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). Increasing of dietary polysavone levels (8 and 12%) caused a significantly decrease in abdominal fat (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 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.