Mozhgan Mazhari

Aim of study: To evaluate the effects of adding Lactobacillus acidophilus (LA), Spirulina platensis (SP) and the encapsulation of LA on the relative weights of carcass parts and meat quality of broilers subjected to heat stress. Area of study: The work was performed at the University of Jiroft, Iran. Material and methods: Two hundred forty 1-day-old male broilers (Ross 308) were used in a completely randomized design, with six treatments and four replicates (cages, 10 birds per cage). Dietary treatments included: (i) corn-soybean as control diet (CON), (ii) 0.02% LA, (iii) 1% SP, (iv) 0.02% LA + 1% SP, (v) 0.02% of encapsulated LA, and (vi) 0.02% encapsulated LA + 1% SP. Main results: The relative weight of the carcass increased in all experimental groups except in the 0.02% LA encapsulated group (p˂0.05). Birds fed diets containing LA+SP (0.02% LA+ 1%SP and 0.02% LA encapsulated+1% SP) had a significantly higher relative weight of the breast (p˂0.05). Dietary supplementation with SP, LA+SP, and encapsulated LA+SP significantly increased water holding capacity and decreased cook loss, respectively (p˂0.05), whereas dietary LA+SP and encapsulated LA+SP decreased drip loss (p<0.05), compared to the CON group. Moisture and pH were not significantly affected by the dietary treatments (p˃0.05). The malondialdehyde content of thigh and breast meat at 30 and 37 days after the slaughter was reduced (p˂0.05) in the SP, LA+SP, and LA encapsulated +SP groups. Research highlights: Based on results, including LA, SP and encapsulated LA in broilerʼs feeds were effective in improving carcass yield, quality and oxidative stability of broiler meat under heat stress condition.