Walter, Freddy, Kurt and Elizabeth Gottschalk with their mother Therese Gottschalk nee Molling, and the maid on an easter egg hunt; Hannover, Germany.

From left to right: Walter Gottschalk, Therese Gottschalk nee Molling, Freddy Gottschalk, the maid, Kurt Gottschalk, and Elizabeth Gottschalk

Egg production in furnished cages

In the European Union, conventional cages for laying hens will be faded out at the beginning of 2012. The rationale behind this is a public concern over animal welfare in egg production. As alternatives to conventional cages, the European Union Council Directive 1999/74/EC allows non-cage systems and enriched (furnished) cages. Layer performance, behavior, and welfare in differently sized furnished cages have been investigated quite widely during recent decades, but nutrition of hens in this production system has received less attention. This thesis aims to compare production and feed intake of laying hens in furnished and conventional cages and to study the effects of different dietary treatments in these production systems, thus contributing to the general knowledge of furnished cages as an egg production system. A furnished cage model for 8 hens was compared with a 3-hen conventional cage. Three consecutive experiments each studied one aspect of layer diet: The first experiment investigated the effects of dietary protein/energy ratio, the second dietary energy levels, and the third the effects of extra limestone supplementation. In addition, a fourth experiment evaluated the effects of perches on feed consumption and behavior of hens in furnished cages. The dietary treatments in experiments 1 3 generally had similar effects in the two cage types. Thus, there was no evidence supporting a change in nutrient requirements for laying hens when conventional cages are replaced with small-group furnished cages. Moreover, the results from nutritional experiments conducted in conventional cages can be applied to small-group furnished cage systems. These results support the view that production performance comparable with conventional cages can be achieved in furnished cages. All of the advantages of cages for bird welfare are sustained in the small-group furnished cages used here. In addition, frequent use of perches and nests implies a wider behavioral repertoire in furnished cages than in conventional cages. The increase observed in bone ash content may improve bird welfare in furnished cages. The presence of perches diminished feed consumption during the prelaying period and enhanced the feed conversion ratio during the early laying period in furnished cages. However, as the presence or absence of perches in furnished cages had no significant effect on feed consumption after the prelaying period, the lower feed consumption observed in furnished cages than in conventional cages could be attributed to other factors, such as the presence of wood shavings or a nest box. The wider feed trough space per hen in conventional than in furnished cages may partly explain the higher feed consumption observed in conventional cages.

Honeydew as a source of nutrition for Lysiphlebus testaceipes (Cresson) (Hymenoptera: Braconidae): Effect of adult diet on lifespan and egg load

Parasitoid survival and fecundity is generally enhanced with access to carbohydrate food sources. In many agricultural ecosystems, there is often a scarcity of suitable carbohydrates for parasitoids. This study compared the suitability of aphid honeydew and buckwheat nectar as diet for the aphid parasitoid Lysiphlebus testaceipes. Wasp lifespan and egg load were both increased with access to carbohydrates, but no differences were detected between the various carbohydrates diets tested. As aphid honeydew is a sufficient source of nutrition and L.testaceipes is a short-lived species, adding additional sources of carbohydrates like floral nectar strips to the agricultural landscape is unlikely to significantly increase the biological control exerted by L.testaceipes. © 2012 Australian Entomological Society.

Effects of weed control and fertilization at early establishment on tree nitrogen and water use in an exotic F1 hybrid pine of subtropical Australia

Purpose We investigated the effects of weed control and fertilization at early establishment on foliar stable carbon (δ13C) and nitrogen (N) isotope (δ15N) compositions, foliar N concentration, tree growth and biomass, relative weed cover and other physiological traits in a 2-year old F1 hybrid (Pinus elliottii var. elliottii (Engelm) × Pinus caribaea var. hondurensis (Barr. ex Golf.)) plantation grown on a yellow earth in southeast Queensland of subtropical Australia. Materials and methods Treatments included routine weed control, luxury weed control, intermediate weed control, mechanical weed control, nil weed control, and routine and luxury fertilization in a randomised complete block design. Initial soil nutrition and soil fertility parameters included (hot water extractable organic carbon (C) and total nitrogen (N), total C and N, C/N ratio, labile N pools (nitrate (NO3 −) and ammonium (NH4 +)), extractable potassium (K+)), soil δ15N and δ13C. Relative weed cover, foliar N concentrations, tree growth rate and physiological parameters including photosynthesis, stomatal conductance, photosynthetic nitrogen use efficiency, foliar δ15N and foliar δ13C were also measured at early establishment. Results and discussion Foliar N concentration at 1.25 years was significantly different amongst the weed control treatments and was negatively correlated to the relative weed cover at 1.1 years. Foliar N concentration was also positively correlated to foliar δ15N and foliar δ13C, tree height, height growth rates and tree biomass. Foliar δ15N was negatively correlated to the relative weed cover at 0.8 and 1.1 years. The physiological measurements indicated that luxury fertilization and increasing weed competition on these soils decreased leaf xylem pressure potential (Ψxpp) when compared to the other treatments. Conclusions These results indicate how increasing N resources and weed competition have implications for tree N and water use at establishment in F1 hybrid plantations of southeast Queensland, Australia. These results suggest the desirability of weed control, in the inter-planting row, in the first year to maximise site N and water resources available for seedling growth. It also showed the need to avoid over-fertilisation, which interfered with the balance between available N and water on these soils.

Isolation of hen's egg yolk very low density lipoproteins by DEAE-cellulose chromatography

A procedure has been developed for the isolation of very low density lipoproteins from hen's egg yolk plasma using DEAE-cellulose chromatography. This procedure is rapid and does not require ultracentrifugation and should, therefore, serve as a useful procedure for use in laboratories where this facility does not exist.

Some Unique Features of Egg Laying and Reproduction in Ichthyophis Malabarensis (Taylor) (Apoda:Amphibia)

The paper describes egg laying and reproduction in ICHTHYOPHIS MALABARENSIS. 100 eggs, the largest ever in Apoda, are laid in a single string and manipulated by the female into a massive clutch. The reproductive strategies in the species are discussed.

Nature of the thiamin-binding protein from chicken egg yolk

A simple, rapid and efficient procedure for the purification of thiamin-binding protein from chicken egg yolk was developed. The method involved removal, by exclusion, of lipoproteins from DEAE-cellulose and subsequent elution of water-soluble proteins held on the ion-exchanger with 1 M-NaCl, followed by treatment of the eluted protein fraction with an aqueous suspension of dextran/charcoal to generate apoprotein from the holoprotein. The resultant protein fraction was subjected to bioaffinity chromatography on thiamin pyrophosphate--AE (aminoethyl)-Sepharose. The protein eluted specifically with 10 microM-thiamin at pH 7.0, was homogeneous by the criteria of polyacrylamide-gel disc electrophoresis, had a mol.wt. of 38 000 +/- 2000 and was not a glycoprotein. The purified thiamin-binding protein specifically interacted with riboflavin-binding protein with no detectable deleterious affect on its (14C)thiamin-binding capacity. The protein bound [14C]thiamin with a molar ratio of 1.0, with dissociation constant (Kd) 0.41 microM. This protein-ligand interaction was inhibited by thiamin analogues and antagonists. The absorption spectrum of the protein in the presence of thiamin exhibited significant hypochromism at the 278 nm band, indicating the involvement of aromatic amino acid residues of the protein, during its binding to the ligand. The protein cross-reacted with the monospecific antiserum to egg-white thiamin-binding protein, showing thereby that thiamin-binding proteins present in chicken egg yolk and white are the products of the same structural gene.

Structural studies of the hen's egg lipovitellins. NMR and fluorescence investigations

The pH dependent reversible association-dissociation reaction of α- and β-lipovitellins from egg yolk has been studied by 1H NMR and fluorescence probe methods. Increased mobility of the choline methyl groups has been demonstrated on dissociation. The lipid methylene resonance of β-lipovitellin shows clear doublet character suggesting that the fatty acid chains exist in distinct environments. The high field component increases with temperature but is suppressed on treatment with pronase, suggesting a significant role for proteins in maintaining the differences in lipid environments. 1-Anilino-8-naphthalene sulfonate has been shown to bind less effectively to the monomeric lipovitellins. This is in agreement with earlier results suggesting that dissociation may be accompanied by increased hydration and conformational changes.

Physicochemical studies on the gelation of hen egg yolk; separation of gelling protein components from yolk plasma

A study of the component(s) in egg yolk responsible for gelation of yolk on freezing and thawing has shown that granule-free yolk plasma, obtained by high-speed centrifugation of yolk, has the capacity to gel. As with the whole yolk, gelation of yolk plasma on freezing and thawing could be inhibited by additives such as sugars, sodium chloride, proteolytic enzymes, and phospholipase-A. Phospholipase-C, which induces gelation of whole yolk at room temperature, has a similar effect on yolk plasma. Yolk plasma has been separated into aggregating (gelling) and soluble fractions by delipidation, using formic acid. Each of these fractions consists of three or four protein components, as observed by gel filtration, ultracentrifugation, and agar electrophoresis. The proteins are glycoproteins and contain bound hexoses, hexosamine, and sialic acid. The gelation of yolk has been attributed to the interactions between protein molecules following disruption of lipid-protein bonds.

Physicochemical studies on the gelation of hen's egg yolk: Delipidation of yolk plasma by treatment with phospholipase-C and extraction with solvents

A method for the delipidation of egg yolk plasma using phospholipase-C, n-heptane, and 1-butanol has been described. An aggregating protein fraction and a soluble protein fraction were separated by the action of phospholipase-C. The aggregating protein fraction freed of most of the lipids by treatment with n-heptane and 1-butanol was shown to be the apolipoproteins of yolk plasma, whereas the soluble proteins were identified as the livetins. Carbohydrate and the N-terminal amino acid analysis of these protein fractions are reported. A comparison of these protein fractions with the corresponding fractions obtained by formic acid delipidation of yolk plasma has been made. The gelation of yolk plasma by the action of phospholipase-C has been interpreted as an aggregation of lipoproteins caused by ionic interactions. The role of lecithin in maintaining the structural integrity of lipoproteins has been discussed.

A monoclonal antibody recognizing the C-terminal region of chicken egg white riboflavin carrier protein terminates early pregnancy in mice

In order to identify the functionally relevant epitopes on chicken riboflavin carrier protein, we have raised monoclonal antibodies to the vitamin carrier. One of these, 6B2C12, was found to interact specifically with a synthetic oligopeptide corresponding to the C-terminal 17 amino acid residues of the chicken egg white riboflavin carrier protein, which is missing in part in the egg yolk riboflavin carrier protein. This epitope is conserved through evolution in mammals including humans. Administration of the ascites fluid of 6B2C12 to pregnant mice intraperitoneally, resulted in the termination of pregnancy indicating that this epitope is involved in or closely associated with the transplacental transport of the vitamin from the maternal circulation to the growing fetus.