Onset of puberty in Angus, Friesian, Friesian x Angus, and Friesian x Jersey heifers

A.B. Pleasants, G.K. Hight and R.A. Barton

Massey University, Palmerston North

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Proceedings of the New Zealand Society of Animal Production. 1975, 35: 97-102

In an investigation of some factors which may be affected the attainment of puberty in 61 Friesian (F x F), 40 Angus (A x A), 60 Friesian x Angus (F x A), and 56 Friesian x (Friesian x Jersey) (F x (F x J) heifers in three seasons, it was found that breed of sire and year affected both weight and age at puberty. Age and weight at puberty were strongly related. Breed of dam influenced weight at puberty, but just failed to reach significance for age at puberty. Age of dam and sire within year within breed did not influence either weight or age at puberty.

Heifers of Friesian breeding were younger and heavier at puberty than those of Angus breeding, while those from Friesian x Jersey dams were lighter, but not older at puberty than those from Angus dams.

Regression equations were fitted for age and weight at puberty on a number of independent variables which measured developments from birth to puberty. Although it was concluded that the attainment of puberty was not consistently influenced by any of the variables studied, pre-weaning traits appeared to have more influence than post-weaning variables.

Keywords: NZSAPAB;

Last Updated 24-08-2000