid: 2525947

Abstract 1. The incidence of microscopically detectable degenerative characteristics in 5 skeletal muscles (m. pectoralis thoracicus, m. supracoracoideus, m. biceps femoris, m. semitendinosus, m. femorotibialis medius) of turkeys was investigated. 2. Samples were obtained from 30 Large White turkey males 14, 16 and 18 weeks old. Hyaline degeneration, infiltration of mononuclear cells and necrotic fibres were observed. 3. Individual fibres varied greatly in size and muscle fibre nuclei were often shrunken and pyknotic. 4. Weak and/or uniform reaction for Ca++‐ATPase and SDH in all types of muscle fibres and loss of alkaline phosphatase activity in cell membranes were noted. A positive reaction for acid phosphatase occurred in regions of perivascular infiltration and in necrotic muscle fibres. The majority of muscle fibres possessed high activity for phosphorylase a and b. 5. Based on the use of fluorescein α‐bungarotoxin conjugate, motor end‐plates appeared to be morphologically intact. Direct immunofluo‐rescence with anti‐chicken IgG showed positive reaction in muscle fibres undergoing necrosis and in the involved connective tissue. 6. Degenerative changes varied with age and were most marked in the oldest birds. 7. Because gross degenerative symptoms were absent from both the birds and the meat from them, the condition appears to be either different from or a precursor to the degenerative myopathy characterised by other authors.

Brenes, A.; Treviño, J.; Centeno, C.; Yuste, P.

doi: 10.1080/00071668908417127pmid: 2787194

Abstract 1. Two experiments were carried out to study the effects of diets containing various concentrations of pea meal (Pisum sativum L.), with or without flavomycin supplementation, on the performance and intestinal microflora of broiler chicks. 2. During the 7 to 28‐d period, chicks fed on diets containing 300, 600 and 800 g pea meal/kg consumed more food and gained more weight than chicks receiving a maize‐isolated soyabean protein control diet. The addition of flavomycin to the diets had similar effects on the performance of both the control and the pea groups. 3. Pea diets, with and without supplemental flavomycin, had little influence on the composition of intestinal microflora. The counts of enterococci in the small intestine and Clostridium perfringens and coliforms in the caeca of pea‐fed chicks exceeded those of control chicks.

Nwosuh, E. N.; Adesiyun, A. A.

doi: 10.1080/00071668908417128pmid: 2545317

Abstract 1. Seventy 1‐d‐old broiler chicks were experimentally inoculated orally with Yersinia enterocolitica serotype 0:3 (1.4×1011cells/chick), 0:8 (1.6×1011 cells) and 0:9 (8.0×1010 cells) with or without sodium bicarbonate solution (10 g/1). 2. None of the chicks showed any overt clinical signs or pathological lesions although the organism was demonstrated in the ileum and shedding was observed up to 13 d after exposure. 3. The serotype, dose of Y. enterocolitica and administration of NaHCO3 solution had no significant effect on the weight gain of exposed broiler chicks. 4. Y. enterocolitica was isolated from the liver, spleen, heart and gall bladder of infected chicks 70 d after exposure. 5. Although broiler chicks appear resistant to high doses of Y. enterocolitica by the oral route, detection of the organism in the organs of infected chickens is of public health significance.