BACKGROUND: Reducing the concentration of energy and nutrients in laying hen diets, as a cost-saving strategy, can impair productive performance, eggshell quality, and physiological status. The use of feed additives such as phytase enzyme and vitamin–mineral premix (VMP) has been proposed as a nutritional approach to compensate for these reductions.
OBJECTIVES: This study evaluated the effects of phytase (PHYTA GOLD) and VMP supplementation (SuperShell) in diets containing standard or reduced nutrient levels in laying hens.
METHODS: A total of 320 Lohmann LSL lite laying hens (54–66 weeks of age) were allocated to a completely randomized 2×4 factorial experiment with eight replicates of five birds each. Experimental treatments included two nutrient levels (recommended level; SND, and low-nutrient diet; LND) and four supplementation regimens: (1) no supplement, (2) phytase, (3) VMP, and (4) phytase + VMP. Compared to the SND, the LND was formulated having 50 kcal/kg less metabolizable energy, 1% less crude protein, and 0.1% less of each available phosphorus and calcium.
RESULTS: A significant interaction between nutrient level and supplement type was observed for egg mass, feed conversion ratio, and the proportion of abnormal eggs (P<0.05). Dietary supplementation, particularly the combination of phytase and VMP in the LND, had greater effects than in the SND. Reducing nutrients in LND decreased yolk weight index, serum triglyceride, and phosphorus concentrations, while increasing serum glucose and alkaline phosphatase activity (P<0.05). Phytase improved Haugh unit, energy digestibility, and nitrogen-corrected apparent metabolizable energy (AMEn), and reduced alkaline phosphatase activity, whereas VMP increased eggshell weight and thickness (P<0.05). The combined use of phytase and VMP improved eggshell breaking strength and crude protein digestibility (P<0.05).
CONCLUSIONS: The results indicated that phytase and VMP exert a synergistic effect on improving productive performance, eggshell quality, and nutrient digestibility, particularly in low-nutrient diets, and can be recommended as an effective strategy in laying hen nutrition management.