INFLUENCE OF NATURAL CAROTENOIDS SUPPLEMENTATION IN DIET ON EGG YOLK COLOR AND SOME PRODUCTIVE PARAMETERS OF LOCAL HEN LAYERS

Abstract

The present study was conducted to study the effect of adding different levels of lutein powder pure (LP),dried tomato pulp (DTP) and dried sweet red pepper powder (DSRP) (as natural colour additives) on some productive, egg quality parameters and economical efficiency of Silver Montazah (SM) local hen layers from the beginning of 40 to 48 weeks of birds age. A 2x3x3 factorial arrangement design was used in this experiment including two levels supplementation of LP (0 and 30 mg/kg diet), three levels of DTP (0, 15 and 30 g/kg diet), and three levels of DSRP (0, 2 and 4 g/kg diet) .A total number of 162 laying hens of Silver Montazah (SM) local strain were used in this experiment. All selected birds were randomly distributed into 18 treatments equal in number (9hens / each treatment). Laying hens of each treatment were nearly of an equal average body weight and similar average daily egg production .All birds of the experimental treatments were individually housed in wire-caged batteries and kept under the same managerial, hygienic and environmental conditions. Results obtained at the end of the experiment showed that the average live body weight of layers at the end of the experimental period was significantly (P≤0.05) affected by dietary LP levels, whereas, dietary DTP, DSRP levels had no significant effect on average live body weight of hens. The heavier live body weight was attained by layers fed 0 mg / kg diet LP and layers fed 30 g / kg diet DTP recorded the average higher LBW. While, layers fed the 0 g / kg diet DSRP showed the higher average LBW. Dietary LP and DTP levels had significant (P≤0.01) effect on average daily feed intake of layers. However, the higher average of daily feed intake was recorded by hens fed dietary 0 mg/ kg diet LP, 0 g/ kg diet DTP level and 2 g / kg diet DSRP levels. Dried sweet red pepper levels had no significant effect on average daily FI of layers during most of experimental periods. The higher average daily FI was shown by layers fed 2 g / kg diet DSRP level. No significant differences were found in average feed conversion of layers attributed to the dietary DTP and DSRP levels. However, the best average FCR values (3.37g feed/g egg mass) was recorded by layers fed the diet contained 0 mg/kg diet lutein powder level. Dietary LP and DTP levels had significant (P≤0.01) effects on average egg production (EP) rate, egg weight and egg mass of layers at the end of the experimental period. While, dietary DSRP levels had no significant effect on averages of egg production rate and egg mass of layers at the end of the experimental period (40-48 weeks of age). The higher averages of egg production rate and egg mass were recorded by layers fed the diet of 0 mg/kg diet LP, 30 g/kg diet DTP and 2 g/kg diet DSRP levels, while, the higher average of egg weight was recorded by hens fed the dietary 0 mg/kg diet LP, 30 g/kg diet DTP and 0 g/kg diet DSRP levels . Dietary supplementation of LP, DTP and DSRP showed significant (P≤0.01) effect on Roche yolk color fan score at all the different experimental periods. Roche yolk color fan score increased with increasing the rate of LP, DTP and DSRP levels in the diet of laying hens. Diets contained 0 mg LP /kg diet, 0 g DTP /kg diet and 4 g DSRP /kg diet levels recorded the higher (best) relative economical efficiency percentage for egg production.