Tapeworm tales about tails

Tapeworm tales about tails

A variable amount of NZ-based research provides little evidence that either a pre-weaning lamb drench or lamb tapeworm drenches give any productivity response. Despite this, over 90% of farmers in the national drench resistance survey drench their lambs pre-weaning.

Many farmers drench pre-weaning. If the aim here is to reduce pasture contamination, this practice could be quite selective for anthelmintic resistance. There is an obvious cost of product and labour, but on many farms there may also be negative effects from yarding at this time which are detrimental to liveweight gain and predispose these lambs to enzootic pneumonia.

Is a pre-weaning drench justified? How much of a productive edge does it really provide? Is there any benefit from including tape treatment? With funding from Beef + Lamb New Zealand, we decided to investigate.

On three farms, lambs were divided into three groups of 50 lambs each - one group received a triple combination drench (worm), another group a triple combination plus praziquantel (worm + tape) and a control group (control) that received no drench. The treatment was given approximately one month prior to weaning at an average of 67 days of age.

At both treatment day and weaning, all lambs were weighed, dag-scored and faecal-sampled for faecal moisture, faecal egg count and the presence of tapeworm.

Results:

• There was a dag reduction response to a worm drench. This response was slightly better with a worm + tape drench
• The liveweight gain response to  a pre-weaning drench was 14g/day over all farms (control versus worm)

• The groups that also received a tape treatment showed a 38g/day response compared to lambs that got no drench. This result is inconsistent with many previous trials

• The worm + tape drench gave a 24g/day liveweight gain advantage over a straight worm drench
• The liveweight response trend was similar over all farms though differed between the properties - on one farm the difference between the control and worm + tape was 20g/day, and another 67g/day.

Figure 1 Figure 1 Faecal Egg Count on each farm for each group at both visits

• The faecal score got runnier in the control group and firmer in both the treated groups
• The amount of tapeworm detected between a month pre-weaning and weaning naturally decreases over time in all animals
• Present in 26-36% of lambs on each farm at treatment
• Present in 6-7% of non-praziquantel treated groups at weaning
• There was a 5% reduction in the presence of tapeworm in the worm + tape group compared to the non-praziquantel treated groups at weaning
• Any drench treatment reduced the dag score with the praziquantel reducing it even more
• Adding a tape drench to a roundworm drench improves dag score (less daggy)
• On most farms, FECs rise from one month pre-weaning until weaning with or without treatment. The treated groups had lower FECs at weaning than the control group.

Note that during the trial, ewes were in moderate to light condition and pasture covers were low. If any liveweight response was to occur in lambs, this would be the year for it to happen.

Take home messages

• Drenching lambs pre-weaning will reduce their dags, adding praziquantal gives a slightly better effect
• In this trial (contrary to many others), there was a liveweight gain effect in
• a) Lambs treated with a triple combination anthelmintic one month pre-weaning compared to no drench
• b) Lambs treated with a triple combination plus praziquantal anthelmintic pre-weaning compared to a triple combination drench only