Evaluation of a vaccine to control bull behaviour
J.G. Jago, J.J. Bass and L.R. Matthews
Animal Behaviour and Welfare Research Centre, AgResearch, Ruakura Agricultural Centre,
Private Bag 3123, Hamilton, New Zealand.
E-Mail:
Proceedings of the New Zealand Society of Animal Production. 1997,
57: 91-95
To determine the effect of Vaxstrate®, an anti-GnRH
vaccine, on the development of bull behaviour, 90 Friesian bull calves
were either castrated at 2 months of age (steers, S), immunised against
GnRH at 2, 2.5, 4 and 7.5 months of age (immunocastrates,
I2), at 4, 4.5 and 7.5 months of age (I4), at 7.5
and 8 months of age (I7.5), or left intact (bulls, B).
Immunocastration delayed the prepubertal increase in testosterone. There
were no differences in behaviour between immunocastration treatments.
Mounting behaviour and paddock damage for immunocastrates and steers
were lower than for bulls until 13 months of age, after which there was
no difference between immunocastrates and bulls, and both were higher
than steers. Bulls had a higher frequency of agonistic behaviour than
both immunocastrates and steers; there was no difference between
immunocastrates and steers until 16 months of age, when immunocastrates
scored higher than steers. Immunisation against GnRH before puberty
temporarily delayed the development of sexual and agonistic behaviour of
young bulls and could provide a practical alternative to traditional
methods used to control bull behaviour.
Keywords: NZSAPAB;
bull; behaviour; immunocastration; GnRH; testosterone.
Last Updated 12-09-1998
