عنوان مقاله [English]
An experiment was conducted to investigate the effect of different levels of alfalfa extract (polysavone), a natural extract of alfalfa, on growth performance, gut characteristics, and some blood parameters in broiler chickens. A total of 200 one-day-old Ross 308 male broiler chicks were assigned to 5 experimental treatments, with 4 replications and 10 birds in each replication with a completely randomized design. The polysavone was used in 4 levels (0, 2, 4, 8, and 12% of feed). The results showed that polysavone had no adverse effects on the average daily gain, average daily feed intake, and European Broiler Index. The addition of polysavone (4, 8, and 12%) to the diet significantly increased relative weight of bursa and spleen but decreased triglycerides concentration in serum (P<0.05). Percentage of abdominal fat decreased by increasing dietary polysavone levels and reached a maximum at 8 and 12% of diet (P<0.05). Also, total cholesterol concentration was reduced (P<0.05) in broilers fed on diet with 12% polysavone. Relative weights and lengths of duodenum, jejunum, and ileum, relative weights of thymus, crop, gizzard, and proventriculus, as well as serum glucose concentration were not affected (P>0.05) by experimental treatments. The results of this research indicated that polysavone may decrease abdominal fat deposition and enhance immunity without showing an adverse effect on the performance of broiler chicken.