Publication Date

5-1981

Advisor(s) - Committee Chair

Gordon Jones, James Worthington, L.D. Brown

Degree Program

Department of Agriculture

Degree Type

Master of Science

Abstract

The calves born in the 1979 and 1980 calf crops at Sam Sells and Sons' Polled Hereford Farm in Moultrie, Georgia, were used in a study comparing immature body measurements with subsequent growth. The measurements taken at birth included weight, front leg length, front cannon bone length, and rear cannon bone length. In addition, hip height was measured at one hundred days, seven months, and twelve months of age. Weight was taken at seven months, twelve months and fifteen months of age.

The data were analyzed in four groups according to year of birth and sex. Coefficients of correlation were determined for all measurement combinations. Birth measurements alone accounted for an insignificant amount of the variability in twelve-month weight. Among the four groups studied, seven-month weight showed inconsistent associations to height and weight at twelve and fifteen months of age. This was due primarily to the amount of environmental influences involved in weight at seven months. Multiple regression analyses were conducted using twelve-month weight as a dependent variable and immature body measures as independent variables. An equation using one hundred-day hip height alone accounted for seventy-six percent of the variability in twelvemonth weight. Another equation including two independent variables, one hundred-day hip height and seven-month weight, accounted for eighty percent of the variability in twelvemonth weight. When twelve-month height was used for a dependent variable, one hundred-day hip height and rear cannon bone length at birth accounted for seventy percent of the variability.

The coefficients of correlation and multiple regression equations reported in this study support the fact that linear measurements are a more consistent measure of size in immature calves than weight alone. Also, linear measurements show little or no variation due to environmental conditions such as age of dam, unpartitioned maternal ability and physiological changes associated with puberty. The findings support the hypothesis that immature linear skeletal measurements are accurate predictors of subsequent growth in Polled Hereford cattle.

Disciplines

Agriculture | Animal Sciences | Beef Science | Life Sciences

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