Effect of garlic and fresh onion supplementation on performance and immune system of broiler chickens

Master's thesis in animal science

Livestock and poultry nutrition trend

Abstract

This experiment was designed and implemented with the aim of investigating the effects of garlic or fresh onion supplementation on performance, immune system and blood lipid profile in broiler chickens. For this purpose, 308 out of 432 day-old male chicks were divided into nine groups with four replicates and 12 birds per replicate. The experiment was conducted in a completely randomized 3x3 factorial design. All birds received the same initial (from 0 to 21 days old) and final (from 22 to 42 days old) diets but with different levels of garlic (0, 0.5 and 1%) or onion (0, 1 and 2%). The results of the experiment showed that the use of fresh garlic and onion had no significant effect on the performance of chickens in the initial period (P<0.05). However, the use of fresh garlic and onion separately and together significantly improved the feed consumption and feed conversion ratio in the growth period and the entire rearing period (P<0.05).  In addition, the use of different levels of garlic and onion had no significant effect on the titer of Newcastle disease and the weight of immune system organs (bursa, spleen and thymus) (P<0.05). Also, the use of fresh garlic reduced blood cholesterol and garlic and onion supplementation together increased HDL in the blood of broiler chickens (P<0.05). In general, based on the results of the recent experiment, supplementation with the highest level of garlic (1%) and fresh onion (2%) had the best effect on feed consumption, conversion factor and HDL metabolite of broiler blood during the growth period and the entire period (P>0.05).

Introduction

With the increasing population, the need for food resources becomes more important day by day. Among the food sources needed by humans, we can mention white meat, which plays a special role in poultry farming. Also, according to international plans, the consumption of chicken meat will reach from 11 kg in 2000 to 16 kg per person in 2020 (Rossigrant et al., 1999). In the basics of modern nutrition, the most important factor to reach the maximum production capacity in monogastric animals is the management of the digestive system in terms of timed growth and also the adjustment of its microbial population. Antibiotics are among the additives that can be used to increase feed efficiency, performance and safety in poultry and other farm animals, and since entering the industry, they have been noticed significantly among breeders, especially poultry breeders (Grasma et al., 1986). As it is clear from the name of antibiotic, the improvement of performance by feeding these substances through the destruction of all the microorganisms of the digestive tract, both useful and harmful, and in this way all the nutrients of the feed are available to the host animal (Knarberg et al., 2002). Despite all the positive features of antibiotics, during the last few decades, due to various reasons, many concerns have arisen for feeding non-therapeutic antibiotics. One of the most important causes of these concerns is the development of resistance of pathogenic bacteria to these antibiotics and the creation of stable pathogenic species (Najafi and Turki, 2010; Grashorn, 2010). Among the other causes mentioned is the accumulation of pharmaceutical residues and creating a risk to human health (Weil et al., 2004). These factors have caused the prohibition of the use of non-therapeutic antibiotics in animals, including meat poultry, by the European Union and the United States on a large scale (Castanon, 2007). In 1999, the European Union banned the use of four common oral antibiotics (virginamycin, spiramycin, tylosin and Xenic Bactericin) during a preventive decision (Hogbert, 2003). If a suitable substitute for growth-promoting antibiotics is not considered, optimal poultry breeding will not be possible due to the problems caused by the resulting diseases and the necessity to use therapeutic antibiotics. In such a situation, efforts to find alternatives that can improve animal growth and do not have harmful side effects on consumer health continue (Hajaid et al., 2004). For this purpose, a natural alternative should be used to improve growth and strengthen the immune system (Holden et al., 1998; Griala, 2007).  Among these compounds, we can mention prebiotics, probiotics and some medicinal plants such as garlic and onion in poultry feed (Rahmtzad et al., 2009). The results of the research indicate that the use of medicinal plants and their derivatives, which are known as phytogenic nutritional supplements, has led to the improvement of broiler production efficiency in the form of improved feed consumption, weight gain, food conversion ratio, increased shelf life, improved health and digestive system performance, and are comparable to antibiotics (Griggs and Yaqoub, 2005), (Windish et al., 2007), (Grashorn, 2010). (Hashmi and Davodi, 2010). On the other hand, plant derivatives with different types of substances can be involved in increasing digestive and enzyme secretions and ultimately improving digestion efficiency (Alkasieh, 2009 and 2010), (Dahal and Faran, 2011) and (Aljaf, 2011). The natural and safe aspects of these materials, along with their availability and economic use, are the main motivations for using plant compounds in livestock and poultry feed (Gross et al., 2007), (Windich et al., 2007), (Ghazala and Ali, 2008) and (Grashorn, 2010). Among medicinal plants, garlic is one of the oldest known plants, whose antibacterial properties were reported by Pasteur in 1858. Also, the effects of garlic on blood parameters (Sabri Najafi, 1375), respiratory system (Gross et al., 1998; Qureshi, 1999), digestion and kidneys (Gross et al., 1998), anti-inflammatory effects (Sas, 1997), antioxidant (Glig, 1995) and cancer cell growth inhibitory effects (Doki, 1992) have been reported. Today, the effect of garlic on the immune system and its antibiotic and antifungal properties have been the focus of poultry industry breeders. Most of the antimicrobial properties of garlic are related to allicin, which is produced by the enzyme phosphopyrodoxal allinase. Ajoni is another compound that has antifungal effects such as Aspergillus niger and Candida albicans (Yoshida, 1987). Also, the amount of selenium in garlic, which is very important in the functioning of the immune system, is about 65-70% (Esko, 2008). Of course, the percentage of selenium in this plant depends on the content of this element in the soil. It has been reported that this plant has anti-tumor effects in mice and increases the delayed hypersensitivity response which is an indicator of cellular immunity, but it has no effect on the humoral immune system and SRBC antibody titers (Patia, 2004). Also, in another study conducted in the field of humoral immunity in broiler chickens, garlic powder did not show any effect on anti-Newcastle antibody (Jaafari et al., 2008), on the other hand, in another study, increasing the consumption of garlic in the diet of broiler chickens increased Newcastle and Gamboro titer levels (Haq et al., 1999).

Another plant that improves performance, the immune system And the most effective blood parameters in the poultry body is onions. Onion with the scientific name of Allium Sepa, belongs to the Sosnian family, which is in the same family as garlic (Shate, 1998). Onion has various compounds, including prostaglandins, pectin, adenosine, quercetin, B, C, E vitamins and essential amino acids (Martin et al., 2007). Among the most important and abundant compounds in onion are polyphenolic compounds that have antioxidant properties (Manch et al., 2004). Onion has been used as an antiseptic for the digestive system, stimulant, diuretic, appetizing, expectorant, to relieve headache, fever, river disorders, cholera, and its crude extract has been used to disinfect and heal wounds (Jakboski, 2003; Lanzodi, 2006). Onion plays an important role in reducing blood cholesterol, improving blood antioxidants, anti-cancer, anti-microbial, anti-hepatitis and neutralization of heavy and toxic metals (Lawson, 1994). Also, the flavonoids in onion such as quercetin and quercetrin have antioxidant and anticancer properties (Kerson, 1987; Reddy, 1993). ).