ABSTRACT Many kinds of feed additives can be used in chicken diets to stimulate intestinal morphological maturation and, consequently, intestinal function. The purpose of this study was to evaluate the effect of zeolite on broiler performance, gut morphology and gut digestive enzyme activity. The one-day old broiler chickens Ross 308 were assigned randomly into 3 groups with 30 birds per treatment. The 3 dietary treatments were: basal diet only (control group), basal diet + 2% zeolite, basal diet + 3% zeolite. Morphological and morphometric intestinal assessments were conducted using a light microscope. There was observed increase in villus height, villus perimeter, villus section area and crypt depth throughout duodenum and mid jejunum of the broilers fed zeolite. Supplementation especially with 2% zeolite was associated with greater villus heights, villus perimeter, villus section area and crypt depth in duodenum and ileum mucosa compared to the controls. The diet with 2% zeolite also contributed to significant increase proventriculus (pepsin) and pancreas (trypsin, lipase) activity compared to the controls The results suggest that dietary supplementation of zeolite increased feed consumption, intestinal morphology parameters and enzyme activity of gastrointestinal tract in broiler which improved growth performance.

ABSTRACT The aim of this study was to evaluate the effect of adding zinc (Zn) mineral supplements from organic (ZnGly) and inorganic (ZnO) sources to growing male Ross 308 chickens on the mechanical, geometric, and histomorphometrical parameters of long bones. A corn-soybean meal basal diet was supplemented with Zn at 50 or 100 mg·kg-1 of a premix, except the control group (0 suppl). The serum concentration of insulin-like growth factor 1 was higher in the ZnGly50 group compared with the control group. Positive influence of Zn on the femur is highlighted when considering the significant increase in parameters such as mean relative wall thickness, and maximum elastic and ultimate strengths after Zn administration. Zinc supplementation did not affect tibial parameters. The histomorphometric analysis showed a positive impact of Zn supplementation (irrespective of source and level) on femoral trabecular thickness. Rapid loss in actual bone volume in tibial metaphyseal trabeculae was observed with ZnGly at 50 mg·kg-1. In conclusion, this study showed that dietary Zn supplementation positively influences bone mechanical properties, confirming its beneficial effect on the development of the skeletal system and bone tissue of broilers tested for a nutritional-osteoporotic factor. Adverse health effects in trabecular bone as a result of the use of Zn at 50 mg·kg-1 of the premix show that supplementing Zn at the recommended dose (100 mg·kg-1) is essential.