Tissue-specific changes in the activities of antioxidant enzymes during the development of the chicken embryo. Br Poult Sci

Abstract 1. Tissue-specific profiles of the expression of the antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) and the concentrations of reduced glutathione (GSH) during the development of the chick embryo were investigated. 2. The liver, brain, yolk sac membrane (YSM), kidney, lung, heart and skeletal muscles were collected at the following days of embryo development: 10, 11, 13, 15, 17, 19, 21 and 22 (day-old chicks). 3. The different tissues of the embryo displayed distinct development strategies with regard to the acquisition of antioxidant capacity. In the liver the specific activity of SOD increased between days 10 and 11 of development, then significantly decreased up to day 15 and remained at the same value during the rest of the developmental period. GSH-Px specific activity increased through the time of development. CAT had 2 peaks of specific activity at day 10 of the development and in day-old chicks. 4. The brain was characterised by comparatively high SOD-specific activity especially during the last days of incubation. The specific activities of GSH-Px and CAT were low throughout development. 5. In the YSM maximal GSH-Px and CAT-specific activities were found on day 15 of incubation. In the kidney and heart GSH-Px-specific activity increased at hatching time. CAT-specific activity in the kidney increased just after hatching. 6. It is concluded that each tissue studied expressed a profile of antioxidant defence mechanisms to deal with oxidative stress at hatching time

Carotenoids in the eggs of American coots : associations with size of eggs, local environment and diet

I studied carotenoids in the eggs of American coots (Fulica americana) from 3 study sites in Saskatchewan, Canada. I supplemented two diet types designed to reduce carotenoids in the diet of laying coots to investigate the relationship of carotenoids and the size of eggs and to examine the allocation of carotenoids into eggs.In chapter 2, I examined influences of local environment, food quantity and food quality on egg size. Carotenoid content and stable nitrogen and carbon isotopes in yolk were measured and used to elucidate whether variation in type of food eaten contributes to egg size. By analyzing isotopes in coot tissues, I confirmed that coots use endogenous lipid reserves for egg formation but not endogenous protein reserves, and the size of eggs is more dependent on exogenous sources of nutrients. My data demonstrate that carotenoids are not causal in egg size, but are components of natural, high quality diets. Carotenoids are obtained through the diet and deposited into egg yolk. It has been hypothesized that concentrations and percentages of individual carotenoids can be labile and dependent on diets or maintained in an optimal balance to meet requirements of embryos. In chapter 3, I investigate deposition of carotenoids in egg yolk among nesting locales, among hens within a site and among treatments in a diet manipulation experiment. My data show maintenance in the percent composition of a suite of 3 important carotenoids, lutein, zeaxanthin and â–carotene, independent of scale of investigation and in contrast to other individual carotenoids that appear to vary in proportions based on diet. These results suggest that birds can maintain nutritional balances in their eggs despite variation in diets.In chapter 4, I tested 3 hypotheses regarding the apportionment of carotenoids into egg yolk over the laying sequence. Without exception, concentrations of these nutrients have previously been shown to decline with egg sequence. In contrast to these findings, coots actually increased the carotenoid concentration in yolks over the laying sequence. My experimental evidence supports the explanation that this pattern of deposition depends on carotenoid availability to the laying female

Nonenzymatic Exogenous and Endogenous Antioxidants

Nonenzymatic exogenous and endogenous antioxidants play an important role in human health and act as preservatives for cosmetics, pharmaceuticals, and food products. This chapter will discuss the chemical structure and mechanism of action of the most important nonenzymatic small exogenous and endogenous organic molecules that act as antioxidants. The chapter will focus on the structural features, functional groups, properties, biosynthetic origin, and mechanism of action of such antioxidants. It also covers damages that free radicals create and the mechanisms by which they are neutralized by the various antioxidants. The scope of this chapter will be limited to nonenzymatic exogenous and endogenous antioxidants since enzymatic antioxidants have been discussed extensively in several reviews

Maternally derived yolk antioxidants buffer the developing avian embryo against oxidative stress induced by hyperoxia

In oviparous animals, maternally transferred antioxidants protect the embryo from oxidative damage from high rates of reactive oxygen species (ROS) production incurred by rapid growth. Elevated ROS exposure - beyond that incurred by normal growth - can occur as a result of exposure to exogenous factors (e.g. pollutants, toxins, radiation), increasing the risk of oxidative damage, with potentially adverse consequences for embryonic development and long-term fitness. The capacity of the avian embryo's antioxidant protection system to counter an increased exogenous oxidative threat is poorly understood. We induced an external oxidative challenge via experimental increase in ambient oxygen concentration throughout incubation of wild great tit eggs in the laboratory. At day 11 of incubation, brain tissue revealed no consistent differences in oxidative stress status - as measured by antioxidant levels (superoxide dismutase and total glutathione), lipid peroxidation and telomere length - between control (21% oxygen) and hyperoxic (40% oxygen) embryos. However, the level of vitamin E was significantly lower and lipid peroxidation was significantly higher in yolks of eggs reared under elevated oxygen concentrations. The results suggest that maternally derived yolk antioxidants successfully buffer developing embryonic tissues against an increased exogenous oxidative threat. Furthermore, vitamin E plays a more important role in protecting the embryo than carotenoids. However, the depletion of antioxidants and increased peroxidation of lipids in the yolk could have negative consequences for embryonic development - in particular for the brain and heart that require highly unsaturated fatty acids - and protection against the oxidative burst following hatching

Improvement of flock productivity through supply of vitamins for higher laying performance and better egg quality

An adequate supply of all nutrients, including proteins, fats, carbohydrates, vitamins, minerals and water, has to be provided to support maximum productivity of laying hens. Among these nutrients, vitamins are particularly important, since they are essential for optimum health as well as normal physiological functions of the hens. As most vitamins cannot be synthesized by poultry in sufficient amounts to meet physiological demand, they must be obtained from the diet. The absence from feed or impaired absorption or utilization of vitamins can lead to specific deficiency disorders. This review reports on the occurrence and the physiological functions of all vitamins and summarizes research related to the requirements for and the beneficial effects of supplemental vitamins for laying hens. The recommendations for dietary supplementation of vitamins from various organizations are compared and put into perspective of modern poultry genotypes and current husbandry conditions. As there is good evidence that the minimum dietary vitamin levels, required to prevent clinical deficiencies may not support optimum health, performance and welfare of poultry under today's conditions it is recommended to include a safety margin to the vitamin requirements of laying hen

A Guide to the Principles of Animal Nutrition

I would like to express my gratitude to Oregon State University Libraries and Press and Ecampus for honoring me with the open access text pilot program award.I. Introduction to NutritionII. Gastrointestinal Tract, Digestive Organs, and ProcessesIII. Carbohydrates, Structures and TypesIV. Carbohydrates, Digestion and AbsorptionV. Carbohydrates, MetabolismVI. Lipids, StructureVII. Lipids, DigestionVIII. Lipids, Transport, Deposition, and MetabolismIX. ProteinsX. Proteins, Digestion and AbsorptionXI. Proteins, MetabolismXII. Proteins and Amino Acids, QualityXIII. VitaminsXIV. Water-Soluble Vitamins (B and C)XV. MineralsXVI. MicromineralsXVII. BioenergeticsXVIII. Water in Animal NutritionXIX. Feed AdditivesXX. Measurement of Feed and Nutrient Utilization in Food-Producing AnimalsThis book entitled “A Guide to Principles of Animal Nutrition” consists of 20 chapters. As the name says, this book is a guide primarily meant to serve students taking animal nutrition courses at the university level and is not a full-scale animal nutrition text. Information digestive anatomy and processes provide the foundation to understand how animals utilize nutrients. The text begins with basic information on feed nutrient analysis, anatomical and physiological bases of digestion in food producing ruminant as well as non-ruminant animals. Description of chemical structure, digestion, absorption, assimilation, and metabolism of energy-producing nutrients followed by vitamins and minerals are emphasized in rest of the chapters. To integrate the basic knowledge of nutrition with practical animal feeding, the book closes with two chapters discussing some of the major feed additives used in animal diets and methods used in assessing feed nutrient utilization

Uzgoj bakterije Methylobacterium organophilum u metanolu za istodobnu proizvodnju proteina i korisnih metabolita

Research background. This study aims to monitor the growth of the methylotrophic bacteria Methylobacterium organophilum in a culture medium with methanol as a carbon source and to verify the production of unicellular proteins and other biomolecules, such as carotenoids, exopolysaccharides and polyhydroxyalkanoates, making them more attractive as animal feed. Experimental approach. Bacterial growth was studied in shake flasks using different carbon/nitrogen (C:N) ratios to determine their best ratio for achieving the highest volumetric productivity of cells and substrate consumption rate. This optimal parameter was further used in a fed-batch operating bioreactor system to define the kinetic profile of cell growth. Methanol consumption was measured by HPLC analysis and the extracted pigments were analyzed by liquid chromatography/mass spectrometry. Chemical composition and rheological properties of the produced exopolysaccharides were also determined. Results and conclusions. The best experimental parameters were verified using an initial methanol concentration of 7 g/L in the culture medium. The same initial substrate concentration was used in the fed-batch operation and after 60 h of cultivation 5 g/L of biomass were obtained. The accumulation of carotenoids associated with cell growth was monitored, reaching a concentration of 1.6 mg/L at the end of the process. These pigments were then analyzed and characterized as a set of xanthophylls (oxidized carotenoids). In addition, two other product types were identified during the fed-batch operation: exopolysaccharides, which reached a concentration of 8.9 g/L at the end of the cultivation, and an intracellular granular structure that was detected by transmission electron microscopy (TEM), suggesting the accumulation of polyhydroxyalkanoate (PHA), most likely polyhydroxybutyrate. Novelty and scientific contribution. Methylobacterium organophilum demonstrated a unique ability to produce compounds of commercial interest. The distinct metabolic diversity of this bacterium makes room for its use in biorefineries.Pozadina istraživanja. Svrha je ovoga istraživanja bila pratiti rast metilotrofne bakterije Methylobacterium organophilum u podlozi s metanolom kao izvorom ugljika, te potvrditi sposobnost tog jednostaničnog organizma da proizvodi proteine i druge biomolekule, kao što su karotenoidi, egzopolisaharidi i polihidroksialkanoati, a koji se mogu upotrijebiti u proizvodnji stočne hrane. Eksperimentalni pristup. Rast bakterije ispitan je na tresilici pri različitim omjerima ugljika i dušika (C:N), radi utvrđivanja njihovog optimalnog omjera za postizanje najveće volumetrijske produktivnosti stanica i najboljeg iskorištenja supstrata. Zatim je pomoću tog optimalnog omjera hranjiva određen kinetički profil rasta stanica u šaržnom bioreaktoru. Potrošnja metanola mjerena je metodom HPLC, a izolirani su pigmenti ispitani tekućinskom kromatografijom spregnutom s masenom spektrometrijom. Također su određeni kemijski sastav i reološka svojstva dobivenih egzopolisaharida. Rezultati i zaključci. Najbolji eksperimentalni parametri potvrđeni su pri početnoj koncentraciji metanola u podlozi od 7 g/L. Ista je početna koncentracija korištena u šaržnom bioreaktoru, gdje je nakon 60 h uzgoja dobiveno 5 g/L biomase. Tijekom uzgoja je praćena akumulacija karotenoida, čija je koncentracija pri završetku procesa bila 1,6 mg/L. Pigmenti su zatim ispitani i okarakterizirani kao ksantofili (podvrsta karotenoida). Osim toga, tijekom šaržne fermentacije identificirana su još dva proizvoda: egzopolisaharidi, čija je koncentracija na kraju uzgoja bila 8,9 g/L; te granularna struktura otkrivena pomoću transmisijskog elektronskog mikroskopa, koja upućuje na to da je u stanici došlo do nakupljanja polihidroksialkanoata (PHA), i to najvjerojatnije polihidroksibutirata. Novina i znanstveni doprinos. Bakterija Methylobacterium organophilum ima jedinstveno svojstvo proizvodnje spojeva od komercijalnog interesa. Iznimna metabolička raznolikost ove bakterije omogućuje njezinu primjenu u biorafinerijama

Degenerative myopathy in ratites

Although there is abundant scientific information regarding vitamin E and selenium deficiency disease in domestic poultry, there is only scant information on exotic species, such as ratites. Several necropsy cases involving ostriches, emus and rheas were presented to the Oregon State University Veterinary Diagnostic Laboratory with gross and/or histologic lesions of degenerative myopathy. Investigation of these cases led to determination of tissue levels of vitamin E and selenium and to determination of the dietary levels of these same substances. A small group of emus with a post-mortem diagnosis of degenerative myopathy was supplemented with dietary vitamin E with excellent clinical results. This success prompted a survey of vitamin E and selenium levels in blood and feed from clinically normal ratites. This information was then used to make recommendations for dietary levels of vitamin E and selenium in ratite formulated diets. Since overzealous supplementation can result in selenium toxicosis in birds, a safe, but effective level of dietary selenium and vitamin E is necessary for optimal propagation of the various ratites species