Are Dairy Cows not Immune to Lungworm?
Yes, adult dairy cows generally have good natural immunity towards lungworm.
The problem is that there are two components to this immunity, which are not equal:
- Immunity against larvae developing into adult lungworm in the lungs. Once cows develop this it usually remains indefinitely.
- Immunity against larvae reaching the lungs in the first place. Unfortunately without constant exposure to lungworm, this component of a cow’s immunity can reduce significantly in just a number of months.
A period without exposure would include the likes of an indoor winter, or a prolonged dry period outdoors. Coughing caused when this second aspect of immunity drops off, or when it becomes overwhelmed by the sheer volume or larvae being ingested, is also called ‘reinfection syndrome’.
Where lungworm causes coughing in adult cows, in the vast majority of cases it is due to reinfection syndrome. In younger cows, it may be a case that neither component of the animal’s immunity is fully developed where a lungworm cough is occurring.
What does a high Ostertagia ODR reading mean?
Based on research, at an Ostertagia ODR of 0.8, cows are losing 1L of milk/head/day, with this figure rising to 2L at a reading of 1.2.
Using worming products with persistent activity, such as eprinomectin, can help to take pressure off the animal’s immune system at and in the weeks post treatment, thus increasing milk yield.
How can I worm dairy cows in milk?
The only active available to dairy farmers, that doesn’t require a milk withdrawal period post treatment, is eprinomectin.
This ingredient belongs in the clear wormer, or ML wormer class. It is a close relation of ivermectin. It is available in pour-on (most common) and injectable formats. It is effective in killing both stomach worm (Ostertagia) and lungworm at treatment, and preventing reinfection with the parasites for up to 28 days thereafter.
Missed part 1 introducing the above? Read it here.
Are Dairy Cows not Immune to Lungworm?
Yes, adult dairy cows generally have good natural immunity towards lungworm.
The problem is that there are two components to this immunity, which are not equal:
- Immunity against larvae developing into adult lungworm in the lungs. Once cows develop this it usually remains indefinitely.
- Immunity against larvae reaching the lungs in the first place. Unfortunately without constant exposure to lungworm, this component of a cow’s immunity can reduce significantly in just a number of months.
A period without exposure would include the likes of an indoor winter, or a prolonged dry period outdoors. Coughing caused when this second aspect of immunity drops off, or when it becomes overwhelmed by the sheer volume or larvae being ingested, is also called ‘reinfection syndrome’.
Where lungworm causes coughing in adult cows, in the vast majority of cases it is due to reinfection syndrome. In younger cows, it may be a case that neither component of the animal’s immunity is fully developed where a lungworm cough is occurring.
What does a high Ostertagia ODR reading mean?
Based on research, at an Ostertagia ODR of 0.8, cows are losing 1L of milk/head/day, with this figure rising to 2L at a reading of 1.2.
Using worming products with persistent activity, such as eprinomectin, can help to take pressure off the animal’s immune system at and in the weeks post treatment, thus increasing milk yield.
How can I worm dairy cows in milk?
The only active available to dairy farmers, that doesn’t require a milk withdrawal period post treatment, is eprinomectin.
This ingredient belongs in the clear wormer, or ML wormer class. It is a close relation of ivermectin. It is available in pour-on (most common) and injectable formats. It is effective in killing both stomach worm (Ostertagia) and lungworm at treatment, and preventing reinfection with the parasites for up to 28 days thereafter.
Missed part 1 introducing the above? Read it here.