Water is one of the most important feed
ingredients in the diet. Clean water improves
the animal’s performance and acidifying
drinking water may even suppress bacteria
that have a negative influence on
performance. But there’s more to acidifying
the water than just adding a simple acid.
By Ing. Pascal Philipsen, technical-marketing manager
We sometimes tend to forget that drinking
water has a large impact on the health status
and performance of farm animals.
Water is indeed the most important nutrient and
healthy animals drink twice as much water than they
eat solid feed. Water intake is even higher when temperatures
rise. Furthermore, farm animals face critical
periods (weaning, stress, etc…) when their feed
intake is reduced.
Treating water can therefore be a good way to
improve performances of animals, quickly treat diseases,
or improve litter quality. It is of course crucial
to use the right product(s) with an appropriate protocol.
When developing products based on (organic)
acids for application in the drinking water, specific
requirements must be taken into account.
Under normal circumstances, inorganic and organic
components will deposit on surfaces inside the water
pipeline. This will promote the growth of naturally
occurring microorganisms and result in the so-called“biofilm”. Biofilms are defined as ‘matrix-enclosing
microbial populations with adherent to surfaces of
interfaces’. This definition includes microbial aggregates
and floccules, and also adherent populations
within the pore spaces of porous media.
Biofilm is formed when bacteria adhere to surfaces
in aqueous environments and begin to excrete a
slimy, glue-like substance that can anchor them to all
kinds of material. The buildup of biofilm is accelerated
when vitamins and medications are administered
via the water line, because their sugar based carriers
become ideal substrates for microbes to proliferate. As
a result, the drinking water is often a source of contamination
to the animals.
On the other hand, when feed consumption is
depressed because of stress, or during the feed withdrawal
prior to transport to the slaughterhouse, the
intake of in-feed health enhancers such as AGP’s
(Antibacterial Growth Promoters) and organic acids is
reduced. The animals must then cope with a high bacterial
load with little or no support, which results in
digestive disorders and impaired performance.
Therefore, treating the drinking water of fast growing
and young chicken or pigs, or and high productive
animals like breeders or layers, is helpful to
ensure a well balanced flora in the digestive tract,
especially when their feed intake in disturbed.
Sanitizing is not enough
Regularly cleaning and sanitizing the drinking water
is one method to prevent contamination, but it has
limitations. Disinfectants based on chlorine and
hydrogen peroxide are the most commonly used. But
they are only effective at a high dosage and preferably
not during production.
Chlorides do not work efficiently when pH is too
high (above 8.5); also, these disinfectants react with
the organic pollution present in the water line and
loose their efficacy. The consequence is that the effective
dosage of such products is often too toxic and/or
negatively influences the crop/gut microbial flora.
Critical periods in a young animal’s
life; falling short in maintaining a
sufficient feed intake:
• First days…. Very susceptible to environmental influences (from
yolk to solid feed)
• Pre transport feed withdrawal
• After vaccination
• Feed transitions
• Heat stress
• Bacterial and viral infections
• Moving from pen to pen (maternity unit > battery unit > finisher
• Post weaning period
• Digestive disorders like diarrhoea
Another recommendation is to remove the biofilm by
increasing the pressure in the waterline. But in many
cases the mineral deposit in the biofilm remains after
flushing, leaving a shelter for microorganisms.
The benefits of organic acids in feed are proven. They
are today recognized as one of the best alternatives to
AGP’s. But what if animals eat less? They can also be
delivered in the drinking water. Indeed, adding
organic acids to the drinking water allows killing bacteria
in the waterline and, at the same time, killing
bacteria in the digestive tract, increasing digestibility
of proteins, stimulating the growth of lactobacilli (in
the crop) and regulating the microflora in the gut. In
order to get all these benefits it is important to use a
well-formulated combination of organic acids and
salts. Otherwise, it can do more harm than bring the
expected benefits. In this respect, it is important to
know that single organic acids can create severe problems
in the waterline, as shown in Table 1.
Safety through buffering
Compared to feed, which usually has a rather high
buffer capacity (due to protein sources and minerals),
water has a very small buffering effect. The only
parameter, which can have an effect, is the hardness
of water. Therefore, when applying single acids in
drinking, water the pH decreases quickly. If the
dosage is too high, it can be fatal to the birds. One
should also know that single acids, especially propionic
and formic acids, are corrosive. To increase the
buffer capacity of the water we formulated a mixture
of organic acids, combined with plant extracts (Acidal
ML). The effect of buffering is reflected in Figure 1.
When using acidifiers in drinking water, the target
acidity, as a general rule, is pH 4. This is because at this pH, pathogenic bacteria
develop and water intake is not yet
impaired. But animal producers who
only take into account this pH target
level often face problems such as blocked
waterlines and nipples due to ‘slime formation’.
This is because using single
acids will have an effect on only a limited
spectrum of microbes. For example,
lactic acid has strong bactericidal effect
against E. coli, but only weak activity
against Salmonella, moulds and yeasts.
Some microbes produce a diffuse layer
around their cell wall in order to protect
themselves against disinfectants or acids and also to
provide them with the possibility to attach to surfaces.
Mostly these water-enriched layers (=slime) consist
of polysaccharides or polypeptides.
When applying single acids to the drinking water,
these acidophilic bacteria start to produce slime as a
direct mechanism of protection. With the slime, the
bacteria attach to the bioflim in the pipelines and
can easily multiply, thus producing more slime. This
causes blocked waterlines and nipples.
A properly formulated combination of acids will
offer a broad anti microbial spectrum. Slime forming
bacteria cannot survive Acidal ML.
Figure 1 - Buffering system of Acidal ML: even in
demineralised water with increased dosage the pH
does not drop under pH 3
Positive effect on performance
Organic acids have their own pKa-value. The pKa
value equals to the pH value at which 50% of the
organic acid is dissociated and 50% undissociated. If
pH is lower than the pKa value, then the undissociated form will be dominant.
This undissociated organic
acid molecule is the one that has the anti-microbial
effect, because it can diffuse through the bacterial
cell wall, then dissociate and disturb the electron-balance
inside the cell. The right combination of acids
with different pKa values results in a synergistic product
that always provides undissociated molecules,
even at a higher pH.
During the development of our drinking water supplement
range we researched all aspects important
for a safe and effective drinking water treatment
using natural ingredients without any withdrawal
period. Many objectives were taken into account during
this development: effect on water intake, stability
during storage and on the farm, antimicrobial properties,
biodegradability, and of course, a positive
effect on performance of poultry and swine.
Table 2 shows performance of a broiler flock (Ross)
with and without addition of Acidal ML. In this experiment,
the acidic combination was used from 1 to 7 days old and 43 to 55 days old. The
dosage was 1 litre
for 1000 litres of water (0.1%). The feed was the same
for both treatments and was supplemented with
Olaquindox (40 ppm) and zinc bacitracin (50 ppm) for
the first 43 days. After that stage (especially during
feed transition), the favourable effect of the acid mix
was more obvious. Over the whole period, birds from
the group given Acidal ML in the drinking water have
shown a better growth and a slightly better feed conversion
ratio. The production factor was improved by
more than 4%.
The power of plant extracts
To enhance the mode of action of organic acids at
higher pH (> 5.5), essential oils can be added.
However, essential oils do not mix properly with
organic acids, and, in order to create a homogenous
drinking water supplement, emulsifiers are required.
Still, when farmers make a pre-solution of this product
(diluting with water to get the recommended
dosage level), in many cases, the essential oil will
float on the surface, and appears as an oily layer.
Plant extracts are obtained by maceration of plants
or spices. Unlike essential oils, plant extracts can be
mixed homogenously with acids without the risk of
separating in two different phases. With this type of
preparation, real extract of plants, still active after
long storage times, are obtained. Building further on
the proven synergistic effect of essential oils and
organic acids, we designed Acidal ML Botanical, a
combination of organic acids and plant extracts. The
product contains a combination of Wintergreen,
Peppermint, Milk thistle, Thyme and Common
juniper extracts. Chemical components in the plant
extracts show anti bacterial effect, but also have
immunostimulating, anti-oxidative, hepato-protecting
and carminative properties.
Herbs and spices are used in human nutrition
so why not use them in animal nutrition too?
The benefits of this botanical variant is especially
interesting in young birds. Because they are born
with a sterile intestinal tract, they need extra support
during their starting period. This is a crucial stage
where the animals build their immunity and develop
their skeletal frame. Almost the same counts for
newly weaned piglets. Because they need extra support
during their new phase of life where almost
everything is changed. This is a crucial stage where
the animals build up their immunity for the rest of
their productive life.
By Ing. Pascal Philipsen, technical-marketing manager