The genetics of poultry color in poultry

1. The chromogen gene for color, CC, acted as a simple dominant. 2. The extension of black pigment, EE, was inherited on a simple monohybrid basis. 3. The heterozygous extension and chromogen genes (Cc Ee) had a balanced relationship. This combination of heterozygous factors weakened the expression of the black melanic pigment in the presence of two or more doses of buff. 4. Buff color was controlled on a dihybrid basis, the following symbols being used, Bu Bu Bu\u27 Bu\u27. 5. Three or more doses of the buff genes in the presence of homozygous color factors, CC, were epistatic to black, and gave a buff color. 6. Two or more doses of the buff color determiners were epistatic to black when they were in the presence of both the extension of black and chromogen factors in a heterozygous state. 7. When the extension factor was homozygous, EE, the buff color was hypostatic to black if not present in three or more doses. 8. All the factors included thus far in the summary were autosomal. 9. The sex-linked factor for barring (BB and B-) appeared to act as a simple dominant to black and buff colors

Factors influencing egg production I. The influence of maturity upon egg production in S. C. White Leghorns

1. A consistent correlation existed between early maturity and high winter egg production in all four years. 2. The correlation between maturity and winter egg production was shown, in graph form, to be negative. 3. Early maturity had a direct negative rectilinear prediction value with winter egg production. 4. Maximum winter egg production was obtained when birds matured in less than 220 days. 5. Very little if any relationship existed between maturity and spring egg production. 6. Great variation in the relation of maturity and total egg pro-production existed from year to year. 7. Maturity bore a high curvilinear correlation with total annual egg production. The mode of this curve was 190 days for maturity and 225.5 eggs for total production while the means were 196.83 days and 204.99 eggs, respectively. 8. The variation in the correlation between maturity and total egg production was due to: First, too few numbers; second, only a sample of the entire population was used; third, the correlation found between maturity and total egg production was curvilinear; fourth, environmental conditions, such as a low protein ration, which retarded development tended to confuse the interpretation of results. 9. In order to secure maximum total egg production, S. C. White Leghorns should mature in 160 to 210 days

The genetics of plumage color in poultry

Bibliography: p. 130-131.Mode of access: Internet

Factors influencing egg production II. The influence of the date of first egg upon maturity and production

1. Pullets that laid their first egg early in their laying year were generally of earlier sexual maturity than those which laid their first egg later in the year. 2. The time that the first egg was laid had a curvilinear association with winter egg production. 3. Birds that laid their first egg in September had the highest winter egg production. 4. Pullets that laid their first egg between the dates of Sept. 6 and Dec. 13 produced 50 or more eggs in the winter period. 5. There was a slight curvilinear association between the date of first egg and the rate of spring egg production. 6. The pullets that produced their first egg in December laid the greatest number of eggs during the spring period. 7. The poorest spring production was 58.4 eggs, the average of the birds that produced their first egg in March. 8. The records showed a curvilinear association between the date of first egg and total or annual egg production. 9. The pullets that laid their first egg in October produced the greatest number of eggs, 223.1 10. A production of 200 or more eggs was attained by those pullets that laid their first egg from Sept. 6 to Dec. 13

Feeding Poultry for Egg Production

Altho there is probably no phase of poultry keeping so profitable as the securing of maximum egg production, it is too often true that little thought is given of how to secure high yields

On the Inheritance of Resistance to Fowl Typhoid in Chickens

Studies at the Iowa Experiment Station during 1927 and 1928 indicate very clearly that selection is effective in increasing resistance to this disease

Evaluation of materials proposed for use in space flight Final report

Irritant and allergic potentials of fireproof paper for space flight use evaluated on human and animal skin

The Nature of Belief-Directed Exploratory Choice in Human Decision-Making

In non-stationary environments, there is a conflict between exploiting currently favored options and gaining information by exploring lesser-known options that in the past have proven less rewarding. Optimal decision-making in such tasks requires considering future states of the environment (i.e., planning) and properly updating beliefs about the state of the environment after observing outcomes associated with choices. Optimal belief-updating is reflective in that beliefs can change without directly observing environmental change. For example, after 10 s elapse, one might correctly believe that a traffic light last observed to be red is now more likely to be green. To understand human decision-making when rewards associated with choice options change over time, we develop a variant of the classic “bandit” task that is both rich enough to encompass relevant phenomena and sufficiently tractable to allow for ideal actor analysis of sequential choice behavior. We evaluate whether people update beliefs about the state of environment in a reflexive (i.e., only in response to observed changes in reward structure) or reflective manner. In contrast to purely “random” accounts of exploratory behavior, model-based analyses of the subjects’ choices and latencies indicate that people are reflective belief updaters. However, unlike the Ideal Actor model, our analyses indicate that people’s choice behavior does not reflect consideration of future environmental states. Thus, although people update beliefs in a reflective manner consistent with the Ideal Actor, they do not engage in optimal long-term planning, but instead myopically choose the option on every trial that is believed to have the highest immediate payoff

The Inheritance of Leg-Feathering in the Chicken

The inheritance of leg-feathering in crosses of the Black Langshan (feathered) with the White Plymouth Rock and Buff Orpington breeds (non-feathered) has been found to be dependent upon two dominant duplicate factors (S1 and S2). This relationship has been verified from data secured from F2 and backcross generations. Of five F1 males used in these studies three proved to be heterozygous for both factors S1 and S2 and two for but one of these factors, while six F1 females proved to be heterozygous for both factors and ten for but one factor. These data indicate, therefore, that the Black Langshan is often heterozygous for at least one pair of these factors