Assessment of a phytase included with lactic acid on productive parameters and on deposition of phosphorus, calcium, and zinc in laying hens fed with sorghum–soybean-meal-based diets

In an acidic pH, the phytic acid is more soluble and therefore, more susceptible to the action of an exogenous phytase (Phy). 50 Hy-Line W36 hens were randomly allocated into five treatments, each one with 10 replicates (one bird/replicate): (1) Positive Control (0.25% of available phosphorus (Pav)); (2) Negative Control (NC; 0.12% Pav); (3) NC + 0.5% lactic acid (LA); (4) NC + 450 FTU/kg Phy; (5) NC + 0.5% LA + 450 FTU/kg Phy. Low levels of Pav (0.12%) negatively affected the production parameters compared to the 0.25% Pav diet. LA alone only improved the egg laying production, egg mass, and feed intake. When Phy was included, the production parameters improved, being similar from 0.25% Pav diet. Additionally, the deposition of P, Ca, and Zn increased in the bone marrow, as well as Fe contents in the yolk. Phy addition decreased P excretion compared to diets with the same level of Pav. There was no difference between the use of Phy alone or in combination with LA. In conclusion, the addition of Phy into low Pav diets produced results that were similar to those obtained with 0.25% of Pav, without any additive effect seen when LA was also added