The impact of different inclusion levels of whole barley in feed on growth performance, carcass, and gastrointestinal traits of broiler chickens

The aim of the present research was to evaluate the effect of feeding graded levels of whole barley (WB) on broiler chicken growth and carcass performance, gastrointestinal morphology, and function. A total of 800 male Ross 308 broiler chickens (1-day-old) were randomly assigned to four treatment groups with four replicate pens of 50 birds each. Diets differed in their WB dosage: without WB (NO-WB); low WB amount (LOW-WB) dosages: 4% (1–7 days of age), 8% (8–21 days of age), 15% (22–35 days of age); medium WB amount (MEDIUM-WB) dosages: 6% (1–7 days of age), 12% (8–21 days of age), 20% (22–35 days of age); high WB amount (HIGH-WB) dosages: 8% (1–7 days of age) 16% (8–21 days of age), 25% (22–35 days of age). Body weight, average daily gain, and mortality of chickens did not statistically differ between treatments (P > 0.05). The feed conversion ratio was higher in the treatments diluted with WB. There were no differences in ammonia nitrogen concentration except for increased butyrate concentration in the caecum and reduced digesta viscosity in the broiler ileum in groups fed LOW-WB, MEDIUM-WB, and HIGH-WB diets (P < 0.05). The high WB amount in the diets increased Lactobacillus spp. in the ileal contents and improved ileum morphology (P < 0.05). The inclusion of graded levels of WB in the diets had no effect on carcass performance but it seemed to enhance the gastrointestinal tract development.