Dietary vegetable oils inclusion on the performance, hormonal levels and hsp 70 gene expression in broilers under heat stress

Abstract

The aim of the present study was to compare the effects of unsaturated and saturated oils on the performance, hormonal levels and hsp gene expression in broiler chickens exposed to heat stress. 300 one-day male broiler chicks were assigned to 4 treatments (Diets containing palm, corn, linseed or olive oils) with 5 replicates. At day 28 of age, 2 chickens were removed from each replicate, then blood samples and liver tissue samples were collected for analyses. Feeding linseed and olive oil reduced feed conversion ratio compared to corn and palm oils. The lowest level of insulin was for chickens fed linseed oil and corn oil. The highest level of corticosterone was found in chickens fed palm oil and the lowest level was for those received linseed oil. Chickens received linseed and corn oils had the highest levels of T3 and T4 and those fed palm and olive oils had the lowest levels. The highest HSP 70 gene expression was for chickens fed diet containing olive and linseed oils and the lowest one was for those fed corn and palm oils. It was concluded that olive oil and linseed oil could improve performance and heat tolerance of chickens under heat stress.

Thermal Comfort, Growth Performance and Welfare of Olive Pulp Fed Broilers during Hot Season

“…According to Mujahid et al [45], the addition of 6.7% olive oil to the diet of broiler chickens reared under thermo-neutral or heat-stress conditions reduced mitochondrial ROS production and decreased oxidative damage in the birds. Recent feedings trials performed in broilers reared at high ambient temperatures revealed the antioxidant effect of olive oil and the improvement of the birds' immune system [46], the improvement of hormonal indicators and chickens' performances as well as the increased activity of heat tolerance genes in chickens [47].…”

“…On the other hand, the review of the literature shows that there are currently no data available on the dietary impact of OP on the thermal comfort of broilers. In contrast, there are a few studies on the nutritional effects of various by-products such as olive oil [45][46][47] and olive leaves [48,49] on heat stress in chickens. Recent nutritional studies in broilers reared at high ambient temperatures have demonstrated the antioxidant effect of olive oil [45,46], improved birds' immune system [46], improved hormonal indicators and chick performance and the increased activity of genes responsible for the birds' thermal resistance [47].…”

“…In contrast, there are a few studies on the nutritional effects of various by-products such as olive oil [45][46][47] and olive leaves [48,49] on heat stress in chickens. Recent nutritional studies in broilers reared at high ambient temperatures have demonstrated the antioxidant effect of olive oil [45,46], improved birds' immune system [46], improved hormonal indicators and chick performance and the increased activity of genes responsible for the birds' thermal resistance [47]. Similarly, the addition of olive leaf extract to broiler water or feed has been shown to alleviate the negative impact of heat stress and improve performance and antioxidant status in heat-tressed chickens [48,49].…”

Dietary supplementation with olive oil co-products rich in polyphenols: a novel nutraceutical approach in monogastric animal nutrition

“…A few genes involved in lipid metabolism [acetyl CoA carboxylase (ACC) and fatty acid synthase (FAS)] had an upregulated expression in the serum of laying hens fed with a diet supplemented with olive cake (118). Furthermore, olive oil increased the expression of many genes encoding for heat shock proteins in broiler chickens, improving their tolerance to heat stress (119).…”