Reciprocal cross differences in Brahman-Hereford F₂ cows : productive and maternal traits /
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| Other Authors: | |
| Format: | Thesis eBook |
| Language: | English |
| Published: |
[College Station, Tex.] :
[Texas A&M University],
[2007]
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| Subjects: | |
| Online Access: | Link to OAK Trust copy |
| Abstract: | Data from 75 F₂ Brahman-Hereford cows of four specific breed combinations, F₂ HB (produced by F₁ HB sires x F₁ HB dams, where "HB" refers to cattle sired by Hereford bulls and out of Brahman cows), F₂ BH (produced by F1₁ BH sires x F₁ BHdams), HB x BH and BH x HB, were evaluated for maternal performance at the Texas A&M Research Center near McGregor. Differences between breed combinations were analyzed for calf crop born (CCB), calf crop weaned (CCW), calf survival (CS), birthweight (BW), weaning weight (WW), and cow weight at palpation (PW). The adjusted means for F₂ HB, F₂ BH, HB x BH, and BH x HB were 0.84 ± 0.06, 0.57 ± 0.07, 0.82 ± 0.06, and 0.62 ± 0.08, respectively, for CCW. F₂ HB cows had a 0.27 ± 0.09 higherpercent calf crop weaned than F₂ BH cows (P < 0.01) and a 0.22 ± 0.11 higher percent calf crop weaned than BH x HB cows (P < 0.05). HB x BH cows had a 0.25 ± 0.08 higher percent calf crop weaned than F₂ BH (P < 0.01) and a 0.20 ± 0.10 higher percent calf crop weaned than BH x HB cows (P < 0.05). As 6-year-olds, the adjusted means for cow weight at palpation for F₂ HB, F₂ BH, HB x BH, and BH x HB cows were 523.65 ± 20.49 kg, 602.61 ± 23.63 kg, 492.84 ± 16.98 kg, and 515.93 ± 22.96 kg, respectively. Averaged across all ages, HB x BH cows weighed 56.59 ± 15.29 kg less than F₂ BH cows (P < 0.001) and 41.11 ± 18.92 kg less than BH x HB cows (P < 0.05). Also, F₂ HBcows weighed 40.45 ± 17.68 kg less than F₂ BH cows (P < 0.05). In this herd, HB-sired cows had higher reproductive efficiency than BH-sired cows. Also, HB-sired cows tended to be lighter than BH-sired cows. Although these differences existed, exact causes could not be determined primarily due to confounding between the birth year of the cow and the sire breed of the cow. |
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| Item Description: | "Major Subject: Animal Breeding" Title from author supplied metadata (automated record created on Apr. 27, 2007.) Vita. Abstract. Electronic resource. |
| Format: | Mode of access: World Wide Web. System requirements: World Wide Web access and Adobe Acrobat Reader. |
| Bibliography: | Includes bibliographical references. |