Effect of the Dietary Oil Mixture for Laying Hens on the Apparent Absorption Coefficients of Some Trace Elements

Abstract

A 4-week feeding trial was conducted on 48 Lohmann Brown layers (55 weeks) to evaluate the effect on zootechnical parameters and coefficients of apparent absorption of micronutrients (Cu, Fe, Mn, Zn). The layers, assigned to 2 groups, were housed in three-tier digestibility cages (4 layers/cage) which allowed the daily recording of the feed intake and excreta, located in an experimental hall under controlled environmental conditions (temperature: 22.41±0.980C; humidity: 66.35±5.68%; ventilation/chick 0.50±0.24%; CO2 level 686.39±104.38 ppm) and 16h/24h light regimen. The control group (C) received a conventional diet (2760 kcal/kg metabolizable energy and 16.8% crude protein). Compared to C formulation, the experimental diet (E) included 0.50% oils mixture (20% buckthorn oil, 20% sesame oil, 20% rosehip oil, 20% grape oil and 20% walnut oil). The daily feed intake (at weeks 3 and 4) recorded significant decreases (P≤0.05) in group E (113.29 respectively 114.38 g/chick/day) compared to C group (115 respectively 116.13 g/chick/day). Copper absorption in E group was significantly (P≤0.05) higher (with 32.21%) than in C group, which means that the concentrations of Cu in the excreta significantly (P≤0.05) decreased in E group (0.36 mg/chick/day) compared to C group (0.52 mg/chick/day). This is a positive aspect regarding the soil pollution with Cu. For Fe and Mn, the mineral concentrations in the excretion did not differ significantly (P≥0.05), showing that the supplement administered in the E diet did not affect the possible mineral load at the soil level.

Keywords

• nutrient digestibility
• oils
• performances
• poultry