Author: Geoffrey Oswald Harwin
Publisher:
ISBN:
Category : Cattle
Languages : en
Pages : 158
Book Description
The present study was initiated to determine the effects of inbreeding and certain environmental and genetic factors on the weaning weight of range Hereford calves. The study was also extended to include an investigation of the effect of these variables on post-weaning traits of range Hereford females including yearling gain and weight at 18 months, 2 1/2 years and 3 1/2 years of age. The data used in the study were obtained from a long term cattle breeding project initiated by Colorado State University in 1946 at the San Juan Basin Experiment Station and included onservations from 16 inbred lines of Hereford cattle, crosses between yhese lines and a control herd. The preliminary phase of the study was concerned with the development of appropriate mathematical models enabling minimum variance unbiased estimates of the various genetic and ebvironmental factors under investigation. The interactions between the various main effects as they affect weaning weight were investigated simultaneously by means of a least squares analysis. The interactions of sex x mating system, sex x age of dam and year x age of dam were significant. Investigation of the within year regression of weaning weight on age of calf also indicated a significant interaction between age of calf and year. Preleminary investigation indicated a marked curvilinear decline in weaning weight with inbreeding and differential response to inbreeding of both lines and sexes. The results of the preliminary studies were used in developing the final models...
The Effect of Inbreeding and Environmental Factors on the Weaning Weight and Post-weaning Growth of Range Hereford Cattle
Author: Geoffrey Oswald Harwin
Publisher:
ISBN:
Category : Cattle
Languages : en
Pages : 158
Book Description
The present study was initiated to determine the effects of inbreeding and certain environmental and genetic factors on the weaning weight of range Hereford calves. The study was also extended to include an investigation of the effect of these variables on post-weaning traits of range Hereford females including yearling gain and weight at 18 months, 2 1/2 years and 3 1/2 years of age. The data used in the study were obtained from a long term cattle breeding project initiated by Colorado State University in 1946 at the San Juan Basin Experiment Station and included onservations from 16 inbred lines of Hereford cattle, crosses between yhese lines and a control herd. The preliminary phase of the study was concerned with the development of appropriate mathematical models enabling minimum variance unbiased estimates of the various genetic and ebvironmental factors under investigation. The interactions between the various main effects as they affect weaning weight were investigated simultaneously by means of a least squares analysis. The interactions of sex x mating system, sex x age of dam and year x age of dam were significant. Investigation of the within year regression of weaning weight on age of calf also indicated a significant interaction between age of calf and year. Preleminary investigation indicated a marked curvilinear decline in weaning weight with inbreeding and differential response to inbreeding of both lines and sexes. The results of the preliminary studies were used in developing the final models...
Publisher:
ISBN:
Category : Cattle
Languages : en
Pages : 158
Book Description
The present study was initiated to determine the effects of inbreeding and certain environmental and genetic factors on the weaning weight of range Hereford calves. The study was also extended to include an investigation of the effect of these variables on post-weaning traits of range Hereford females including yearling gain and weight at 18 months, 2 1/2 years and 3 1/2 years of age. The data used in the study were obtained from a long term cattle breeding project initiated by Colorado State University in 1946 at the San Juan Basin Experiment Station and included onservations from 16 inbred lines of Hereford cattle, crosses between yhese lines and a control herd. The preliminary phase of the study was concerned with the development of appropriate mathematical models enabling minimum variance unbiased estimates of the various genetic and ebvironmental factors under investigation. The interactions between the various main effects as they affect weaning weight were investigated simultaneously by means of a least squares analysis. The interactions of sex x mating system, sex x age of dam and year x age of dam were significant. Investigation of the within year regression of weaning weight on age of calf also indicated a significant interaction between age of calf and year. Preleminary investigation indicated a marked curvilinear decline in weaning weight with inbreeding and differential response to inbreeding of both lines and sexes. The results of the preliminary studies were used in developing the final models...
Evaluation of Response to Selection and Inbreeding in a Closed Line of Hereford Cattle
Author: J. S. Brinks
Publisher:
ISBN:
Category : Agriculture
Languages : en
Pages : 40
Book Description
Publisher:
ISBN:
Category : Agriculture
Languages : en
Pages : 40
Book Description
Estimation of Genetic and Environmental Parameters of Weaning Weight and Weaning Grade in Hereford Cattle
Author: Kurt Eberhard Sittmann
Publisher:
ISBN:
Category :
Languages : en
Pages : 322
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 322
Book Description
The Effect of Genetic and Environmental Factors on Weaning Weight of Hereford Calves
Author: James Andrew Carpenter
Publisher:
ISBN:
Category :
Languages : en
Pages : 72
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 72
Book Description
Journal of Animal Science
The Effects of Mild Inbreeding on Weaning Weight and Grade of Hereford Cattle
Author: Neil B. McCleery
Publisher:
ISBN:
Category : Hereford cattle
Languages : en
Pages : 58
Book Description
Publisher:
ISBN:
Category : Hereford cattle
Languages : en
Pages : 58
Book Description
Dissertation Abstracts International
Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 1248
Book Description
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 1248
Book Description
Livestock Research of the United States Department of Agriculture and in Cooperation with State Agricultural Experiment Stations
Author: United States. Department of Agriculture. Livestock Research and Marketing Advisory Committee
Publisher:
ISBN:
Category : Livestock
Languages : en
Pages : 166
Book Description
Publisher:
ISBN:
Category : Livestock
Languages : en
Pages : 166
Book Description
Bibliography of Agriculture
Some Factors Affecting Weaning Weights and Weaning Scores in Beef Calves
Author: James S. Brinks
Publisher:
ISBN:
Category : Beef cattle
Languages : en
Pages : 102
Book Description
Publisher:
ISBN:
Category : Beef cattle
Languages : en
Pages : 102
Book Description