Responses of broiler chicken to different oil levels within constant energy levels from 20 to 40 days of age under hot weather conditions

• Main Authors: Youssef A. Attia, Mohammed A. Al-Harthi, Saber Sh. Hassan
• Format: Article
• Language: English
• Published: Taylor & Francis Group 2021-01-01
• Series: Italian Journal of Animal Science
• Subjects: broilers; high temperature; performance; carcase; immunity
• Online Access: http://dx.doi.org/10.1080/1828051X.2021.1906169
• ISSN: 1594-4077; 1828-051X

In total, 144 Arbour Acres broiler chickens were distributed among four treatment groups (six replicates per treatment; six chickens per replicate) during days 20–40 of age. The chickens were offered iso-caloric and iso-nitrogenous diets containing four dietary oil levels (DOL): 0 (oil non-supplemented diet, control), 2, 4, and 6% in a relatively low-energy diet (12.4 MJ ME/kg diet). During the experimental period, the chickens were reared under natural hot weather conditions (32.5 ± 4 °C, 54 ± 7% relative humidity). Growth, feed conversion ratio (FCR), protein (PCR), metabolisable energy (MECR) ratio, and European production efficiency index (EPEI) were similar among groups fed up to 4% DOL but raising DOL to 6% impaired these traits. Besides, DOL at 6% decreased digestibility of dry matter, crude protein, and ash. Furthermore, a 6% DOL showed the lowest digestibility of dry matter, crude protein, and ash. Dressing percentage was the highest in 2%, and abdominal fat percentage showed the same trend in 6% DOL, but the gizzard percentage was the lowest in 6% DOL. The liver percentage increased significantly with fat/oil inclusion compared to the control. Meat dry matter and either extract increased considerably due to offering different DOLs, with maximum values at 6%. The inclusion of dietary oils in diets significantly increased serum malondialdehyde (MDA) but decreased serum total antioxidant capacity (TAC)/MDA ratio compared to the 0% DOL. In conclusion, under natural summer conditions, from 20 to 40 days of age, broilers' best productive characteristics were achieved using 0-2% DOL, and the best immune response was obtained for 4–6% DOL.Highlights Hot weather negatively influences the productivity of broilers. Fats/oils are essential for animal and human nutrition for several reasons; however, they are expensive compared to other energy sources. Improving the production index is essential to keep broilers farming profits under hot weather.