This study investigated the ameliorative effect of dietary tomato powder (TP) on performance and blood characteristics of broilers under heat stress condition. A total of 240 (21 days old), unsexed Marshall broiler chicks were allotted to four dietary treatments having 6 replicates of 10 birds each in a completely randomized design (CRD). The birds were exposed to ambient temperature of 33 °C between 8:00am and 5:00 pm and relative humidity of 81.5% for 2 h per day, throughout the 21-day feeding trial. Data was analyzed using one-way analysis of variance and polynomial contrast (linear (L) and quadratic (Q)) applied using IBM SPSS version 20. The experimental diets 1 (control), 2, 3, and 4 contained 0%, 2.5%, 5%, and 7.5% TP, respectively. Results showed that live weight, weight gain, feed intake, and feed conversion ratio increased (L.Q: P < 0.05) while mortality rate reduced (P < 0.05) following increasing dietary inclusion of TP. Birds fed diets containing 0, 2.5, and 5.0% TP had similar feed cost per weight gain which was lower (L: P < 0.001: Q: P < 0.05) than those of birds fed diet containing 7.5% TP. Most hematological parameters and serum enzymes measured were not affected (P > 0.05) by inclusion of TP. Birds fed diets containing 5.0 and 7.5% TP had similar serum cholesterol (L.Q: P < 0.05) and triglyceride (L:P < 0.001:.Q:P < 0.05) concentration which is lower than those of control. It was concluded that tomato powder (especially at 5% inclusion) in the diet of heat-stressed broiler chickens is beneficial for improved growth, health, and production cost with no adverse effect.
Keywords: Growth markers; Heat stress; Hematological parameters; Serum metabolites; Tomato powder.
© 2022. The Author(s), under exclusive licence to Springer Nature B.V.