Interactions between nutrition and gastrointestinal infections with parasitic nematodes in goats

Parasitic nematodes of the digestive tract remain one of the main constraints to goat production both in temperate and tropical countries. The usual mode of control of these gastrointestinal nematodes (GIN) based on the repeated use of anthelmintics is now strongly questioned because of the increasing development of resistance to these molecules. Among the alternative methods to anthelmintics currently available, the manipulation of host nutrition in order to improve the host resistance and/or resilience to parasitic infections seems to represent one of the most promising options to reduce the dependence on conventional chemotherapy and to favour the sustainable control of gastro intestinal nematode infections. This paper will review the available information on the interactions between nutrition and nematode parasitism in dairy or meat goats both in temperate and tropical conditions. It will refer to quantitative aspects of the diet (influence of the protein and/or energy parts) as well as to qualitative components (effects of plant secondary metabolites on worm biology) and will discuss the specificities of goats in regard of theses interactions

The influence of nutrition on the periparturient rise in fecal egg counts in dairy goats : Results from a two-year study

The periparturient relaxation in immunity (PPRI) to nematode infection in ewes is well known and it is associated with a rise in faecal egg counts during the periparturient period. In order to assess an eventual relationship between the PPRI and the nutritional status of periparturient females, a twoyear study was carried out in a dairy goat flock. On year 1, pregnant does were fed at 26 % below their energy (UFl) requirements and 5 % above their protein (PDI) ones during the last 3 weeks before parturition (week 0) and an increase in nematode egg counts occurred from week -2 to week +4 with a predominance of Oesophagostomum larvae in coprocultures. In year 2, two groups of pregnant goats were fed at about 100 % their energy requirements and 28 and 44 % above the protein requirements respectively during the same period. In this latter situation, no nematode egg count increase occurred in any of the two groups of animals, Teladorsagia and Trichostrongylus being the prevalent larval genera in coprocultures. As the study covered two consecutive years, the implication of several factors related to host physiology, parasite epidemiology and host nutrition are discussed

Relationship between nematode parasitism of the digestive tract and the characteristics of dairy goat farms in two French regions

East of France for nematode infection. The intensity of infection was assessed by means of individual faecal egg counts performed four times per year. The possible occurrence of resistance to benzimidazoles on the farms was evaluated by a faecal egg count reduction test. In parallel, information on the typological characteristics of the farms have been collected through a questionnaire on the general structure, the flock and the mode of management of parasitism. A Principal Component Analysis (PCA) was performed in order to examine the associations or oppositions between variables defining the farm and the level of parasitism. On the other hand, a Discriminant Analysis was applied to examine the factors explaining the mean annual number of anthelmintic treatments. Results from the PCA showed that the high level of infection was associated with the size of the flock, the total surface of farm and with the presence of other host species. On the other hand, nematode parasitism was inversely related to the milk production and to the stocking rate. The Discriminant Analysis indicated that farms with a low number of annual treatments (less than 2) were characterised either by a low stocking rate or by a large distribution of concentrates indoors despite the use of pastures. On the other hand, the group of farms with the highest number of antiparasitic treatments (more than 4) corresponded to farms where anthelmintic resistance to benzimidazoles has been identified during the survey. (Résumé d'auteur

Production of antihydrogen at reduced magnetic field for anti-atom trapping

We have demonstrated production of antihydrogen in a 1$,$T solenoidal magnetic field. This field strength is significantly smaller than that used in the first generation experiments ATHENA (3$,$T) and ATRAP (5$,$T). The motivation for using a smaller magnetic field is to facilitate trapping of antihydrogen atoms in a neutral atom trap surrounding the production region. We report the results of measurements with the ALPHA (Antihydrogen Laser PHysics Apparatus) device, which can capture and cool antiprotons at 3$,$T, and then mix the antiprotons with positrons at 1$,$T. We infer antihydrogen production from the time structure of antiproton annihilations during mixing, using mixing with heated positrons as the null experiment, as demonstrated in ATHENA. Implications for antihydrogen trapping are discussed

Proton drip-line nuclei in relativistic mean-field theory

The position of the two-proton drip line has been calculated for even-even nuclei with $10 \leq Z \leq 82$ in the framework of the relativistic mean-field (RMF) theory. The current model uses the NL3 effective interaction in the mean-field Lagrangian and describes pairing correlations in the Bardeen-Cooper-Schrieffer (BCS) formalism. The predictions of the RMF theory are compared with those of the Hartree-Fock+BCS approach (with effective force Skyrme SIII) and the finite-range droplet model (FRDM) and with the available experimental information.Comment: 18 pages, RevTeX, 2 p.s figures, to appear in Phys. Rev.