title: Viability of the Happy Factor™ targeted selective treatment approach on several sheep farms in Scotland.
abstract: The aim of this study was to examine the use of Happy Factor™ weight based targeted selective treatment (TST) on several commercial farms in Scotland in combination with findings from a long term trial on a research farm to assess the potential for TST use in varying farming operations as an alternative to the current regimen of whole flock treatment. Lambs on each farm were regularly weighed and climatic conditions and pasture availability measured for inclusion into the Happy Factor™ model to calculate weight targets. Half of the lambs were allocated to TST treatment and any failing to reach the weight target was treated with the anthelmintic of choice on that farm, while the remaining half of each flock was treated with anthelmintic as per normal practice on that farm (routine treatment, RT). The research farm (farm 1) hosted a long term trial using four anthelmintic treatment regimes over 6 years, and data from two regimes are presented here, alongside findings from three further farms: two commercial enterprises (farms 2 and 3) and a research farm operating as a commercial analogue with two breeds (farms 4a and 4b). The effect of TST strategy on lamb productivity and the number of anthelmintic treatments was investigated. There was no evidence (p>0.300) that mean bodyweight or growth rate was different between TST and RT groups on any of the farms and 95% confidence intervals of TST and RT groups generally suggested that TST had negligible unfavourable effects on the average growth of lambs for most of the farms. Growth rates ranged from 97.39 to 189.16g/day reflecting the varied nature of the farms. All commercial farms used significantly less (1.34 RT versus 1.14 TST treatments per animal, p<0.05) anthelmintic in lambs following TST, with a reduction from 1, 1, 1.03 and 1.14 to 0.77, 0.57, 0.82 and 0.81 in the number of treatments per animal for farms 2, 3, 4a and 4b respectively. This study suggests that TST is a viable means of controlling parasitic disease without incurring production losses.
authors.affiliation: Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, UK. Electronic address: dave.mcbean@moredun.ac.uk.
authors.forename: David
authors.initials: D
authors.lastname: McBean
authors.affiliation: Biomathematics and Statistics Scotland, James Clerk Maxwell Building, The King's Buildings, Peter Guthrie Tait Road, Edinburgh, UK.
authors.forename: Mintu
authors.initials: M
authors.lastname: Nath
authors.affiliation: Scotland's Rural College, Hill & Mountain Research Centre, Kirkton Farm, Crianlarich, UK.
authors.forename: Nicola
authors.initials: N
authors.lastname: Lambe
authors.affiliation: Scotland's Rural College, Hill & Mountain Research Centre, Kirkton Farm, Crianlarich, UK.
authors.forename: Claire
authors.initials: C
authors.lastname: Morgan-Davies
authors.affiliation: Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, UK.
authors.forename: Fiona
authors.initials: F
authors.lastname: Kenyon
mesh_terms: D000822:Animal Husbandry / Q000379:methods* / Q000592:standards*; D000818:Animals; D000871:Anthelmintics / Q000008:administration & dosage*; D001835:Body Weight / Q000502:physiology; D005243:Feces / Q000469:parasitology; D005260:Female; D006374:Helminthiasis, Animal / Q000188:drug therapy*; D008297:Male; D008954:Models, Biological; D010270:Parasite Egg Count; D012606:Scotland; D012756:Sheep; D012757:Sheep Diseases / Q000188:drug therapy*
chemical_list: D000871:Anthelmintics
keywords: Gastrointestinal nematodes; Refugia; Sheep; Targeted selective treatment