Induced cryptochidism no solution to the rut
A.M. NICOL AND M.J. KEELEY
Animal and Food Sciences Division, PO Box 84, Lincoln University
E-Mail:
NZSAP 2002 Abstract No. 37
Proceedings of the New Zealand Society of Animal Production 62:
145-148
Two experiments were made to determine if induced cryptorchidism
(short-scrotum) would modify behaviour and reduce liveweight loss during
the rut without affecting subsequent velvet production. In the first
experiment, groups (n = 10) of entire and induced cryptorchid mixed-age
stags were used in a behaviour study in consecutive years. In
mid-January, stags in the cryptorchid group were sedated with xylazine,
and their scrotum shortened as much as possible (two thirds of the
length) by the application of two standard lamb castration rings.
Behavioural observations made during the rut showed significant (P<
0.05) reductions in the incidence of roaring, chasing and pacing in the
cryptorchid group. In a larger scale experiment on six commercial
properties, the live weight and condition score change over the rut, and
subsequent velvet production was compared on 100 entire and a similar
number of cryptorchid stags. Average liveweight loss during the rut
(Feb-June) was 17 kg with no significant difference between entire and
cryptorchid stags. There was no difference in mean live weight of the
two groups the following Sept/Oct and the average velvet weight was 2.48
and 2.41 kg for the entire and cryptorchid stags respectively (P>0.05).
Although induced cryptorchidism influenced stag behaviour during the
rut, this was not reflected in reduced live weight or condition score
loss during this period.
Keywords: NZSAPAB;
stags, cryptorchidism; rut; behaviour; live weight
Last Updated 30/07/2002
