Analysis of the influences on plumage condition in laying hens: How suitable is a whole body plumage score as an outcome?

An important indicator of the health and behavior of laying hens is their plumage condition. Various scoring systems are used, and various risk factors for feather damage have been described. Often, a summarized score of different body parts is used to describe the overall condition of the plumage of a bird. However, it has not yet been assessed whether such a whole body plumage score is a suitable outcome variable when analyzing the risk factors for plumage deterioration. Data collected within a German project on farms keeping laying hens in aviaries were analyzed to investigate whether and the extent to which information is lost when summarizing the scores of the separate body parts. Two models were fitted using multiblock redundancy analysis, in which the first model included the whole body score as one outcome variable, while the second model included the scores of the individual body parts as multiple outcome variables. Although basically similar influences could be discovered with both models, the investigation of the individual body parts allowed for consideration of the influences on each body part separately and for the identification of additional influences. Furthermore, ambivalent influences (a factor differently associated with 2 different outcomes) could be detected with this approach, and possible dilutive effects were avoided. We conclude that influences might be underestimated or even missed when modeling their explanatory power for an overall score only. Therefore, multivariate methods that allow for the consideration of individual body parts are an interesting option when investigating influences on plumage condition.

A water-soluble cholesteryl-containing trisgalactoside: synthesis, properties, and use in directing lipid-containing particles to the liver.

The synthesis of a trisgalactoside-terminated cholesterol derivative is described. Tris(galactosyloxymethyl)-aminomethane is coupled to cholesterol by using glycyl and succinyl as intermediate hydrophilic spacer moieties. The resulting cholesteryl ester dissolves easily in water, forming monodisperse micelles. When added to dispersions of liposomes or plasma lipoproteins in water, the substance becomes incorporated rapidly into these structures, causing an increase of their buoyant density. Liposomes or low-density lipoproteins, preloaded with the substance, are rapidly cleared from the circulation and taken up by the liver after intravenous injection in rats. This uptake is inhibited by N-acetylgalactosamine but not by N-acetylglucosamine, indicating the specificity of this process.

Solubilization and partial characterization of a tumor-associated transplantation antigen of the guinea pig L2C leukemia.

A tumor-associated transplantation antigen (TATA) from guinea pig L2C leukemia cells was solubilized by different methods. It was found that the 3 M KCl extraction yielded the most immunogenic TATA of L2C cells. Immunization of normal strain 2 guinea pigs with this extract in complete Freund's adjuvant gave complete protection against a subsequent challenge with tumor cells. Further fractionation of the KCl extract of L2C cells by Sephadex G-200 chromatography suggested that the immunogenic activity was present in the fraction containing materials with estimated m.w. of less than 20,000 daltons.