Is it possible to differentiate meat products of a local breed from those of its sister breed based on genotypes?

peer reviewedTo maintain endangered breeds and preserve their intrinsic diversity, it is often advocated to develop derived labelled products and the related certification process. However, this certification process is not always easily implemented if the endangered breed is closely related to another one. The breed traceability is only possible if the genetic diversity between those breeds is high enough. In this study, it was determined if meat of Dual-Purpose Blue (DPB) animals can be differentiated from meat of its sister breed, the Beef Belgian Blue (BBB), by the application of a genomic test. The results showed that the meat of DPB was completely distinguished from the meat of BBB, and this, with a probability of one for all meat samples. It therefore seemed possible to differentiate the DPB derived products from those of BBB with a high accuracy, meaning the implementation in routine of a certification process seemed possible

Genetic parameters for direct and maternal calving ease in Walloon dairy cattle based on linear and threshold models

Calving ease scores from Holstein dairy cattle in the Walloon Region of Belgium were analysed using univariate linear and threshold animal models. Variance components and derived genetic parameters were estimated from a dataset including 33,155 calving records. Included in the models were season, herd and sex of calf age of dam classes group of calvings interaction as fixed effects, herd year of calving, maternal permanent environment and animal direct and maternal additive genetic as random effects. Models were fitted with the genetic correlation between direct and maternal additive genetic effects either estimated or constrained to zero. Direct heritability for calving ease was about 8% with linear models and about 12% with threshold models. Maternal heritabilities were about 2% and 4%, respectively. Genetic correlation between direct and maternal additive effects was found to be not significantly different from zero. Models were compared in terms of goodness of fit and predictive ability. Criteria of comparison such as mean squared error, correlation between observed and predicted calving ease scores as well as between estimated breeding values were estimated from 85,118 calving records. The results provided few differences between linear and threshold models even though correlations between estimated breeding values from subsets of data for sires with progeny from linear model were 17% and 23 % greater for direct and maternal genetic effects, respectively, than from threshold model. For the purpose of genetic evaluation for calving ease in Walloon Holstein dairy cattle, the linear animal model without covariance between direct and maternal additive effects was found to be the best choice

La Bleue Mixte - Schéma de Sélection

BlueSel (projet Interreg IV France-Wallonie-Vlaanderen

Fecundity of cows and dairy herds in Wallonia. Management effects.

audience: professional, studentL’intervalle moyen entre vêlages est de 409 jours. Pour les 25 % meilleurs troupeaux (3125 annéesz troupeaux) et vaches (107.700 lactations), il est respectivement de 387 et 346 jours. L’objectif classiquement proposé d’un veau par vache et par an n’est atteint que dans 0,38% des troupeaux et par une vache sur quatre (27%). L’augmentation de la production laitière moyenne s’accompagne d’un allongement de l’intervalle entre vêlages. Des performances de reproduction comprises entre 380 jours pour les élevages dont la production est inférieure à 8000 kg et de 390 jours pour les élevages dont la production est supérieure à 8000 kg de lait sont néanmoins tout à fait possibles. L’impact de l’augmentation du niveau de production sur l’allongement de l’intervalle entre vêlages est limité. Les éleveurs dont les troupeaux ont des moyennes de production égales ou supérieures à 8.000 kg tirent un meilleur parti de l’environnement (effet positif) que ceux dont les troupeaux ont des moyennes de production inférieures à 7.000 Kg. La marge brute par vache augmente avec le niveau de production laitière moyen du troupeau

Genetic evaluation of calving ease for Walloon Holstein dairy cattle.

Calving complications have an incidence on the economic profitability of dairy herds. In the Walloon Region of Belgium, calving ease data recording is being done on voluntary basis since 2000. This allows now the implementation of a genetic evaluation of Holstein dairy cattle addressing the need of dairy breeders to select bulls in order to reduce frequency of calving problems. Calving ease scores were analyzed using univariate animal linear models, which were fitted with the genetic correlation between direct and maternal additive genetic effects either estimated or constrained to zero. Variance components and related genetic parameters were estimated from a dataset including 33,155 calving records. Included in the models were fixed season effects, fixed herd effects and fixed sex of calf*age of dam classes*group of calvings interaction effects, random herd*year of calving effects, random maternal permanent environment effects, and random animal direct and maternal additive genetic effects. For both models, direct and maternal heritabilities for calving ease were about 8% and about 2%, respectively. Genetic correlation between direct and maternal additive effects was found to be non-significantly different from zero. So, an animal linear model with genetic correlation between direct and maternal effects constrained to zero was adopted for the routine genetic evaluation of calving ease for Walloon Holstein dairy cattle. This model was validated by Interbull in January 2013 and, since April 2013, the Walloon Region of Belgium has officially participated to the international MACE evaluation for calving traits