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Evaluation of postpartum udder characteristics of F1 cows sired by Angus, Gray Brahman, Gir, Indu-Brazil, Nellore and Red Brahman bulls
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Semen from Angus (A), Gray Brahman (GB), Gir (G), Indu-Brazil (IB), Nellore (N) and Red Brahman (RB) bulls was used to artificially inseminate Hereford cows for four years. The F, heifer offspring of these matings were bred to calve annually from 1985 through 1996. Teat length and teat diameter were estimated on each quarter of each cow, and a subjective udder support score was assigned to each cow postpartum. Calving records (n = 1016) were evaluated for teat length and diameter average (TLA and TDA, respectively), front teat length and diameter average (FTLA and FTDA, respectively), rear teat length and diameter average (RTLA and RTDA), left front teat length and diameter (LFTL and LFTD), right front teat length and diameter (RFTL and RFTD), left rear teat length and diameter (LRTL and LRTD) and right rear teat length and diameter (RRTL and RRTD) and udder support score (US). These characters were also evaluated with all parity 12 records excluded (n = 1006) and with all parity 10, I I and 12 records excluded (n = 929). IB cross cows had the longest teat lengths and largest teat diameters (P < .05) in most analyses; N cross cows had the shortest teat lengths and smallest teat diameters. N-sired cows had the tightest udders as indicated by the highest udder support scores; IB sired cows had the most pendulous and(or) broken down udders as indicated by the lowest udder support scores. Grouping of RB and GB did not change these results. Grouping of GB, G, IB, N and RB resulted in no significant difference between this group and A cross cows for any character analyzed. A sire breed by parity of cow interaction (P < .05) was found for all characters analyzed except RTDA, RRTD, and LRTD. Descriptively, after attempting to remove the selection effect of culling by eliminating all cows that did not have at least nine records (n = 813), TLA increased from parity one through parity seven and then decreased through parity I 1. TDA increased from parity one through parity 10, followed by a slight decrease for parity I 1. US tended to decrease from parity one through parity I 1. Estimated heritabilities ranged from .65 to .83 for teat length traits, from .01 to .32 for teat diameter traits. Estimated repeatabilities ranged from .51 to .57 for teat length traits, and from .42 to .54 for teat diameter traits. Estimated heritability and repeatability for US were .5 6 and .3 5, respectively.
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Includes bibliographical references: p. 110-118.
Issued also on microfiche from Lange Micrographics.
Riley, David Greg (1997). Evaluation of postpartum udder characteristics of F1 cows sired by Angus, Gray Brahman, Gir, Indu-Brazil, Nellore and Red Brahman bulls. Master's thesis, Texas A&M University. Available electronically from
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