- - - Department of Animal Science, Islamic Azad University, Arak Branch, Arak, Iran.
- - - Department of Animal Science, Islamic Azad University, Arak Branch, Arak, Iran.
- - - Animal Science Research Institute, Agricultural Research, Education, and Extension Organization, Karaj, Iran.
- - - Department of Animal Science, Islamic Azad University, Arak Branch, Arak, Iran.

The primary aim of this study was to assay the influence of pellet and mash diets supplemented with different levels of mesquite fruit on performance, energy and protein efficiency ratio, carcass characteristics, and intestinal morphology of broiler chickens. In this study, a total of ۵۶۰ one-day-old (mixed sex) Ross ۳۰۸ were distributed in a completely randomized design with ۷ treatments, ۴ replicates, and ۲۰ chicks per replicate. Seven iso-caloric and iso-nitrogenous diets including a control diet (mash form without mesquite fruit), and pelleted and mash diets, consisting of three levels of mesquite fruit (۳, ۶, and ۹%) were adjusted. The results exhibited that mesquite fruit contained a high percentage of dietary fiber. The results also showed that pelleted and mash diets containing different levels of mesquite caused a significant difference in feed intake, body weight gain, and feed conversion ratio in starter and grower periods. At the finisher period, there was a significant difference between the experimental treatments in terms of feed intake and body weight gain, but there was no significant difference in feed conversion ratio. Experimental treatments also caused a significant difference in energy and protein efficiency ratio in the starter and grower periods. Dietary treatments also exhibited a significant difference in the relative weight of breast and intestine, but no effect was found on carcass yield and relative weight of other internal organs. The findings revealed that pelleted and mash diets containing different levels of mesquite fruit did not show significant differences in morphological traits of the intestine. Taken together, our results suggested that, the use of mesquite fruit in pelleted diets can have positive effects on the performance of broilers.

Broiler, Mesquite, Performance, Energy efficiency ratio, Protein efficiency ratio