Einfluss von Jahreszeit, Rasse und Alter auf die Samenqualität beim Eber

Ziel der vorliegenden Studie war es, die jahreszeitlichen Schwankungen der Samenqualität bei Zuchtebern (n=491) unter Berücksichtigung von Rasse und Alter zu untersuchen. Während drei Jahren wurden insgesamt 1’686 Ejakulate jeweils im Februar, Mai, August und November untersucht. Bei allen Ejakulaten wurden Volumen, Dichte, Gesamtspermienzahl, Motilität und Morphologie bestimmt. Die Ergebnisse zeigen, dass die Jahreszeit alle untersuchten Samenqualitätsparameter beeinflusste. Volumen (ml) und Dichte (Mio./ml) waren im Herbst (209.7±2.7 bzw. 270.3±6.2) signifikant (P<0.05) höher bzw. geringer als im Winter (185.6±2.8 bzw. 308.9±6.3), Frühling (180.9±2.7 bzw. 308.0±6.1) und Sommer (188.5±2.7 bzw. 288.6±6.0). Die Gesamtspermienzahl (x109) war im Frühling (54.2±1.0) und Sommer (52.7±1.0) signifikant geringer als im Herbst (55.5±1.1) und Winter (55.2±1.1). Die Motilität (%) war im Frühling (80.7±0.3) deutlich besser als im Sommer (79.7±0.3), Herbst (79.9±0.3) und Winter (79.9±0.3). Bezüglich Spermienmorphologie zeigte sich, dass der Anteil normaler Spermien (%) im Sommer (78.7±0.8) signifikant geringer und der Anteil an Hauptdefekten signifikant grösser (13.6±06) war als im Herbst (81.6±0.8 bzw. 11.8±0.6), Winter (82.9±0.8 bzw. 10.4±0.6) und Frühling (81.7±0.8 bzw. 11.7±0.6). Im Verlaufe der 3-jährigen Versuchszeit war ein signifikanter Einfluss des Jahres auf die Dichte, Gesamtspermienzahl und Motilität vorhanden, während Rasse und Alter alle untersuchten Parameter signifikant beeinflussten. The aim of this study was to investigate the influence of season, breed and age on boar semen quality. During a 3-year period a total of 1’686 ejaculates were collected from 491 boars in February, May, August and November. For all ejaculates, the volume, concentration, total sperm number, motility and the percentage of normal sperm and major defects were evaluated. Significant (P < 0.05) seasonal changes were observed in all semen quality parameters. The volume (ml) und concentration (mio./ml) were significant higher and lower respectively in autumn (209.7±2.7 and 270.3±6.2, respectively) than in winter (185.6±2.8 and 308.9±6.3, respectively), spring (180.9±2.7 and 308.0±6.1, respectively) and summer (188.5±2.7 and 288.6±6.0, respectively). Total sperm number (x109) was significantly lower in spring (54.2±1.0) and summer (52.7±1.0) than in autumn (55.5±1.1) and winter (55.2±1.1). Motility (%) was clearly higher in spring (80.7±0.3) compared to summer (79.7±0.3), autumn (79.9±0.3) and winter (79.9±0.3). Regarding sperm morphology the percentage of normal sperm was significantly lower in summer (78.7±0.8) and major defects significantly higher (13.6±06) than in autumn (81.6±0.8 and 11.8±0.6, respectively), winter (82.9±0.8 and 10.4±0.6, respectively) and spring (81.7±0.8 and 11.7±0.6, respectively). In addition to seasonal changes a significant effect of the year was observed on sperm concentration, total sperm number and motility, while breed and age had a significant influence on all evaluated parameters

Farm-level risk factors for digital dermatitis in dairy cows in mountainous regions.

Reduction of risk factors for bovine digital dermatitis (BDD) is crucial in current disease control. However, risk factors that might arise especially in mountainous regions are unknown until now, and an adapted BDD control program is consequently missing. The objective of this observational case-control study was to identify farm-level risk factors for BDD in dairy herds in mountainous regions. To investigate predictors for the occurrence of BDD, 100 farms were visited and information about herd characteristics and management practices, potentially relevant explanatory variables for either introduction or establishment of BDD, were gathered by completing a questionnaire with the farmer or herd manager. Within-herd prevalences of BDD assessed during 3 routine claw trimmings with an interval of 6 mo before the survey were used to define cases (BDD within-herd prevalence of ≥26% during each claw trimming) and controls (no BDD cases in each of the 3 routine claw trimmings before the survey). Data were analyzed using 2 separate binomial generalized linear models according to either establishment or introduction of BDD. After prescreening, 15 of 23 explanatory variables were included in the final analysis, which showed 3 variables related to introduction and establishment, each being significantly associated with the occurrence of BDD within a farm. Results of model 1 (i.e., aspects related to BDD introduction) revealed that access to mountain pastures during the summer season (odds ratio, 95% confidence interval: 0.12, 0.04-0.35), participation in dairy shows (0.32, 0.11-0.94), and the number of new animals introduced into the farm during the last 2 yr (1.28, 1.12-1.52) were significantly associated with the occurrence of BDD. Model 2 (i.e., aspects related to BDD establishment) showed that cows kept in freestalls were at higher risk for BDD compared with those kept in tiestalls (20.65, 1.59-649.37). Furthermore, number of days between diagnosis and treatment of a BDD lesion (10.31, 3.55-81.21) and the amount of concentrate feeding (median 5 kg) per cow and day (7.72, 2.46-6.47) were positively associated with BDD occurrence. In conclusion, the findings of this study provide a set of risk factors that are associated with BDD status within herds in mountainous regions. These results may help in development of adapted control programs for BDD in dairy cows

An Unusual Splice Defect in the Mitofusin 2 Gene (MFN2) Is Associated with Degenerative Axonopathy in Tyrolean Grey Cattle

Tyrolean Grey cattle represent a local breed with a population size of ∼5000 registered cows. In 2003, a previously unknown neurological disorder was recognized in Tyrolean Grey cattle. The clinical signs of the disorder are similar to those of bovine progressive degenerative myeloencephalopathy (weaver syndrome) in Brown Swiss cattle but occur much earlier in life. The neuropathological investigation of an affected calf showed axonal degeneration in the central nervous system (CNS) and femoral nerve. The pedigrees of the affected calves suggested a monogenic autosomal recessive inheritance. We localized the responsible mutation to a 1.9 Mb interval on chromosome 16 by genome-wide association and haplotype mapping. The MFN2 gene located in this interval encodes mitofusin 2, a mitochondrial membrane protein. A heritable human axonal neuropathy, Charcot-Marie-Tooth disease-2A2 (CMT2A2), is caused by MFN2 mutations. Therefore, we considered MFN2 a positional and functional candidate gene and performed mutation analysis in affected and control Tyrolean Grey cattle. We did not find any non-synonymous variants. However, we identified a perfectly associated silent SNP in the coding region of exon 20 of the MFN2 gene. This SNP is located within a putative exonic splice enhancer (ESE) and the variant allele leads to partial retention of the entire intron 19 and a premature stop codon in the aberrant MFN2 transcript. Thus we have identified a highly unusual splicing defect, where an exonic single base exchange leads to the retention of the preceding intron. This splicing defect represents a potential explanation for the observed degenerative axonopathy. Marker assisted selection can now be used to eliminate degenerative axonopathy from Tyrolean Grey cattle

Klauengesundheit (6/6): Das Grippeli, besonders auf Rinderalpen ein Problem. Sumpfstellen sind ein Risiko

Das Grippeli ist bei Alprindern ein Problem, das den Tieren Schmerzen und den Hirten Mehraufwand für Behandlungen bereitet. Befestigte Tränkestellen und die Trennung trächtiger und nicht trächtiger Rinder helfen