What is SCC?
SCC is a measure of the alert level of the immune system in your animals – from inflammation of the mammary gland – usually from Mastitis.
The majority of somatic cells are leukocytes (white blood cells) – which become present in increasing numbers in milk usually as an immune response to a mastitis-causing pathogen – and a smaller number of epithelial cells, which are milk-producing cells shed from inside of the udder when an infection occurs.
Why is SCC used?
SCC is an indicator of infection
The SCC of the bulk tank is a reasonable indicator of the subclinical mastitis infection rate in your herd.
300 SCC is approximately 30% of the herd with subliclinical mastitis, 200 SCC approximately 20%, etc.
It impacts your productivity and milk quality
Higher SCC cows produce less milk, and milk of a lesser quality.
It impacts survival rate
Cows with low SCC will survive longer in the herd.
SCC for Mastitis Management?
Does a macro approach to mastitis management work?
Yes, partially and with some caveats: False positives and false
negatives abound.
At herd level, it is possible to infer the general level of mastitis in your herd, but not to determine which animals are infected, or by which pathogen(s), nor how to resolve the issue(s) you may have. It’s hard to guess without testing, but for example:
- You may have a high SCC level due to a flare up of opportunistic pathogens, that only require small tweaks, and don’t require much action.
- You could have a low SCC level with a few cows with low immune response infected with a contagious pathogen (such as Staphaureus), which could be a disaster in the making.
At cow level, SCC is a measurement of immune response. It tells you something is wrong when it’s high but not why. Even a relatively low SCC can hide a serious situation for your
animal or herd.
SCC – The Imperfect Tool
SCC is a simple and globally recognised way to indicate your animals’ health and productivity. It is an important measure for milk quality evaluation linked to bonuses and penalties from milk processors. By all accounts something you cannot ignore.
Limitations
Its popular status for bulk tank evaluation has spilled over into a measurement for individual cow’s health, and in this realm, it owes its prominent status more to its affordability and ease of implementation than its usefulness. Because what SCC holds in convenience it lacks in interpretive powers. A high SCC level tells you, like a fever, that something is wrong. It does not however tell you what is wrong. Likewise, a low SCC does not mean nothing is happening.
Did You Know ?
“Conductivity measurement versus SCC levels have poor agreement. It is however cheap and easy to implement, especially inline.”
The macro solution
For years, our industry has taken a macro, treatment focused, approach to improving animal welfare and farm systems. We have had access to a convenient, easy to measure metric, SCC. And we have tried to make it say more than it can. We have started to infer probable mastitis causes, tried to derive meaning from its fluctuations by looking at patterns. Is there a link? There is at best a symptom: a high SCC. And there is a cause: herd or cow subclinical illness. But you cannot establish a strong causal link. Is it even a bacterial infection? With SCC you cannot say. With SCC alone nobody can conclude anything- there is simply not enough information.
Too often, troubleshooting means our animals are viewed under the light of speculative assumptions, using over-simplified generalisations and short cuts. We believed in the power of SCC because it was easy. Everybody wanted to believe. It was the standard. Easy. Convenient.
“Everything should be made as simple as possible, but no simpler.”
Albert Einstein
The rise of blanket antibiotic treatments
This is most exemplified by the explosion of blanket antibiotic treatments (intramammary and dry cow therapy) that everybody would agree now are not an adapted or a responsible course of treatment. Administering treatments without full information results in less-than-optimal outcomes, sometimes even detrimental ones. In human health, doctors will always, when they suspect bacterial infection, order a culture, establish a diagnosis, and select treatment on that basis. Surprisingly in the dairy industry, little resource is allocated to thorough diagnosis prior to treatment. This results in a limited understanding of the herd specific situation and consequently the implementation of suboptimal treatments (e.g. blanket antibiotics, culling) with poor documented efficacy.
“Trial and error. Should it be at the farmer’s expense?”
What is more, routine misuse of antibiotics disregards any possible collateral damage. i.e.: the wellbeing of animals, farmer’s financial stability, and the future effectiveness of antibiotics for future generations because of antimicrobial resistance; in dairy farms and for human health.
Did You Know ?
Pathogens such as yeast are introduced accidentally during intramammary antibiotic treatments. Because they are chronic, treatment resistant mastitis, yeast infections often result in culling.
Time to go Microbiology
The paradigm shift.This reactive, treatment focused approach often based on imperfect data and flawed rational needs to stop and give way to a preventative evidence-based and solution-oriented model; that uncovers, based on evidence, the pathogen challenge we face and its origins.
Everyone is demanding that our industry adapts its mastitis management to support better antibiotic stewardship. As well as consumers, concerned with animal welfare and food safety, there are new regulations requiring we preserve antibiotics effectiveness.
It is high time we considered SCC for what it really is, at most an entry point into diagnosing the underlying mastitis issues faced. And antibiotics one of the available treatment options when they are necessary.
What we need is a diagnostic solution to tell us which pathogens are causing issues to determine the best course of action and put the control of your farm back in your hands.
“There is no magic bullet.”
Thanks to Farm Medix, this solution exists. Microbiological culture used to be costly, impractical, and required a lot of sensitive equipment. With our revolutionary technology it is now available, practical, accurate, accessible 24/7 and affordable. Farm Medix solutions empower farmers with the precise identification and quantification of causative mastitis pathogens. So you can implement the most appropriate preventive or corrective actions.
Results show that we provide significant positive impacts on farms’ profitability and risk management, animal welfare, food safety. We are able to help reduce the entry of antibiotics into the environment and food chain (estimate – 70%) and reduce productivity losses by up to 20% – a huge positive environmental impact.
