Impact of conservation measures on demography and genetic variability of livestock breeds.

Conservation of animal genetic resources requires regular monitoring and interventions to maintain population size and manage genetic variability. This study uses genealogical information to evaluate the impact of conservation measures in Europe, using (i) data from the Domestic Animal Diversity Information System (DAD-IS) and (ii) a posteriori assessment of the impact of various conservation measures on the genetic variability of 17 at-risk breeds with a wide range of interventions. Analysis of data from DAD-IS showed that 68% of national breed populations reported to receive financial support showed increasing demographic trends, v. 51% for those that did not. The majority of the 17 at-risk breeds have increased their numbers of registered animals over the last 20 years, but the changes in genetic variability per breed have not always matched the trend in population size. These differences in trends observed in the different metrics might be explained by the tensions between interventions to maintain genetic variability, and development initiatives which lead to intensification of selection.

Cardiac hydatid cyst in the interventricular septum: A literature review.

Human hydatidosis occurs mainly as a result of infection with the larvae of Echinococcus granulosus. Cardiac echinococcosis is an uncommon disease and the interventricular septum is rarely involved. This article is a review of all of the literature related to hydatid cyst in the interventricular septum included in the PubMed database. Forty-five cases reported between 1964 and 2019 were identified.

Review: Domestic herbivores and food security: current contribution, trends and challenges for a sustainable development.

Herbivores are found in a variety of ecosystems all over the world. Permanent pastures and meadows cover about 25% of global land. We currently count one domesticated herbivore for two people in the world and the number is growing. Production systems and products are highly diverse. This high diversity is the result of thousands of years of natural selection and human-controlled breeding, as well as migration and trade. Because of the high diversity of domestic herbivore genetic resources, herders have been able to live in regions where no alternative for income generation exists. Meat and milk from domestic herbivores provide 16% and 8% of the global protein and kilocalorie consumption, respectively. They also provide a variety of essential micronutrients but can contribute to overweight and obesity when consumed in excess. Domestic herbivores also make significant contribution to food security through the production of manure, draught power and transport and the generation of income at household and national level. They have a key role to play in women's empowerment and gender equality, both in rural and urban areas.Demand for meat and milk is increasing because of population growth, rising incomes and urbanisation. This trend is expected to continue, especially in Latin America, South Asia and China. The sustainable development of domestic herbivore production needs to address the feed/food and the efficiency of herbivores in turning forages into protein. It also needs to address the contribution of herbivores to greenhouse gas emissions, especially of ruminants through enteric fermentation, and their mitigation potential, including through carbon sequestration. Animal genetic resources have a key role to play in mitigating and adapting to climate change. The role of ruminants in the circular bioeconomy needs to be enhanced, promoting the use of by-products and waste as livestock feed and the recycling of manure for energy and nutrients. Finally, the role of domestic herbivores in providing secure livelihoods and economic opportunities for millions of smallholder farmers and pastoralists needs to be enhanced. The sustainable development of the sector therefore requires adequate policies, and there are already a variety of mechanisms available, including regulations, cross-compliance systems, payments for environmental services and research and development. Priority areas for policy makers should be aligned with the global framework of the Sustainable Development Goals and include: (i) food security and nutrition, (ii) economic development and livelihoods, (iii) animal and human health and finally, (iv) environment, climate and natural resources.

Effect of genetic European taurine ancestry on milk yield of Ankole-Holstein crossbred dairy cattle in mixed smallholders system of Burundi highlands.

Different breeding systems associated with specific bovine genetic resources have coexisted in Burundi. To prepare for the development of a national action plan for the improvement of bovine genetic resources in Burundi, we aimed at performing genetic characterization of Ankole and Ankole × European crossbred individuals and assessing the effect of European ancestry on milk productivity of cows kept under the mixed crops livestock system. To that end, we genotyped 37 Ankole and 138 crossbred individuals on 42 636 SNPs and combined these genotypes with those from 21 cattle breeds, representative of the bovine genetic diversity. We also measured milk yield not suckled and estimated suckled milk. Given the results, we confirmed the indicine × African taurine admixed origin of the Ankole in Burundi and showed that crossbred individuals present a high proportion of European ancestry (i.e. 57% on average). As the proportion of European ancestry increased, milk yield increased by 0.03 ± 0.01 l/day, at a lower extent than expected. We also observed that breeders were unable to correctly evaluate the European proportion in their livestock. Our results may provide useful information for objective dairy breeding in Burundi. As an example, an ex-situ conservation program of Ankole within the framework of value chains is proposed as an accompanying strategy to improve the sustainability of the crossbreeding program.

Rare phenotypes in domestic animals: unique resources for multiple applications.

Preservation of specific and inheritable phenotypes of current or potential future importance is one of the main purposes of conservation of animal genetic resources. In this review, we investigate the issues behind the characterisation, utilisation and conservation of rare phenotypes, considering their multiple paths of relevance, variable levels of complexity and mode of inheritance. Accurately assessing the rarity of a given phenotype, especially a complex one, is not a simple task, because it requires the phenotypic and genetic characterisation of a large number of animals and populations and remains dependent of the scale of the study. Once characterised, specific phenotypes may contribute to various purposes (adaptedness, production, biological model, aesthetics, etc.) with adequate introgression programmes, which justifies the consideration of (real or potential) existence of such characteristics in in situ or ex situ conservation strategies. Recent biotechnological developments (genomic and genetic engineering) will undoubtedly bring important changes to the way phenotypes are characterised, introgressed and managed.

Community-based livestock breeding programmes: essentials and examples.

Breeding programmes described as community-based (CBBP) typically relate to low-input systems with farmers having a common interest to improve and share their genetic resources. CBBPs are more frequent with keepers of small ruminants, in particular smallholders of local breeds, than with cattle, pigs or chickens with which farmers may have easier access to alternative programmes. Constraints that limit the adoption of conventional breeding technologies in low-input systems cover a range of organizational and technical aspects. The analysis of 8 CBBPs located in countries of Latin-America, Africa and Asia highlights the importance of bottom-up approaches and involvement of local institutions in the planning and implementation stages. The analysis also reveals a high dependence of these programmes on organizational, technical and financial support. Completely self-sustained CBBPs seem to be difficult to realize. There is a need to implement and document formal socio-economic evaluations of CBBPs to provide governments and other development agencies with the information necessary for creating sustainable CBBPs at larger scales.

Genetic improvement of laying hens viability using survival analysis.

The survival of about eight generations of a large strain of laying hens was analysed separating the rearing period (RP) from the production period (PP), after hens were housed. For RP (respectively PP), 97.8% (resp., 94.1% ) of the 109,160 (resp., 100,665) female records were censored after 106 days (resp., 313 days) on the average. A Cox proportional hazards model stratified by flock (= season) and including a hatch-within-flock (HWF) fixed effect seemed to reasonably fit the RP data. For PP, this model could be further simplified to a non-stratified Weibull model. The extension of these models to sire-dam frailty (mixed) models permitted the estimation of the sire genetic variances at 0.261 +/- 0.026 and 0.088 +/- 0.010 for RP and PP, respectively. Heritabilities on the log scale were equal to 0.48 and 0.19. Non-additive genetic effects could not be detected. Selection was simulated by evaluating all sires and dams, after excluding all records from the last generation. Then, actual parents of this last generation were distributed into four groups according to their own pedigree index. Raw survivor curves of the progeny of extreme parental groups substantially differed (e.g., by 1.7% at 300 days for PP), suggesting that selection based on solutions from the frailty models could be efficient, despite the very large proportion of censored records.

Solution of multiple trait animal models with missing data on some traits.

SUMMARY: In multiple trait animal model evaluations, several transformations (canonical, triangular, combined) can be used to decrease the size of the mixed model equations or to increase their sparsity. A simple method based on an EM argument and replacing missing records by their expectation given the current parameters allows the use of the canonical transformation in situations where data are missing and selection is ignorable. The convergence behavior of these different approaches were compared on real data sets simulating different missing patterns. The combined transformation is always better than the triangular transformation. The extended version of the canonical transformation clearly leads to the fastest convergence, in terms of overall CPU time, especially when a reduced animal model is used (2 to 3 times faster than the triangular transformation) and when more traits are considered simultaneously. RÉSUMÉ: Solution des modèles animales multicaractères avec fichiérs manquantes Dans les évaluations multicaractères de type modèle animal, diverses transformations (canonique, triangulaire, combinée) peuvent être utilisées pour diminuer la taille du système d'équations du modèle mixte ou pour en accroître le nombre d'éléments nuls. Une méthode simple basée sur un raisonnement de type EM et remplaçant les données manquantes par leur espérance sachant la valeur courante des paramètres permet l'utilisation de la transformation canonique dans des situations avec données manquantes et où le processus de sélection peut être ignoré. Les vitesses de convergence de ces différentes approches ont été comparées ` partir de fichiers réels simulant différent types de données manquantes. La transformation combinée s'est revelée toujours meilleure que la transformation triangulaire. La version étendue de la transformation canonique conduit clairement ` la convergence la plus rapide, tout spécialement quand un modèle animal réduit est utilisé (2 ` 3 fois plus rapide que la transformation triangulaire) et quand un grand nombre de caractères sont considérés simultanément. ZUSAMMENFASSUNG: Lósung bei Mehrmerkmalsmodellen und teilweise fehlenden Daten bei einzelnen Merkmalen Beim Mehrmerkmal-Tiermodell können mehrere Transformationen (kanonisch, Winkel, kombiniert) zur Reduktion der Gleichungszahl oder zur Steigerung der null Elemente verwendet werden. Eine einfache Methode, die auf EM-Schlußfolgerungen beruht und fehlende Beobachtungen mit ihren Erwartungswerten (aufgrund gegebener Parameter) ersetzt, gestattet Verwendung kanonischer Transformation bei teilweise fehlenden Daten und vernachlässigbarer Selektion. Das Konvergenzverhalten verschiedener Ansätze wurde an realem Datenmaterial mit simulierten Fehlmustern verglichen. Die erweiterte Transformation ist immer besser als die Winkeltransformation, und diese kanonische Transformation führt hinsichtlich CPU-Zeit zur schnellsten Konvergenz, besonders wenn ein reduziertes Tiermodell mit mehreren Merkmalen verwendet wurde (2- bis 3 mal schneller als Winkeltransformation).