Arthrospira (Spirulina) Platensis Can Be Considered as a Probiotic Alternative to Reduce Heat Stress in Laying Japanese Quails

Brazilian Journal of Poultry Science Revista Brasileira de Ciência Avícola ISSN 1516-635X 2020 / v.22 / n.1 / 001-008 http://dx.doi.org/10.1590/1806-9061-2018-0977 Arthrospira (Spirulina) Platensis Can Be Considered as a Probiotic Alternative to Reduce Heat Stress in Laying Japanese Quails Original Article ABSTRACT Author(s) Hajati HI https://orcid.org/0000-0002-9080-7742 Zaghari MI https://orcid.org/0000-0003-4440-3584 Oliveira HCII https://orcid.org/0000-0001-7317-2004 I II Department of Animal Science, College of Agriculture and Natural Resource, University of Tehran 31587-11167, Karaj, Iran. Department of Animal Science, Universidade Federal de Viçosa, Viçosa, MG, 36570000, Brazil. Mail Address Corresponding author e-mail address Hosna Hajati Department of Animal Science, College of Agriculture and Natural Resource, University of Tehran 31587-11167, Karaj, Iran. Phone: +989111566684 Email: Keywords Egg production; Heat stress; HSP70 gene; Japanese quails; Spirulina platensis. Submitted: 25/June/2019 Approved: 04/January/2020 This study was conducted to investigate the effects of Arthrospira platensis (Spirulina platensis, SP) on feed intake, feed conversion ratio, egg weight, hen day egg production, intestinal microflora, heat stress biomarkers, and HSP70 gene expression in laying Japanese quails (Coturnix coturnix japonica) suffering heat stress condition. A total of 250 female quails were allocated to 5 treatments, 5 replicates and 10 birds in each replicate in a completely randomized design. Experimental treatments included: 1) basal diet, 2) basal diet+ 0.03 % probiotic, 3) basal diet+ 0.1 % SP, 4) basal diet+ 0.3 % SP, 5) basal diet+ 0.5 % SP. During the last 6 days of the experiment, the quails were exposed to 8h of 34±1°C. The birds had free access to feed and water during the experiment. The results showed that using probiotic and different levels of Spirulina had no significant effect on laying performance of Japanese quails (p>0.05). Probiotic supplement increased Lactobacil bacteria population in laying quails’ ileum under heat stress (p<0.05). Different levels of SP decreased Escherichia coli population in laying quails’ ileum suffering heat stress (p<0.05).SP at the level of 0.5% caused the lowest blood Malondialdehyde level, heterophil, and H/L ratio (p<0.05).However, HSP70 gene expression in the heart or the liver of laying quails was not different (p>0.05). In conclusion, the results of the present study revealed that SP at the level of 0.5 % has the potential to be considered as a probiotic alternative in the diet of laying quails suffering heat stress condition. INTRODUCTION Heat stress threats poultry productivity and economic benefits especially on summer days in many countries of the world (Attia et al., 2011; Hajati et al., 2015). Thermo-neutral temperature for adult quails is between 23-26°C (Sousa et al., 2013), thus higher environmental temperatures may lead to heat stress in the birds. In fact, stress alter normal behavior, biochemical and physiological processes in birds that disrupts the body homeostasis (Sahin et al., 2009).Oxidative stress induced by heat stress has detrimental effect on egg production by activation of the hypothalamic-pituitary-adrenal (HPA) axis, change the bird’s neuroendocrine profile, and reduction of feed intake (Lara & Rostagno, 2013). Heat stress may lead to intestinal flora disorders in laying birds (Li et al., 2015). It was documented that the expression of heat stress-related genes, like HSP70, increases in heat stress condition (Zhang et al., 2014). In regard to some negative side effects of synthetic antioxidants in the body, poultry nutritionist are searching for organic compounds that can improve the health and welfare of the birds under heat stress condition. In addition, considering the effect of egg quality on human health, organic feeding of laying birds has high concern to ensure the quality of the eggs and support the health state of 1 eRBCA-2018-0977 Hajati H, Zaghari M, Oliveira HC Arthrospira (Spirulina) Platensis Can Be Considered as a Probiotic Alternative to Reduce Heat Stress in Laying Japanese Quails consumers. It was reported that using additives such as probiotics may improve performance, and intestinal microbial ecology of birds suffering heat stress (Sugiharto et al., 2017). Also, it was found that algae contain bioactive compounds, or phytochemicals that may help to consumer’s health (Hafting et al., 2012). S. platensis is a microalgae rich in protein, vitamins, minerals, phytopigments (Farag, 2016), gamma linoleic acid, phycocyanins, phenolic acids, betacarotene and chlorophyll (Mariey et al., 2012). These substances have antioxidant (Fazilati et al., 2016), antimicrobial, anti-cancer, and anti-inflammatory activity (Kulshreshtha et al., 2008). Mariey et al. (2012) reported dietary inclusion of S. platensis at the levels of 0.1-0.2% improved egg production in laying hens. Recently, Park et al. (2018) documented that dietary S. platensis improved cecal Lactobacillus population and antioxidant enzyme activity in broiler chickens. However, there is no information about the potential effects of SP in heat-challenged laying quails. Therefore, the aim of the present study was evaluating the effects of Arthrospira platensis on feed intake, feed conversion ratio, egg weight, hen day egg production, intestinal microflora, heat stress biomarkers, and HSP70 gene expression in laying Japanese quails (Coturnix coturnix japonica) suffering heat stress condition. were analyzed for crude protein (CP), ether extract (EE), starch and total sugar. Then, metabolisable energy (MEn) of the main ingredients was calculated based on analyzed values of the feedstuffs (NRC, 1994). The MEn of corn was calculated by the following formula: MEn= 36.21 × crude protein + 85.4 × ether extract + 37.26 × nitrogen free extract. The MEn of soybean meal was calculated by the following formula: MEn=37.5× crude protein + 46.39 × ether extract+ 14.9 × nitrogen free extract. The probiotic used in this experiment containing Bacillus subtilis (21336) 4×109CFU/g of the supplement (Biorun company, Iran). The ash, CP, EE, calcium, phosphorus, and total phenol content of S. platensis was 12.51± 0.6, 64.86 ±0.31, 4.73±0.11, 1.02±0.08, 1.41±0.09, 10.19 ± 0.04 mg GAE / g S. platensis, respectively. Experimental treatments included: 1) basal diet, 2) basal diet+ 0.03 % probiotic, 3) basal diet+ 0.1 % S. platensis, 4) basal diet+ 0.3 % S. platensis, 5) basal diet+ 0.5 % S. platensis. Basal diet (Table 1) were formulated using WUFFDA software according to nutritional requirements of laying Japanese quails described in NRC (1994). Table 1 – The ingredients and nutrient compositionof basal diet. Ingredients (g kg-1) Yellow Corn Soybean meal (44%) Vegetable oil Oyster shell Mono calcium phosphate Common salt (NaCl) DL-Methionine Vitamin and mineral premix 1 Calculated contents ME (MJ kg-1) Crude protein (g kg-1) C (...truncated)