Effect of dietary phyto-humic preparations on lipids indices of commercial laying hen eggs

The aim of the study was to determine the effect of three different phyto-humic feed preparations on the basic qualitative characteristics of eggs, i.e. total cholesterol content and fatty acid profile of the yolk. The study was carried out on 80 Lohmann Brown (LB) laying hens in an experimental facility with a floor maintenance system on a straw bedding (5 layers/m2). A control group (K) and three experimental ones (A, B, C), with 20 birds in each (in separate pens), were created. The birds were placed in the 16th week of life, while the experimental preparations were introduced in the 22nd week of life and were administered for 43 weeks (constant 3% addition to the feed mixture).The following preparations were applied: humic-peat (H-t) in group A, humic-herbal (H-z) in group B, and humic-lucerne (H-1) in group C. The eggs for the study were collected three times, 30 eggs from each group in the following periods: 1st series – 31st week of life (peak of laying period); 2nd series – 54th week of life (later phase of laying period) and 3rd series – 65th week of life (final phase of laying period). Six samples (mean of 5 well-mixed yolks) from each group in three laying periods (360 eggs were used in total) were prepared for laboratory analyzes (lipids examination). Laboratory analyzes were performed using a chromatograph – Finnigan Focus PolarisQ manufactured by Thermo Electron with capillary columns: HP-88 by Agilent J&W (fatty acids) and Rtx-1MS by Restek (cholesterol). The applied phytohumic preparations – but only those with a share of dried lucerne or herbs – significantly (p ≤ 0.05) reduced total cholesterol content, especially in group C (10.88 mg/g yolk) compared to group K (11.94 mg/g yolk). All preparations positively influenced the fatty acids profile of yolk; there was a significant (p ≤ 0.05) increase in the concentration of n-3 PUFAs (max 2.84% in the group B), the n-6/n-3 ratio decreased significantly (most beneficial 8.33 in group B), and lipids quality improved: atherogenic index (AI) decreased significantly (p ≤ 0.05) in group A (0.32) and thrombogenic index (TI) was a significantly (p ≤ 0.05) lower in all experimental groups (0.83 – 0.84) compared to group K (0.36 and 0.87 respectively). Dietary phyto-humic preparations increased the nutritional and dietary value of hen eggs.