Guts of Growth: Why winning water maters

Water is one of those forgotten nutrients in poultry production. It’s always there but is usually hidden in the water lines and drinkers. As a result, many producers are overlooking this important nutrient.

Ignoring the water quality and flow in your barn can be harmful to the health of your flock and, ultimately, your bottom line. Water makes up approximately 55 to 75 per cent of a bird’s body and around 65 per cent of the egg. Therefore, water plays an important role in the bird; especially in metabolism, chemical process of life and nutrition.

Water has many key roles in the body that include helping with nutrient transport, enzymatic and chemical reactions, temperature regulation as well as lubrication for joints and organs. In broilers, the bird consumes around 1.6-2.0 as much water as feed on a weight comparison basis; this number can change depending on the age of the bird, environmental temperature and health status.

Water to feed consumption is different in layers, breeders and turkeys. That said, generally a healthy bird consumes more water than feed. On the farm, water consumption helps drive feed consumption and vice versa. Consequently, water quality and how the bird has access to water are one of the many critical components to support bird health.

The focus of this article will be on water quality, but the birds must be able to access the water (e.g., enough drinkers per bird, appropriate height, no air blocks) in order to benefit from the water at all.

Water quality is a term that covers several factors such as organic matter and mineral content. These factors can have an impact on other aspects such as the pH of the water, how cloudy the water is, biofilm formation and the colour of the water.

In poultry production, there is often the case where one water source can supply many birds. In this situation, if the water is not of high quality it can have a negative impact on the entire flock.

pH level
The pH of the water line is the measure of acidity (pH 0 to 6) or alkalinity (pH 8 and above) of the water. A pH above eight means that the water has high alkalinity and often has higher calcium and magnesium levels. The higher alkaline water could negatively impact how water sanitizers work (e.g., chlorine), lead to a bitter and undesirable taste of the water and often require more product to lower the pH of the water.

There are different opinions as to what is an acceptable pH of the water line and, depending on what the goal is for the flock, this may vary. Generally, chlorine works best at a pH around 6. Birds can tolerate pH levels between four and eight, but often a pH around 6 is acceptable.

Very low pH levels that are acidic (below 5) can be corrosive and turn the birds away from the water. Nevertheless, some producers have been successful using lower pH levels (e.g., pH 4 to 5) throughout the flock as one method to help control bacteria growth.

Mineral content
An important role of water is the capability to act as a universal solvent, meaning it can readily dissolve other substances. A good example is how minerals readily dissolve in water. All water available for drinking will have some amount of mineral dissolved in the water and often these minerals are within acceptable ranges. However, minerals may be present at levels outside acceptable ranges or at levels that interact with other minerals, vitamins and medications.

In some situations, birds can tolerate the levels of minerals in the water. However, in situations where water consumption increases, such as during heat stress, the bird consumes more of these minerals and a tolerated level could become a problem. In other situations, mineral residues may slowly build-up in different areas along the water line system. Therefore, it does not present as an immediate issue but could slowly impact water flow and, eventually, water access.

When minerals are present at levels that cause issues, they can be related to equipment failure, poor performance or encourage the presence of certain bacteria and fungi. Bicarbonate, sulfates and calcium carbonate for the alkalinity value and high levels (e.g., 300 mg/L alkalinity) can be associated with a bitter taste of the water, more basic pH levels.

Calcium and magnesium predominantly relate to the hardness of the water and can cause scaling if at higher levels (e.g., 110 mg/L for calcium) and can interfere with the effectiveness of soap, disinfectants and some water medications. Magnesium can cause flushing in birds if there are sulfate levels of 50mg/L or more. Iron and manganese can also contribute to the hardness of the water.

Higher iron levels (e.g., around 0.3 mg/L) can lead to scale build-ups in the water line but, more importantly, can act as food for iron-loving bacteria such as E. coli and Pseudomonas. Sodium and chloride react together to form salt. Alone, sodium and chloride levels need to be 150 mg/L each to be considered high, but together you only need 14 mg/L of chloride with 50 mg/L sodium to potentially have issues such as loose droppings, intestinal issues and encouraging growth of Enterococci bacteria.

In broiler breeders and layers, high sodium chloride levels (e.g. 200 mg/L or more) have been shown to lead to negative impacts on shell quality, hatchability and embryo survivability. Loose droppings, intestinal issues and encouraging certain bacterial growth can also appear if sulphate levels are 50 mg/L or more with higher sodium levels.

Sulphate levels, alone, around 200 to 250 mg/L can lead to wet droppings and encourage growth of sulfur-loving bacteria such as Campylobacter, Pseudomonas and Salmonella. High levels of sulphates in the water interfere with copper absorption. Sulfur-loving bacteria eat the sulfate and turn it into hydrogen sulfide which can gas off in the water and lead to air locks.

If hydrogen sulfide is formed, then when a test is done the actual level of sulfates may be underestimated if most of the sulfate has been eaten and changed form. Copper can be found in water due to corrosion of pipes or fittings or it can also be added as an antibiotic alternative.

High copper levels (e.g., 0.6 mg/L or more) can cause oral lesions or gizzard erosion similar to what can be seen in some high mycotoxin challenges. In older barns where lead or other heavy metals were used in pipes, fittings or sodder this heavy metal can get into the water. Higher levels of lead (e.g. 0.05 mg/L) can lead to weak bones and fertility issue whereas other heavy metals can lead to growth issues as well as lower egg production and embryo survivability.

In barns where galvanized metal was used the zinc levels may be higher (e.g., 1.5 mg/L) and have an impact on growth. Fluoride is another compound that is found in water. At high levels (e.g., over 40 mg/L), fluoride has been associated with skeletal issues, such as soft bones. While it is important to monitor all mineral levels, it is critical to pay attention to those minerals that can lead to wet droppings as well as encourage scale and bacterial growth.

Organic matter
When water has dissolved other components, such as minerals, it can provide the ideal condition for pathogens to multiply and survive. These pathogens can include viruses, bacteria, parasites and fungi. Some of these pathogens multiply quickly at alkaline pH levels (e.g., above pH 8); whereas, others multiply quickly at acidic pH levels (e.g., 5 or below).

When water is tested, it is often examined for bacteria and bacteria indicators such as coliforms, nitrates/nitrate nitrogen and nitrites. Coliforms are a group of bacteria that are found in the environment. Total coliforms represent all coliforms present in soil, water, human or animal waste whereas fecal coliforms represent a subset of total coliforms that are present in the intestine and feces of many animals.

Within this coliform test there can also be tests for bacteria like E. coli and Pseudomonas. While not all coliforms are bad, some can become an issue when present at higher levels and can be enough of an intestinal irritant to lead to other issues.

Additionally, some within the coliform group can be bad and cause direct issues. Regardless, coliforms in the water system suggest contamination and can turn birds off drinking water as well as carry pathogens. The ideal level for coliforms is 0 CFU/mL. If levels are higher than biofilms can start to develop over time and become an issue.

Nitrate and nitrate nitrogen are terms are used interchangeably despite the values representing slightly different concepts. Nitrate indicates the amount actual nitrate (NO3) in the water while nitrate nitrogen indicates the percentage of nitrogen contribution to the formation nitrate. Nitrite (NO2) is the more toxic form of nitrate.

Both nitrate and nitrite are indicators of bacterial contamination. In humans, nitrate nitrogen levels are considered safe at 10 mg/L. In poultry, various research has suggested that broilers can tolerate low levels of nitrate nitrogen (e.g., below three to five mg/L), broiler breeders can tolerate moderate levels of nitrate nitrogen (e.g., below 10 to 11 mg/L) and layers have been shown to tolerate higher levels of nitrate nitrogen.

However, in all cases the levels of nitrate nitrogen that caused an issue may be impacted by water pH levels, bacterial levels and even indirectly with higher water temperatures.

Nitrate nitrogen has been found to have an impact on vitamin A absorption, growth, hen day egg production, fertile hatchability. In mammals, nitrate nitrogen has been found to lower protection against respiratory and gastrointestinal infections. Nitrate can also be transformed into nitrite by intestinal bacteria. If nitrite passes into the bloodstream it can reduce the oxygen-carrying capacity of red blood cells.

Using additives in the water
In many situations different products can be administered through the waterline. These products can include: vitamins, electrolytes, acidifiers, flavours, and medications. These products can all be used effectively, but the efficiency of their use is dependent on the quality of the water and possible interactions with other water line additives. A good water line cleaning program that includes flushing the water lines can help to properly use water line additive products.

Conclusion
Since water is an important nutrient for birds, providing good quality water is vital for their health. Poor water quality interferes with digestion, has negative impacts on intestinal health and bird performance, reduces effectiveness of water-administered vaccines and may create equipment issues that can decrease access to water.

In order to ensure water quality, it is key to have an effective and consistent waterline cleaning program. It should consist of a two-part protocol. Firstly, the water lines need to be descaled and cleaned thoroughly between flocks. Secondly, there should be a sanitation program for when the flock is in the barn and consistent monitoring of water quality and quantity during the duration of the flock. Water quality is an important insurance policy for the health of the flock and should be a part of the team management strategy.

Dr. Kayla Price is poultry technical manager for Alltech Canada and is an expert in poultry intestinal health.