Enzymes and feed economy – broilers
In a study on the effect of the use of enzymes on feed costs, a blend of amylase, protease, and phytase was used in corn-based broiler feeds at 1 g/kg.
The results show that these enzymes reduced the amounts of nutrients required in the diet, while maintaining live-weight gain and feed conversion at the same level as birds fed a standard diet (145 Kcal/kg reduction in ME, 4% reduction in amino acids, 0.10% reduction in total phosphorus, and 0.12% reduction in calcium), with a resulting feed cost saving of around US$ 11.00 per tonne.
The addition of exogenous enzymes also appears to reduce feed costs by replacing expensive feed materials with cheaper ones. For example, it was found that adding phytase enzyme to rapeseed meal – a cheap protein source – was just as nutritious for broiler chicks as the widely-used soybean meal (rapeseed meal is about US$ 130 a tonne cheaper than soybean according to a 2014 estimate).
In addition, phytase releases phosphorus from the phytate molecule in the GI tract and makes it bioavailable to the birds, thus reducing the cost of inorganic phosphorus supplementation that is needed for the development and maintenance of their skeletal system.
It also minimizes the amount of phytate-bound phosphorus that is excreted and hence prevents negative impacts on the environment. While common phytase is derived from various species of fungi, new generation products are derived from bacterial sources.
The new-generation phytase is around 45% more effective in increasing body weight gain and around 70% more effective in improving feed conversion. These improvements are due to the superior ability of the new-generation phytase to liberate more phosphorus from the dietary phytate, in addition to its beneficial effect in reducing the anti-nutritive properties of phytate. Economically, the use of the new-generation phytase can result in a saving of about US$ 4.0-6.0 per tonne of low-quality feed.