The Repeatability of the Yearly Production of Range Cows

Repeatability of growth in Retinto beef cattle

“…This method of calculation has been little used. KOGER and KNOX (1947) obtained a repeatability for weaning weight of 0.49 in Hereford, and GREGORY et al (1950) estimated the correlation between consecutive records as -0.03 to 0.24 for birth weight and 0.37-0.50 for weaning weight.…”

Beef calf weights at 100 days and 205 days as indicators of dams' producing ability

“…Chambers ^ al. (1956) Repeatability estimates of weaning weight as measured by the regression of the first record on each later record or by the regression of the first record on the mean of subsequent records range from approximately 0.3 to 0.7 (Botkin and Whatley, 1953;Gregory et al, 1950;Koger and Knox, 1947). The intraclass correlations or repeatability estimates calculated in these data show that variations which may be attributed to differences between dams do vary with the trait being measured and that these differences do apparently change as the suckling period progresses.…”

“…As would be expected, the largest constants were observed for 2, 3, and 4 year old dams. Koch (1951) In several studies where the calves were weaned at 205 days the males exceeded the females by 26, 30, 29, 34 and 32 pounds (Koger and Knox, 1945a;Koger and Knox, 1947;Rice et al , 1954;Reynolds _et al , 1958;Meade jet , 1961), respectively. Similar values for calves weaned at 210 days were 25, 22 and 17, 38, 46, 39 pounds (Botkin and Whatley, 1953;Evans et al,.…”

“…(1955) and Chambers _et (1956). Minyard and Dinkel (1960) The other most common methods of correcting for age of calf are by covariance analysis (Koger and Knox, 1945a) or by the regression of weight on age within year, sex, and age of dam subclass groups (Koger and Knox, 1945b;Koger and Knox, 1947). …”

A note on estimates of the repeatability of weaning weight in beef cattle

“…The range in estimates is 0-34 to 0-52, and the mean of these estimates 0-45. Koger and Knox, 1947 0-49 1406-various types Gregory et ai, 1950 0-37-0-50 339-various types Koch, 1951 0-52 745-Herefords Botkin and Whatley, 1953 0-43 701-Herefords Rollins and Wagnon, 1956 0-34-0-51 577-Herefords Cunningham and Henderson, 1965 0-48 0-42 The closeness of the estimates of repeatability from this analysis and American work is interesting, since they have been obtained under quite different conditions of management and levels of nutrition. The results from the U.S.A. generally relate to range conditions, whilst the data for this analysis were derived from pedigree herds.…”