Chicken Stock Research Articles

Hematological Response of Different Stocks of Chickens to Iron-Copper Deficient Diet

TINDELL et al. (1967) reported that genotype-environmental interactions for body weight, although statistically significant, were relatively unimportant when genetically different stocks were reared under different management and geographical environments. This type of study enables one to obtain information about differences in the effects of the average environment of one location compared to that of another location. Another approach is to create a definable stress environment and then compare the stocks in stress and non-stress environments.Genetic differences between stocks and lines of chickens have been reported for packed erythrocyte volume (Washburn and Smyth, 1968). Slight genetic differences in packed erythrocyte volume values may have little or no effect on a stock as long as certain environmental conditions are not present. However, a bird with slightly decreased packed erythrocyte volume values might be more severely affected by marginal deficiencies of nutritients necessary for hematopoiesis. If this is true, genotype—environmental interactions…

Genotype-Environment Interactions in Broiler Stocks of Chickens: 3. Main Effects and Interactions of Parent Flock Location, Parent Flock Stock, Trial and Growing Locations

GUTTERIDGE and O’Neil (1942) tested three strains of Barred Plymouth Rocks at three diverse locations in Canada. They concluded that strain by location interaction was of little consequence for eight-week body weight. Strain by location interactions were found to be nonsignificant by Merritt and Gowe (1956) at ten weeks of age in both sexes for body weight, keel length and shank length. The stock by location interaction was not greater than two percent of the total variance for any of the traits measured. Lewis and Blow (1965) indicated that genotype by location or trial interactions made up less than one percent of the total phenotypic variance in ten-week body weight. Their study involved four strains of broilers that were tested at each of three locations in North Carolina in three replicate trials.Tindell et al. (1967) analyzed data for eight stocks (five commercial and three experiment station) tested in three .

Agglutinating antibodies in the sera of chickens with regressing Rous sarcomas.

SEVERAL antigens specific for tumour cells have been identified1–7 in tumours induced by viruses, and virus-induced resistance to tumour cell antigens has been established8–11. It now seems important to investigate surface tumour cell antigens because they may be involved in the induction of resistance. I have studied the surface cell antigens of chicken sarcomas induced by the Rous virus (Carr–Zilber strain), using sera from adult chickens in which tumours, induced by the virus or by transplanted tumour cells, had regressed after an initial period of active growth. Regression was most frequent in chickens inoculated with low doses of virus or tumour cells. The sera were heated at 56° C for 30 min and added to a cell suspension prepared from chicken Rous sarcoma. The suspension contained 2 × 107 cells/ml. Sera taken from intact healthy chickens were used as a control. The mixtures of cells and immune or control sera were kept at 4° C for 18 h. The reaction was checked under the microscope (magnification × 120). Table 1 shows that of thirteen sera taken from chickens in which the tumours had regressed, nine produced agglutination of tumour cells (Fig. 1). Sera from fifteen control chickens and twenty-five chickens with actively growing sarcomas showed no agglutinating activity. Agglutinating antibodies appeared in the blood at the time of tumour regression arid remained there in some cases for a period of 60–105 days after regression. Our stock of chickens was not inbred so it was necessary to find whether immune sera would also agglutinate normal chicken cells. Sera were therefore added to a cell suspension prepared from the spleen, liver, thymus and bursa of Fabricius of untreated chickens. Immune sera also agglutinated normal chicken cells. These results show that the antibodies, or at least some of them, were isoantibodies directed against the isoantigens of tumour and normal tissue.

Genotype-Environment Interactions in Broiler Stocks of Chickens: 2. Stock by Location, Stock by Floor Space and Stock by Trial Interactions

PREVIOUS studies with broilers have indicated that interactions of stock with rearing location are of minor practical importance for body weight and other broiler traits (Gutteridge and O’Neil, 1942; Merritt and Gowe, 1956; Lewis and Blow, 1965). Significant (P < .05) or highly significant (P < .01) interactions of stocks and locations were indicated at all ages of measurement for body weights of both sexes in a study by Tindell et al. (1967). In the latter study the stock by location interaction component made up less than one percent of the total phenotypic variance regardless of sex or age at measurement; therefore, such interactions, although statistically significant, were concluded to be of minor concern. The stock by trial interactions in the same study were also statistically significant (P < .05), and made up from three to six percent of the total phenotypic variance for body weight at various ages in .

Genotype-Environment Interactions in Egg Production Stocks of Chickens: I. The Importance of Stock by Location and Stock by Year Interactions

IN THE last 15 years poultry breeding has rapidly changed from a large number of local breeders serving small areas to several dozen very large breeders operating on a national or international basis. The large breeders generally produce for commercial use only one or two egg production lines or stocks which are sold over a wide range of environments. Strains that generally perform satisfactorily over a wide range of environments may not be superior in specific environments such as in different areas of the country or under various types of management conditions or levels of disease exposure. As the industry becomes more specialized, the stocks with general adaptability may become less useful.The current study is one of a series of studies conducted by participants in the Southern Regional Poultry Breeding Project (S-57) to determine the importance of genotype-environment interactions in egg production stocks. In determining whether stock by location .

A fluorescent-antibody technique for the rapid detection of Salmonellae in foodstuffs.

SYNOPSISThe development of a rapid, indirect fluorescent‐antibody technique for the detection of Salmonella; in dried egg powder, frozen chicken meat, and frozen chicken stock is described. Experiments using the technique in parallel with a conventional cultural technique have shown the results to be comparable and it is concluded that, provided the fluorescent‐antibody technique is used in conjunction with such a cultural technique, the small incidence of false positive results encountered does not constitute a great disadvantage in routine work.

Genotype-Environment Interactions in Broiler Stocks of Chickens: I. The Importance of Stock by Location and Stock by Trial Interactions

THE importance of non-additive genotype-environment interactions in broiler stocks is of considerable interest to breeders, as such interactions will influence the breeder’s testing program. The regional approach, with a number of state agricultural experiment stations cooperating, is one logical way of investigating these interactions since environments in different states may be more diverse than those existing at locations within a state or station. Investigations at the regional level more nearly represent the actual distribution of commercial stocks as compared with research that is limited geographically. This study is one of a series conducted by participants in the Southern Regional Poultry Breeding Project (S-57) to determine the relative importance of genotype-environment interactions in broiler stocks.Only a limited number of studies with broiler stocks have been conducted to determine the importance of genotype by environment (location, diet, management, etc.) interactions; however, a large number of studies (see Hale, 1961) have been …

On the Probability That the Best Chicken Stock Will Come Out Best in a Single Random Sample Test

WHEN samples taken from several stocks (or strains, varieties, etc.) are compared with a view to selecting the best stock, it is of interest to know the probability of correct selection. The problem of computing this probability is complicated by the fact that the true stock means are usually either fixed but unknown, or else are themselves a more or less random sample from a larger population. Some mathematical expressions for the probabilities of correct selection in the latter case, assuming a normal distribution of the true stock means, were given by Dunnett (1960), but they involve multiple integrals which have not been numerically evaluated so far.On the other hand, the conditional probability of correct selection given any particular fixed configuration of the true stock means is much simpler to compute. Assuming (as usual) that the data for individual layers are normally distributed around the true stock means, X1,…

Responses of Different Stocks of Chickens to Inoculation as Embryos and as Chicks with Strain RPL 12 and Field Isolates of Leukosis Virus

The RPL 12 strain of avian tumor virus has been used extensively in studies on viral oncology at this Laboratory. This strain of virus was isolated from a transplantable lymphoid tumor that came originally from a field case of visceral lymphomatosis in 1938 (3). The pattern of neoplastic disease induced by RPL 12 in line 15I chickens is quite similar to that occurring spontaneously among chickens in commercial populations, though with notable differences. High doses of RPL 12 cause high incidence of erythroblastosis, a disease rarely encountered in the field, whereas low to moderate doses induce visceral lymphomatosis, the commonly occurring neoplastic disease among commercially raised chickens (4,6,11). Also, mortality from visceral lymphomatosis induced by RPL 12 is rare until at least 120 days after inoculation, whereas many deaths from the natural disease may occur as early as 40 days after hatching in so-called acute leukosis (2,9). For these reasons it was thought desirable to compare the oncogenic potency and spectrum of strain RPL 12 virus with viruses isolated directly from field cases of visceral lymphomatosis. Most studies on RPL 12 virus have been done in line 151

The Hatchability of Chicken Eggs as Influenced by Diallel Crossing

THE ability of fertile chicken eggs to hatch is dependent upon many genetic and environmental variables which have been adequately presented by Landauer (1937). In the light of past genetic research no specific genes would appear to account for hatchability in toto. Indeed, the prevalence of embryonic lethal genes in chicken stocks, together with the egg environment, would be apt to mask the action of any such specific genes.There are so many variables associated with the hatchability of eggs that certain very fundamental facts may be overlooked. There are at least three major sets of variables which decide whether a developing embryo will or will not hatch. First, there are the genetic potentialities of the developing embryo which consist of contributions from both parents. Second, there is the internal composition of the egg together with the shell which is part of the dam’s own genetic make-up and this egg .