Coxiella burnetii: Serological reactions and bacterial shedding in primiparous dairy cows in an endemically infected herd—impact on milk yield and fertility

Coxiella burnetii (C. burnetii) is the causative agent of Q fever both in humans and animals. The objectives of this study were to investigate seropositivity and bacterial shedding in heifers and primiparous cows in an endemically infected herd and to assess the effects on post‐partum diseases, fertility and milk production. At the age of 9 months, 96 Holstein heifers were included. Sampling was performed reproduction‐orientated: at the beginning of the study, at detection of first pregnancy, 3 weeks before expected calving date (blood serum), at parturition and after 21, 42, 100 and 150 days in milk (DIM) (blood serum, vaginal swabs and milk). Serum samples were investigated by a commercial ELISA for the presence of specific antibodies and vaginal swabs and milk samples by PCR to detect C. burnetii DNA. Individual animal data (calving ease, stillbirth, retained foetal membranes, puerperal metritis, endometritis after 42 DIM, presence of corpus luteum after 42 DIM, interval calving‐first service, interval calving‐conception, number of inseminations until 150 DIM, proportion of pregnant cows until 100 and 150 DIM, proportion of pregnant cows after first service and data of the dairy herd improvement test) were documented. All heifers were seronegative at the age of 9 months and 3 weeks before the expected calving date. Subsequently, the proportion of seropositive animals and the antibody score increased significantly towards 42 and 100 DIM, respectively. Vaginal C. burnetii shedding was highest at parturition (30.9%), while the most positive milk samples were detected after 100 DIM (15.3%). Coxiella burnetii seropositivity and shedding had no impact on parameters of reproduction. However, milk fat yield was declined in puerperal vaginal shedders and cows which seroconverted during their first 42 DIM, respectively.     

Ameliorative Effects of Melatonin against Hydrogen Peroxide‐Induced Oxidative Stress on Boar Sperm Characteristics and Subsequent In Vitro Embryo Development

Melatonin, the major secretory product of the pineal gland, scavenges a variety of reactive oxygen and nitrogen species in vivo and in vitro, indicating that melatonin is a potent function as an antioxidant. The objective of this study was to investigate the effect of melatonin in the presence or absence of hydrogen peroxide (H₂O₂) on sperm characteristics (motility, viability, survival rate, membrane integrity, lipid peroxidation (LPO) and mitochondria activity) and also to examine the developmental rates to the blastocysts stage of porcine oocytes fertilized in vitro with semen treated with or without melatonin (100 nm ) in the presence or absence of H₂O₂ (250 μm ). The sperm were treated with melatonin in the presence or absence of H₂O₂ for 3, 6, 9 and 12 h at 37°C and then analysed for the sperm characteristics. The porcine embryos were produced by in vitro maturation and in vitro fertilization (IVM/IVF) using semen treated with or without melatonin (100 nm ) in the presence or absence of H₂O₂ (250 μm ) for 6 h. The semen characteristics, including motility, viability, survival rate, membrane integrity and mitochondria activity, were higher in the groups that were treated with melatonin in comparison to other groups, irrespective of incubation periods. Malondialdehyde levels in control, melatonin and melatonin + H₂O₂ groups were lower than H₂O₂ only group. A positive correlation was shown among motility, viability, survival rate and membrane integrity, but a negative correlation was observed between LPO and the other evaluation methods. The developmental rates to blastocysts of IVM/IVF porcine oocytes fertilized by semen treated with melatonin were significantly increased compared with any other groups, with the cell number of blastocysts shown to have a similar trend to the developmental rates. These results demonstrate that melatonin can improve the semen characteristics during in vitro storage and support the developmental ability of IVM/IVF embryos in pigs.     

Diagnosis of early pregnancy by testing the progesterone level

Measuring serum or plasma levels of progesterone can be used to determine if conception has occurred in horses. If the mare's progesterone level is below 2 ng/ml 18 days after mating has occurred, conception has not taken place. This method can be used as an addunct to genital examination, and it can be used to determine if hormonal irregularities are present in mares who have not been able to conceive.     

Assessment of Genetic Variability in the Coding Sequence of Melatonin Receptor Gene (MTNR1A) in Tropical Arid Sheep Breeds of India

Seasonal behaviour in sheep, which varies in tropical and temperate environmental conditions, is a matter of study, because it can provide a clue to address the problem of seasonality in sheep. Melatonin receptor is the membrane‐bound G‐coupled receptor, sensing the message of photoperiodic cues thorough melatonin. Restriction fragment length polymorphism (RFLP) studies were carried out to assess the variability of gene at G612A and C606T SNPs in MTNR1A gene, which have been studied to be markers for out‐of‐season breeding. Allelic frequency distribution corresponded to higher frequency of GG and CC genotype, in tropical arid sheep breed in comparison with temperate region sheep breed. PCR amplification of MTNR1A gene of 30 animals was performed and single nucleotide polymorphisms (SNPs) identification was carried out using Lasergene software. Seven SNPs/mutations were identified, but most of them were synonymous, except the one G706A, leading to substitution of valine by isoleucine. Polyphen‐2 analysis of G706A mutation revealed that it is a benign mutation. Two important SNPs C426T and G555A, which were identified in temperate sheep breeds, could not be traced in Magra and Marwari breeds of sheep. Thus, the Magra and Marwari breeds of tropical, arid region demonstrated the presence of both polymorphic SNPs markers G612A and C606T, associated with out‐of‐season breeding. GG and CC genotypes were having a higher prevalence in the studied population.     

Effect of a Gonadotropin-releasing Hormone Vaccine (ImprovacTM) on Steroid Hormones, Boar Taint Compounds and Performance in Entire Male Pigs

The objective of this study, comprising two trials, was to evaluate the effect of a gonadotropin‐releasing hormone (GnRH‐vaccine Improvac^TM; Pfizer Ltd) in a sample of the Swedish pig population. The pigs (n = 120) were assigned to three groups: control (entire male pigs), surgical castration and immunization against GnRH. Surgically castrated pigs did not express detectable levels of either testosterone or estrone sulphate (E1S) in plasma, or androstenone in fat and had lower skatole and indole levels in fat than entire male pigs. Immunization significantly reduced testes weight and bulbourethral gland length, plasma levels of the testicular hormones testosterone and E1S, and fat levels of androstenone, skatole and indole. Skatole levels in plasma were significantly lower than in entire male pigs in the second trial, but not in the first due to overall low skatole levels. All immunized pigs and surgically castrated pigs expressed skatole concentrations in fat below the level of 0.2 μg/g, above which meat is regarded as tainted. In contrast, eight entire male pigs exceeded this level. Indole levels in plasma from immunized pigs were lower than those from entire male pigs. Surgical castration caused lower daily weight gain in the suckling period compared with piglets raised intact, whereas in the post‐weaning period no difference was observed. Immunization resulted in higher feed intake and daily weight gain after the second injection. The estimated lean meat content was improved in comparison with the castrated pigs, but was lower than for entire male pigs. Dressing percentage was lower in immunized pigs than in surgically castrated and entire male pigs. The frequency of skin damage did not differ between immunized and entire male pigs or between immunized and surgically castrated pigs.     

Gonosomenanomalien bei Stuten sowie Ergebnisse zytogenetischer Unter-suchungen bei Stuten mit erheblich gestörter Fertilität*

Gonosomanomalies in mares and results of cytogenetic investigations in mares with major disturbances in fertility In the present study 28 mares with heavy disturbed fertility were examined on chromosome defects. Especially numerical anomalies on the gonosomes were taken into consideration. The preparation of the chromosomes was done by blood lymphocyte cultures. For that purpose blood tests were taken by the Venojekt** system. The preparations were stained by Giemsa- und c-band-technique. The caryotype by Hare 1980) served as the standard caryotype, by which at least 30 metaphases of each mare were analysed. The results of this examination are the following: 1. McCoy's 5A-medium with Hepes-supplement was suitable for the culture of lymphocytes for preparation of chromosomes of mares. 2. On the individual mitogenbatches important quality differences were stated. The mitogen Pokeweed turned out to be better qualified for the stimulation of lymphocytes than the mitogen Phytohaemagglutinin. 3. Good preparations resulted from the following medium-combination: 75% McCoy's 5A-medium with Hepes-buffer — 25% fetal calves' serum — 0, l ml Pokeweed as mi-togen. 4. Even after two days of storing the lymphocytes in the medium-combination good preparation results were obtained. 5. A modified staining-method for the presentation of c-bands respecting the exact identification of the gonosomes brought forth better results than the method of Schmidt (1976). 6. Although considerable fertility disturbances were present, not one gonosom anomaly was stated in the examined mares.     

Vorubergehende Thrombozytopenie während der frühen Trächtigkeit bei zur Superovulation stimulierten und unbehandelten Kühen*

Inhalt: An 52 Kuhen aus verschiedenen ET-Programmen (n=39) sowie aus dem normalen Besamungsbetrieb (n=13) wurde geprüft, ob es auch bei dieser Spezies in der frühen Trachtigkeit im Blut zu einer vorübergehenden Thrombozytopenie kommt, wie es von O'Neill (1985) bei Mausen beobachtet wurde. Die Blutproben (Sepzialrohrchen, 5 ml mit EDTA als Antikoagulans) wurden am Tag der Besamung und an den 4 folgenden Tagen aus der V. jugularis und V. subcutanea abdominis entnommen. Die Zahl der Thrombozyten wurde aus dem Volblut im Coulter Counter, Modell S-Plus bestimmt. Nach Gruppierung der Kühe in solche mit transfertauglichen und solche rnit unbefruchteten Eizellen ergab sich bei den ersteren ein Abfall der Thrombozytenzahl bis zur 4. Probe, bei den letzteren dagegen ein vorübergehender Anstieg der Thrombozytenzaht. Dieser Unterschied erwies sich für den gesamten Untersuchungszeitraum als hochsignifikant (p ≤ 0,001). Bei den Kühen aus dem normalen Besamungsbetrieb tendier-ten die Ergebnisse nach Gruppierung der Tiere hinsichtlich ihres Trächtigkeitsstatus in die gleiche Richtung. Contents: Transitory thrombozytopenie during early pregnancy in superovulated and non-treated cows 52 cows from different ET-programs (n=39) and from the normal AI-service (n=13) were checked to see wether there is during early pregnancy a similar transitory thrombozytopenie as O'Neill has detected it in mice. Venous blood samples (5 ml EDTA as anticoagulant) were taken for 5 days, beginning from the day of AI. The number of thrombocytes was counted from whole blood in a Coulter counter, modell S plus. After grouping the tested cows in such with suitable embryos and such with unfertilized ova in the first group a drop of the thrombocytes up to the fourth sample was seen, in the second group however a transitory increase of the number of thrombocytes. This difference was highly significant (p ≤ 0,001) for the whole test periode but not from day to day. In the cows of the normal AI-service the results tended in the same direction after grouping them according their pregnancy-status.