Evaluation of birth, weaning and carcass traits of F1 calves sired by Brahman bulls /
This study evaluated a total of 15 Brahman bulls and I Nellore bull over a period of three calf crops. The bulls were mated to Angus and Hereford cows, with a total of 363 Fl calves out of Angus cows and 136 out of Hereford cows being bom in the three year period. Birth and weaning records evaluat...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1996.
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| Summary: | This study evaluated a total of 15 Brahman bulls and I Nellore bull over a period of three calf crops. The bulls were mated to Angus and Hereford cows, with a total of 363 Fl calves out of Angus cows and 136 out of Hereford cows being bom in the three year period. Birth and weaning records evaluated were gestation length (n 418), birth weight (n =496) and weaning weight (n = 364). Carcass traits were evaluated on steers (n = 176) and included warm carcass weight, external fat thickness at the 12th rib, longissimus muscle area, estimated internal fat percentage U.S.D.A. yield grade, skeletal maturity, lean maturity, (KPH), marbling score, Wamer-Bratzler shear force and 14 d Wamer-Bratzler shear force. There was a 7 d difference in gestation length among the averages for sires, with male calves being carried slightly longer at gestation (292.53 ± .44 d) than heifer calves (290.29 ± .45 d). Sex of calf had a major impact on birth weight as bull calves had an average birth weight of 44.52 ± .40 kg while heifer calves had an average birth weight of 38.78 ± .38 kg. Calves out of Angus dams were higher (P <.05) in average weaning weight (227.23 ± 1.72 kg) than those calves out of Hereford dams (205.88 ± 2.84 kg). Similarly, steers out of Angus dams had heavier (P <.05) warm carcass weights, larger (P <.05) ribeye areas and more (P <.05) KPH fat, external fat thickness and marbling than those calves out of Hereford dams. Among the 176 steer calves evaluated, 52% of the carcasses graded U.S. Choice, 47% graded U.S. Select and 1% were no-rolled. Each minimum standard for retail sale with a high average shear force of 3.61 ± 0.06 kg and a low of 2.94 ± 0.09 kg. Year of birth had a significant effect (P <.05) on 14 d Wamer-Bratzler shear force as steers bom in 1994 had an average shear force of 3.52 ± 0.05 kg while those bom in 1995 averaged 2.29 ± 0.04 kg. |
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| Item Description: | Vita. "Major subject: Animal Science". In title, numerals are subscript. |
| Physical Description: | xi, 95 leaves : illustrations ; 28 cm. Issued also on microfiche from Lange Micrographics. |
| Bibliography: | Includes bibliographical references: pages 84-94. |