IntroductionDuring the last decades, phytobiotics, probiotics and prebiotics became increasingly used in modem livestock husbandry by reason of emerging problems with nutritional antibiotics utilisation and general antimicrobial resistance (Neu, 1992). The application of probiotics in poultry farming is associated with increased resistance to bacterial and protozoal diseases, improved feed conversion and better growth performance (Gupta, 2013). Lactic acid bacteria (LAB): lactobacilli and bifidobacteria, are among the most frequently used probiotics. The role of Lactobacillus spp. as dietary probiotic in poultry nutrition comprises promotion of growth of useful microflora, higher activity of digestive enzymes, improved feed intake and digestibility, growth-promoting effect (Jin et al., 1998). Some negative issues are the most expensive feed containing probiotics, difficulty to guarantee a minimum probiotic content after prolonged storage, sensitivity to most probiotic bacteria to high temperatures, inconsistent effects on production performance and intestinal health in adult birds and last but not least, possible transfer of antimicrobial resistance to microbial pathogens.Prebiotics are indigestible nutrients that stimulate the growth and activity of beneficial intestinal microflora and thus, have a positive effect on the whole body. The supplementation of prebiotics to poultry rations improves intestinal health of birds, their productive performance, improves nutrient utilization, reduces cost of produce and contributes to maintenance of a proper environment (Hajati and Rezaei, 2010). The most commonly used prebiotics are from the group of oligosaccharides: fructooligosaccharides (FOS), inulin, oligofructan, isomalto-oligosaccharides, etc. Plants rich in FOS and inulin are garlic, chicory, onion, artichoke, asparagus, bananas, wheat, tomatoes, etc. (Niness, 1999).Garlic (Allium sativum) is used widely at a global scale as a spice, as well as for control of some infectious and non-infectious diseases in phyto-and traditional medicine, including reduction of blood and liver cholesterol contents. Garlic powder contains FOS with prebiotic effect (Campbell et al., 1997). Furthermore, it contains a varying amount of allicin, vitamins (vitamin С, thiamine, riboflavin and niacin), selenium and potassium (Anonymous, 2014a). The dietary supplementation of garlic powder in chickens was found to be beneficial for growth performance (Raeesi et al., 2010;Issa and Omar, 2012;Elagib et al., 2013).The combination of probiotics with substances with prebiotic activity improves the effect of the former due to creation of more favorable environment for replication of probiotic bacteria in poultry gut. This study was aimed at evaluating the growth performance of male classic broiler chickens whose feed was supplemented with either garlic powder, probiotics or both.
Material and methodsA total of 120 male day-old Ross 308 broiler chickens were divided into 4 groups. Each comprised three subgroups with 10 sexed male chicks provided...