Plasma Concentrations of Pregnancy‐Associated Glycoproteins Measured Using Anti‐Bovine PAG‐2 Antibodies on Day 120 of Gestation Predict Abortion in Dairy Cows Naturally Infected with Neospora caninum

The present study sought to determine: (i) the effects of Neospora caninum infection and twin pregnancy on plasma pregnancy‐associated glycoprotein‐2 (PAG‐2) concentrations throughout pregnancy and (ii) whether plasma PAG‐2 concentrations could predict abortion in N. caninum‐infected cows. The study was performed on a commercial Holstein‐Friesian dairy herd in northeastern Spain and the final data included those recorded in 53 non‐aborting and 19 aborting animals. Blood samples were collected immediately before pregnancy diagnosis (on Days 40, 90, 120, 150, 180 and 210 post‐insemination) in non‐aborting cows or until the time of abortion detection in aborting cows. General lineal models (GLM) repeated measures anova revealed the different behaviour of PAG‐1 and PAG‐2, and significant effects of Neospora seropositivity, cool season and twin pregnancy on plasma PAG‐2 concentrations throughout gestation (between‐subject effects). In addition, based on the odds ratios, the likelihood of abortion increased in Neospora‐seropositive cows (by a factor of 7.0) compared to seronegative animals and decreased in cows with a high plasma PAG‐2 concentration (>4.5 ng/ml) on Day 120 of pregnancy (by a factor of 0.24), compared to the remaining cows. In conclusion, there is a relationship between plasma PAG‐2 concentrations and the risk of abortion in Neospora‐infected dairy cows. Thus, plasma PAG concentrations measured using anti‐boPAG‐2 antiserum on Day 120 of gestation could serve as an indicator of the abortion risk in N. caninum infected animals; values <4.5 ng/ml indicating a high risk of abortion in chronically infected animals.     

An International Delphi Study of the Causes of Death and the Criteria Used to Assign Cause of Death in Bovine Perinatal Mortality

The objective of the present study was to elicit opinion from two groups of veterinarians [subject matter experts and non‐subject matter experts] about the causes of bovine perinatal mortality and the criteria used to assign such causes. The subject matter experts were selected on the basis of their scientific publications or experience of working in a veterinary diagnostic or research laboratory in the area of bovine perinatal mortality. The non‐subject matter experts were self‐selected as cattle veterinarians without particular expertise in bovine perinatology. A total of 74 veterinarians (46 subject matter experts and 28 non‐subject matter experts) from 23 countries responded. The study was conducted using Delphi methodology over seven rounds. Respondents were asked to agree the causes of bovine perinatal mortality and for each cause to agree the supporting diagnostic criteria. There was a close agreement between groups on 16 causes of death apart from intra‐uterine growth retardation (IUGR) and micronutrient imbalances which were accepted by fewer subject matter experts. There was inter‐group consensus on the criteria to diagnose accidents, congenital defects, dystocia, hyperthermia, infections, premature placental separation, prematurity and prolonged calving. There was inter‐group consensus on the criteria to diagnose anoxia, apart from gingival cyanosis; on haemorrhage, apart from haemorrhagic anaemia; on IUGR, apart from organ weights; and on iodine imbalance, apart from goitre and thyroid iodine content. The results from this study highlighted the current lack of standardization of the criteria used to define the cause of death for bovine perinatal mortality and the need for such standardization.     

64, XX,SRY‐negative,Testicular DSD Syndrome in a Lusitano Horse

Here is reported a disorder of sex development found in the Portuguese Lusitano horse breed. The complex genital phenotype included mammary glands, abdominal testes without epididymis, connected through oviducts to pelvic hypoplastic uterine horns and fused vulvar labia majora from which protruded ventrally a penis‐like structure. This structure was presented in a reversed position, the urethral opening placed dorsally in the glans. However, it was functional both for micturition and erection. The horse exhibited female micturition posture and aggressive male‐like behaviour, including flehmen, mounting, thrusting and flagging of the tail. Plasma testosterone concentrations were below detection limits and the genetic evaluation revealed a 64, XX, SRY‐negative karyotype. Surgery consisted in the removal of abdominal gonads followed by amputation of the penis and repositioning of the urethra. This case of reversion between the chromosomal and gonadal sex, associated with mixed anatomical and behavioural phenotype, illustrates that development of the testes may occur in the absence of the SRY gene and that other genetic and cellular pathways leading to gonad differentiation should be investigated.     

The occurrence of Cryptosporidium parvum,Campylobacter and Salmonella in newborn dairy calves in the Manawatu region of New Zealand

AIM: To determine the occurrence of Cryptosporidium parvum oocysts, Campylobacter spp and Salmonella spp in faecal samples taken from newborn dairy calves on 24 dairy farms in the Manawatu region of New Zealand.

METHODS: A cross-sectional study was conducted during the 2002 calving season. Faecal samples were collected from 185 newborn calves from a convenience sample of 24 dairy farms. The samples were tested microscopically for the presence of C. parvum oocysts, and bacteriologically for the presence of Campylobacter spp and Salmonella spp.

RESULTS: Infections with C. parvum were identified in 33/156 (21.2%) calves from 10 farms. More than 10⁶ oocysts/g (OPG) faeces were detected in calves from four farms. Campylobacter spp were isolated from 58/161 (36%) calves from 18 farms; in particular, C. jejuni subsp jejuni was isolated from 11/161 (6.8%) calves from seven farms. Salmonellae were not detected.

CONCLUSIONS: Despite the short and concentrated calving pattern and the long interval between calving seasons characterising most dairy farms in New Zealand, C. parvum is widespread among calves. Campylobacter spp, especially C. jejuni, rapidly colonise the intestinal tract of newborn calves.

RELEVANCE: This study provided an estimate of the ecological impact of newborn dairy calves with regard to the potentially zoonotic enteric pathogens most frequently isolated from human gastrointestinal infections in New Zealand.     

Pregnancy Rates in Angus Cross Beef Cows Bred at Observed Oestrus With or Without Second GnRH Administration in Fixed‐Time Progesterone‐Supplemented Ovsynch and CO‐Synch Protocols

Crossbred cows (n = 1073) from five locations had oestrous cycles synchronized with 100 μg of GnRH IM and insertion of controlled internal drug release device (CIDR) on Day 0 followed by 25 mg of PGF_2α IM and CIDR removal on Day 7. Kamar^® patches were placed on all cows at CIDR removal. Cows were observed three times daily for oestrus after PGF_2α administration. In the Ovsynch‐CIDR group, cows detected in oestrus (n = 193) within 48 h after PGF_2α were inseminated using the AM–PM rule. Among these cows, 80 received and 113 did not receive a second GnRH at 48 h after PGF_2α. Cows (n = 345) not detected in oestrus received a second GnRH at 48 h after PGF_2α on Day 9, and fixed‐time AI 16 h after the GnRH on Day 10. In the CO‐Synch‐CIDR group, cows detected in oestrus (n = 224) within 48 h after PGF_2α were inseminated using the AM–PM rule. Among these cows, 79 received and 145 did not receive a second GnRH at 64 h after PGF_2α. Cows (n = 311) not detected in oestrus received a second GnRH on Day 10 at the time of AI, 64 h after PGF_2α. The AI pregnancy rates were not different between the Ovsynch‐CIDR and CO‐Synch‐CIDR groups (p = 0.48). There were no differences in the AI pregnancy rates for cows inseminated at a fixed time (p = 0.26) or at detected oestrus (p = 0.79) between the treatment groups. Among cows inseminated in oestrus, there were no differences in the AI pregnancy rates between cows that received or did not receive the second GnRH (p = 0.47). In conclusion, acceptable AI pregnancy rates can be achieved with or without inclusion of oestrus detection in the Ovsynch‐CIDR and CO‐Synch‐CIDR protocols. Among cows detected in oestrus, cows that received a second GnRH yielded similar pregnancy rates when compared with cows that did not receive the second GnRH.     

Measurement of Ovine Pregnancy-Associated Glycoprotein (PAG) During Early Pregnancy in Lacaune Sheep

This study describes ovine pregnancy‐associated glycoprotein (ovPAG) concentrations in 20 Lacaune sheep during early pregnancy. Measurements were performed by using semi‐purified ovPAG as standard, tracer and immunogens for antibody production in rabbits. Antisera R780 (against ovPAG_57+59kDa) and R805 (against ovPAG5_58+61kDa) were used respectively in RIA‐780 and RIA‐805. Blood samples were collected at days 0, 18, 20, 22 and 25 after artificial insemination. From day 18 after breeding onward, the mean ovPAG concentration was significantly higher (p < 0.001) in plasma samples from pregnant ewes (n = 17) than in non‐pregnant ones (n = 3). The specific activity of the tracer was 11 760 Ci/mmol in RIA‐780 and 14 900 Ci/mmol in RIA‐805. The minimal detection limits for RIA‐780 and RIA‐805 were 0.2 ng/ml and 0.3 ng/ml, respectively. The intra‐assay CV of samples with low (1.0 ng/ml), medium (2.5 ng/ml) and high (4.0 ng/ml) PAG concentrations were 3%, 6% and 9% for RIA‐780 and 8%, 9% and 5% for RIA‐805. The inter‐assay CV in the same samples were 13%, 12% and 7% for RIA‐780 and 13%, 11% and 5% for RIA‐805. The recovery was higher than 95% in both assays. No cross‐reaction was observed with members of aspartic proteinase family as well as with other tested proteins. In both RIA‐780 and RIA‐805, inhibition of the binding of the tracer by antisera was parallel between standard curve and serial dilutions of pregnant ewe samples. In conclusion, the two homologous RIA systems are suitable for early quantification of ovPAG concentrations in ewe plasma samples from day 18 after breeding.     

Follicular Dynamics,Interval to Ovulation and Fertility After AI in Short‐Term Progesterone and PGF2α Oestrous Synchronization Protocol in Sheep

The study was aimed to assess the influence that short‐term progesterone treatments have on follicular dynamics, oestrus and ovulation in sheep. The treatment was tested thereafter in a field trial to assess its fertility after AI with fresh semen. In a first experiment, 12 ewes without CL were grouped to receive a new (n = 6) or used CIDR (n = 6) for 7 days and blood samples were obtained to follow plasma progesterone profiles. In a second experiment, 39 cycling ewes were synchronized by a 7‐day P4+PGF2α protocol using a new (n = 20) or a 7‐day used CIDR (n = 19). Half of both groups received 400 IU eCG and half remained untreated as controls. Ultrasound ovarian examination and oestrous detection were used to compare follicular dynamics, oestrus and ovulation in both groups. In a third experiment, 288 ewes in 3 farms were synchronized by the short‐term P4+PGF2α+eCG protocol and ewes were AI with fresh semen 24 h after oestrous detection. Lambing performance was used to test the fertility of the treatment. In Experiment 1, ewes with new inserts presented higher P4 concentration than ewes with used inserts throughout the sampling period (p < 0.05) and exhibited a P4 peak at days 1‐2 of the treatment that was not observed in ewes with used inserts. In Experiment 2, ewes treated with new and used inserts show similar ovarian and behavioral traits (p > 0.10). However, ewes treated with eCG show shorter interval to oestrus (p = 0.004) and tend to have larger mature CL (p = 0.06). In Experiment 3, oestrous presentation and lambing performance after AI with fresh semen was considered normal compared to published results. Results suggest that the oestrous synchronization protocol based on P4+PGF2α allows little control of follicular dynamics without compromising fertility after AI with fresh semen provided that eCG is added at the end of the treatment.     

Administration of Thyroxine Affects the Morphometric Parameters and VEGF Expression in the Uterus and Placenta and the Uterine Vascularization but does Not Affect Reproductive Parameters in Gilts During Early Gestation

The aim of this study was to evaluate the effects of thyroxine administration on morphometric parameters, expression of vascular endothelial growth factor (VEGF) and vascularization in the uterus and placenta and reproductive parameters in gilts at 70 days of gestation. At 150 days of age, i.e., before first heat, 20 gilts were randomly divided into two experimental groups: treated (n = 10) and control (n = 10). The treated group received a daily dose of 400 μg of l ‐thyroxine (T₄) in their diet until slaughter and the control group received only typical meals. Before artificial insemination, blood was collected to determine plasma total T₄. The gilts were inseminated in the second oestrus and slaughtered at 70 days of gestation. The foetal thyroid follicular epithelium height, number, size and weight of foetuses; foetal myogenesis, corpora lutea number, embryonic mortality rate, uterine weight, placental weight and placental fluid volume were measured. Histomorphometric and immunohistochemical analysis of uterus and placenta were determined. The averages of all variables were compared by the Student’s t‐test. The gilts treated with thyroxine showed significant increase of plasma total T₄. At 70 days of gestation, the heights of the trophoblastic epithelium, endometrial epithelium and endometrial gland epithelium were significantly higher in the group treated with T₄. The expression of cytoplasmatic and nuclear VEGF in trophoblastic cells and the number of blood vessels per field in endometrial stroma were significantly higher in the gilts treated with T₄. No other significant differences between groups were obtained with respect to other parameters (p > 0.05). We conclude that oral administration of T₄ up to 70 days of pregnancy in gilts affects the morphometric parameters, the expression of placental VEGF and the uterine vascularization but does not affect reproductive parameters in gilts during early gestation.