Fifteen Years of Selection for Viability in White Leghorns

Additional Evidence for Genetic Variation in Resistance to “Blue Comb” Disease

“…Losses from reproductive disorders which are usually quite numerous were practically absent in 1948; this observation was reported previously by Moultrie, King, and Cottier (1953). The percentage of deaths from reproductive disorders for 1948 is compared to that for the other years from 1944 to 1951, inclusive, in Table 3.…”

“…The flock involved consisted of 1,095 pedigreed Single Comb White Leghorn pullets of the Auburn Strain, which had been selected several years for resistance to leucosis and for general viability (Sturkie, 1943;Moultrie, King and Cottier, 1953). All birds were placed in laying houses either before or during the outbreak; however, only pullets from the first 4 of the season's 9 hatches suffered mortality from the disease, and all deaths from blue comb in the affected hatches occurred after housing.…”

The Effects of Relaxed Selection on Performance of a Strain of Disease-Resistant White Leghorns

“…Details of development and performance of the strain have been reported by Sturkie (1943) and Moultrie et al (1953). Strain A is a disease-resistant strain with fairly good egg production.…”

“…Selection in Strain A during the 3 years involved was based on the progeny test and family selection as in past years (Moultrie et al, 1953). Selection in Strain Ar was relaxed, no intended genotypic or phenotypic selection being practiced.…”

Role of egg "cytoplasm" in transmission of resistance to an avian leukosis tumor

“…The successful development of strains of chickens re sistant to lymphomato si s have been reported by Hutt and Cole (1947, 1948, Poirier (1952), Moultrie et al (1953) and Coles (1954). Poirier )1952) and Coles (1954) Saline was then added to give the proper dilution.…”