7 ways to prevent colostrum contamination
© Tim Scrivener Colostrum cleanliness should be given as much attention as immunoglobulin levels if farmers are to optimise calf health and performance.
This is according to vets in a Glasgow University Veterinary School farm study, which found most units could improve colostrum handling and hygiene.
See also: How to make routine dairy tasks easier with a calf kitchen
Farm facts: Slagnaw Farm, Castle Douglas
- 304ha grassland
- 640 Holsteins calving all-year-round
- 305-day average yield 9,000 litres at 4.33% fat and 3.33% protein
- Supplying Arla
- Rears own replacements with average age at first calving 24.5 months
- Calves fed 2 litres of calf milk replacer (150g/litre) twice a day, increasing to 3 litres twice a day
- Aberdeen Angus beef calves sold to Pathway Farming
In the 2023 study, 76.3% of feeders on 11 Scottish dairy farms failed to meet the quality threshold for colostrum total coliform count (TCC), which includes faecal bugs.
Both TCC and total bacteria count also increased the more times colostrum was handled, with the feeder proving a major critical control point (see “Colostrum contamination levels at different stages of the handling process”).
“Coliforms block the uptake of immunoglobulins from the calf’s gut into the bloodstream. That’s why it’s important to measure coliforms in the colostrum.
“You can have excellent immunoglobulins in the colostrum, but poor uptake into the bloodstream if it’s contaminated,” says Dr Katie Denholm, academic clinician at Glasgow University Veterinary School.”
Feeding calves pathogenic bacteria also increases the likelihood of disease, impacting growth and future performance.
Katie and vet Ali Haggerty of Stewartry Vet Centre advise the following to prevent colostrum contamination:
Thorough cleaning routine
The number-one action farmers can take to prevent colostrum contamination is to buy washing-up liquid and a brush, and ensure all feeding equipment is scrubbed with hot water between uses.
This will remove milk scum and biofilms that can harbour bacteria.
Colostrum contamination levels at different stages of the handling process |
||
| Percentage failing to meet total bacteria count quality threshold | Percentage failing to meet total coliform count quality threshold | |
| Harvest (teat) | 7.8 | 17.8 |
| Storage bucket | 50.3 | 54.4 |
| Storage bucket 2 | 79 | 76.3 |
| Storage bucket 3 | 85.71 | 100 |
| Feeder | 71.21 | 76.3 |
| Source: 2023 study of 11 Scottish farms by Glasgow University Veterinary School | ||
Katie stresses disinfectant is not a sticking plaster for poor cleaning.
Both acid and alkali parlour disinfectants can eat away at plastic and cause microcracks or breaks that can harbour bacteria, and mean equipment will need replacing more frequently, she adds.
Ease of cleaning
How easy is it to clean equipment? Are feeders worn, with rough edges? Can the handle of the bottle be scrubbed?
Bigger colostrum storage containers (4-5 litres and above) were found to be more hygienic in the farm study, probably because they were easier to clean or disposable.
If reusing 1-2 litre bottles for storing colostrum, check they can be cleaned effectively between uses.
Minimal handling
The risk of contamination increased the more times colostrum was handled (see “Colostrum contamination levels at stages of the handling process”), so handling should be limited wherever possible.
“If you look at the storage buckets, by the time you are at the third bucket, 100% are failing for coliform and 85% for total bacteria count, so we need to streamline this process,” Ali explains.
Chilled storage
Bacterial colonies double every 30 minutes at ambient temperature, so it is essential to refrigerate colostrum at 4C or freeze it at -20C as soon as it is harvested. Do not leave it sitting in a bucket.
It will keep in a fridge for two to three days and a freezer for six months.
If colostrum has to be kept at ambient temperature for more than six hours, use a preservative such as a colostrum acidifier.
Katie advises using potassium sorbate rather than citric or formic acid to keep bacterial counts low.
Dedicated storage equipment
Avoid using the same bucket for colostrum, mastitic milk and milk containing antibiotics.
This will reduce the risk of antibiotics residues, which could cause antibiotics resistance and impact the calf’s gut flora.
Regular replacement of teats
Old teats on feeders are less supple and likely to have microcracks that can harbour bacteria. Ensure they are checked, cleaned thoroughly and replaced frequently.
Regular testing for bacteria levels
If colostrum cleanliness has not been established before, get your vet to sample every two to four weeks to establish “normal” contamination levels.
Then test twice yearly to check that standards are being maintained.
Colostrum coliform stats
- Less than 10,000 cfu/ml: target level for total coliform count (TCC) in colostrum
- 76.3%: percentage of colostrum from feeders that failed to meet the target TCC*
- 182 million cfu/ml -the highest TCC in colostrum identified on one of the sample farms*
- 39.3%: percentage of colostrum samples that failed quality testing either because of poor immunoglobulin levels, bacteria contamination or both**
Sources:
* – 2023 study on 11 Scottish dairy farms involving University of Glasgow Vet School, Galloway Vets, SRUC and Stewartry Vet Centre.
** – University of Glasgow Vet School Masters study on 38 Scottish dairy farms, 2019, involving Clyde Vet group, SRUC and Stewartry Vet Centre. Both studies funded by Hannah Dairy Research Foundation.
How one farm has improved colostrum cleanliness
An old dump bucket proved the main pinch point for colostrum cleanliness at Slagnaw Farm, Castle Douglas, testing above target levels for total coliform count.
Results showed colostrum got gradually dirtier the more it was handled – from the teat to the dump bucket, into a transport bucket and then to the tube for feeding.
This was likely contributing to scours and mortality.
Harry Campbell, who farms with his father, Kenneth, had already started the process of improving calf management prior to involvement with the 2023 colostrum quality trial involving vet Ali Haggerty.
This included installing a second calving box so cows could be rotated between the two, improving cleanliness.
A milk taxi was purchased to improve feeding consistency, and testing for colostrum immunoglobulin levels also became routine, with calves only fed supplies testing higher than 25% on a Brix refractometer.
Attention to detail
After seeing the results on colostrum cleanliness, Harry’s focus is now on ensuring colostrum does not “sit around” in buckets.
Every piece of equipment is scrubbed with a brush, warm water and washing-up liquid between uses.
He says: “We’re just trying to improve the consistency of how we’re doing things. Everything is very clean and tidy now.
“We knew we weren’t doing our calves any favours by feeding them colostrum with bacteria in it.”
The old, self-contained dump bucket, which had its own cluster, has been replaced with one that can be plugged into any milking unit in the parlour.
This means the cluster is washed as part of the parlour wash cycle and the bucket can be easily cleaned.
To further promote cleanliness, good-quality colostrum is now pasteurised and frozen. It is then defrosted, and 4 litres are fed to calves within one hour of birth.
Harry says calf management improvements are ongoing, but changes have already been reflected in a 1.5% reduction in calf mortality in the past nine months.
During that time, the farm has also started vaccinating cows for scours.