Effect of Different Levels of Chlorella Vulgaris Microalgae Extract on Performance in Heat-Stressed Broilers

Abstract

The aim of this study was to compare the levels of chlorella vulgaris microalgae extract with additives on performance, carcass characteristics and blood biochemical metabolites in heatstressed broilers. This experiment has been done using 280 one day-old Ross 308 broiler chicks for 6 weeks. This experiment has been done in completely randomized design with 7 treatments and 4 replicates. Experimental treatments were including: 1-control; 2-diet containing 0.2 g/Kg chlorella extract; 3-diet containing 0.4 g/Kg chlorella extract; 4-diet containing 100 mg/Kg vitamin E; 5-diet containing prebiotic; 6-diet containing probiotic; 7-diet containing antibiotic. Heat stress program applied from 25-42 d.Treatment 2 caused an increase of feed intake and weight gain in comparison to other treatments (P<0.05). Treatment 3 showed the lowest conversion ratio in comparison to other treatments (P<0.05). Concentration of glucose, protein, albumin and HDL were increased with consumption of treatment2 in comparison with other treatments. The most and the least concentration of cholesterol, triglyceride and VLDL was observed in control and treatment 2, respectively. Weight of empty carcass and proventriculus had the most increase in treatments 2 and 3 (P<0.05). Generally, chlorella in concentration of 0.2 g/kg can be a suitable substitution for other additives specially antibiotics in order to improve the performance of boilers.

Dietary supplementation with Chlorella vulgaris in broiler chickens submitted to heat-stress: effects on growth performance and meat quality

“…In the present study, dietary microalgae inclusion did not alleviate the negative impact of heat stress on broiler performances. Contrarily, beneficial effects of dietary microalgae or carotenoids from microalgae supplementation on performance and health of poultry exposed to heat stress ( Ziar-Larimi et al, 2018 ; Tolba et al, 2020 ) where results in the different studies can also depend on differences in management of animals, besides type and level of microalgae. In fact, Tolba et al (2020) reported that a dietary supplementation with microalgae ( Hematococcus pluvialis ) astaxanthin (10–80 mg/kg) to broilers exposed to heat stress linearly decreased hepatic mRNA levels of several redox status-controlling genes, heat shock protein 70 ( HSP70 ), heat shock transcription factor 1 ( HSTF1 ), c-Jun N-terminal kinase 1 ( JNK1 ), tumor necrosis factor-α, and sterol regulatory element-binding protein 1 ( SREBP1 ), and increased diacylglycerol acyltransferase 2 ( DGAT2 ) mRNA levels, modulating molecular profiles of stress, inflammation, and lipid metabolism.…”

“…In fact, Tolba et al (2020) reported that a dietary supplementation with microalgae ( Hematococcus pluvialis ) astaxanthin (10–80 mg/kg) to broilers exposed to heat stress linearly decreased hepatic mRNA levels of several redox status-controlling genes, heat shock protein 70 ( HSP70 ), heat shock transcription factor 1 ( HSTF1 ), c-Jun N-terminal kinase 1 ( JNK1 ), tumor necrosis factor-α, and sterol regulatory element-binding protein 1 ( SREBP1 ), and increased diacylglycerol acyltransferase 2 ( DGAT2 ) mRNA levels, modulating molecular profiles of stress, inflammation, and lipid metabolism. Moreover, the dietary supplementation with very low levels of C. vulgaris (0.2 g/kg) has been reported to improve growth performance in heat-stress broilers ( Ziar-Larimi et al, 2018 ). The supplementation in drinking water (300–500 mg/kg) with the same microalgae had beneficial impacts on serum contents of triglycerides, cholesterol, LDL, and HDL in laying hens exposed to chronic heat stress ( Moradi kor et al, 2016 ), which were ascribed to a radical scavenging and hypolipidemic action of the β-1, 3-glucan found in the cell wall of this microalgae and/or the presence of antioxidant substances.…”