Effect of in ovo and post-hatch administration of honey on the immunity and intestinal microflora of growing chickens

Abstract

Infectious diseases, particularly enteric diseases, constitute a major problem for commercial poultry farmers mainly because of the associated production losses, increased mortality rates and subsequent contamination of poultry products intended for human consumption. Therefore, the manipulation of gut microbiota and immunity of poultry chickens using feed additives has been known as an important strategy for improving the growth performance and reducing losses caused by diseases (Kamboh et al., 2016). In addition, a growing concern related to anti-microbial resistance of pathogens isolated from humans and food animals, together with the ban of the use of antibiotics as feed additives, have enhanced the focus of research on natural alternatives for the production of food animals (Raheema et al., 2016). In ovo feeding refers to an administration of exogenous nutrients into avian fertile eggs in the form of a solution. Some natural substances can also be used for exogenous administration into fertile eggs. ABSTRACT. The present study evaluated the effect of honey administration in preand post-hatch sessions on the immunity and intestinal microflora of growing broilers. The pre-hatch experiment was conducted on fertile eggs (n = 160) that were inoculated either with 0.5 ml 20% diluted honey (+pre-hatch) or with the same quantity of normal saline (−pre-hatch) on day 15 of incubation. After hatching, the chicks from each group were divided into two groups: control (−post-hatch) and the other receiving 1% honey (+post-hatch) in drinking water up to day 21. The experimental groups: C = −pre-hatch/− post-hatch, T1 = −pre-hatch/+post-hatch, T2 = +pre-hatch/−post-hatch and T3 = +pre-hatch/+post-hatch, were evaluated for performance parameters, antibody titer against Newcastle disease virus (NDV), relative weight of lymphoid organs and counts of gut microflora. It was shown that the pre-hatch honey administration significantly (P < 0.05) improved feed intake, final body weight, relative weight of spleen and anti-NDV antibody titer. Post-hatch honey supplementation significantly (P < 0.05) increased feed intake, FCR, final body weight, anti-NDV titer, relative weight of spleen and Lactobacilli count, while decreased (P < 0.05) the counts of Escherichia coli and Salmonella on day 21. The interaction of both the preand post-hatch honey administrations also significantly affected (P < 0.05) performance and immunity parameters, as well as the intestinal microflora. So, in ovo and post-hatch administration of honey had positive impacts on performance, immune organ indices, gut microbiota and anti-NDV titer in growing broiler chickens. Received: 27 March 2019 Revised: 18 August 2019 Accepted: 29 November 2019