Zinc prevention for Facial Eczema (FE)
There is no cure for FE so prevention is the only way of protecting animals. This preventative program needs to be in place at least 2-3 weeks before the spore count starts to rise. In our area, zinc treatment usually begins around Christmas time.
Farmers usually either dose animals with zinc or spray their pastures with a fungicide spray.
Animals are either drenched with zinc oxide, water dosed with zinc sulphate, zinc given in feed, or as an intraruminal bolus (Time Capsule or Face Guard).
The drench or the bolus will give more reliable protection than adding zinc sulphate to the water system, as you can’t control the amount of water an animal will drink on any given day.
Also, remember zinc is toxic in high doses, so use a weigh band or scales to get a representative weight of a number of animals first.
DairyNZ has recipes and dose rates for oral zinc dosing here: https://www.dairynz.co.nz/publications/farmfacts/animal-health-welfare-and-young-stock/farmfact-3-7/
Zinc Boluses
We sell two brands of Zinc Bolus: Time Capsule or Face Guard. They each have their own applicators which have been identified so please ensure the correct one is used. Top-up doses can be given, but if animals are needing a third dose it is recommended to perform a faecal zinc level test to ensure toxic doses aren’t being reached. Do not use boluses when other forms of zinc are being given. Do not use at times other than the Facial Eczema risk period.
- Time Capsule lasts 4 weeks in cattle and 6 weeks in sheep. The bolus has to be matched to the weight of the animal. If you have a larger cattle beast (up to 800kg), two of the 250-400kg boluses can be given at one time.
Do NOT give damaged boluses.
Ensure there are adequate yards available. You will require a head bail for larger animals.
Allow plenty of time (up to 2 minutes per animal).
Only use the Time Capsule applicators.
Read over the dosing instructions in the box before starting. Push the bolus as far as it will go into the correct brand and sized applicator, with the pointed end facing outwards. The animals’ nose should be held up and forward so that the neck is straight. In sheep, it is easiest to do this whilst straddling the sheep. The applicator should be inserted in the centre of the mouth, over the back of the tongue. The applicator trigger is then pressed and the head held up until the bolus is swallowed. Then let the head go and ensure the bolus is not regurgitated.
- Face Guard comes in 3 sizes: sheep, cattle 90-250kg and cattle 251-660kg. It is important to read the package insert to ensure you are giving the correct number of boluses for the weight of the animal. They are packaged in pairs taped together with paper tape which will dissolve when in the rumen. You can put up to 3 boluses for sheep, 5 boluses for cattle 90-250kg or 4 boluses for cattle 251-660kg in one applicator.
The initial Face Guard bolus lasts 6 weeks in cattle and sheep, with each subsequent top-up lasting 4 weeks in cattle and 6 weeks in sheep. The top-up doses are lower than the initial dose (see table below). Check the package to ensure correct dosing.
Use only the Face Guard applicators. Ensure the correct size is used.
Read over the dosing instructions in the box before starting. Push the bolus(es) as far as it/they will go into the correct brand and sized applicator, with the rounded end facing outwards. The animals’ nose should be held up and forward so that the neck is straight. In sheep, it is easiest to do this whilst straddling the sheep. The applicator should be inserted in the centre of the mouth, over the back of the tongue. The applicator trigger is then pressed and the head held up until the bolus is swallowed. Then let the head go and ensure the bolus is not regurgitated.
| Class and bodyweight of stock | Number/strength of bolus | Top-up 6 weeks later |
| Sheep 25-40kg | 2 x 30g | 2 x 30g |
| Sheep 40+kg | 3 x 30g | 2 x 30g |
| Cattle 90-130kg | 3 x 60g | 2 x 60g |
| Cattle 131-200kg | 4 x 60g | 2 x 60g |
| Cattle 201-250kg | 5 x 60g | 3 x 60g |
| Cattle 251-330kg | 3 x 132g | 2 x 132g |
| Cattle 331-440kg | 4 x 132g | 2 x 132g |
| Cattle 441-550kg | 5 x 132g | 3 x 132g |
| Cattle 551-660kg | 6 x 132g | 3 x 132g |