title: Administration of a long-acting antiparasitic to pre-pubertal ewe-lambs in Greece results in earlier reproductive activity and improved reproductive performance.
abstract: We studied the reproductive effects of administration of a long-acting antiparasitic (moxidectin) given to pre-pubertal ewe-lambs in Greece at the beginning of the reproductive season. 45 animals, naturally infected with trichostrongylids, were allocated into treated (n=30, treatment on D0, 21 June) or control (n=15) group. Rams of confirmed fertility, were introduced from 15 August (D55) to 20 December (D182) into the ewe-lambs. Throughout the study (performed at latitude N 36°26', in a flock free from brucellosis, Chlamydophila infection and toxoplasmosis), epg counts were monitored and reproductive performance of ewes was assessed. Up to D112, arithmetic mean epg counts in treated animals were 0; thereafter and up to D350, they were 23-473. Respective figures for controls were 190-977 epg. Reproductive performance parameters for treated and control animals respectively, were as follows; median 'Interval to first mating after ram introduction': 36.5 d and 71.0 (P=0.04); median 'Age at first mating': 8.5m and 10.0m (P=0.045); 'Cycling rate': 20.0% and 6.7% (P=0.03); 'Mating rate': 86.7% and 66.7%; 'Return-to-oestrus rate': 26.7% and 26.7%; 'Abortion rate': 3.3% and 0%; 'Lambing rate': 83.3% and 66.7%; 'Total lambs born per ewe' and 'Liveborn lambs born per ewe': 1.5 and 1.1 (P=0.01); 'Stillbirth rate' 0% and 0% and 'Lamb bodyweight per ewe': 5.0 kg and 3.8 kg (P=0.005). Anthelmintic treatment of pre-pubertal ewes, in order to maximise reproductive performance may be employed as a management strategy according to targets set in individual flocks.
authors.affiliation: Veterinary Faculty, University of Thessaly, 43100 Karditsa, Greece. vmavrog@vet.uth.gr
authors.forename: V S
authors.initials: VS
authors.lastname: Mavrogianni
authors.forename: E
authors.initials: E
authors.lastname: Papadopoulos
authors.forename: I A
authors.initials: IA
authors.lastname: Fragkou
authors.forename: D A
authors.initials: DA
authors.lastname: Gougoulis
authors.forename: I
authors.initials: I
authors.lastname: Valasi
authors.forename: D C
authors.initials: DC
authors.lastname: Orfanou
authors.forename: S
authors.initials: S
authors.lastname: Ptochos
authors.forename: E
authors.initials: E
authors.lastname: Gallidis
authors.forename: G C
authors.initials: GC
authors.lastname: Fthenakis
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000008:administration & dosage / Q000494:pharmacology*; D003692:Delayed-Action Preparations; D005260:Female; D018942:Macrolides / Q000008:administration & dosage / Q000627:therapeutic use; D011247:Pregnancy; D012098:Reproduction / Q000187:drug effects*; D012756:Sheep; D012757:Sheep Diseases / Q000517:prevention & control*; D013997:Time Factors; D014253:Trichostrongylosis / Q000188:drug therapy / Q000662:veterinary*
chemical_list: D000871:Anthelmintics; D003692:Delayed-Action Preparations; D018942:Macrolides; C027837:moxidectin