On the basis of pedigree records and a number of additional factors (e.g. farm size and management, breed) 30 suitable goat farms will be preselected for the project in early summer 2011. Subsequent parasitological data (faecal egg count (FEC) and strongyle genera determination) collected from animals on the farms will allow the selection of 15 farms for study in 2012 with a total minimum of 1500 animals.
Farms enrolled in the study will, amongst other common features, have comparable GIN genera composition and maximum pedigree information within and between farms. In 2012 data for co-variance estimates will be collected for all animals present on the farms. First, FEC will be performed at moderate to high herd FEC (as determined by bulk sample monitoring). Infections will then be cleared by anthelmintic treatment and a second FEC will be performed on new infections (i.e. on a new GIN population).
Concurrently with FEC, FAMACHA eye scores will be recorded and blood samples will be taken from all animals in order to determine haematological parameters (PCV, leukocyte counts). Milk production data from all does >15 months will be collected at both sampling occasions.
Multivariate statistical procedures will be used to infer the genetic correlation of FEC/FAMACHA/PCV and leukocytes with milk yield. Furthermore, heritability of FEC/FAMACHA/PCV and leukocytes will be estimated separately for does >15 months and young animals. The correlation between repeated measures of FEC/FAMACHA and haematological parameters will be used to see whether those parameters are really measuring the same trait. The heritability of each of those traits at different times will allow for the choice of the best parameter (phenotype) to perform selection on. The genetic components will be the basis for routine genetic evaluation and our proposal on integrating selection for GIN resistance into the breeding scheme.
Schweizer Ziegenzuchtverband (SZZV)
Beratungs- und Gesundheitsdienst für kleine Wiederkäuer (BGK)