Leader Ignacio Ferre
Deputy: Yan Landau
An integrated sustainable control of parasites supposes the evaluation of innovative methods of control assimilating the specificities of the goat-parasite interactions.
Task 4.1: Genetic selection strategies between and within caprine breeds.
Variations in the host-parasite relationship between breeds or between lines within the same breed will be investigated in order to examine the consequences on the dynamics of infection in a large range of production systems within Europe. In regard of the between breed comparison, the potential offered by local breeds will be particularly explored. The respective role of the development of immune response and/or of differences in behaviour in the origin of both between- and within-breed differences will be considered in order to generate information to propose a theoretical, conceptual model aiming at a better understanding of the relationship between these two regulative mechanisms.
Task 4.2: Interactions Nutrition-Parasite infections in goats to improve the host response.
Nutrition is a key factor affecting the consequences of parasite infections. This modulation has been related either to quantitative (Task 4.2) or qualitative (Task 4.3 ) aspects of nutrition. Based on data acquired on GIN infections, a theoretical model has been proposed to explain the interrelationships between i) the physiological priorities imposed to the animals; ii) the demands for production and iii) the reduced coverages of nutriments due to the parasite infections. A contrario, many experimental results have underlined that the manipulation of major nutritive components (i.e. proteins and energy) permit to improve the host response (either resistance or resilience) towards parasites. However, most results have been acquired on meat producing sheep. Goat will allow to explore the validity of the model on a dairy animal, the milk production being a source of main variations in requirements between animals and/or according to the physiological stage. Interactions between nutrition and infections with parasites which do not inhabit the gut and disturb the digestive physiology will also be explored.
Task 4.3: Specifities of browsing caprine behaviour and use of non conventional, natural compounds with antiparasitic properties.
The need to find novel approaches to control parasites has given a strong, recent impetus to the scientific exploration of the antiparasitic properties of natural plant compounds. The highest ability of goat to tolerate the consumption of PSMs compared to sheep means that a large range of plants deserve to be examined for their potential activities. This will be measured based first on in vitro screening methodologies, then in in vivo experimental studies. Last, it will be validated in conditions of farm production. Hence, controlled and field trials with local breeds of goats will be carried out to identify and evaluate local bioactive plants containing secondary metabolites with antiparasitic properties.
The objectives of this task are also the standardization of methods to identify and characterize the active components, the understanding of the mode of action of plant-derived bioactive compounds, and the evaluation of the most beneficial methods to exploit those bioactive forages. Guidelines for field and laboratory assays for efficacy studies will be produced. Practical application of this knowledge in European countries would support integrating productive improved pastures with high nutritive value and natural vegetation that contribute to achieve sustainable goat production systems.
Task 4.4: Specificities of caprine behaviour and development of grazing strategies.
The levels of complementarity between the domestic ruminant species in their grazing behaviour will affect the productivity and sustainability of the systems, as a high dietary overlap between animal species means a high inter-specific competition for the same plant resources. Field trials using mixed flocks of local goats, sheep and cattle will be carried out to know which association would be the most appropriate to achieve sustainable systems from the animal production; health (parasitism) and vegetation use points of view.