Acta Vet. Brno 2007, 76: 31-37
Positive Effect of Plant-Based Diet on the Performance and Health of Laying Hens
An entirely plant-based feed mixture was prepared to minimize the potential risk of transmitting prion infections through animal feed. It consisted of two protein components (soya extracted meal and lupin seed meal) and was compared with a diet containing animal protein components (fish meal). The objective of the present work was to prepare and verify the effect of the entirely plant-based diet on the performance, selected qualitative indicators of eggs and the hens' state of health. A specially prepared feed mixture containing fish meal was used as a control diet. The tested plant-based diet administered to experimental hens produced no negative effect on egg production variables such as number of eggs per hen or laying performance. The weight of eggs laid by experimental hens was significantly higher (61.66 g, P ⪬ 0.01), as compared with the control group (60.03 g). The higher average weight of eggs in the experimental group increased the production of egg mass per layer by 540 g in 252-day experimental period. the beneficial effect of the plant-based diet was demonstrated particularly in the improved egg quality, manifesting itself in a highly significant improvement in yolk colour (P ⪬ 0.01) and a significant decrease (P ⪬ 0.05) in cholesterol level in egg yolk. Haematological examination did not indicate statistical differences between experimental and control layers in red blood cell indices such as RBC, haemoglobin, hematocrit, MCHC, MCH, and MCV, while white blood cell indices showed a highly significant increase (P ⪬ 0.01) in Le in experimental hens. Biochemical tests performed in blood plasma revealed significantly lower molar concentrations of glucose (P ⪬ 0.05) and highly significantly lower levels of total lipids, cholesterol, lipoproteins (HDL and LDL) in experimental hens (P ⪬ 0.01), as compared with the control group. The results of the study confirm that animal protein in diet for laying hens can be replaced by combination of vegetable protein feeds (soybean and lupin protein) without a negative impact on their performance and health, thereby contributing to solving issues of food safety (a prevention of prion infections).
