مجله دانش و پژوهش علوم دامی
سال بیست و یکم شماره 2 (پیاپی 20، تابستان 1394)

This experiment was carried out to investigation of the effect of egg inovo feeding and dietary feeding of Silybum marianum extract on broiler intestine development under heat stress condition. In day 17th,360 fertile eggs from Ross 308 broiler breeding strain were used for inovo injection of three levels (0,100 and 200ppm) of water extract Silybum marianum. After hatch, 240 chicks transferred to experimental cages and they fed experimental diets (without Silybum marianum and 100ppm Silybum marianum). Then birds were located under heat stress 4 hours in daily, from 7th till 28th day of breeding (4oC upper than optimum temperature).The experimental design was CRD with 6 treatment and 4 replicates in each in factorial method. Feeding of 100ppm Silybum marianum increased relative weight of jejunum and ileum. Also, relative weight and length of cecum were decreased in treatment that fed with Silybum marianum. Reciprocal effect of inovo feeding and dietary feeding of Silybum marianumshowed increase in relative weight of ileum in100ppm fed treatment. Length of cecum was low in dietary feeding Silybum marianum treatment.At 42th day, dietary feeding decreased length and weight of cecum , in100ppm fed treatment. Dietary feeding increased length and width of villis at 28th