مقایسه اثرات دو شیوه فرآوری دانه جو (پرتوتابی با مایکروویو و افزودن آنزیم) بر راندمان رشد، صفات لاشه و فراسنجه های خونی در جوجه های گوشتی

In order to investigate the effects of microwave irradiation of barley or enzyme supplementation of barley based diets, 12-day-old broiler chicks (n=320) from Ross 308 strain were arranged in a 2×2 factorial experiment consisting of 2 duration times of microwaves irradiation of barley (0 and 220 second) and 2 levels of dietary Rovabio multienzyme level (0 and 1 g.kg-1) with 4 replicates per treatment and 20 birds in each replicate. Four treatments were included: 1) basal diet with non-irradiated barley, 2) basal diet with non-irradiated barley + multienzyme, 3) basal diet with microwave irradiated barley and 4) basal diet with microwave irradiated barley+ multienzyme. Irradiation of barley was carried out by a microwave oven (Model 245, Butan Co, Iran) at 880 W and 220 S.  Feed intake (FI), weight gain (WG) and feed conversion ratio (FCR) were recorded weekly. At the end of experiment 8 birds per each treatment were selected and blood sampling was done. To measure carcass characteristics, 2 birds per each pen were weighed and slaughtered at 42 days of age.  Results indicated that irradiated barley had no effect on broilers FI. However, the overall WG and FCR and gizzard relative weight increased. Use of Irradiated barley resulted in increases in the concentration of serum total cholesterol, HDL-C and LDL-C. Broilers fed diets containing β-glucanase enzyme had 4% improvement in overall FCR.  Use of enzyme resulted in increase in abdominal fat, gizzard weight and serum HDL-C and also resulted in a decrease in thigh weight. Serum ALP and TP in the broiler chicks were not affected by barley irradiation, enzyme supplementation and their interaction. There was a significant linear regression relationship between weight gain in the whole experimental period and serum HDL-cholesterol concentration (at day 42) in broiler chicks. It was found a significant linear regression relationship between serum total cholesterol and HDL-cholesterol concentrations in the 42 d-old broiler chicks. It is concluded that β-glucanase enzyme and dietary barley irradiation had some useful effects on broiler's performance. Due to independency of the effects of these two processing methods on performance and blood characteristics, simultaneous use of them has not any problems.