The Efficiency of Feed Utilization by Barred Plymouth Rock and Crossbred Broilers

Feed Utilization in Growing Chickens in Relation to Shank Length

“…The two strains of New Hampshires are relatively more efficient than the Barred Plymouth Rocks used in this study, although the shortshanked Barred Plymouth Racks were more efficient in the beginning than the short-shanked New Hampshires. The findings of this analysis are in accord with those of Hess, Byerly, and Jull (1941); namely that the faster-growing chickens are the more efficient utilizers of feed. The period from the second to the eighth week appears as the desirable time to study feed utilization.…”

“…Asmundson and Lerner (1942) found in a study of twelve groups of turkeys, composed of three strains of Bronze, five other varieties, and crossbreds, a high correlation between logarithmic shank length and logarithmic body weight. As Hess, Byerly,' and Jull (1941) pointed out, a number of investigators have obtained efficiency figures for chickens, considering the population as a whole, but in no case known to them had the problem of feed utilization in poultry been attacked from the viewpoint of genetics. These workers demonstrated that efficiency is variable in different strains and crosses of poultry.…”

An Unexpected High Requirement of Chicks for Pyridoxine

“…Recently, Hess, Byerly,.and Jull (1941) reported that chicks from a cross of Barred Plymouth Rock males on New Hampshire females had a higher efficiency of feed utilization than did purebred Barred Rocks from the same sires. It was noted that certain sires, transmitted the higher efficiency whether mated to the Barred Rock females or the New Hampshire females.…”

Size of Thymus and Bursa Fabricius in Relation to Rate of Growth in Chicks

“…Chicks from relatively efficient progenies from the project recently reported by Hess, Byerly, and Jull (1941) were killed 12 hours after hatching, and their endocrine glands and segments of empty [116] at D H Hill Library -Acquis Dept S on March 29, 2015 http://ps.oxfordjournals.org/ Downloaded from digestive tract were removed and weighed on an analytical balance. The organic makeup of the chicks from matings producing efficient progency was not measurably different from that of chicks from matings producing relatively inefficient progeny.…”