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

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed 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 Sandelin, B. A. Articles by Stelzleni, A. M. Search for Related Content PubMed PubMed Citation Articles by Sandelin, B. A. Articles by Stelzleni, A. M.

Genotype x environmental interaction for mature size and rate of maturing for Angus, Brahman, and reciprocal-cross cows grazing bermudagrass or endophyte infected fescue¹

B. A. Sandelin^*,2, A. H. Brown, Jr.^*, M. A. Brown, Z. B. Johnson^*, D. W. Kellogg^* and A. M. Stelzleni^*

^* University of Arkansas, Fayetteville 72701 and and USDA, ARS, Grazinglands Research Laboratory, El Reno, OK 73086

² Correspondence:
Phone: 479-575-7254; fax: 479-575-5756; E-mail:
bsandel{at}uark.edu.

Mature weight and rate of maturing were estimated in 177 Angus, Brahman, and reciprocal-cross cows grazing bermudagrass or endophyte-infected tall fescue over a 4-yr period to evaluate genotype x environment interactions. Data were collected every 28 d until cows were approximately 18 mo of age and then at prebreeding, postcalving, and weaning of calf. All cows with weight data to at least 42 mo of age were included in the analysis. Mature weight and rate of maturing were estimated using the three-parameter growth curve model described by Brody (1945). Data were pooled over year and analyzed by the general linear model procedure of SAS. Included in the models for mature weight and rate of maturing were the independent variables of genotype, environment, and genotype x environment interaction. There was a genotype x environment interaction (P < 0.01) for mature body weight (BW) but not for rate of maturing. Angus cows grazing fescue pastures had greater (P < 0.01) mean mature BW than Angus x Brahman cows grazing bermudagrass (611 ± 17 vs 546 ± 16 kg). Angus x Brahman cows grazing bermudagrass had lower (P < 0.05) mean mature BW than Brahman x Angus cows grazing bermudagrass or endophyte-infected fescue and Brahman cows grazing bermudagrass (546 ± 16 vs 624 ± 19, 614 ± 22 and 598 ± 20 kg, respectively). Brahman cows grazing endophyte-infected fescue had smaller (P < 0.05) mean mature BW than all genotype x forage combinations except for Angus x Brahman cows grazing bermudagrass. Angus cows had a smaller (P < 0.05) mean rate of maturing than Angus x Brahman and Brahman x Angus cows (0.039 ± 0.002 vs 0.054 ± 0.002 and 0.049 ± 0.002%/mo, respectively), respectively, and Angus x Brahman cows had a larger (P < 0.05) mean rate of maturing than Brahman x Angus and Brahman cows (0.054 ± 0.002 vs 0.049 ± 0.002 and 0.041 ± 0.002 %/mo, respectively). There was a direct breed x forage interaction (P < 0.05) for mature BW. These data suggest that the choice of breed type is important in maintaining a crossbreeding program, in that mature BW and rate of maturing are critical to the matching of animal requirements to available production resources.

Key Words: Body weight • Environment • Genotypes • Maturity Stage

This article has been cited by other articles:

				E. L. Oxford, A. H. Brown Jr., Z. B. Johnson, G. T. Tabler, and B. R. Kutz Preweaning Performance, Heterosis, and Direct and Maternal Breed Effects in Angus, Hereford, Red Poll, Santa Gertrudis, and Reciprocal-Cross Calves Professional Animal Scientist, October 1, 2009; 25(5): 529 - 535. [Abstract] [PDF]