More lambs

Authors: Edwards JD
Publication: New Zealand Veterinary Journal, Volume 31, Issue 10, pp 186, Oct 1983
Publisher: Taylor and Francis

Animal type: Livestock, Production animal, Ruminant, Sheep
Subject Terms: Animal welfare, Endocrine/autocrine/paracrine, Reproduction, Immune system/immunology, Reproduction - female, Reproduction - hormones, Vaccination
Article class: Correspondence

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Abstract: The impending release of a drug to enhance ewe fecundity brings the veterinary profession to new horizons of medicine. The implications of the resulting increase in the number of lambs born following the simple technique of injections will place those veterinarians in sheep practice on their mettle. The net effect of treatment is an increased ovulation rate which is reflected by a higher number of lambs. With good management, the end result can be more lambs reared for sale or replacements. This technique of steroid immunization is an entirely new application in the field of practical immunity which up until now has been associated with disease prevention. Here it is used to stimulate productivity by lifting reproductive performance. The average increase in lamb drop in the Results indicate that the ovulation rate response for nutrition and immunization are approximately additive. Ewes are capable of responding to immunization, even under levels of low nutrition. This latter aspect has been confirmed by Australian trials run under drought conditions. The use of steroid immunization to supplement or replace flushing effects in areas of New Zealand where autumn pasture growth rates are low raises the first possibility of this drug being used as a panacea for poor management. The most critical factor influencing the success of this treatment regime is the management of the flock of pregnant ewes, and subsequently the ewes with their lambs…

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