Abstract
This study was performed to determine the effect of different levels of soya lecithin (SL) added to the diets for growing V-line rabbits in the winter and summer seasons. One hundred sixty 35-day-old rabbits were used in two experiments, one was conducted in the winter and the other in the summer (each for 49 days). Animals were randomly assigned to 4 experimental groups and fed diet supplemented with 0, 0.5, 1.0 and 1.5% of SL. The addition of SL to the diet improved weight gain, feed intake and feed conversion ratio in both seasons. Body weight gain and carcass traits were improved by the inclusion of SL in the summer (P < 0.05). Dietary SL increased (P < 0.05) ether extract apparent faecal digestibility, levels of triglycerides, total lipids, phospholipids, high-density lipoprotein cholesterol (HDL), and the enzymatic activity of acid phosphatase, whereas decreased (P < 0.05) the levels of total cholesterol and low-density lipoprotein cholesterol (LDL), and the activities of aspartate amino transferase and alanine amino transferase in the blood. In the winter, lower nutrient digestibility coefficients and lower relative weights of the heart and spleen were found. In the summer season the elevated (P < 0.05) blood levels of glucose, HDL and LDL were observed in comparison to the winter season. Supplementation of feed with 1% or 1.5% SL improved rabbit growth performance, fat digestibility and HDL blood level in both seasons. So, the soya lecithin can be a useful feed additive also in the heat stress conditions.