Who Is Dermanyssus gallinae? Genetic Structure of Populations and Critical Synthesis of the Current Knowledge

Despite the economic and animal welfare importance of the Poultry Red Mite Dermanyssus gallinae, its genetic structure has been studied in a scattered way so far. The prophylaxis and control of such a globally distributed ectoparasite can be significantly improved by understanding its genetic population structure (composition in species and intraspecific variants). The present study aims to establish a rigorous framework for characterizing the neutral genetic structure of D. gallinae based on a literature review combined with an integrative analysis of the data available in GenBank on population-level nucleotide sequence diversity supplemented by a new dataset. The integrative analysis was conducted on sequence data extracted from GenBank coupled with new sequences of two fragments of the mitochondrial gene encoding Cytochrome Oxidase I (CO1) as well as of an intron of the nuclear gene encoding Tropomyosin (Tpm) from several PRM populations sampled from European poultry farms. Emphasis was placed on using the mitochondrial gene encoding CO1 on which the main universal region of DNA barcoding in animals is located. The species D. gallinae sensu lato is a species complex, encompassing at least two cryptic species, i.e., not distinguishable by morphological characters: D. gallinae sensu stricto and D. gallinae L1. Only D. gallinae s.s. has been recorded among the populations sampled in poultry farms worldwide. Current knowledge suggests they are structured in three mitochondrial groups (haplogroups A, B, and C). Haplogroup A is cosmopolitan, and the other two present slightly contrasted distributions (B rather in the northern part of Europe, C most frequently found in the southern part). Recent data indicate that a dynamic geographic expansion of haplogroup C is underway in Europe. Our results also show that NUMT (nuclear mitochondrial DNA) pseudogenes have generated artifactual groups (haplogroups E and F). It is important to exclude these artifact groups from future analyses to avoid confusion. We provide an operational framework that will promote consistency in the analysis of subsequent results using the CO1 fragment and recommendations for future analyses

Circulating Cell-Free DNA in Dogs with Mammary Tumors: Short and Long Fragments and Integrity Index

Circulating cell-free DNA (cfDNA) has been considered an interesting diagnostic/prognostic plasma biomarker in tumor-bearing subjects. In cancer patients, cfDNA can hypothetically derive from tumor necrosis/apoptosis, lysed circulating cells, and some yet unrevealed mechanisms of active release. This study aimed to preliminarily analyze cfDNA in dogs with canine mammary tumors (CMTs). Forty-four neoplastic, 17 non-neoplastic disease-bearing, and 15 healthy dogs were recruited. Necrosis and apoptosis were also assessed as potential source of cfDNA on 78 CMTs diagnosed from the 44 dogs. The cfDNA fragments and integrity index significantly differentiated neoplastic versus non-neoplastic dogs (P<0.05), and allowed the distinction between benign and malignant lesions (P<0.05). Even if without statistical significance, the amount of cfDNA was also affected by tumor necrosis and correlated with tumor size and apoptotic markers expression. A significant (P<0.01) increase of Bcl-2 in malignant tumors was observed, and in metastatic CMTs the evasion of apoptosis was also suggested. This study, therefore, provides evidence that cfDNA could be a diagnostic marker in dogs carrying mammary nodules suggesting that its potential application in early diagnostic procedures should be further investigated

Canine mammary tumours, an overview

Canine mammary tumours (CMTs) are the most common neoplasms in intact female dogs. Although the prevalence of these tumours decreases in regions where preventive ovari(ohyster)ectomy is performed, it remains an important disease entity in veterinary medicine. Moreover, treatment options are limited in comparison with human breast cancer. Nevertheless, recent human treatment protocols might have potential in bitches suffering from CMTs. This review article summarizes the most important characteristics of canine mammary tumours (CMTs) and recommendations for diagnosis and treatment. First, the anatomy and physiology of the normal mammary gland is described. Next, the prevalence of CMTs is discussed. Thereafter, the classification and the aetiology and pathogenesis are presented. Subsequently, the clinical signs, diagnosis, treatment options and prognosis of CMTs are discussed. Finally, a special disease entity of CMTs, inflammatory mammary carcinoma (IMC), is covered

Effects of split feeding on performance, egg quality, and bone strength in brown laying hens in aviary system

© 2018 Poultry Science Association Inc. Brown laying hens are kept in production on average until 80 weeks. In the last phase of the production cycle, however, egg production decreases, and there is a proportional increase in cracked eggs due to decreased shell quality. Laying hens are expected to produce 500 first-quality eggs until 100 wk of age without being molted in extended production cycles. Therefore, problems related to decreased shell quality have to be addressed by genetic selection and also by optimizing nutrition and management. Conventional feeding systems in laying hens might need to be re-evaluated regarding daily Ca requirement, time, and source of its supplementation and absorption. In this experiment, feeding different diets in the first and second half of the d in a split feeding system was tested as a potential strategy to improve shell quality by offering a better match between Ca supplementation and requirements in the laying hen. Although the aim was to keep hens for an extended laying cycle, the flock had to be depopulated at 85 wk due to increased cracked eggs and low performance in the last phase of the experiment. The split feeding system could not maintain shell quality; however, it did show some potential to improve relative shell weight. The practical application of split feeding was challenging in the aviary system, and the flock also experienced health and welfare problems before and during the experiment, which influenced overall performance and the outcome of the experiment. Further long-term studies are needed to address these issues related to shell quality and health of laying hens kept in extended laying cycles.status: publishe