نسرین رشیدی

In order to study theeffects of various levels of organic chromium on performanceand egg quality characteristics oflaying hens reared at high stock density, an experiment was done using twolevels of density (three and five birds per cage) and four levels of organic chromium (0, 300, 600and 900 ppb) with 192 laying hens (Hy-line W-36) in a completely randomizeddesign with factorial arrangement of 4×2 with six replicates. The results showed that dietarysupplementation of chromium at normal and high stock density had notsignificant effect on performance of layers. Egg weight significantly increasedat levels of 600 and 900 ppb (56.96 and 56.91 g) and feed intake significantlydecreased (99.34 vs. 105.05) in birds reared at high stock densitycompared to the birds reared at normal stock density (P<0.05). In thefirst four, second, and whole periods of sampling, dietary inclusion ofchromium at normal and high stock density, increased significantly egg yolkcolor and egg shell strength compared to the control (P<0.05). Dietarysupplementation of chromium at normal and high stock density had notsignificant effect on blood parameters and tibia charachteristics of layers. Ingeneral, the results of the experiment showed that by increasing dietarysupplementation of chromium at high stock density up to 900 ppb, egg yolk colorand egg shell strength significantly increased in laying hens.

Using 350 Ross broiler chickens, the effect of licorice extract (LE), probiotic, antifungal and boiler litter biochar on performance of broiler chickens fed aflatoxin B1 contaminated diet in a completely randomized design with 7 treatment (negative control (basal diet without aflatoxin and additives), positive control (basal diet 1 mg aflatoxin B1 and without additives) and 5 other treatments were positive control with LE (3 and 6 g/kg), Protexin probiotic (0.5 gr), Agrabond (0.5 gr/kg) and biochar toxin binder (10 g/kg)) and 5 replicates (10 birds in each replicate) considered. The treatments were. The result showed that aflatoxin B1 lowered body weight gain and breast relative weight and increased FCR and abdominal fat of broilers (P

This experiment was conducted to evaluate the effect of different levels of silybum marianum seed on performance and carcass characteristics and blood parameters of broiler chickens. Research was performed in a completely randomize design with 5 treatments, 4 replicate and 12 broilers in each replicate for 42 days. The treatments consist of the control diet, and 0.5, 1, 1.5 and 2% of silybum marianum seed. To evaluate the different part of carcass and blood parameters, at the end of experiment two bird of each replicate were bleed and then slaughtered. The results of exprement showed that the highest feed intake in the starter and finisher period respectively observed in the 1(357.71) and 1.5 (1701.9) % of silybum marianum seed, and the lowest was in the control diet (312.08) and 0.5 (1426.6) % of silybum marianum seed. The highest weight gain was in the 1.5 % of silybum marianum seed (801.27) and the lowest was in the control diet 687.40). The highest relative weight of gizzard and intestine were in the 0.5 and 2 % of silybum marianum seed (3.18 and 7.65 respectively) (P<0.05) but had no effect on the other carcass characteristics (P>0.05). The lowest cholesterol (91), triglyceride (62.75) and VLDL (12.55) and the highest level of HDL (44.50) observed in the 1.5 % of silybum marianum seed. So use of the 1.5 % of silybum marianum seed had positive effects on performance, carcass characteristics and blood parameters of broiler chickens.