Friday, September 2, 2016

No Benefit to Removing Tapeworms

In 2012 and 2013, an experiment was conducted on a commercial sheep farm in the Northern Tablelands of New South Wales, Australia, to test the hypothesis that the growth rates of meat-type lambs would not be affected by the removal of tapeworms (Monieza spp.).

In 2012 and 2013, 93 and 85 lambs respectively were randomly allocated to two treatment groups. One group (Prazi) was treated with praziquantel, levamisole and abamectin to remove tapeworm and gastrointestinal nematode infection (GIN) while the second group (Control) was treated with levamisole and abamectin to remove only GIN.

Tapeworm prevalence and egg counts of Control lambs ranged from 25 to 77% and 7 to 730 eggs per gram (epg) respectively and were significantly reduced in Prazi lambs, following treatment, at all time-points in both years. Pre-treatment GIN worm egg counts ranged between 1684 and 3368 epg with Haemonchus contortus being the dominant species. Post-treatment GIN worm egg counts were similar between Prazi and Control groups, expect on one occasion (Day 65, 2013) when GIN worm egg counts were expectantly higher in Control lambs.

81 g/d
0.18 lb/d
134 g/d
0.30 lb/d
95 g/d
0.21 lb/d
132 g/d
0.29 lb/d

No significant difference in growth rates were observed between treatment groups in either year with overall group mean daily body weight gains being 95 and 81 g/day  (0.18 and 0.21 lb/d)  in 2012 and 132 and 134 g/day (0.30 and 0.29 lb/d) in 2013 for the Prazi and Control groups respectively. This experiment confirmed that removal of tapeworm burdens did not increase growth rates in meat-breed lambs.

Source:  Veterinary Parasitology, March 2015

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