Guar Meal Diets as an Alternative Approach to Inducing Molt and Improving Salmonella Enteritidis Resistance in Late-Phase Laying Hens

Abstract

Induced molting of laying hens is a practice used by commercial egg producers to increase the productive lifetime of their flock. However, the conventional method of inducing molt, which involves removal of feed, water, or both as well as a reduction in photoperiod to less than a natural day has drawn criticism due to animal welfare and food safety concerns. The objective of this study was to explore the efficacy of diets containing high levels of guar meal (GM) in inducing molt and reducing susceptibility to Salmonella Enteritidis colonization in late-phase laying hens. Late-phase (68 wk old) Lohmann laying hens were either full-fed standard laying hen diets (nonmolted control), induced to molt by feed withdrawal, or full-fed standard laying hen diets containing 20% GM with or without 250 units/kg of mannanase Hemicell supplementation. On the fourth day of treatment, all hens were orally challenged with SE (1.65 x 10(7) cfu). Hens were killed and evaluated for Salmonella colonization and differences in organ weights 5 d postinoculation. Salmonella Enteritidis present in crop, liver, ovary, and cecal contents were significantly reduced by feeding GM with enzyme supplementation compared with feed withdrawal hens. No significant differences were observed in reproductive tract weights of molted groups, although a difference in liver weight was detected. Results indicate that feeding diets containing 20% GM are as effective as complete feed withdrawal with respect to inducing molt with the added benefit of improved resistance to Salmonella Enteritidis colonization and translocation.

Effects of Dietary Inclusion of Guar Meal Supplemented by β-Mannanase on Performance of Laying Hens, Egg Quality Characteristics and Diacritical Counts of White Blood Cells

“…It has been reported that laying hens induced to molt by GM feeding exhibit improved resistance to Salmonella Enteritidis colonization when compared with hens molted by complete feed withdrawal. Furthermore, supplementation of β-mannanase (Hemicell) to diets containing high levels of GM appears to enhance resistance to Salmonella Enteritidis colonization in molted laying hens (Gutierrez et al, 2008).…”

Practical Application of Guar (Cyamopsistetragonoloba L. Taub) Meal in Poultry Nutrition

“…Supplementation of β-Mannanase in poultry diets containing guar meal has revealed beneficial impacts like lowered viscosity of intestinal digesta, better growth performance, improved FCR (Lee et al, 2003b; Ehsan, and Torki, 2010) optimum gut health and immune status (Mehri et al, 2010). Moreover, it enables the bird to fight Salmonella enteritis (Gutierrez et al, 2008). β-mannanase hydrolyzes β-1, 4-glycosidic bonds in β-mannans (Ooi and Kikuchi, 1995).…”

Fungal β-mannanases: Mannan hydrolysis, heterologous production and biotechnological applications

“…Fernandez [112] demonstrated that feeding of chickens with yeast-derived MOS or palm kernel meal decreased S. enteritidis numbers, while increasing the numbers of probiotic lactic acid bacteria. By feeding laying hens guar meal supplemented with ␤-mannanase, Gutierrez et al [111] could demonstrate the combined positive effects of natural molting (the non-starch polysaccharides in guar meal cannot be used as energy source) with improved resistance to S. enteritidis.…”

“…To stimulate multiple egg laying cycles and improve egg quality, laying hens are often starved for food or water (called molting), which are detrimental to their health and making them often more susceptible to Salmonella enteritidis infections [111]. Fernandez [112] demonstrated that feeding of chickens with yeast-derived MOS or palm kernel meal decreased S. enteritidis numbers, while increasing the numbers of probiotic lactic acid bacteria.…”