Impact of changes to Bovatec® labelling

Recent changes have been made to the range of Bovatec® products (Avatec Bovatec Technical, Bovatec 20 Liquid and Bovatec 20CC) which will impact how dairy farmers and calf rears in particular can use the products. The changes have been made because of trade considerations in relation to EU markets. From 3 September 2026, antimicrobials including coccidiostats such as Bovatec® should only be used for therapeutic purposes such as the control or prevention of coccidiosis or reduction of bloat and may not be used for growth or yield promotion. There has been no change to the efficacy or safety of the Bovatec range of products.

Dr. Rob Derrick - Technical Product Nutritionist

Shop with Farmlands: A group of cows stands closely together on a grassy field with mountains and a clear blue sky.

The biggest change resulting from a review of maximum residue limits (MRLs) in meat and milk. The MRL is legally enforceable – not the withholding period - but the cattle milk withholding changes from Nil days to 35 days which will effectively stop the use of Bovatec® for lactating and springer cows.

The withholding period for cattle and goat meat will also change from Nil days to 5 days meaning that Bovatec® will have to be removed from the diet of finishing stock at least 5 days prior to being sent to the works.

Calf rearers will see changes on the calf feed bags by the replacement of the statement “this product must not be used for growth promotion in ruminants intended for human consumption” with the statement “BY LAW, THIS PRODUCT MUST NOT BE USED FOR THE PURPOSE OF PROMOTING GROWTH OR INCREASED YIELD IN RUMINANTS”.

The Bobby calf statement “Not for use in bobby calves” will be replaced with the following, in bold: “NOT FOR USE IN BOBBY CALVES, MILKLAMBS, AND DAIRY KIDS INTENDED FOR SLAUGHTER”. Bobby calves are rather unique in that specialist products such as rennet may be harvested from very close to the digestive tract so for a long time coccidiostats have not been permissible for bobby calves – including male calves that are discovered in the heifer pens and heifers that don’t thrive after being moved out of the colostrum pens where they may have access to medicated hard feed and milk replacers.

The Bovatec20 Liquid and Bovatec20CC labels will no longer include the 2mg/kg“ severe challenge” use guidance for calves.

Implementation

Bovatec may only to be used (off label) for lactating cows for the remainder of the2025/26 milking season, ahead of initiation of certification requirements of the EU Commission Regulation 2023/095 but should not feed to milking cows after 31 May 2026. Monensin, the active ingredient in a range of additives including Rumensin and Rumenox, can still be used for lactating dairy cows and may the preferred option to aid in the prevention of ketosis and reduction in bloat.

Farmlands has taken the opportunity to increase the coccidiosis options available to calf rearers once we use up existing packaging. The SealesWinslow Calf Max range will continue to include Bovatec, the economy Seales Winslow option of Value Calf will move to Rumensin at a rate designed to support higher levels of feeding, the Reliance calf feed range will move in time to Deccox later in 2026.

As the Farmlands manufactured calf feed and milk replacer range transitions to the new bags through 2026, they will give calf rearers greater choice to decide the option best suited to their calves, budget and system.

Coccidiostat	Products (by Dec2026)	Positives	Negatives
Rumensin MillMix 20% Active ingredient monensin	SealesWinslow Value Calf 19% and 16%	A powerful tool that arguably needs to be used with a bit more care than the other coccidiostats. Lower cost Effective – monensin recommended as low as 0.5-1mg/kg live weight. Nil withhold on cattle meat or milk so monensin can still be used in dairy cows to aid in the control of ketosis, prevention and control of coccidiosis and as an aid I the reduction of bloat. These products have a been designed for higher feeding rates so the monensin level has been set at 60mg/kg. Public domain data indicates most of the monensin is broken down in the rumen and bioavailability is low in adult cattle at least. In calves there may well be a higher quantity entering the small intestine, but this appears to be rapidly metabolised by the liver and there is no tissue accumulation. On that basis it seems unlikely that calves fed at a higher dose rate would have tissue residues above the MRL but possible effects on intake should be considered (see negatives on the right).	Associated with a bitter taste which lowers palatability when first introduced and probably long term. Generally, more toxic than lasalocid and decoquinate to non-target species and to cattle if over consumed. Just 2.7mg/kg live weight has been associated with reduced feed intake in calves suggesting that some calf feeds have contained too much monensin (typically 100mg/kg) if fed at above typically recommended feeding rates. No monensin option for milk replacer and should not be fed with Bovatec (mandatory warning on products containing Bovatec not to feed with monensin). Not for use in bobby calves, milk lambs and dairy kids intended for slaughter.
Bovatec 20 CC Active ingredient lasalocid	SealesWinslow Calf Max 20% Pellets and Moozlee, Calf Max 16%	A reliable tool for decades which is now off the menu for springer and milking cows but still a sound option for calves. An ionophore, so like monensin effectively a coccidiostat with benefits – changes rumen fermentation to reduce the risk of bloat. Bovatec in some calf milk replacers and can be added to whole milk as a liquid concentrate (with care) to boost protection early when hard feed intakes are low. Reduced daily gain at 5 times maximum recommended dose – hard to reach and unlikely to be necessary in normal calf rearing situations with calf feed containing 100mg/kg lasalocid.	Roughly half as powerful as monensin but also roughly half as toxic. Unlike monensin, delivering only 0.5mg/kg live weight may not control coccidiosis (recommended rat is 1mg per kg liveweight) but also delivering more than 1mg/kg LW is unlikely to cause any pain or distress to calves. Feeding more than 1mg/kg LW is ‘off label’ as per the off-label use label statement "the user must take due care, obtaining expert advice when necessary, to avoid unnecessary pain and distress when using the product other than as directed on the label". This does not convey a mandatory requirement to consult with a vet. A farmer that has experience feeding at higher rates with no adverse consequences can choose to do so again based on that knowledge. 35 - day withholding on milk means that cross contamination of calf finished feed are more serious both in the paddock and famer silos. Milk MRL has been set at 5ppb. 400mg/h/day did not create residues over 6ppb which was the analytical detection limit used when Bovatec was registered in NZ. 5-day withhold on cattle and goat meat Not for use in bobby calves, milk lambs and dairy kids intended for slaughter.
Deccox 6% Active ingredient decoquinate	Kiwi Calf 19%, Reliance Calf Grower 20% and Finisher 16%	A tool that has proven itself in niche markets that deserves wider use because it is effective but super safe. One trick pony but it does its trick very well - kills more stages of the parasite than ionophores. Prevention at 0.5mg/kg LW and treatment at 1mg/kg – effective but allows higher feeding rate to be recommended Much, much safer to target and non-target livestock – safer option for lifestylers with dogs or horses. Nil withhold on cattle meat.	More expensive 35-day withholding period on milk Do not use in feeds containing bentonite Not for use in bobby calves, milk lambs and dairy kids intended for slaughter.
Coccistop Active ingredient decoquinate	Kiwi Power Whey Reliance Calf Milk Replacer Level Up milk additive	A great option for milk with no contra-indications to ionophores in hard feed. Deccox 6% on a soluble carrier so suitable for inclusion in milk and milk replacer. Kills more stages of the parasite. Prevention at 0.5mg/kg LW and treatment at 1mg/kg – effective but allows higher feeding rate to be recommended Much safer to target and non-target livestock – safer option for anyone with dogs around the rearing sheds. Nil withhold on cattle meat.	More expensive 35-day withholding period on milk No not use in feeds containing bentonite Not for use in bobby calves, milk lambs and dairy kids intended for slaughter.

Coccidiostat

Products (by Dec2026)

Positives

Negatives

Rumensin MillMix 20%

Active ingredient monensin

SealesWinslow Value Calf 19% and 16%

A powerful tool that arguably needs to be used with a bit more care than the other coccidiostats.

Lower cost

Effective – monensin recommended as low as 0.5-1mg/kg live weight.

Nil withhold on cattle meat or milk so monensin can still be used in dairy cows to aid in the control of ketosis, prevention and control of coccidiosis and as an aid I the reduction of bloat.

These products have a been designed for higher feeding rates so the monensin level has been set at 60mg/kg.

Public domain data indicates most of the monensin is broken down in the rumen and bioavailability is low in adult cattle at least. In calves there may well be a higher quantity entering the small intestine, but this appears to be rapidly metabolised by the liver and there is no tissue accumulation. On that basis it seems unlikely that calves fed at a higher dose rate would have tissue residues above the MRL but possible effects on intake should be considered (see negatives on the right).

Associated with a bitter taste which lowers palatability when first introduced and probably long term.

Generally, more toxic than lasalocid and decoquinate to non-target species and to cattle if over consumed.

Just 2.7mg/kg live weight has been associated with reduced feed intake in calves suggesting that some calf feeds have contained too much monensin (typically 100mg/kg) if fed at above typically recommended feeding rates.

No monensin option for milk replacer and should not be fed with Bovatec (mandatory warning on products containing Bovatec not to feed with monensin).

Not for use in bobby calves, milk lambs and dairy kids intended for slaughter.

Bovatec 20 CC

Active ingredient lasalocid

SealesWinslow Calf Max 20% Pellets and Moozlee, Calf Max 16%

A reliable tool for decades which is now off the menu for springer and milking cows but still a sound option for calves.

An ionophore, so like monensin effectively a coccidiostat with benefits – changes rumen fermentation to reduce the risk of bloat.

Bovatec in some calf milk replacers and can be added to whole milk as a liquid concentrate (with care) to boost protection early when hard feed intakes are low.

Reduced daily gain at 5 times maximum recommended dose – hard to reach and unlikely to be necessary in normal calf rearing situations with calf feed containing 100mg/kg lasalocid.

Roughly half as powerful as monensin but also roughly half as toxic. Unlike monensin, delivering only 0.5mg/kg live weight may not control coccidiosis (recommended rat is 1mg per kg liveweight) but also delivering more than 1mg/kg LW is unlikely to cause any pain or distress to calves.

Feeding more than 1mg/kg LW is ‘off label’ as per the off-label use label statement "the user must take due care, obtaining expert advice when necessary, to avoid unnecessary pain and distress when using the product other than as directed on the label". This does not convey a mandatory requirement to consult with a vet. A farmer that has experience feeding at higher rates with no adverse consequences can choose to do so again based on that knowledge.

35 - day withholding on milk means that cross contamination of calf finished feed are more serious both in the paddock and famer silos. Milk MRL has been set at 5ppb. 400mg/h/day did not create residues over 6ppb which was the analytical detection limit used when Bovatec was registered in NZ.

5-day withhold on cattle and goat meat

Not for use in bobby calves, milk lambs and dairy kids intended for slaughter.

Deccox 6%

Active ingredient decoquinate

Kiwi Calf 19%, Reliance Calf Grower 20% and Finisher 16%

A tool that has proven itself in niche markets that deserves wider use because it is effective but super safe.

One trick pony but it does its trick very well - kills more stages of the parasite than ionophores.

Prevention at 0.5mg/kg LW and treatment at 1mg/kg – effective but allows higher feeding rate to be recommended

Much, much safer to target and non-target livestock – safer option for lifestylers with dogs or horses.

Nil withhold on cattle meat.

More expensive

35-day withholding period on milk

Do not use in feeds containing bentonite

Not for use in bobby calves, milk lambs and dairy kids intended for slaughter.

Coccistop

Active ingredient decoquinate

Kiwi Power Whey

Reliance Calf Milk Replacer

Level Up milk additive

A great option for milk with no contra-indications to ionophores in hard feed.

Deccox 6% on a soluble carrier so suitable for inclusion in milk and milk replacer.

Kills more stages of the parasite.

Prevention at 0.5mg/kg LW and treatment at 1mg/kg – effective but allows higher feeding rate to be recommended

Much safer to target and non-target livestock – safer option for anyone with dogs around the rearing sheds.

Nil withhold on cattle meat.

More expensive

35-day withholding period on milk

No not use in feeds containing bentonite

Not for use in bobby calves, milk lambs and dairy kids intended for slaughter.

Bovatec FAQ’s

1. What’s changed?

Bovatec Liquid & Bovatec 20CC have had some further restrictions imposed by AVCM.
The higher 2mg/kg dose has been removed
A 5-day meat withholding period now applies
A 35 Day Milk withholding period now applies and must be clearly communicated on feed labels, certificates, or supporting materials.

2. If a cow accidently eats some calf feed will MRL be reached?

Bovatec was registered in NZ based on trials showing the MRL in milk of 6ppb was not reached. The new MRL of 5ppb is very unlikely to be reached by accidental consumption of calf feed by a small portion of the milking herd but nevertheless reasonable precautions should be taken on farm to ensure calf feed containing Bovatec is not fed to the milking herd.

3. How will residue’s & compliance be tested & enforced?

Milk testing continues as normal (National Chemical Contaminants Programme).
After May 31 2026, any residues above limits could result in regulatory action.

4. Why the change?

To ensure NZ continues to meet export requirements.

Found this helpful? Share it with others...

Back

Related advice

Stay up to date with the latest from Farmlands and the rural sector. News, insights, and stories to help you stay informed and make better decisions on-farm.