The Great tape debate!!!
Ginny had given up debating the need or otherwise for tapeworm control in lambs. However, she decided she was obviously in need of a good argument and has decided to wade into this topic again for a bit of fun!
The weight-gain argument
Based on the accumulated results of many trials, we have always told you that there is no good evidence that there is a liveweight response to removing tapeworm in lambs.
A 1986 review of world literature of 20 or more properly conducted studies concluded that there was no evidence of a production benefit from treating with any of the tapeworm-specific drugs that were available at that time.
However, the drug we use nowadays, Praziquantel, is inherently much more effective at removing tape than the older drugs. Perhaps by using Praziquantel we would be more likely to see weight-gain responses?
Again, there is little evidence for this. Only one study has been able to demonstrate a weight-gain advantage. In 1996, Ancare found a 36g/day advantage from drenching lambs with a drench with added Praziquantel compared to an ordinary worm drench. No-one has been able to reproduce this result.
Subsequent work in the Wairarapa has found tapeworm that appear to be resistant to Praziquantel. In these cases, Praziquantel was no better than white drench (which has some efficacy against tape) at removing tapeworm; only 62% of the tapeworm heads were removed. This situation could be quite widespread - we don't really know.
The dags and flies argument
Conventional wisdom suggests that tapeworm infestations cause scouring, dags and an attractiveness to flies.
However, in most cases it is impossible to separate the effect of tapeworms per se from the effect of a mixed burden of intestinal worms. Where a tape drench miraculously cleaned up a mob of scouring daggy lambs, it is not possible to say whether it was the removal of the tapeworms or the removal of the other worms that had the most effect.
In studies just drenching for tape and leaving the other worms behind, the removal of tapeworms had no effect on the consistency of the faeces or dag formation.
Inside the lamb, a tapeworm attaches to the intestine by its head, but feeds by absorbing nutrients across its ‘skin'. All other worms feed by physically ‘grazing' on the gut lining or sucking blood. Who do you think is most likely to cause scouring?
Pulpy kidney?
Another piece of conventional wisdom says that heavy tapeworm burdens predispose lambs to pulpy kidney deaths. Being an unprotected, fast-growing lamb on high-quality feed is the biggest risk factor for such deaths. This suggests tapeworms aren't knocking growth rates too much! For many other reasons, it is good practice to have a sound 5-in-1 vaccination programme in place, so approach pulpy kidney control from this angle!
