Salt is essential in poultry feeds and they prefer food that has been seasoned by salt. Salt (NaCl) is made up of sodium (Na) and Chloride (Cl) where Na makes up 39% and Cl 60% of salt. Sodium makes up about 93% of the basic mineral elements in the blood serum and is the chief caution regulating blood pH. Muscle contraction, nerve impulse transmission and the rhythmic maintenance of heart action are dependent on proper sodium levels. Body stores of sodium are negligible and last only about a week. Chloride is the blood's primary anion and makes up 2/3 of the acidic ions. Chloride is needed in maintaining the acid-base balance and is part of hydrochloric acid used in the stomach in digestion.

The source of NaCl for poultry rations is common table salt. There are other salts but NaCl is the most commonly used. Salt is added to the diet to satisfy the birds requirement for Na and Cl and to improve the birds appetite. Both nutrients are used not only in the acid-base equilibrium of the body in regulating body pH, but are necessary for growth, bone development, egg shell quality and amino acid and monosaccharide utilization.

Poultry diets have recommendations for levels of Na and Cl. Though salt is the major source of Na and Cl, grains, meals and supplements also contain these molecular nutrients.

It is important to understand that the individual nutrient level of sodium gives a direct indication of the salt level present. Therefore when discussing salt level in the diet, the amount of Na is usually sought. Sodium is an ingredient that has a very small optimum range in poultry diets. The minimum level of Na in poultry rations is .15% or 1500 ppm. The best level for layers, chickens and turkeys is .18% and it can be reduced to .17% later in the flock. A level of .19% may be OK but at .20% and above there will be a laxative effect. At less than .17% the ration consumption will be effected.

"Water follows salt!" Remembering this chemical principle we recognize that water is drawn to high concentrations of sodium chloride. This is important when considering that NA and Cl help to maintain blood pressure and cellular osmotic pressure in the body. Any excesses or deficiencies will lead to problems in poultry. When problems occur adjusting the ration to a proper level will usually bring the flock back to normal production levels.

Why Salt Problems Occur:

The Na and Cl in the poultry diet are essential to maintain homeostasis of osmotic relationships and pH throughout the body of the bird. The level of dietary concentrations employed will just support maximum growth rate or egg production. When the diet is deficient in Na (salt) feed consumption will decrease.

Too Much - Toxicity:

When Na, Cl or salt are too high in a ration, water consumption will increase leading to a laxative effect. This is the bodies response trying to maintain the acid-base balance. Keeping the Na level in the diet down will remedy this. The lethal dose of a diet is 8.0% salt but rations seldom have more than .25-.35% salt added to the ration. Higher water consumption leads to the problems of wetter droppings, increased carcass quality problems and ventilation needed to maintain optimum litter condition and % RH (relative humidity) in the poultry shed.

The maximum level for Na in water without a problem is 500 ppm. Diets not adjusted when water softeners are used can lead to excess in Na consumption. Water softeners when flushing add Na to the water. Sodium will readily replace other minerals in the water and is beneficial in that it doesn't scale on equipment. The amount of Na added is proportional to the hardness of the water, so every situation is different.

Laying hens are more susceptible as they drink a higher portion of water to feed intake effecting Vitamin D3 metabolism and calcification. Birds drinking water that is high in Na and Cl can adjust over time to these levels, but later in the lay cycle the interference in shell calcification is more evident with drastic increases in cracks and downgrades. Well water too high in salt will mean drilling for a new source of water. For those using a water softener, Table 1 can help determine whether you need to adjust your ration for the extra Na being added to the water.