The Happy Factor treatment threshold, used to determine Targeted Selective Treatment decisions for lambs, is transferable between farms

Author: McBean, D. W.; Greer, Andrew W.; Kenyon, F.

Date: 2021-02-13

Publisher: Elsevier on behalf of the Animal Consortium

Type: Journal article

Link to this item using this URL:

Lincoln University


Weight gain-based treatment decision-making has been shown to successfully reduce the number of anthelmintic treatments without compromising production as part of a Targeted Selective Treatment (TST)-based worm control strategy in sheep. The effects of using an efficiency threshold (Standard Threshold (ST)) developed on one farm were examined to establish whether there was a need to tailor the threshold for individual farm conditions. The Standard Threshold had been used on a number of farms, and data from these trials were used here. The ideal threshold (Estimated Treatment Threshold) for each farm was calculated using the same method as the original threshold, and the effect on the number of treatments given and subsequent productivity was estimated. Estimated treatment thresholds were calculated to be higher on all farms including the original, resulting in increased numbers of treatments due. The effect of the increased number of treatments was calculated to have no effect on productivity however, and it was concluded that the ST was sufficient, at least initially, for successful implementation of TST and that further refinement could be made using locally derived data if required.

Subjects: anthelmintic resistance, nematode parasites, production, refugia, sheep, Dairy & Animal Science, 070202 Animal Growth and Development, 0702 Animal Production, 0701 Agriculture, Land and Farm Management, 060804 Animal Immunology, 06 Biological Sciences, 07 Agricultural and Veterinary Sciences

Copyright: Crown Copyright © 2021 Published by Elsevier Inc. on behalf of the Animal Consortium. (With the exceptions noted in, this metadata is available under a Creative Commons Zero license.)