Effects of dietary supplementation on egg yolk mineral and cholesterol concentrations in laying quails

Abstract

Feeds have an influence on quail growth, both on their physiological development and, to some extent, on the composition of the eggs obtained from these birds. Traditionally, feeds include mixtures of cereals and grits, but for better nutrition they contain some supplements. In this research, studies were conducted to determine the effect of supplementation of quails' feed with ZooBioR, which is a bioproduct based on extracts from the cyanobacterium Spirulina Platensis biomass. The research was focused on determining the evolution of content of minerals (P, Fe, Ca) and cholesterol fractions (HDL, LDL, free cholesterol), accumulated in quail egg yolk after feed supplementation. The quails tested belonged to the breed Texas Super. The eggs produced by quails had the following characteristics: egg mass – 12.91±1.30 g, yolk mass – 4.49±0.63 g, yolk/white ratio – 1:1.40, yolk pH – 6.43±0.21. Bioproduct ZooBioR, being rich in easy assimilable nutrients (amino acids, phospholipids), contributed to improving the nutritional value of the quail yolk. The mineral content of yolk was found to be enhanced – for P from 248.0 mg/100 g (control group) to 265.8 mg/100 g yolk (tested group), and the amount of Ca – from 24.5mg/100 g (control group) to 32.6 mg/100 g yolk (tested group). The total amount of cholesterol does not differ much, ranging from 1152.6 mg/100 g yolk in the control group to 1088.1 mg/100 g yolk in the tested group. Instead, there are trends in the decrease of the free cholesterol fraction, from 1.86 to 0.15 mg/100 g yolk. The argument is that the ZooBioR supplement, rich in phospholipids, contributed to the increase in esterified cholesterol fractions and decrease of free cholesterol. Consequently, the decrease in free cholesterol is a beneficial factor in reducing easily assimilated cholesterol from eggs. An increase in the HDL esterified cholesterol fraction was also recorded, from 410.9 (control group) to 416.5 mg/100 g yolk (tested group).