This study was conducted in collaboration with the Department of Reproduction, Obstetrics and Herd Health Faculty of Veterinary Medicine, Ghent Belgium. Associations between dairy herd management practices and both bacterial counts (BC) and coliform counts (CC) from 254 and 242 dairy herds in Flanders (Belgium), respectively, were studied. Data were analyzed using multivariable, multilevel linear regression analysis, allowing variance components analyses. Both BC and CC fluctuated throughout the year, although the milk quality parameters followed an opposite pattern. Multivariable, multilevel regression analysis revealed several management practices associated with either BC or CC. Increasing the cleaning frequency of the housing during wintertime under the Belgian weather conditions and implementing premilking teat disinfection before attaching the milking unit will likely result in lower BC values. Herds with a conventional milking parlor had substantially lower BC than herds where the cows were milked using an automatic milking system. Lower BC were observed when the dry cows were supplemented with a mix of minerals and vitamins, whereas in herds where prepartum heifers were often treated with antimicrobials before calving had a lower CC than farms where heifers were either not or only rarely treated. The variation in both BC and CC seems to be mainly determined by differences in management between the herds, as most variation in both parameters resided at the herd rather than at the observation level. Still, only a small proportion of the total variance was explained by factors capturing information related to the milking, herd health, and dry cow management, which suggests that the bacteriological milk quality and, in particular, CC is primarily driven by other factors than the ones included in this study.
COBISS.SI-ID: 3811706
Sex steroid hormones secreted by gonads influence development and expression of many behaviors including parental behaviors. The capacity to display many behaviors develops under the influence of sex steroid hormones; it begins with gonadal differentiation and lasts through puberty. The timing of gonadectomy may have important and long lasting effects on the organization and activation of neural circuits regulating the expression of different behaviors. The present study investigated the importance of exposure to endogenous gonadal steroid hormones during pubertal period/adolescence on parental behavior in adult mice. Male and female WT mice were gonadectomized either before puberty (25 days of age) or after puberty (60 days of age) and tested for parental behavior with and without estradiol benzoate (EB) replacement in adulthood. Additional groups of mice were gonadectomized at P25 and supplemented with estradiol (females) or testosterone (males) during puberty. Female mice gonadectomized after puberty or gonadectomized before puberty and supplemented with estradiol during puberty, displayed better pup directed parental behaviors in comparison to mice gonadectomized at 25 days of age regardless of treatment with estradiol in adulthood. However, mice treated with EB in adulthood displayed better non-pup directed nest building behavior than when they were tested without EB treatment regardless of sex and time of gonadectomy. Mice were also tested for female sex behavior and there were no differences between mice gonadectomized at P25 or P60, although this could not completely rule out the possibility that parental behavior is more sensitive to prolonged absence of steroid hormones than female sex behavior. These results suggest that the absence of gonads and thereby the absence of appropriate gonadal steroid hormones during puberty/adolescence may have a profound effect on pup directed parental behaviors in adult mice.
COBISS.SI-ID: 3874426
Glucose metabolism is under the cooperative regulation of both insulin receptor (IR) and β2-adrenergic receptor β2AR, which represent the receptor tyrosine kinases (RTKs) and seven transmembrane receptors (7TMRs), respectively. Studies demonstrating cross-talk between these two receptors and their endogenous coexpression have suggested their possible interactions. To evaluate the effect of IR and prospective heteromerization on β2AR properties, we showed that IR coexpression had no effect on the ligand binding properties of β2AR; however, IR reduced β2AR surface expression and accelerated its internalization. Additionally, both receptors displayed a similar distribution pattern with a high degree of colocalization. To test the possible direct interaction between β2AR and IR, we employed quantitative BRET2 saturation and competition assays. Saturation assay data suggested constitutive β2AR and IR homo- and heteromerization. Calculated acceptor/donor (AD50) values as a measure of the relative affinity for homo- and heteromer formation differed among the heteromers that could not be explained by a simple dimer model. In heterologous competition assays, a transient increase in the BRET2 signal with a subsequent hyperbolical decrease was observed, suggesting higher-order heteromer formation. To complement the BRET2 data, we employed the informational spectrum method (ISM), a virtual spectroscopy method to investigate protein-protein interactions. Computational peptide scanning of β2AR and IR identified intracellular domains encompassing residues at the end of the 7th TM domain and C-terminal tail of β2AR and a cytoplasmic part of the IR β chain as prospective interaction domains. ISM further suggested a high probability of heteromer formation and homodimers as basic units engaged in heteromerization. In summary, our data suggest direct interaction and higher-order β2AR:IR oligomer formation, likely comprising heteromers of homodimers.
COBISS.SI-ID: 3896954
Alterations in serum protein profile, presence of circulating immune complexes (CIC) and proteinuria were investigated in a large group of dogs naturally infected with the Anaplasma phagocytophilum (A. phagocytophilum) bacterium. The aim of our study was to evaluate the presence of hypergammaglobulinaemia, CIC and proteinuria as a possible result of an immune-mediated disease following infection by or exposure to A. phagocytophilum. Dogs were divided into three groups - IFA positive (188 dogs with confirmed exposure to A. phagocytophilum ), PCR positive (31 dogs with confirmed infection), and control (IFA and PCR negative) (19 dogs). Serum and urine protein patterns were determined by electrophoresis and CIC concentrations by absorbance nephelometry. No significant differences in hypergammaglobulinaemia were observed between the different groups, as shown by the presence of acute phase proteins α2 and β1-2 globulins. CIC concentrations in the IFA and PCR positive groups were, on average, higher than in controls by 151.3 µg/ml, though the differences were not significant. The proportion of dogs with proteinuria did not differ significantly between groups. Our results confirm the assumption that anaplasmosis in dogs is most probably a disease with an acute course, with a good prognosis under the right treatment.
COBISS.SI-ID: 3863674
The aim of the study was to examine age-dependent and seasonal changes in the circulating leptin concentration in female donkeys (jennies) and thus contribute to the knowledge about the physiological characteristics of this species. The study was performed on CSR Vremščica over a whole year on 20 jennies, which were kept on pasture from May to September and stabled for the rest of the year. Leptin concentrations in the jennies were lower than those measured for horses. Lower leptin values in yearling versus adult jennies indicated age-related leptin variations. Significant seasonal leptin fluctuations with peak leptin levels in late spring correlated with photoperiod in yearling, barren as well as pregnant/lactating jennies. Therefore, it was impossible to identify any effects of gestation or lactation on leptin concentrations. The results of this study reflect changes induced by various external or internal factors enabling adaptations of grazing animals in variable submediterranean environments.
COBISS.SI-ID: 3902586