Research note: fructose feeding increases lower gut weights in germ-free and conventional chicks

Effects of adding different levels of fructooligosaccharide to diet on productive performance, egg quality traits, immune response and blood metabolites in commercial laying hens

BACKGROUND

A prebiotic is defined as an indigestible feed substance that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the large intestine, thereby improving host health and products.

OBJECTIVES

This study was conducted to determine the effects of supplementing prebiotic fructooligosaccharide (FOS) to the diets of Hy-Line W-36 laying hens.

METHODS

A total of 168 Hy-Line W-36 laying hens were allocated to four dietary levels of FOS (0, 1.0, 2.0, 3.0 g/kg diet), 6 replicates of 7 birds each during 63-74. The experiment was performed using a completely randomized design.

RESULTS

Productive performance was not significantly affected by the FOS supplementation. Body weight gain was linearly decreased with increasing FOS levels in the diet (p < 0.01). However, eggshell strength, shell thickness and Ca and p percentages were not significantly affected, as were anti-sheep red blood cell titres, blood parameters and blood metabolites. In the first period of the experiment (63-65 weeks), shape index and Haugh unit at the dose of 3.0 g/kg FOS were significantly increased and decreased in comparison with control, respectively (p < 0.05). In the third and fourth periods (69-71 and 72-74 weeks of age), the FOS had no significant effect on the internal egg quality traits. Furthermore, FOS had a linear decrease in the most saturated fatty acids (SFAs), including myristic, palmitic, margaric and stearic fatty acids; some of the mono-un-SFA (MUFA; palmitoleic and ginkgolic acids), and poly-unsaturated fatty acids (γ-linolenic and eicosatrienoic).

CONCLUSIONS

Supplementing different levels of FOS to the diet of commercial laying hens had no significant effect on the layers' performance, immune response and blood parameters, whereas there was a significant effect on some of the internal egg quality traits and egg yolk fatty acid contents.

Symbiotic Synergy from Sponges to Humans: Microflora-Host Harmony Is Crucial for Ensuring Survival and Shielding against Invading Pathogens

Gut microbiota plays several roles in the host organism's metabolism and physiology. This phenomenon holds across different species from different kingdoms and classes. Different species across various classes engage in continuous crosstalk via various mechanisms with their gut microbiota, ensuring homeostasis of the host. In this Review, the diversity of the microflora, the development of the microflora in the host, its regulations by the host, and its functional implications on the host, especially in the context of dysbiosis, are discussed across different organisms from sponges to humans. Overall, our review aims to address the indispensable nature of the microbiome in the host's survival, fitness, and protection against invading pathogens.

Comparative biology of germ-free and conventional poultry

Interaction between the host and the enteric microbiome is highly complex. Microbial involvement in certain pathologies is moderately well established, but the contribution of the microbiome to animal welfare, behavior, sustainability, immune development, nutritional status, physiology, and maturation is less clear. A valuable experimental model to enable scientists to explore the role of the microbiome in various domains is to compare various phenotypes of a conventionally reared (CV) cohort with those in a germ-free (GF) state. A GF animal is one that is devoid of any detectable microbial life including bacteria, viruses, protozoa and parasites. The GF state is different from gnotobiotic animals where the microbiome is fully described, or ‘specific pathogen free’ (SPF) animals where a moderately normal microbiome is present but devoid of pathogenic microorganisms. Pioneering GF research in poultry in the late 1940s and 1950s has its origin in a need understand the mode of action of antibiotics. Early researchers quickly established that GF chicks responded differently to antibiotics than CV counterparts. The GF experimental model has since been exploited in many divergent fields including pathology, immunology, metabolism, anatomy, physiology, and others. The absence of a microbiome presents the host with a range of advantages and disadvantages. For example, GF chicks often grow more quickly and have lower feed conversion ratio (FCR) than their CV counterparts but may be less resilient to external stress and have a compromised immunological maturation rate. This review will summarize the literature on GF animal research with a special emphasis on poultry. The objective of the review is to establish a frame of reference to understand the extent of the role of the microbiome in animal health, welfare, nutrition, and growth, to provide opportunities for targeted modulation of the microbiome to achieve desired phenotypic responses whilst simultaneously minimizing unintended collateral effects.

Intestinal microbiome of poultry and its interaction with host and diet

The gastrointestinal (GI) tract of poultry is densely populated with microorganisms which closely and intensively interact with the host and ingested feed. The gut microbiome benefits the host by providing nutrients from otherwise poorly utilized dietary substrates and modulating the development and function of the digestive and immune system. In return, the host provides a permissive habitat and nutrients for bacterial colonization and growth. Gut microbiome can be affected by diet, and different dietary interventions are used by poultry producers to enhance bird growth and reduce risk of enteric infection by pathogens. There also exist extensive interactions among members of the gut microbiome. A comprehensive understanding of these interactions will help develop new dietary or managerial interventions that can enhance bird growth, maximize host feed utilization, and protect birds from enteric diseases caused by pathogenic bacteria.

Utilization of various carbohydrate sources as affected by age in the chick

In 3 experiments, New Hampshire x Columbian male chicks were fed carbohydrate-soybean meal (SBM) or casein diets from 0 to 21 d of age, and MEn was determined at 0 to 2, 3 to 4, 7, 14, and 21 d of age. Carbohydrate sources evaluated in experiment 1 were dextrose (D-glucose), conventional cornstarch, dextrinized cornstarch, corn-syrup solids, pregelatinized unmodified cornstarch, pregelatinized tapioca starch, tapioca dextrin, high-amylose starch, and polycose (mixed glucose polymers). Carbohydrate sources evaluated in experiments 2 and 3 were conventional corn, waxy corn, high-oil corn, corn flour, rice flour, dextrose, and sucrose. In experiment 1, chicks fed the dextrose diet had the highest weight gains, and the chicks fed high-amylose starch and pregelatinized unmodified cornstarch diets had the lowest weight gains. The MEn values varied among carbohydrate sources with MEn being highest for the dextrose diet and lowest for the high amylose starch diet. In experiment 2, chicks fed waxy corn, high-oil corn, or dextrose-SBM diets had (P < 0.05) higher growth rates than chicks fed conventional corn, corn flour, or rice flour. The MEn values increased with age for all diets except the dextrose-SBM, which was consistently high at all ages. In experiment 3, the dextrose diets (SBM or casein) yielded higher growth performance and MEn values than the sucrose-diets, and the differences were greater at younger ages. The MEn values were also much higher for the casein than the SBM diets, and MEn of the SBM diets increased with increasing age. The results of this study indicate that MEn, varies among carbohydrate sources and increases with age for most carbohydrate-SBM diets.