Poultry industry is one of the fastest growing sector in India. Poultry occupies a unique position in the livestock economy of India characterized by coexistence of intense (technology, capital, scale) with integrated production, marketing and the others based on the traditional knowledge and practices. The annual growth rate is more than 11% in broiler production and more than 5% in egg production.
The overall growth rate of poultry industry is around 7-8% per annum, highest among all sectors of agriculture. Poultry industry contributes 8% of the value of the livestock sector and poultry and poultry products account for 20% of livestock output and 0.57% from all sectors. In poultry industry, poultry meat accounts for two third of the value of output and one third by eggs. Poultry industry generates direct employment for more than 3.5 million people and indirect employment for another 3.5 million people in different facets of allied activities.
India is the third highest egg producer and fifth largest poultry meat producer. The annual poultry production in India stands at 88,000 million eggs (Animal Husbandry Statistics 2016 – 17) and 3.48 million metric tonnes of poultry meat providing per capita availability of 69 eggs and 2.75 kg poultry meat (2016-17). The total poultry market size is estimated at around Rs. 83,000 crore at the wholesale price level in 2016-17 with the growth rate of more than 8%.
This makes poultry sector is the fastest growing sector among all livestock sectors. The broilers in India are typically reared for 35-40 days to a market weight of 1.8 to 2.2 kg. The feed conversion ratio for broilers has reportedly improved considerably over the years to 1.65 from 2.2 in the 1990s. Poultry nutrition plays an important role in improving body weight, feed conversion ratio (FCR) and immune status.
Feed forms the major component of total expenditure (about 70-80 %) of poultry business. Feed additives are group of compounds improving the efficiency of feed utilization and reducing high expenditure on feed amongst all regularly used growth promoters, antibiotics were most common feed additives. However, now a days use of antibiotics have been baned in many countries due to reason like alteration of natural gut mibrobiodata and emerging drug resistance in bacteria and humans (Bostoglou et al. 2002).
Consequently, the use of non-antibiotic growth promoters such as probiotic, prebiotic, synbiotic, enzymes, toxin binder, organic acids, oligosaccharides, phytogenetics and other feed additives to improve the growth and health performance of broilers have been advocated (Borazjanizadeh et al. 2011).
Apart from in-feed and in-water supplementation, in ovo feeding of probiotics have gained more attention recently. In ovo feeding of nutrients would be a more effective option, and this is the approach that has been developed by Uni and Ferket (2003).The first administration of in ovo delivery of exogenous material was reported in the 1980s for vaccination against Marek’s disease (Sharma and Burmester, 1982).
At early stages of development, day 0 or on or before day 7 of incubation, the preferable site of injection is the air cell or albumin part of the egg, which may be termed ‘in ovo administration’. Pre-hatch birds naturally consume the amniotic fluids on 19th day of incubation. Therefore addition of a nutrient solution to the embryonic amniotic fluid would deliver essential nutrients into the embryo’s intestine. These early developments have led to increased research on in ovo techniques in poultry to improve starting weights, better feed utilization, faster growth rate and higher final weight.
According to WHO and FAO (2001), probiotics are “live microorganisms which when administered in adequate amounts confer a health benefit on the host”. Probiotics acts in several effective ways on the host viz., by adhering to the different binding sites of intestinal epithelium thus compete with pathogenic harmful bacteria, by producing the bactericidal substance, by stimulation of immune system, by facilitating digestion and absorption of nutrients, by suppression of ammonia production caused by pathogenic microbes, which might be toxic to intestinal cell and also responsible for neutralization of enterotoxins (Menten, 2002). Commonly used probiotic bacteria in livestock feeding are lactic acid-producing strains like Enterococcus, Pediococcus, Lactobacillus and Bifidobacterium, which are also genera commonly found in the poultry gut.
Prebiotics are non-digestible food ingredients that beneficially affect the host by selectively stimulating the growth and activity of one or a limited number of bacteria in the colon (Gibson and Roberfroid, 1995). The most common used prebiotics are oligosaccharides, (MOS, FOS, GOS, XOS). They act either by supplying nutrients to beneficial microbes, or by tricking pathogenic bacteria into attaching to the oligosaccharide rather than to the intestinal mucosa. This reduces the intestinal colonization thereby decreasing the incidence of infection in the birds. Because the oligosaccharide is non-digestible, the microbes that are attached with them are excreted from the bird along with other undigested food.
Synbiotic is a combination of probiotics and prebiotics (Ashraf et al., 2013) and act in form of synergism. Main reason for using a synbiotic is that a true probiotic, without prebiotic food, does not survive well in the digestive system. Due to in the gut less tolerance to oxygen, low pH, and temperature. As prebiotics provide a platform for probiotic to thrive, the population of these good bacteria is known to preserve.
The combination of a prebiotic and probiotic in one product has been shown to confer benefits beyond those of either on its own. The way of potentiating the efficacy of probiotic preparations may be the combination of both prebiotics and probiotics as synbiotics that beneficially affects the host by improving the survival and implantation of live microbial dietary supplements in the gastrointestinal tract.
However, there have been no studies regarding the regulatory effects of probiotic, prebiotic and their combination through in ovo feeding method. All above mentioned products are used to improve performance of broilers by manipulation of microflora present in gut and all of them serve functions of improving health and immunity.
Hence a biological experiment has planned at Department of Poultry Science, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University, Chennai to study the effect of in ovo injection of probiotic, prebiotic and synbiotic on the production performance and gut health of commercial broiler chicken with following objectives.