Effects of immunisation against LHRH on body growth, scrotal
circumference, and carcass composition in yearling Red deer stags
D.O. Freudenberger, P.R. Wilson, R.W. Purchas, T.N. Barry, B.A.
Moss, T.E. Trigg
Department of Animal Science, Massey University, Palmerston
North, New Zealand
Proceedings of the New Zealand Society of Animal Production.
1991, 51: 63-66
Red deer stags received a series of immunisations against LHRH
with the aim of suppressing the reduction in growth normally associated
with the rut, but without affecting carcass fatness. Immunisations
commenced at 10 months of age (September), including a series of either
early (October) or late (November) booster immunisations. The
immunisations produced antibodies to LHRH and delayed testes
enlargement, with effects being greatest during summer (December-
January). Liveweight changes were similar in the late booster and
control groups. Mean liveweight declined during the rut (April and May)
in all groups. However, stags that received the early booster were
significantly heavier (P<0.05) than the other two groups in October (11
months old) and from February to October of the following year (15-23
months old). Twenty four hours prior to slaughter (October), mean (±SE)
liveweight was 110.2±4.9, 100.8±1.7 and 102.3±1.5 kg in the early
booster, late booster and control groups respectively, with
corresponding carcass weights being 63.67±2.92, 58.26±1.01 and
58.92±1.17 kg. Immunised deer tended (P<0.10) to be fatter than their
control counterparts, but the effect was of very small magnitude.
Keywords: NZSAPAB;
Stags; LHRH immunisation; body growth; testes; carcass
composition
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Last Updated 25-01-1997
