5: Control of Worms Sustainably Flashcards
Which part of the intestine do Ostertagia, Haemochus and Trichostrongylus live in?
Abomasum
Which part of the intestine do Cooperia, Trichostrongylus, Nematodirus and Toxocara live in?
Small intestine
Which part of the intestine does Trichuris live in?
LI
How long after turnout do you get PGE in calves?
3-4 weeks
When in the season does Ostertagia hypobiosis occur?
Late season infection
How do calves get infected with Toxocara?
Through milk
What part of the larvae’s life cycle causes disease in Ostertagia?
Maturation of the larvae in the abomasum
What disease does Ostertagia cause in adult cattle?
Usually none
How many exposures do you need for immunity in Ostertagia vs Cooperia?
Two in Ostertagia, one in Cooperia
What is the main contributor to faecal egg counts?
Cooperia
How badly does Cooperia affect calves?
Mild pathogen
What does high serum pepsinogen indicate?
Reduced abomasal activity
How many samples should you take to perform an egg count?
At least 10
Which animals should you take egg counts from?
Healthy animals
How soon should you transport faecal samples to the lab?
Cool and to the lab within 48 hours
What happens in faecal egg samples are too old?
Hatch
What must you do if you are pooling faecal egg samples?
Equal amounts from each
What % calves have innate immunity to worm infection?
25%
What % calves generate acquired immunity to worms?
50%
What % calves have inadequate response to worms and therefore a high burden?
25%
What % of animals carry the bulk of the parasite infection?
20%
What does resistance vs resilience to worms mean?
Resistance is lower burden, resilience in unaffected by a higher burden
Why does protein supplementation reduce egg count and worm burdens?
Compensates for parasitism and improves immunity
What is a group 1 drug?
Benzimidazole (white)
What is a group 2 drug?
Levamisole (yellow)
What is a group 3 drug?
Macrocyclic lactones (clear)
What do you use narrow spectrum anthelmintics for?
Liver fluke
How do you administer doramectin, ivermectin and moxidectin?
Injectable and pour-on
How do you administer eprinomectin?
Pour-on
What weeks do you give ivermectin in the early season?
3-8-13
What weeks do you give doramectin?
0-8
How long can moxidectin last?
6 months
When do you administer boluses?
Start of the season
What are the two types of boluses?
Sustained or pulse-release
Which drugs are effective against L4 and adult dictyocaulus?
All
Which life cycle stages are refractory to treatment?
Larval
Which kinds of lice are macrocyclic lactones effective against?
Sucking and chewing
What parasite is macrocyclic lactones especially effective against?
Warble fly
Below what % egg count reduction is a genotype considered resistant?
95%
In which species is drug resistance more of a problem?
Sheep
Which species show BZ resistance?
Cooperia, Haemonchus, Ostertagia, Trichostrongylus
Which species is usually resistant to MLs?
Cooperia, but resistance to these are less common
Which life cycle stages are not considered to be in refugia?
Eggs, L1, L2, L3
What size are in refugia populations in cattle compared to sheep?
Large
What frequency treatments generate resistance faster?
More frequent
How do you avoid introducing resistant worms?
Have a quarantine period
How long do you keep new cattle off the pasture so they can pass all eggs?
24-48 hours
Which calves are worm free so don’t need treatment?
Born and raised indoors
What will happen if you give a product too soon (at turnout)?
Will wear off too soon
Why should you not use dose and move?
Will contaminate the pasture with resistant worms
What do you do instead of dose and move?
Delay the move after the dose so they can pick up susceptible worms
What are the three types of grazing management you can use?
Preventiate, evasive or diluting
What is an example of bioactive forage?
Chicory
Which tests can you use to detect resistance?
Wormer test or FECRT
Does the wormers test show efficacy or resistance?
Efficacy, but not necessarily resistance
What does FECRT test anthelmintic against?
A control group
At what two points do you perform a FECRT?
Prior to treatment, then later (reduce below 95%)
How does mixed grazing (cattle and sheep) reduce contamination?
Reduces stocking density
Which kind of summers precede a heavy worm burden?
Dry summer
Which kind of parasite especially follows a dry summer?
Lung worm
What are some clinical signs of type I ostertagiosis?
Loss of appetite, sudden profuse green diarrhoea, affects many animals, loss of BCS
What is mortality like in type I ostertagiosis?
Mortality rare
What is happening in type II ostertagiosis?
Hypobiosed larvae all emerge together in late winter
What are the clinical signs of type II ostertgiosis?
Profuse unresponsive diarrhoea
How fast is immunity to Cooperia?
Rapid
How fast is immunity to Ostertagia?
Slower - two breeding seasons
