Prevalence of subclinical endometritis in dairy cows that recovered after treatment of clinical endometritis with cephapirin and PGF2α.

The aims of our study were to evaluate (1) the prevalence of subclinical endometritis (SE) in clinically cured cows after treatment of clinical endometritis (CE) with uterine cephapirin infusion or with systemic application of PGF2α and after self-healing, (2) the prevalence of SE in clinically cured cows in relation to the type of vaginal discharge. The study was conducted on 222 Polish Holstein Friesian cows with CE diagnosed by vaginoscopy and ultrasound. The animals were randomly allocated to one of three groups: Group 1 (n = 72): intrauterine cephapirin infusion; Group 2 (n = 73): single intramuscular injection of dinoprost; and Group 3 (n = 77): left untreated as a control. All cows were reexamined two weeks later (Exam 1). If there was still CE at this examination, these cows were treated using the same method as previously and were examined 2 weeks later (Exam 2). Cows still having CE at the second examination were examined two weeks later (Exam 3). Cows without signs of CE at Exams 1, 2 and 3 were considered cured, and endometrial samples from the uteri were collected by cytobrush to diagnose SE using cytological evaluation of PMN percentage. The threshold for SE was set at ≥ 5% PMNs. Two cows each from Groups 1 and 3 and three cows from Group 2 were not clinically recovered at Exam 3 and were excluded from the analysis. In total, SE was diagnosed in an average of 40.9% of clinically cured cows. The prevalence of SE in Group 1, 2 and 3 was 35.0%, 47.1% and 40.0%, respectively (p > 0.05). There were significantly higher (p < 0.05) SE cases after treatment of CE associated with purulent vaginal discharge than with mucopurulent discharge. In relation to the method of treatment, the prevalence of SE was significantly higher (p < 0.05) in cows treated with cephapirin with purulent vaginal discharge than with mucopurulent vaginal discharge. In conclusion, the study showed a high prevalence of SE in cows clinically cured after treatment of clinical endometritis with cephapirin or PGF2α and after self-healing. The prevalence of SE was significantly higher in cows with purulent vaginal discharge than with mucopurulent vaginal discharge. Therefore, in cows clinically recovered from clinical endometritis, the prevalence of SE should always be considered a negative consequence, and the resulting management of this uterine disease should be implemented at the herd level.

Aglepristone Administration in Mid-Proestrus Reduces the LH Peak but Does Not Prevent Ovulation in the Bitch.

The aim of the study was to evaluate the influence of administration of aglepristone in mid-proestrus on progesterone concentration, LH release, and occurrence of ovulation in the bitch. Experimental bitches (n = 7) were treated on days 4 and 5 of proestrus with aglepristone at the dose of 10 mg/kg body weight s.c. (i.e., the two treatments were 24 h apart). Control animals (n = 7) received s.c. injections of saline. For progesterone determination, blood was collected daily until the first day of cytological diestrus. For LH determination, blood was collected daily and in the periovulatory phase every 8 h. The progesterone concentration showed a similar pattern in both groups. The LH peak value in bitches treated with aglepristone was significantly lower (p < 0.05) than that in control bitches (4.83 ± 1.20 vs. 13.66 ± 1.21 ng/mL). The area under the curve (AUC) for LH was significantly (p < 0.05) lower in treated than in control animals (6.85 ± 1.21 ng/mL/d vs. 12.25 ± 1.35 ng/mL/d). The ovulation occurred in all animals in both groups. The study showed that administration of aglepristone in the mid-proestrus significantly reduced the preovulatory LH surge, but it had no effect on progesterone concentration and the occurrence of ovulation.

[Development of a large intraprostatic cyst following the use of a GnRH agonist-implant in a male dog with benign prostatic hyperplasia]. / Entwicklung einer großen intraprostatischen Zyste nach Einsatz eines GnRH-Agonist-Implantats bei einem Rüden mit benigner Prostatahyperplasie.

A male dog with benign prostatic hyperplasia and several small intraprostatic cysts was treated with a GnRH-agonist implant containing 4,7 mg deslorelin (Suprelorin®). Within 2 weeks after the implantation, the prior urethral bleeding worsened. A large intraprostatic cyst was detected sonographically. The patient was subsequently treated with osaterone acetate (0.4 mg/kg p. o. once a day for 7 days) and enrofloxacin (5 mg/kg p. o. once a day for 21 days). The clinical symptoms receded within 10 days. Within one month, the cyst regressed completely. The mechanisms of cyst enlargement are discussed.

Is similarity in Major Histocompatibility Complex (MHC) associated with the incidence of retained fetal membranes in draft mares? A cross-sectional study.

The failure of the maternal immune system to recognize fetal antigens and vice versa due to MHC similarity between the foal and its dam might result in the lack of placental separation during parturition in mares. The aim of the study was to investigate the influence of MHC similarity between a mare and a foal on the incidence of retained fetal membranes (RFM) in post-partum mares. DNA was sampled from 43 draft mares and their foals. Mares which failed to expel fetal membranes within three hours after foal expulsion were considered the RFM group (n = 14) and mares that expelled fetal membranes during the above period were the control group (n = 29). Nine MHC microsatellites of MHC I and MHC II were amplified for all mares and foals. MHC compatibility and MHC genetic similarity between mares and their foals was determined based on MHC microsatellites. The inbreeding coefficient was also calculated for all horses. The incidence of RFM in the studied population was 33%. Compatibility in MHC I and MHC II did not increase the risk of RFM in the studied population of draft mares (P>0.05). Differences in MHC similarity at the genetic level were not observed between mare-foal pairs in RFM and control group (P>0.05). We suspect that RFM in draft mares may not be associated with MHC similarity between a foal and its dam. Despite the above, draft horses could be genetically predisposed to the disease.

Bacteriophages and associated endolysins in therapy and prevention of mastitis and metritis in cows: Current knowledge.

Bacteriophages and the associated endolysins have been proposed as an alternative to antibiotic treatment of mastitis and metritis in cows. Many bacteriophages have been isolated and characterized with a large amount of lytic potential against the bacteria causing mastitis and metritis in cows. Several endolysins with marked lytic activity against mastitis pathogens in vitro were also produced from staphylococcal and streptococcal bacteriophages. In the few clinical studies, however, there has been marginal efficacy of bacteriophages in the therapy of mastitis caused by Staphylococcus aureus. Similarly, lytic bacteriophages have marked antimicrobial activity in vitro against E. coli strains from the uteri of postpartum dairy cows. In clinical studies, however, neither administration of bacteriophages early postpartum nor prepartum was effective in the prevention of metritis in cows. More clinical studies on the effectiveness of bacteriophages and the associated endolysins in the prevention and therapy of mastitis and metritis in cows, therefore, are needed.

The oxytocin-prostaglandins pathways in the horse (Equus caballus) placenta during pregnancy, physiological parturition, and parturition with fetal membrane retention.

Despite their importance in mammalian reproduction, substances in the oxytocin-prostaglandins pathways have not been investigated in the horse placenta during most of pregnancy and parturition. Therefore, we quantified placental content of oxytocin (OXT), oxytocin receptor (OXTR), and prostaglandin E2 and F2 alpha during days 90-240 of pregnancy (PREG), physiological parturition (PHYS), and parturition with fetal membrane retention (FMR) in heavy draft horses (PREG = 13, PHYS = 11, FMR = 10). We also quantified OXTR and prostaglandin endoperoxide synthase-2 (PTGS2) mRNA expression and determined the immunolocalization of OXT, OXTR, and PTGS2. For relative quantification of OXT and OXTR, we used western blotting with densitometry. To quantify the prostaglandins, we used enzyme immunoassays. For relative quantification of OXTR and PTGS2, we used RT-qPCR. For immunolocalization of OXT, OXTR, and PTGS2, we used immunohistochemistry. We found that OXT was present in cells of the allantochorion and endometrium in all groups. PTGS2 expression in the allantochorion was 14.7-fold lower in FMR than in PHYS (p = 0.007). These results suggest that OXT is synthesized in the horse placenta. As PTGS2 synthesis is induced by inflammation, they also suggest that FMR in heavy draft horses may be associated with dysregulation of inflammatory processes.

Survival and fertility of bitches undergoing caesarean section.

BACKGROUND: With the increasing popularity of planned caesarean section, the need for knowledge regarding this surgery has become increasingly important. The reported death and survival rates for caesarean sections vary widely. Another important aspect is the fertility rate in subsequent oestrous after caesarean section. The aim of this study was to investigate the mortality and survival rate of bitches during caesarean section. Additionally, the fertility of bitches after caesarean sections was determined. METHODS: Caesarean sections which were performed in the years 1997-2009 at two university clinics were evaluated retrospectively. A distinction was made between bitches in which a conservative caesarean section was performed and bitches with a caesarean section followed by an ovariohysterectomy. RESULTS: A total of 482 caesarean sections were included in the study. The overall mortality rate was 3.11 per cent, with 2.59 per cent during or after a conservative caesarean section and 4.19 per cent during or after caesarean section with ovariohysterectomy. The reason for ovariohysterectomy was the owner's preference in 63 bitches (47.01 per cent); in 71 (52.98 per cent) bitches, ovariohysterectomy was performed due to a medical indication. The fertility rate after caesarean section was 100 per cent. CONCLUSION: The results show a high mortality rate during and after caesarean section. On the other hand, caesarean section does not seem to have a big impact on further fertility. Further studies are needed to investigate possible reduction of litter sizes and the suitability of caesarean section in subsequent pregnancies.

Attempts to downregulate ovarian function in the bitch by applying a GnRH agonist implant in combination with a 3ß-hydroxysteroid-dehydrogenase blocker; a pilot study.

Approaches to downregulate ovarian function in the sexually mature bitch by applying slow release GnRH agonist implants are hampered by the initial stimulation of folliculogenesis (flare up) and the resulting side effects. The present pilot study was designed to test to what extent these effects can be suppressed by simultaneous treatment with the 3ß-hydroxysteroid-dehydrogenase (HSD3B) blocker trilostane (T). Treatment with T in 6-h intervals completely blocked adrenal cortisol production. However, in parallel and concomitant with the increase of LH, progesterone and estradiol levels increased, ending up in pro-estric steroid levels in two of the three dogs. Hormonal changes were reflected in the respective clinical symptoms. During the whole observation period the course of LH concentrations did not indicate downregulation of pituitary function as a result of treatment with the GnRH-agonist Suprelorin®, 4.7 mg. The incomplete inhibitory effect of T on the follicular production of sex steroids could be explained by an insufficient transfer of T into the follicular compartment or the existence of a HSD3B isoform in the dog ovary different from the adrenal enzyme. Concerning the lack of downregulation and when accounting for published data different pharmacodynamics/pharmacokinetic activities of GnRH-agonists should be taken into account.

Global Transcriptomic Analysis of the Canine corpus luteum (CL) During the First Half of Diestrus and Changes Induced by in vivo Inhibition of Prostaglandin Synthase 2 (PTGS2/COX2).

The canine luteal phase exhibits several peculiarities compared with other species. In early diestrus, the corpus luteum (CL) is, at least in part, independent of gonadotropins, and prostaglandins (PGs) appear to be among its main regulators. This was also observed with the inhibition in vivo of COX2, when also transcriptional capacity, vascularization and immune-related factors were affected. Here, we aimed to further investigate the potential effects of PGs withdrawal on the CL transcriptome by performing deep RNA sequencing (RNA-Seq). Samples from a previous in vivo study were used; bitches were treated for 5, 10, 20, or 30 days after ovulation with firocoxib (Previcox®), a PTGS2/COX2 inhibitor, or a placebo. Analysis of results was performed with SUSHI (framework from FGCZ) and with pathways and functional networks analyzers. Time-dependent effects were also investigated and used for quality control. More highly represented differentially expressed genes (DEGs, P < 0.01, FDR < 0.1) in the early CL (days 5 and 10) referred to proliferation and immune system, while in the mature CL (days 20 and 30) they were related with steroidogenesis. The absence of genes concomitantly affected by the treatment at all time-points suggested stage-dependency in the observed effects. Little effect was observed on days 5 and 10. Day 20 had the highest number of DEGs (n = 1,741), related with increased immune response. On day 30, DEGs found (n = 552) referred to decreased steroidogenesis and vascularization. Our results suggest the presence of strong compensatory effects in the early CL and multidirectional effects toward gonadotropin-dependency of the CL after COX2 inhibition.

The preliminary studies on protein profile in retained and not retained foetal membranes in heavy draft mares.

Protein profile of the placenta expresses its function and maintenance. Any alterations can be reflected in qualitative and quantitative changes in this profile. The aim of the present study was the evaluation of protein profile in the placenta of mares suffering from the retention of foetal membranes (FMR) by two separation methods and the comparison with physiologically released tissues. Placentas from 14 healthy, heavy draft mares were collected immediately after the expulsion of newborn. Tissues after homogenization and staining with fluorescent dyes were subjected to electrophoretic as well as chromatographic separation. Electrophoretic gels were statistically analysed for the presence and abundance of examined proteins, while some proteins were identified in chromatographic fractions. Out of 248 spots detected in endometrium, 38 differed significantly between FMR and control animals, while in allantochorion, respective values reached 241 and 27 spots (p < .05). Among identified proteins that expressed higher abundance in endometrium of FMR mares than control animals were prostaglandin reductase, dehydrogenase/reductase SDR family, and placental growth factor. These proteins are involved in regulation of parturition. Additionally, the following proteins responsible for physiological activity of a cell-guanine methyl transferase, aspartyl/asparaginyl beta-hydroxylase and GTP-binding protein, were identified. These proteins expressed higher abundance in allantochorion of FMR mares than in controls. This preliminary study confirmed the disturbances in protein pattern between foetal membranes in FMR and healthy mares. Further qualitative and quantitative experiments are necessary to deepen our knowledge on the mechanisms of the retention of foetal membranes in mares.

Improvement of Sperm Motility Within One Month Under Selenium and Vitamin E Supplementation in Four Infertile Dogs with Low Selenium Status.

INTRODUCTION: Significant improvement of sperm motility within one month effected by oral supplementation of selenium and vitamin E was described in four infertile male dogs which failed to conceive in their last three matings with different bitches. MATERIAL AND METHODS: The dogs (a Golden Retriever, an English Cocker Spaniel, and two Tibetan Mastiffs) were supplemented daily with selenium (Se) (0.6 mg/kg organic Se yeast) and vitamin E (vit. E) (5 mg/kg) per os for 60 days. Semen was collected on days 0, 30, 60, and 90. The sperm concentration and motility parameters were evaluated by the CASA system, sperm morphology was explored by Diff-Quick staining, and live and dead spermatozoa were differentiated by eosin/nigrosin staining. The concentrations of Se and vit. E were measured in peripheral blood serum on semen collection days. RESULTS: Before administration, the concentrations of Se in blood plasma were low (86.0-165.0 µg/L). After 30 days of treatment there was an observable improvement in total and progressive sperm motility and kinematic parameters (VAP, VSK, VCL, ALH, BCF, and RAPID). The percentages of live and normal morphology sperm cells were also higher. There was also an observable increase in Se and vitamin E concentrations in blood serum. Bitches were successfully mated and delivered four to six puppies. CONCLUSION: Supplementation with Se and vit. E improved rapid sperm motility and restored fertility in infertile dogs with low Se status.

Prostaglandin-mediated effects in early canine corpus luteum: In vivo effects on vascular and immune factors.

Prostaglandins (PGs) are important regulators of the early corpus luteum (CL) in the dog. Whereas, initially, CL is gonadotropin independent, in the second half of its lifespan, hypophyseal support is required. The transition period is marked by decreased availability of PGs, in particular of PGE2. We previously reported that inhibition of COX2/PTGS2 in vivo suppressed luteal production of PGE2, lowered circulating progesterone and negatively affected luteal development. Therefore, bitches were treated with a COX2-specific blocker, firocoxib, for 5, 10, 20 and 30 days after ovulation, leading to suppression of the steroidogenic machinery. Control groups received a placebo for the same periods. Considering the wide range of possible modulatory roles of PGs shown in different organ systems, this follow-up project aimed to understand further possible PG-mediated effects in early canine CL. Thirty-four (34) factors related predominantly to vascularization and immune response were screened (mRNAs and proteins) on samples from the above described in vivo study. Most of the effects were observed during the transitional period (days 20 and 30). The inhibition of COX2 diminished the expression of angiopoietin family members ANGPT1, -2, Tie1 and -2 receptors. The expression of endothelin (ET)-1 was increased. Concerning the immune system, increased expression of the pro-inflammatory cytokines, IL1ß, IL6 and IL12a, and elevated expression levels of CD4, was observed. Cumulatively, besides its involvement in regulating steroidogenesis, our results indicate a broader role of PGs in the canine CL, including modulation of angiogenesis, vascular stabilization and local immunomodulation. Possible cross-species translational effects are strongly implied.

Development of specific fetometric formulas of ICC and BP for predicting the parturition date in Maine Coon queens.

The objective of study was to derive specific growth curves of ICC and BP for Maine Coon. Twenty-three pregnant queens aged 1-6 years, with body weight of 4.5-7.6 kg, were included in the study. In each queen, serial ultrasonographic examinations of pregnancy were performed through the abdomen with the MyLab Gold Vet scanner with a 6.6-7.5 MHz microconvex probe (Turin, Italy). ICC or BP was measured, depending on the stage of pregnancy. Each examination was regarded as a separate observation. In 18 queens, ICC was measured 33 times, and in 21 queens, BP was measured 60 times. The linear regressions of specific models of ICC and BP in Maine Coon pregnancies and specific formulas for predicting the parturition date in this breed were derived. The ICC formula was: days before parturition (DBP) = -0.79 * mm + 57.9, and the BP formula was: DBP = -1.86 * mm + 49.3. The proposed fetometric formulas of ICC and BP for Maine Coons after application in clinical patients can improve obstetric management in this breed.

Total antioxidant capacity and protein peroxidation intensity in seminal plasma of infertile and fertile dogs.

The aim of this study was to evaluate the total antioxidant capacity and protein peroxidation intensity in seminal plasma of infertile and fertile dogs. The study was conducted on 10 infertile and 10 fertile dogs of various breeds. Infertility was defined as conception failure at least three matings with different bitches. Semen was collected by manual manipulation. The sperm concentration and motility parameters were evaluated using CASA Hamilton Thorne, Vers. IVOS 12.3. The morphology of spermatozoa and the percentage of live and dead sperm cells were assessed microscopically, total antioxidant capacity and the content of SH-groups in seminal plasma were determined spectrophotometrically, the contents of protein peroxidation markers in seminal plasma, bityrosine and formylokinurenine, were determined using spectrofluorimetric methods. Sperm concentration and total sperm count were significantly (p < 0.05) lower in infertile dogs than in fertile dogs (99.92 ± 3 0.05 × 106 /ml vs. 282.07 ± 48.27 × 106 /ml; 214.19 ± 114.74 × 106 vs. 747.57 ± 210.94 × 106 , respectively). The percentage of spermatozoa with normal morphology and the most determined motility parameters differed significantly (p < 0.05) between both groups. The mean values of total antioxidant capacity in the seminal plasma were significantly (p < 0.05) lower (19.95 ± 20.94 vs. 25.66 ± 23.18 µmol/g protein), whereas the mean contents of bityrosine and formylokinurenine in seminal plasma were significantly (p < 0.05) higher in infertile dogs than in fertile dogs (3.71 ± 4.83 µg/mg protein vs. 1.55 ± 2.00 µg/mg protein and 0.37 ± 0.45 µg/mg protein vs. 0.14 ± 0.08 µg/mg protein, respectively). In conclusion, the obtained results suggest that the poor semen quality and infertility in dogs could be associated with lowered total antioxidant capacity and increased protein peroxidation in seminal plasma as a consequence of oxidative stress.

Elastography as a diagnostic tool in the prostate tumour detection in Labrador retriever.

Prostate tumours are hard to detect in dogs. Early diagnosis is a key to maintain fertility and to protect against metastasis and death. Elastography is a diagnostic tool to obtain very detailed results of changes in tissue stiffness of this organ. There are no studies about the application of elastography to diagnose the prostate tumours in dogs. In our case, in male Labrador retriever there was state a prostate lesion by both scanning-grey ultrasonogram and elastography. Fine needle aspiration biopsy (FNA) confirmed the adenocarcinoma only in elastography-changed area. Thus, this method is helpful to diagnose prostate tumours and should be the first additional survey in routine examination of the prostate in the dog.

Arterial ovarian blood flow in the periovulatory period of GnRH-induced and spontaneous estrous cycles of bitches.

The aim of this study was to compare arterial blood flow determined by repeated Doppler sonographic examinations in the periovulatory period in GnRH-induced and spontaneous estrous cycles of bitches. The study was performed on 10 bitches with GnRH agonist implant-induced estrus (Suprelorin® containing 4.7 mg deslorelin), and 10 bitches with spontaneous estrus (group B), which served as a control. Pulsed-wave Doppler ultrasonography was performed daily from the beginning of proestrus until early metestrus. The ovarian blood flow parameters in the left and right ovarian arteries, including systolic peak velocity (SPV), end diastolic velocity (EDV) and resistance index (RI), were measured. Obtained outcomes from the period of three days before ovulation (Days -3, -2, -1), ovulation (day 0) and three days after ovulation (Days +1, +2, +3) were evaluated statistically. There were no differences between blood flow variables in the bitches with spontaneous and induced cycles recorded on the same day. The values of SPV and EDV were higher (p < 0.05) on days -1, 0, +1, +2 and + 3 than the velocimetric variables collected on days -3 and -2. Then, a significant increase in blood flow was detected one day before ovulation and was continued during next 3 days (p < 0.05). In contrast, the mean RI values remained constant during the entire experiment or even showed a slight declining trend in both groups (p > 0.05). We concluded that arterial blood flow measured around ovulation does not allow for precise detection of exact ovulation time in bitches in induced and spontaneous cycles.

Comparison of three different fetometric formulas of ICC and BP for calculating the parturition date in a population of German Shepherd.

The aim of this study was to evaluate the suitability of three different formulas to predict the parturition date in German Shepherds, using the ultrasonographic fetometry method involving inner chorionic cavity diameter (ICC) and biparietal diameter (BP) measurements in the same population of a single breed. Overall, 53 ICC and 42 BP measurements were taken on 34 bitches. The measured values were substituted into breed-specific formulas for the German Shepherd as well as non-specific formulas for medium-sized bitches. Comparisons of clinical accuracy and statistical analyses of regression lines were performed to test the compatibility of the formulas used. We confirmed the similarity of our clinical results to outcomes obtained using the one breed-specific (Groppetti et al. 2015) and non-specific fetometry models (Luvoni and Grioni 2000), whereas another breed-specific formula (Milani et al. 2013) showed rather low accuracy. Comparing the clinical accuracy of the three formulas, the authors demonstrated that the Luvoni and Grioni (2000) formula for ICC dedicated to medium-sized dogs can also be effectively used in the German Shepherd, even with better results than breed-specific formulas by Groppetti et al. (2015). By contrast, the evaluation of BP formulas proves the successful usage of the Groppetti et al. (2015) formula to determine the date of birth by measuring scull bone structures (p < 0.05). The statistical analysis of regression lines were in agreement with the clinical results and confirmed the higher predictability of Groppetti et al. (2015) and Luvoni and Grioni (2000) formulas, than those of Milani et al. (2013).

Endometrial mRNA expression of prostaglandin synthase enzymes PTGS 2, PTGFS and mPTGES 1 in repeat-breeding cows with cytologically determined endometritis.

Little is known about the inflammatory response of the endometrium in repeat-breeding cows with subclinical endometritis (SE). The objective of this study was to evaluate the mRNA expression of prostaglandin-endoperoxide synthase 2 (PTGS 2), prostaglandin F2α synthase (PTGFS) and prostaglandin E2 microsomal synthase 1 (mPTGES 1) in the endometrium of repeat-breeding cows with and without SE. SE was diagnosed cytologically using the cytobrush method, with the threshold being set at 5% polymorphonuclear neutrophils. Biopsy samples were obtained from the endometrium of repeat-breeding cows with SE (n = 10) and without SE (n = 10). The mRNA expression of the synthases was evaluated using qRT-PCR. Significantly higher (P < 0.05) expression of the PTGS 2 gene was detected in the repeat breeders with SE, whereas there was no significant difference in the expression of PTGFS and mPTGES 1 mRNAs between repeatbreeding cows with SE and those without it (P > 0.05). Our study confirms that increased endometrial expression of the PTGS 2 gene is involved in the inflammatory response in repeat breeders.

OvSynch Protocol and its Modifications in the Reproduction Management of Dairy Cattle Herds - an Update.

Current knowledge about the function of the reproductive tract and appropriate use of hormonal drugs affords control of the oestrus cycle of cows. One of the hormonal protocols is OvSynch, which enables artificial insemination (AI) to be performed at the precise optimum time without control of the ovaries and uterus. Use of such protocols in reproductive management allows oestrus cycles to be synchronised and cows to be effectively inseminated without oestrous detection, which is time-consuming and difficult in farms with numerous cows. Therefore, OvSynch has become the first management tool for AI and is an alternative method to heat detection. Over the 20 years since its first implementation, OvSynch has been modified many times to improve its reproduction outcomes and widen its use. Besides its original use for heat synchronisation, it is also used in many ovarian disorders as a therapeutic method. This review article describes the possibilities which OvSynch provides, its current modifications, various applications, and the advantages and disadvantages of its use in practice.

Selection of active spaces for multiconfigurational wavefunctions.

The efficient and accurate description of the electronic structure of strongly correlated systems is still a largely unsolved problem. The usual procedures start with a multiconfigurational (usually a Complete Active Space, CAS) wavefunction which accounts for static correlation and add dynamical correlation by perturbation theory, configuration interaction, or coupled cluster expansion. This procedure requires the correct selection of the active space. Intuitive methods are unreliable for complex systems. The inexpensive black-box unrestricted natural orbital (UNO) criterion postulates that the Unrestricted Hartree-Fock (UHF) charge natural orbitals with fractional occupancy (e.g., between 0.02 and 1.98) constitute the active space. UNOs generally approximate the CAS orbitals so well that the orbital optimization in CAS Self-Consistent Field (CASSCF) may be omitted, resulting in the inexpensive UNO-CAS method. A rigorous testing of the UNO criterion requires comparison with approximate full configuration interaction wavefunctions. This became feasible with the advent of Density Matrix Renormalization Group (DMRG) methods which can approximate highly correlated wavefunctions at affordable cost. We have compared active orbital occupancies in UNO-CAS and CASSCF calculations with DMRG in a number of strongly correlated molecules: compounds of electronegative atoms (F2, ozone, and NO2), polyenes, aromatic molecules (naphthalene, azulene, anthracene, and nitrobenzene), radicals (phenoxy and benzyl), diradicals (o-, m-, and p-benzyne), and transition metal compounds (nickel-acetylene and Cr2). The UNO criterion works well in these cases. Other symmetry breaking solutions, with the possible exception of spatial symmetry, do not appear to be essential to generate the correct active space. In the case of multiple UHF solutions, the natural orbitals of the average UHF density should be used. The problems of the UNO criterion and their potential solutions are discussed: finding the UHF solutions, discontinuities on potential energy surfaces, and inclusion of dynamical electron correlation and generalization to excited states.