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Relation between Holstein bulls’ proofs for milk in USA and the survival and body weights up to 18 months of their F 1 zebu progeny in Venezuela
Author(s) -
Pacheco J. R.,
Vaccaro L.,
Mejías H.,
Pérez A.,
López J.,
Dorta D.
Publication year - 2003
Publication title -
journal of animal breeding and genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.689
H-Index - 51
eISSN - 1439-0388
pISSN - 0931-2668
DOI - 10.1046/j.1439-0388.2003.00389.x
Subject(s) - zebu , zoology , biology , mathematical proof , mathematics , geometry
Summary The purpose of the study was to determine the relation between Holstein bulls’ proofs for milk in USA, and the survival and body weights of their F 1 progeny under lowland grazing conditions in Venezuela. Semen was selected from sires with the highest proofs available locally (class H, n = 23) or with proofs close to the breed average (class A, n = 18). Mean proofs were 934 kg (H) and 237 kg (A), respectively, when semen was purchased (1989–93), falling to 204 and −386 kg when updated in 2001. Dams were Brahman‐type zebus on seven farms, raising the F 1 progeny (n = 866) on native or cultivated pasture with only mineral supplements. Records of survival to 8 and 18 months and weights at birth, 8 and 18 months of age were analysed using linear models. Sire class had no effect on survival or weight at birth, but H progeny were slightly heavier than A progeny at 8 (4.0%, p = 0.06) and 18 months (2.6%, p < 0.05). The interaction class × farm was only significant for survival, with H progeny equal or superior to A groups on six farms. The effect of sire within class was highly significant for survival to 8 months and weight at 18 months. Rank correlations using sires’ milk proofs and F 1 progeny weights and survival were not significant. It was concluded that the use of Holstein bulls with high milk proofs may lead to slightly higher 18‐month weights in their F 1 progeny in tropical grazing systems, covering the additional cost of H semen, but that sire evaluation for weight gain and progeny survival rates may be justified under these conditions.