Breeders of layers focus on increasing egg yield, weight of eggs, and increasing internal quality such as decreasing the cholesterol content of their production to enhance economic performance.
Besides these aspects breeders should also concentrate on to the mechanism of egg production and the health condition of the layers. This can be done by the use of probiotics as these products have shown positive effects on layers and their products.
Probiotics are defined as bio-preparations that include living cells or metabolites of stabilised autochthonous microorganisms that optimise colonisation and composition of gut microflora in both animals and humans and have a stimulating effect on digestive processes and immunity.
Once ingested with live microbial cells, the probiotic microorganisms can modulate the balance and activities of the gastrointestinal microflora. The addition of live microorganisms to the diet has been found to stimulate the immune system and strengthen nonspecific immunity. Other effects include improved feed conversion for target species, reduction of morbidity or mortality, and improved product quality.
Butyrate is produced in the caecum and colon of animals via the fermentation of carbohydrates such as dietary fibre. Sodium butyrate can induce absorption of water and sodium and proliferation of intestinal cells, be used as energy resources, and stimulate intestinal blood flow and the synthesis of gastrointestinal hormones.
In a study combinations of probiotics (Lactobacillus salivarius L.s, Clostridium butyricum, C.b, and Bacillus subtilis, B.s) and sodium butyrate, that could improve the health condition and egg quality of layers, were tested. 1,800 white feather layers (Lohmann) were used.
Several combinations of microorganisms and butyrate were tested. .s. and B.s. mixtures added to the diet improved egg production, daily egg yield, damaged egg ratio, and decreased feed conversion. L.s. plus butyrate increased daily egg yield, feed conversion, damaged egg ratio and Haugh units.
In other groups feed conversion was significantly decreased. In serum, the effects were minimal, except for some groups were total cholesterol and low-density lipoprotein cholesterol were affected. These results demonstrate that several combinations of probiotics and butyrate, have a positive impact on the performance and egg quality.