PERFORMANCE CHARACTERISTICS OF BROILER CHICKENS FED GRADED LEVELS OF ONION (Allium cepa) AND ONION WITH BACTOFORT

Thesis Overview

<p> </p><p>Cost-effective poultry meat production is reliant on many vital factors. Securing optimum digestibility and assimilation of nutrients for improvement of broiler performance is certainly one of the most important elements. In this respect, the gastrointestinal tract needs special attention, because any impairment of the secretion of enzymes or disturbance of the microbiological equilibrium in the gut can negatively affect the digestibility of the feed, resulting in reduced growth rate or impaired feed conversion of growing birds. Various feed additive concepts, called eubiotics have been proposed to improve the nutrient utilization and to maintain gut health, which ultimately should result in improved performance (Wenk, 2002). Eubiotics as described by Broz and Paulus (2015) are groups of some feed additives (such as probiotics, prebiotics, essential oils e.t.c) which are used for the purpose of maintaining intestinal eubiosis (optimal balance of microflora in the gastrointestinal tract), thereby resulting in an improved health status and performance of farm animals.</p><p>Prebiotics are non-digestible feed components that beneficially affect the host by selectively altering the composition and metabolism of the gut microbiota (Huyghebaert <em>et al.</em>, 2011). Prebiotics may provide energy for the growth of favourable endogenous bacteria in the gut, such as bifidobacteria and lactobacilli, thus improving the host microbial balance (Das <em>et al.,</em>&nbsp;2012). Prebiotics are found naturally in a variety of foods and can also be synthesized enzymatically. Commonly used prebiotics are oligosaccharides i.e., fructo-oligosaccharides (FOS), mannan oligosaccharides (MOS), lactulose, inulin (Brijesh <em>et al.,</em>&nbsp;2013). Inulin is present in significant quantities in <a target="_blank" rel="nofollow" href="https://www.modishproject.com/chemical-composition-of-some-lesser-known-wild-fruits-and-vegetables-consumed-in-ayamelum-local-government-area-of-anambra-state/">vegetables</a>&nbsp;such as onions, artichokes, asparagus, leeks, and garlic. A substantial amount of FOS is also found in suc vegetables and some cereals such as barley, and wheat (Espinosa-Martos <em>et al.,</em>&nbsp;2006; Judprasong <em>et al.,</em>&nbsp;2011).</p><p>The genus Allium includes about 550 species. A few of these are important as food plants and as drugs in human medicine, notably onion (<em>Allium cepa L.</em>) and garlic (<em>Allium sativum</em>&nbsp;<em>L</em>.). Onion is a bulbous plant widely cultivated in almost every country of the world withChina, India and United States leading in production (Ebesunun <em>et al.,</em>&nbsp;2007). Most of the plant parts contain compounds with proven antibacterial, antiviral, anti-parasitic, antifungal properties and have antihypertensive, hypoglycemic, antithrombotic, anti-hyperlipidemic, anti-inflammatory and anti-oxidant activity (Lampe, 1999). Administration of onion extract in rabbits significantly reduced serum, liver and aorta triglycerides and serum and liver proteins as reported by Sebastian <em>et al.</em>&nbsp;(1979). Aji <em>et al.</em>&nbsp;(2011) observed the beneficial influence of onion bulbs on growth performance of broiler chickens.</p><p>Probiotics are single or mixed culture of living microorganisms which when administered in adequate numbers exert health benefits for the host by improving the host intestinal microbial balance, enhancing of colonization resistance against pathogens and improving the immune responses (Brisbin <em>et al.</em>, 2010; Cencic and Chingwaru, 2010; Das <em>et al.</em>, 2012). The species of microorganisms currently being used in probiotic preparations are varied, and lactose fermenting bacteria (LAB) i.e., <em>Lactobacillus bulgaricus, Lactobacillus acidophilus,</em>&nbsp;<em>Lactobacillus casei, Lactobacillus helveticus, Lactobacillus lactis, Lactobacillus salivarius, Lactobacillus plantarum, Streptococcus thermophilus, Enterococcus faecium, Enterococcus faecalis, Bifidobacterium spp</em>., are the most common types of bacteria used as probiotics(Khaksefidi and Rahimi, 2005; Kabir, 2009). Recently, the emphasis has been on selection and preparation of mixed strains of microorganisms as probiotics (Chateau <em>et al.</em>, 1994).</p><p>Khaksefidi and Rahimi (2005) reported lower numbers of <em>Coliform</em>&nbsp;and <em>Campylobacter</em>&nbsp;in the gut of broiler chickens fed probiotics (mixed strains). Competition with pathogenic <em>E.</em>&nbsp;<em>coli </em>has also been documented (Watkins<em>&nbsp;et al.</em>, 1982), and an increase in production ofantibodies at the systemic and local (intestinal) level (Haghighi <em>et al.,</em>&nbsp;2006). The combination of prebiotics and probiotics (symbiotic) has not been well studied, but their beneficial effects might be additive or even synergistic (El-banna <em>et al</em>., 2010).</p><p><strong>1.1 Justification</strong></p><p>Antibiotic feed additives have been used in the poultry industry for many years to improve the productivity in terms of weight gain and feed conversion ratio by helping to control infections in the gut mucosa. However, the use of dietary antibiotics has resulted in common problems such as the development of drug-resistant bacteria (Van Boeckel <em>et al.,</em>&nbsp;2015), drug residues in the body of the birds and imbalance of normal micro flora (Andremont, 2000; Kabir, 2009). As a consequence, it has become necessary to develop alternatives using either beneficial microorganisms or non-digestible ingredients that enhance the growth of beneficial micro organisms. Intensive studies have been conducted to find alternatives and to solve this problem, some components such as probiotics, prebiotics, organic acids and phytogenic feed additives are introduced instead of antibiotics (Patterson and Burkholder, 2003; Ricke, 2003). The beneficial influence of onion bulbs on growth performance of broiler chickens as a substitute for antibiotics has also been reported (Aji <em>et al</em>., 2011). Factors such as tolerance to bile and low gastrointestinal pH are needed to be considered in using any probiotic material. Resistance to bile and acidic gastrointestinal conditions are the important characteristic that enables Lactose-fermenting bacteria to survive and grow in the intestinal tract (Jin <em>et al.,</em>&nbsp;1998). It has been suggested that probiotics and prebiotics are much more efficient when used in combinations than singly (Alloui <em>et al</em>., 2013)</p><p><strong>1.2 Aim and Objectives of the </strong><strong>Experiments</strong></p><p>The aim of this study was to evaluate the effect of dietary addition of Onion (<em>Allium cepa</em>) and Onion with Bactofort® on performance of broiler chickens. The specific objectives were to determine:</p><br> <br><p></p>