Effects of caprylic acid and Yucca schidigera extract on growth performance, relative organ weight, breast meat quality, haematological characteristics and caecal microbial shedding in mixed sex Ross 308 broiler chickens

Caprylic acid (CA) and Yucca schidigera (YS) extract have many functional and nutritional properties that may have applications in animal nutrition. These beneficial effects include improvement of growth performance, immunity and anti-microbial activity. This study was conducted to assess the effects of dietary supplementation with CA and YS extract on growth performance, relative organ weight, meat quality, blood characteristics and caecal microbial shedding in broilers. In total, 672 one-day-old Ross 308 (BW of 34.05 ± 0.21 g) mixed-sex broiler chicks were allotted randomly into three dietary treatment groups with 14 replicate pens per treatment and 16 birds per pen. The experiment lasted for five weeks and dietary treatments were as follows: (1) PC, basal diet; (2) PC, basal diet + 44 mg/kg of avilamycin; and (3) CAY100 (basal diet + 100 mg/kg CA + 100 mg/kg YS extract). Chicks fed the CAY100 diet exhibited improved overall body weight gain (BWG) and feed intake (FI), and reduced feed conversion ratio (FCR) compared with those fed the NC diet (P < 0.05). Compared with the NC and PC treatments, mortality was decreased in chicks fed the CAY100 diet during the finisher phase and also overall. Broilers fed the CAY100 diet exhibited increased (P < 0.05) relative organ weight of bursa of Fabricius, compared with the PC diet and demonstrated decreased relative organ weight of the gizzard compared with those fed the NC diet. The relative organ weight of the liver, spleen, breast, and abdominal fat was unaffected by any of the dietary supplements tested. The breast meat redness (a*) was reduced (P < 0.05) in the CAY100 diet compared with the NC and PC diets. White blood cell (WBC) counts were increased in the CAY100 treatment compared with the NC treatment (P < 0.05). Moreover, the CAY100 diet resulted in improved lymphocyte counts compared with the PC and NC diets (P < 0.05). Broilers fed the CAY100 diet exhibited reduced caecal E. coli counts compared with those fed the NC diet (P < 0.05). In conclusion, the CAY extract-supplemented diet improved growth performance, relative weight of bursa of Fabricius and reduced mortality rate, breast muscle a* and caecal E. coli counts in broiler chickens.