This reduces the total required phosphorus levels in the diet. A corn-soybean based diet, for example, has about a 20 percent digestibility of phosphorus, but by adding phytase to the ration the digestibility can be increased to 50 percent. DeLange adds that an additional 1 to 2 percent improvement in feed utilization can be gained in starter and grower pigs because the phytase also increases the digestibility of calcium and other trace minerals that are tied up in the phytate complex. This is true for both phosphorus and nitrogen. However, a more careful look at amino acid balancing can reduce nitrogen excretion in growing pigs by close to 40 percent.
Protein is made up of amino acids of which lysine is the first limiting amino acid.
This means that when lysine is restricted, the remaining amino acids are of no use as use for building lean meat, and as a result are degraded as an expensive source of energy. In an example ration, DeLange pointed out a greater than 10 percent reduction in excreted nitrogen and a lower total ingredient cost when adding Lysine. HCL to a standard Corn-Soybean premix. When land base is limited, these decreases can be significant. Feed additives to reduce the nutrient content of manure is a promising tool in manure management along with manure and soil analysis, timely spreading, uniform application, and most importantly proper crediting of nutrients applied from manure.