Comparison of Worm Control Strategies in Grazing Sheep in Denmark

Abstract

Boa ME, Thamsborg SM, Kassuku AA, Bøgh HO: Comparison of worm control strategies in grazing sheep in Denmark. Acta vet. Scand. 2001, 42, 57-69. -Control of nematode parasites with reduced reliance on the use of anthelmintics was studied in 16 ewes with suckling twin lambs on contaminated pasture in Denmark. Ewes and lambs were treated with albendazole at turn-out 3 May. Ewes were removed from the groups on 26 July, and lambs were slaughtered on 11 October. The animals were allocated to 4 groups of 8 lambs and their 4 ewes. Group TS was treated with albendazole at weeks 3, 6 and 8 after turnout and set-stocked; group TM was similarly treated but moved to clean pasture in conjunction with the last drenching; group US was untreated and set-stocked, and group UM was left untreated but moved to clean pasture week 8 after turn-out. Supplementary feed was offered in June and August due to scarcity of pasture. Strategic treatments of ewes and lambs weeks 3, 6 and 8 after turn-out, with or without a move to clean pasture, were highly effective in controlling nematode infections for most of the season. This was reflected in better weight gains and carcass characteristics in the treated compared to untreated lambs, resulting in an average increase in the value of the product by 36%. The effect of moving without treatment (UM) on faecal egg counts was limited but peak pasture infectivity was reduced to less than 10% compared to the set-stocked group and weight gains of lambs were significantly better despite poor feed availability in late season. The study showed that under set-stocked conditions repeated anthelmintic treatments of both ewes and lambs in early season may ensure sufficient nematode control whereas moving animals to clean pasture without dosing was less efficient. The latter may, however, still be a viable option in organic and other production systems where routine use of anthelmintics is banned, particularly if weaning and moving are combined or a second move is performed. gastrointestinal nematodes; parasite control; sheep; ruminants; grazing management.

Potential risk factors associated with ill-thrift in buffalo calves (Bubalus bubalis) raised at smallholder farms in Egypt

“…This postulation is in concern with that reported by Davies [19] . Contributing factors other than early weaning have also been found to render the calves unable to take sufficient milk intake [5,20] .…”

Worm control practice against gastro-intestinal parasites in Norwegian sheep and goat flocks

“…Such practices were especially used for ewes and lambs before transporting them to the common grazing areas in the forest or mountains during the summer months. The dose-and-move strategy in small ruminant flocks has also been noticed as a common practice in other European countries [ 25 , 31 - 33 ]. However, moving drenched sheep onto pastures with a low level of parasite contamination increases the risk for AR [ 34 , 35 ].…”