Effects of replacement genetically modified soybean meal by a mixture of: linseed cake, sunflower cake, guar meal and linseed oil in laying hens diet. Production results and eggs quality

Abstract The Kulmilk® (KulM®) preparation containing linseed cake (300 g/kg), sunflower cake (350 g/kg), guar meal (300 g/kg) and linseed oil (50 g/kg) was studied as alternative to genetically modified soybean meal (GM SBM) in the diet of laying hens. Two hundred forty hens maintained in cages were divided into 5 groups (8 hens per cage × 6 replications). From 18 wk of life, the hens were fed five diets for 33 wks: Control without KulM®, and A, B, C, D with respective KulM® content: 109, 170, 222 and 292 g/kg replacing GM SBM. Laying performance, egg weight, conversion ratio and hen mortality was continuously controlled throughout the experiment. Hen body weight was determined on 0 and 32 wk of production. On 7, 15 and 23 wk of laying, analysis of fresh eggs and eggs were stored for 21 d was performed (20 eggs per group). On 7 and 23 wk of hen laying, cholesterol level and fatty acid profile was determined on fresh eggs and eggs stored for 21 d (6 eggs per group). Sensory assessment of eggs was performed on eggs 15 wks laying. Introduction of KulM® to the diet replacing GM SBM contributed to increas laying performance, reduced mean egg weight and the final hen body weight but it did not influence the weight of eggs per hen, conversion ratio and mortality. The best production results were obtained in group A. Positive impact of KulM® was observed on the albumen quality and the yolk index of fresh and stored eggs, as well as reduction of yolk adhesiveness after 21 d. Cholesterol level in yolks depended on the laying performance, thus KulM® had indirect influenced on its reduction, especially in group A. Linear relationship was demonstrated between KulM® level and reduction of SFA acids, particularly of C16:0 acid. KulM® contributed to increas share of C18:1, C18:3 and C22:6 acids and reduction of C20:1 and C18:2 acids in the yolk. The influence of KulM® on the content of individual mono- and polyunsaturated fatty acids was observed primarily in group D. No impact of KulM® on the sensory quality of eggs could be demonstrated. In summary, KulM® can be recommended as a safe and efficient substitute of GM SBM in laying hens diet, particularly at a concentration of the diet at 109 g/kg.