Proper use and impact of ‘Computer Assisted Semen Analysis’ technique on semen evaluation of farm animals

Σκοπός της παρούσας ανασκόπησης είναι η παρουσίαση της λειτουργίας του αυτόματου αναλυτή σπέρματος υποβοηθούμενου από ηλεκτρονικό υπολογιστή (CASA) και των εφαρμογών του στον τομέα της αναπαραγωγής των παραγωγικών ζώων, ώστε να γίνει ευρέως αντιληπτή η συμβολή του ως εργαλείο πρόγνωσης της γονιμότητας των αρσενικών ζώων Παρατίθενται οι προϋποθέσεις ορθής λειτουργίας του αναλυτή, οι παράγοντες που επηρεάζουν αυτήν και η αξιολόγηση των εκτιμούμενων παραμέτρων, με ιδιαίτερη έμφαση στην κινητικότητα των σπερματοζωαρίων. Ο αναλυτής CASA αποτελεί σημαντικό εφόδιο για τους ασχολούμενους με τη διαχείριση υγείας των παραγωγικών ζώων, ωστόσο απαιτείται τήρηση των κανόνων για ορθή εκτίμηση των δειγμάτων και για αξιοπιστία και δυνατότητα σύγκρισης των αποτελεσμάτων.Objective of this review is to present the use of ‘Computer Assisted Semen Analysis’ technique application in farm animal health management, in particular the steps for accurate semen evaluation and the impact of the method in predicting male animal fertility under field conditions. Requirements for proper use of the equipment, factors affecting the evaluation process and the role of the estimated parametres for fertility under field conditions are described. Special reference is made in sperm motility evaluation. It is concluded that the method is an effective and efficient tool for semen evaluation, provided good practices are strictly applied and adhered to, by means of which valid results may be obtained

The changing global distribution and prevalence of canine transmissible venereal tumour.

BACKGROUND: The canine transmissible venereal tumour (CTVT) is a contagious cancer that is naturally transmitted between dogs by the allogeneic transfer of living cancer cells during coitus. CTVT first arose several thousand years ago and has been reported in dog populations worldwide; however, its precise distribution patterns and prevalence remain unclear. RESULTS: We analysed historical literature and obtained CTVT prevalence information from 645 veterinarians and animal health workers in 109 countries in order to estimate CTVT's former and current global distribution and prevalence. This analysis confirmed that CTVT is endemic in at least 90 countries worldwide across all inhabited continents. CTVT is estimated to be present at a prevalence of one percent or more in dogs in at least 13 countries in South and Central America as well as in at least 11 countries in Africa and 8 countries in Asia. In the United States and Australia, CTVT was reported to be endemic only in remote indigenous communities. Comparison of current and historical reports of CTVT indicated that its prevalence has declined in Northern Europe, possibly due to changes in dog control laws during the nineteenth and twentieth centuries. Analysis of factors influencing CTVT prevalence showed that presence of free-roaming dogs was associated with increased CTVT prevalence, while dog spaying and neutering were associated with reduced CTVT prevalence. Our analysis indicated no gender bias for CTVT and we found no evidence that animals with CTVT frequently harbour concurrent infectious diseases. Vincristine was widely reported to be the most effective therapy for CTVT. CONCLUSIONS: Our results provide a survey of the current global distribution of CTVT, confirming that CTVT is endemic in at least 90 countries worldwide. Additionally, our analysis highlights factors that continue to modify CTVT's prevalence around the world and implicates free-roaming dogs as a reservoir for the disease. Our analysis also documents the disappearance of the disease from the United Kingdom during the twentieth century, which appears to have been an unintentional result of the introduction of dog control policies.This is the author's accepted manuscript. The final version of this article has been published by BioMed Central: http://www.biomedcentral.com/1746-6148/10/168

Chromatin integrity of ram spermatozoa. Relationships to annual fluctuations of scrotal surface temperature and temperature-humidity index

The objective of the present study was to explore the potential relationships of ovine sperm chromatin integrity, quantified using the sperm chromatin structure assay (SCSA), to the heat load of the scrotum and the discomfort felt by the animals because of fluctuations of microclimatic factors at different time periods before ejaculation. Ejaculates were collected once per week from five Chios rams and four East Friesian rams for 12 months and stored in liquid nitrogen. Frozen-thawed semen samples were analyzed using the SCSA, to determine the DNA fragmentation index (DFI) and the percentage of cells outside the main sperm population (%DFI) in each one of the samples. Scrotal surface temperature (SST) of each ram was measured using an infrared thermometer on a daily basis. Ambient air temperature and relative humidity were recorded at hourly intervals throughout the experimental period and temperature-humidity index (THI) was used to assess the discomfort felt by the rams. Mean values of SST (SST mean) and THI (THI mean) were computed for eight different time periods (up to 61 days) preceding each ejaculation day (Day 0). A linear mixed-effect model analysis was performed to describe the relation of SCSA parameters to collection month, SST mean, and THI mean of different time periods before ejaculation. The results of the statistical analysis revealed a relation of %DFI to the SST mean of the last 12 days preceding ejaculation, namely the period that resembled the phase of epididymal maturation. On the contrary, the variation of DFI was most adequately described by the linear mixed-effect model applied for Days 54 to 48 before ejaculation, which resembled the phase of spermatogonial mitoses. The effect of collection month was significant for DFI and %DFI, with semen samples collected in September and February exhibiting the lowest DFI values; a less profound seasonal pattern was detected for %DFI. The effect of THI mean on DFI and %DFI was proven nonsignificant in regard to all time periods. In conclusion, a relation of SCSA parameters to SST mean of different periods before ejaculation was shown in the present study, implying an effect of scrotal microenvironment on intratesticular and epididymal sperm population. In contrast, we failed to detect any effect of microclimate-induced discomfort felt by the animals on the chromatin integrity of frozen-thawed ram spermatozoa

Diagnosis of clinical or subclinical mastitis in ewes

Objectives of this paper are to review (i) diagnostic methods and procedures available for clinical or subclinical mastitis in ewes and (ii) applications of these procedures in the diagnosis of mastitis. Early and correct diagnosis of the disease is important for identification of affected animals. The following diagnostic procedures can be used: clinical examination, imaging techniques (ultrasonography, endoscopy), bacteriological examination of milk samples, immunological tests, identification of biomarkers (cytological examination of milk and measurement of milk electroconductivity). In most cases, diagnosis of clinical mastitis is straightforward, based on the findings of clinical examination. The differential diagnosis includes primarily (i) bacterial mastitis (usually sporadic occurrence in a flock, usually unilateral, isolation of bacteria from milk samples), (ii) mycoplasmal mastitis [usually epidemic occurrence in a flock, usually bilateral accompanied by other signs (e.g., arthritis), isolation of Mycoplasma spp. from milk samples] and (iii) infection by Small Ruminant Lentivirus [usually epidemic occurrence in a flock, usually bilateral accompanied by various signs (e.g., respiratory or neurological signs) in the same or other animals of the flock, detection of antibodies to the virus, pro-viral DNA or viral RNA in blood samples]. Subclinical mastitis should be always suspected as one of the primary causes in cases of decreased milk production in dairy flocks; it should also be considered as a possible factor in cases of suboptimal growth rate of lambs in mutton-type production flocks. Diagnosis of subclinical mastitis is based on detection of infection (i.e., isolation of microorganisms from milk samples) and/or inflammatory reaction in the mammary gland. The best method for detection of the inflammatory reaction remains the demonstration of increased cellular content in milk, although various other methods, have been proposed. For individual animals, values 1.0 x 10(6) cells mL(-1) indicate a mammary gland with clinical or subclinical mastitis, with no need to perform a simultaneous bacteriological examination of milk samples to confirm the problem; values between 0.5 x 10(6) and 1.0 x 10(6) cells mL(-1) indicate 'suspected disease', hence there is a need for performing bacteriological examination in milk. Two consecutive measurements increase accuracy of results. In bulk milk samples, counts of 0.65 x 10(6) cells mL(-1) indicate approximately 15% prevalence of subdinical mastitis in the flock. In the differential diagnosis of cases of reduced milk yield in ewes, other possible causes of the problem should be taken into account (e.g., parasitic infections, chronic wasting diseases, suboptimal level of nutrition); in cases of suboptimal growth rate of lambs, other factors may be responsible (e.g., protozoan or parasitic infections, energy or micronutrient deficiency, viral disease). (C) 2013 Elsevier B.V. All rights reserved

Urine protein-to-creatinine ratio in cattle with subclinical renal disease

Background: Urinalysis is not routinely used in bovine medicine, and there is no evidence as to whether urine protein-to-creatinine ratio (UPC) could be used for the diagnosis of renal diseases in cattle. Objective: The goal of the study was to determine alterations in UPCs observed with different subclinical renal diseases in clinically healthy cattle and to investigate whether UPC can efficiently differentiate cattle with and without subclinical renal pathology. Methods: Kidney and urine samples from 57 clinically healthy adult dairy (44) and beef (13) cattle were collected after slaughter. Urinary protein and creatinine concentrations were measured in an automatic analyzer, and urinary-specific gravity (USG) was measured using a temperature compensated refractometer. Kidney samples underwent histopathologic examination, and the cattle were classified as NL (no renal lesion) and L (lesions detected even in one kidney). Based on USG, the cattle were divided into the Normal USG (≥1.020) and Low USG (.05). The analysis revealed that a UPC of ≥0.19 provided an optimal cut-off point for the differentiation between normal animals and those with renal disease with 66.0% sensitivity and 90% specificity. Conclusions: The UPC calculation is a useful tool for the differentiation of normal cattle and those with renal disease. A UPC of less than 0.19 is associated with the absence of renal damage, whereas higher values raise suspicion for renal disease. © 2020 American Society for Veterinary Clinical Patholog