Diseases affecting calves up until weaning can have a detrimental impact on their growth, which means hygiene when feeding milk is critical.
The biggest risks to calf health during the first few weeks of life are pneumonia and scours.
Scours are commonly caused by rota and coronavirus, e-coli and cryptosporidium.
James Anderson, Shropshire Farm Vets, says: “When calves are scouring very badly, even if the handler is replacing the fluids with electrolytes they may still die of dehydration.
“And as soon as the immune system is challenged by a bacteria load which may be causing scouring, they are more susceptible to viruses which would cause pneumonia.”
Therefore, Mr Anderson says prevention is better than cure and farmers must pay special attention to hygiene, especially during the first few weeks of life.
“The heifer crop is so important to the future of the herd,” he says.
“If growth rates are low and heifers are not able to be bred at the right age you are going to get heifers calving too late.”
Prevention of calf disease starts even before birth and Mr Anderson says it is possible to provide the calf with some immunity in utero by vaccinating the dam.
In the calving pen, it is also critical to ensure calves are navel dipped with an iodine solution and provided with adequate, timely colostrum.
“Ensure the calf has the best immunity and strong defence against bacterial challenge before going into the calf hutches or calf building,” he says.
“This starts with good colostrum management and feeding in the first few hours.
“The naval is a portal of entry for infection so it is very important to calve in clean areas. Do not mix the sick cow pen with the calving pen.”
Calves are usually reared in a relatively intensive environment, which means the spread of disease is often quick.
Mr Anderson says milk buckets or bottles and teats must be thoroughly cleaned between each feed using a chlorine-based detergent and scrubbed to break down milk residues, fatty build-ups and biofilms.
“We recommend that housing and equipment is easy to clean, with smooth, non-porous surfaces which are less likely to harbour dirt and bacteria, and they are much easier to keep clean,” he says.
He says calves should be provided with a fresh supply of water from the time they enter the building or hutches.
“Buckets can get soiled easily so should be cleaned daily to ensure clean water is on offer,” he says.
“Off the floor drinking troughs are easier to keep clean and it is less likely calves will stand in them or knock them over.
“During summer there are often dead flies in water buckets and troughs. They are vectors for bacteria and disease, so it is important water is cleaned frequently.”
If possible, Mr Anderson says it is a good idea to rotate pens or hutches, leaving a number which can be cleaned and left free of calves for at least two weeks.
“Pressure washers are good for cleaning housing, but be careful not to wash hutches too close to other calves, as this can make bacteria airborne and spread it through the air infecting calves in the other hutches,” he says.
Mr Anderson says many detergents can be used for both cleaning housing and feeding equipment, but at different concentrations, so be sure to read the manufacturer’s guidelines carefully.
He also says procedure in the calving pen and calf house need to be consistent, so it is important to dedicate some time to developing protocols and training staff in the event of someone being away or for new starters.
“They are simple principles, but it is so important to get them right,” he adds.
“Losing calves can be a knock-on effect from the very beginning.”
ACCORDING to Abi Fisher, from Volac, many calf rearers are not aware that commonly-used feeding equipment, such as teats, buckets and whisks, can easily harbour invisible biofilms.
These can provide the perfect substrate for disease-causing bacteria to thrive and lead to colostrum or milk becoming contaminated.
Ms Fisher explains that biofilms develop on feeding equipment through inadequate or incorrect cleaning practices.
Virtually no surface is immune to the build-up of biofilms, she says; they can quickly develop on plastic, stainless steel and metal.
She says: “A biofilm forms when milk residues are left on a surface.
“Bacteria then bind to these residues and multiply quickly. The bacteria adhering to the surface also produce a substance to protect themselves from being moved.
“Consequently, the biofilm layer is able to preserve microbes that would not previously have survived in this environment, allowing a greater range of harmful bacteria to be present on feeding utensils to potentially contaminate any substance coming into contact with them.
“Usually biofilms are invisible to the naked eye, although the surface of feeding equipment may feel rough or slimy. In extreme cases, a biofilm may show up as a yellow or white scum.”
Ms Fisher also says the basics of milk chemistry compound the biofilm problem.
“Whey is a milk protein with heat sensitive bonds. If exposed to high temperatures – such as hot wash water – these bonds weaken, and the whey protein molecules become sticky,” she says.
“They then adhere to the inside of your feeding equipment unless it is washed regularly and correctly.”
Biofilms are caused…
■ When the initial wash is too hot, allowing fat and protein to bond to the surface of equipment
■ Through inadequate brushing, not removing all organic material
■ When washing water is too cool and particles stick back on to surfaces
■ When equipment is aged and plastic becomes rough and cracked, making it easier for particles to stick
1 Rinse with lukewarm water (32-38degC). Do not use hot water because this allows milk proteins and fats to stick more tightly to feeding equipment surfaces. Aim to reduce all dirt and milk residue.
2 Soak in hot water (54-57degC). Use hot water for soaking and add a chlorinated alkaline detergent. Soak for at least 20 minutes.
3 Scrub. Remove any remaining residues from feeding equipment using a brush to loosen any solids.
4 Wash. Re-wash all of the feeding equipment in hot water (at least 49degC) to remove any remaining residues.
5 Rinse again. Rinse the inside and outside of feeding equipment again using an acid sanitiser. This lowers the surface pH and makes it very difficult for any remaining bacteria to thrive.
6 Dry. Equipment should be left on drying racks to dry thoroughly. Do not stack buckets inside each other and do not sit feeding equipment upside down on a concrete floor because this will provide bacteria with the perfect environment to multiply.