Inheritance of Rate of Growth in Barred Plymouth Rocks

Selection for Body Weight at Eight Weeks of Age

“…This would tend to decrease the genetic correlation. The close association of both the hereditary and environmental influences on weight at eight weeks of age and body weight at 24 and 38 weeks of age were consistent with the results of the two-way selection experiment of Schnetzler (1936) and the comparison of a fast growing line to a control by Singh (1960). The genetic correlations reported here between body weights at eight and 24 weeks of age were in good agreement with those obtained between weight at broiler age and weight at sexual maturity by Peeler et al (1955) and Hale (1961).…”

“…Schnetzler (1936) found that two generations of selection for fast and slow growth to eight or nine weeks of age influenced adult body weight, egg weight and chick size. Maloney and Gilbreath (1962) observed that ten generations of selection in opposite directions for 12-week weight resulted in differences between the lines for 6-week weight, egg weight, age at first egg, and percentage egg production.…”

The Heritability of Body Weight in Turkeys

“…Oregon Agr. Schnetzler (1936) found that there was a positive correlation between weight in chickens at 8 and 12 weeks and weight at maturity. Sta.…”

Effects of Nutrition on Variability in the Growth of Chickens

“…Asmundson and Lerner (1933) reported that there were genetic differences with respect to rate of growth within their strain of the White Leghorn breed, and that those differences were determined by multiple factors. Schnetzler (1936) found that fast growing chicks grow larger, lay larger eggs, and beget faster growing offspring than slow growing chicks. Titus and Jull (1928) pointed out that chicks that received skimmilk did not increase in variability after the fourth week of age, whereas those that did not receive skimmilk continued to increase in variability until the seventh or eighth week.…”