The excretion of Ca, Mg, Zn and Cu via excreta of laying hens fed low phosphorus diets and phytase
University of Prishtina, ‘Hasan Prishtina’, Faculty of Agriculture and Veterinary, Department of Biotechnology in Zootechnics, Tahir Zajmi 34, XK10000 Prishtinë, Republic of Kosovo
**This author contributed equally to this work
An 8–week experiment was conducted to study the effect of adding phytase (Natuphos® 5000 BASF) to low and normal available phosphorus diets of laying hens on the excreta content and excretion of Ca, Mg, Zn and Cu. A total of 144 Hisex Brown laying hens that were 22 weeks old at the start of the experiment were randomly assigned to four dietary treatments. Treatments included three replicates (12 hens each) or 36 hens per treatment in total. Four corn-soybean meal-based diets were formulated to contain two levels of available phosphorus (AP; 0.12 and 0.46%) and two phytase levels (0 and 600 FTU kg–1). The results showed that there was no significant effect of added phytase on excreta Ca and Mg content (P > 0.05), but there was a significant effect of the dietary treatment on the content of Zn (P = 0.0075) and Cu (P = 0.0002). In terms of the excretion of these minerals, the dietary treatment had no effect on Ca and Zn excretion and a borderline effect (P = 0.0522) on Mg excretion measured as the amount of the mineral excreted per egg mass produced is observed. The results however showed a very strong effect of all three factors (available phosphorus, phytase and their interaction) on Cu excretion. The results indicate that adding 600 FTU to the corn-soybean meal laying hen diet with 0.12% or 0.46% AP beneficially affects the content and the excretion of Ca, Mg, Zn and Cu. Therefore, we can conclude that a laying hen diet containing 0.12% available phosphorus and 600 FTU during the first production cycle may not only satisfactorily support hens’ performance but will also beneficially affect the environment.