HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Milagres, J. C. Articles by Robison, O. W. Search for Related Content PubMed Articles by Milagres, J. C. Articles by Robison, O. W.

Heritability Estimates for some Measures of Reproduction in Hereford Heifers^{1 ,2 ,3,}

North Carolina State University, Raleigh 27650

Abstract

Records on 491 Hereford cows were analyzed to estimate heritabilities of some measures of reproduction in the first calving. Estimates were obtained from paternal half-sibs by both analysis of variance (ANOVA) and chi-square (x²)- Heritabilities estimated from ANOVA and from x² for binary variables were corrected to a normal basis (ANOVA—C and x² —C). For calving rate at 2 years of age the heritabilities were .01 ± .02 (ANOVA), .02 ± .04 (ANOVA-C), .13 ± .09 (x²) and .22 ± .12 (x²—C). When heifers that failed to calve at both 2 and 3 years of age (barren) were excluded from the data, estimated heritabilities were .21 ± .13 (ANOVA), .45 ± .19 (ANOVA-C), .22 ± .14 (x²) and .48 ± .20 (x² —C). The heritability of barrenness was .0 ± .04 (ANOVA), .16 + .10 (x²) and .33 ± .15 (x² —C). Analysis of perinatal survival evaluated as a characteristic of the dam yielded heritability estimates of .64 ± .21 (ANOVA), 1.25 ± .35 (ANOVA—C), .61 + .25 (x²) and 1.19 ± .34 (x² —C). Heritability of services per conception for the first calving was estimated at .64 ± .29.

¹ Paper No. 5824 of the Journal Series of the North Carolina Agr. Exp. Sta. Raleigh.

² The authors express their appreciation to the personnel of the Research Stations at Plymouth and Raleigh for their assistance in collecting the data.

³ Conducted in cooperation with the Southern Regional Project S-10, The Improvement of Beef Cattle for the Southern Region through Breeding Methods.

⁴ Present address: Universidade Federal de Vicosa, 36.570 Vicosa — MG — Brasil.

⁵ Department of Animal Science.

This article has been cited by other articles:

				G. Martinez-Velazquez, K. E. Gregory, G. L. Bennett, and L. D. Van Vleck Genetic relationships between scrotal circumference and female reproductive traits J Anim Sci, February 1, 2003; 81(2): 395 - 401. [Abstract] [Full Text] [PDF]