Milking hygiene is no longer a “mere” parameter within yield control. In recent years, we have focused not only on the quality of milk components, but also on the volume of milk produced with regard to parameters affecting the economy of farming. The modern farmer knows very well the direct effect of PSB to the loss in dairy production (Table 1) as well as the relationship with mastitis and other health problems in dairy cows, which can be compared with the results of the questionnaire in Graph 1.

Table 1: PSB in relation to milk loss in %

Source: Milk Quality Management Protocol, Prof. David L. Lee

A special attention should be paid to the care of teats during dry period and early lactation. Did you know that most of the clinical mastitis and the low quality and quantity of colostrum after calving are the results of the high number of somatic cells during dry period and early lactation?

Milking hygiene is undoubtedly the basic pillar for sufficient production of quality milk. It directly affects CPM and PSB as well as the health of the mammary gland. It depends on the following basic factors:

1. Selection of preparation for udder hygiene
2. Correct procedures
3. Hygienic program in milking parlour
4. Personal hygiene of staff

How to choose the right product for teat hygiene?

First, let's ask why we should use it?

Let's ask what we actually need from teat or udder disinfectants:

1. Do I want milk without high PSB and CPM?
2. Do I need to remove bacteria from teat skin and base before milking even from problematic areas?
3. Do I need efficiency also on organically contaminated teats (wash off dirt and bacteria)?
4. Do I require perfect disinfection even in skin wrinkles pre and post milking so as to prevent mastitis?
5. Do I want to re-hydrate the teat skin so as to avoid skin cracking?
6. Do I want to prevent the skin from drying out, reducing its defence capability?
7. Do I want a disinfectant not to leave any residue on skin or in milk?
8. Do I choose yield and PSB and mastitis reduction or just colouring, albeit azo dyes?

The preparations based on peracetic acid designed for pre-milking treating of teats are highly effective against bacteria only for 10 minutes after dilution. However, it is just a pure fantasy that it would be possible, without any non-ionic surfactant, to remove bacteria from skin in the teat wrinkles or even to wash the microorganisms from the teat biofilm! Regardless of whether it is a barrier-free or barrier disinfectant, to use such an active ingredient for post-milking teat disinfection means to expose the capillaries of damaged teat skin to increased bleeding. Moreover, no one is able to say whether a diluted solution in “farm” quality is still effective after 30 seconds. In many cases, we also encounter buckets of dirty water full of bacteria. It is just for these reasons, why dairy farmers worldwide use such preparations only up to 1%. Sometimes, unfortunately, also in the Czech Republic.

Teat disinfectants based on chlorine dioxide (ClO₂) take up to 5% of the world market. Although it is an almost non-toxic active substance and exceptionally effective in the food industry, unfortunately, it has not found its use in the teat hygiene and environment. This is due to the absence of surfactants and at the same time ineffective concentration in relation to the amount of CPM on the surface.

If we choose biguanides (chlorhexidine), we should firstly consider EU program of actions against AMR. However, without the content of non-ionic surfactants, we can rely on an eight-hour action on the teat against bacteria, but only if the teats are not organically contaminated, e. g. it is impossible without the use of sand bedding. These preparations should be diluted for the period of 1 milking. Let us not forget that chlorhexidine is ineffective when dissolved in hard water above 300 ppm and nobody in the world can know that the solution is effective! This substance is used up to 15% in 80 countries worldwide (also outside the EU).

An interesting question is why cattle farmers use products for teat hygiene based on lactic acid (up to 15%). It is an acid which in an anaerobic environment guarantees a reduction of pathogen content. Unfortunately, at a concentration that does not cause teat skin irritation, it no longer has such efficiency against pathogens. Its effect, at the permitted concentration, depends mainly on the intolerance of several pathogens to pH.

Last but not least, iodine-based preparations are used worldwide in 65% of cases.

Why it is so? Firstly, it is an element. And an element is not a molecule! Therefore, it is exceptionally stable. Moreover, it is purely natural. In contrast with too low intake that represents a risk of limited development of the individual (thyroid)/struma/dementia/infertility, there is no evidence of overdose effect in the world because there is no such limit. In recent years, efforts have been made to limit the use of iodine, even by some dairy representatives! So, please excuse the lack of iodine in their organism with the hope that such activities will not intensify! If only a single CPM bacterium remains in the milk, then there is no iodine molecule. In addition, such efforts to discredit the use of iodine, pre or post milking, have been rebutted long ago by the fact that when iodophor preparation is applied at a maximum concentration of 0.5% iodine, the entire 15 ppm of iodine gets in during one milking, and stratus corneum absorbs up to 1.2 ppm, which is taken to the bloodstream, where the concentration of up to 0.072 ppm can be found without any disease; and in practice this is not possible, only if the MIC is denied.

Although it is not well-suited for many manufacturers, the iodine plays world's leading role not only because of its efficacy on bacteria, viruses and fungi (it can easily handle, for example Streptococcus uberis (the most common one-quarter mastitis) or Staphylococcus aureus. But here too, we must carefully distinguish between PVP iodine and iodophor. The first one is a great antiseptic for the skin of humans or even animals when injured. It is significantly better when compared to hydrogen peroxide for open wounds or operations. For use in veterinary applications in agriculture, however, it is 10 times weaker compared to iodophor!

So, if we want to reduce PSB and CPM in milk, same as 65% of breeders in the world, we use iodophor products.

BUT! IS IT ENOUGH? CERTAINLY NOT!

What is commonly known:

1. Using iodophor predip is the most important step in preventing PSB and mastitis! High-quality predip contains iodine with a strong bactericidal effect in the form of iodophor and thus regulates PSB and CPM in treated areas very easily. 0.1% of free iodine has an immediate effect on bacteria and dries within 15 seconds. It prevents the transmission of pathogens not only from the environment, but mainly from properly treated teats even in the case of milking for 5 minutes!

The predip must also contain non-ionic surfactants, so that the active ingredient gets into even the smallest folds of skin.

2. The requirements for the content of substances in the preparation are even stricter in the case of post-milking teat disinfection!

In addition to the active substances, we must not forget conditioners (emolients). These include mainly Glycerol, at least 5% of content (glycerine in aqueous solution), which softens the skin by means of re-hydration even from the air humidity and also protects it from cracks during milking for more than 5 minutes. In the event that skin cracks or other irritations (e.g. under pressure) do occur, sorbitol above 3% is absolutely necessary to cool and soothe it at this concentration. These substances include also lanolin, but it repels water and dehydrates the skin.

Further, the post-milking preparations can be divided into non-barrier and barrier products. The difference between non-barrier and barrier postdips is in the creation of a protective film on the teat after milking. The non-barrier preparation creates an antiseptic microfilm that does not protect the teat in the long term. On the contrary, the barrier preparation dries on the treat and, thanks to polymer, it forms a protective film that protects the teat until further milking (usually for 8 hours). In the case of barrier preparations, it is very important that they do not run off of teats within 30 minutes after treatment in the summer and within 5 minutes in winter. This is determined by the correct preparation density. Therefore, xanthan gum is also included in some product for post-milking treatment of teats.

And what to say in conclusion?

Who is so rich that he can afford to select the preparations for teat treatment by price, aware of the fact that an individual threat of PSB of only 220,000 at 100 dairy cows of ČESTR at 21.5 kg milk/dairy cow a day means a terrible loss of CZK 289,000 per year plus the cost of curing the mastitis?

Please pay close attention to the preparations you choose!

Graph 1: Occurrence of health problems in dairy cows in the CR/SR