Positive Pregnancy Diagnosis Research Articles

Fungal endometritis associated with embryonic loss in a maiden mare

SummaryFungal endometritis and placentitis have been reported as a rare but important cause of infertility in the mare. There are no reported clinical cases of fungal endometritis causing embryonic loss in the mare. This case report aims to highlight the potential of fungal endometritis as an aetiological agent in embryonic loss in the mare; an incidental diagnosis of a case of fungal endometritis and embryonic loss while undertaking routine pregnancy assessments in a Standardbred mare. After a positive pregnancy diagnosis after 13 days post‐ovulation, a mare was diagnosed with endometritis and pregnancy loss associated with the growth of an unusual fungus, likely of the Acremonium spp., 28 days post‐ovulation. While fungal embryonic loss is rare, it should be considered a potential reason for pregnancy wastage in the mare.

Microwave Dielectric Response of Bovine Milk as Pregnancy Detection Tool in Dairy Cows.

The most reliable methods for pregnancy diagnosis in dairy herds include rectal palpation, ultrasound examination, and evaluation of plasma progesterone concentrations. However, these methods are expensive, labor-intensive, and invasive. Thus, there is a need to develop a practical, non-invasive, cost-effective method that can be implemented on the farm to detect pregnancy. This study suggests employing microwave dielectric spectroscopy (MDS, 0.5-40 GHz) as a method to evaluate reproduction events in dairy cows. The approach involves the integration of MDS data with information on milk solids to detect pregnancy and identify early embryonic loss in dairy cows. To test the ability to predict pregnancy according to these measurements, milk samples were collected from (i) pregnant and non-pregnant randomly selected cows, (ii) weekly from selected cows (n = 12) before insemination until a positive pregnancy test, and (iii) daily from selected cows (n = 10) prior to insemination until a positive pregnancy test. The results indicated that the dielectric strength of Δε and the relaxation time, τ, exhibited reduced variability in the case of a positive pregnancy diagnosis. Using principal component analysis (PCA), a clear distinction between pregnancy and nonpregnancy status was observed, with improved differentiation upon a higher sampling frequency. Additionally, a neural network machine learning technique was employed to develop a prediction algorithm with an accuracy of 73%. These findings demonstrate that MDS can be used to detect changes in milk upon pregnancy. The developed machine learning provides a broad classification that could be further enhanced with additional data.

Multivariable analysis to investigate factors associated with day 14 to 16 pregnancy rate in Thoroughbred mares on an intensively managed UK stud farm

Reproductive losses limit the output of the Thoroughbred mare. Identifying factors that influence pregnancy rates could help inform practices aimed at maximizing productivity. The most recent UK-based study to identify factors influencing day 14-16 pregnancy rates utilized only univariable analysis and was conducted on data from over 20 years ago. The aim of this study was to use multivariable analysis to investigate associations between mare and cycle level factors and day 14-16 pregnancy rates (PRs) on an intensively managed UK Thoroughbred stud farm. A retrospective cohort study was performed on all available reproductive data from farm and veterinary records for the 2017-2021 breeding seasons. Information was collected on season, month of cover, stallion, mare age, status, parity, location at cover, covered cycle number (within the season), number of coverings and ovulations (within the covered cycle), and all reproductive therapeutics (estrous induction agents, ovulatory agents, and pre-and post-covering treatments) administered. Multivariable mixed effect logistic regression modelling, with mare included as a random effect in all analyses, was used to identify factors associated with a positive pregnancy diagnosis at days 14-16 post-cover. Data were available for 1098 covered estrous cycles in 360 mares over 5 breeding seasons. The overall day 14-16 PR (proportion of coverings with a positive pregnancy diagnosis at day 14-16 post-cover) for the study period was64.5% (708/1098; 95% confidence interval (CI) =61.6, 67.3). In the final multivariable model (adjusted for the effect of the mare (Theta 0.39, P=0.003) increasing mare age (OR 0.93 per year increase in mare age, 95% CI 0.89, 0.98 P=0.01), a course of altrenogest pre-cover (administered to n=61/833 cycles OR 0.47, 95% CI 0.26, 0.85 P=0.01), treatment with intrauterine hyperimmune plasma pre-cover (n=61/829 OR 0.39, 95% CI= 0.21, 0.75 P=0.005), and the use of sole -oxytocin therapy post-cover (n=183/829 OR 0.59, 95% CI 0.40, 0.87 P=0.007) were all associated with reduced likelihood of a positive pregnancy diagnosis at days 14-16 post-cover. Although therapeutic agents could directly influence PRs, it is also likely that their use represents conditions such as acyclicity, subfertility and/or post-breeding endometritis, which may themselves affect PR. Controlled studies to further evaluate the efficacy of these treatments, particularly concerning the use of oxytocin and/or carbetocin, are therefore recommended. In conclusion, this study has provided up-to-date estimates of day 14-16 PRs in Thoroughbred broodmares in a UK setting and enhanced understanding of factors that may be associated with these rates. In addition, knowledge gaps around the rationale and efficacy of some therapeutic agents have been identified; these can help inform future research priorities.

The Uterus as an Influencing Factor for Late Embryo/Early Fetal Loss—A Clinical Update

Simple SummaryPregnancy loss following a positive pregnancy diagnosis in the absence of infectious disease of the reproductive system is a main factor limiting reproductive efficiency in high producing dairy cows. We describe here some circumstances such as the age of the dam, retained placenta and uterine size in which the uterus may be associated with pregnancy loss.Here we revise circumstances of non-infectious causes in which the uterus may be associated with pregnancy loss during the late embryo/early fetal period (following a positive pregnancy diagnosis in lactating dairy cows). As the uterine size increases with parity and pregnant heifers with no detrimental effects of a previous parturition, a primigravid uterus is proposed as a reference for identifying risk factors that negatively influence pregnancy in lactating cows. Cows suffering placenta retention or with a large uterus at insemination were selected as topics for this revision. Retained placenta, that occurs around parturition, has a long-lasting influence on subsequent pregnancy loss. Although retained placenta is a particularly predisposing factor for uterine infection, farm conditions along with cow factors of non-infectious cause and their interactions have been identified as main factors favoring this disorder. A large uterus (cervix and uterine horns lying outside the pelvic cavity) with no detectable abnormalities has been associated with low fertility and with a greater incidence of pregnancy loss. A large reproductive tract may well derive from an inadequate uterine involution. Therefore, peripartum management and strategies to reduce the incidence of uterine disorders should reduce their associated financial losses in the herds.

Recent Possibilities for the Diagnosis of Early Pregnancy and Embryonic Mortality in Dairy Cows.

Simple SummaryPregnancy diagnosis plays an essential role in decreasing days open in dairy farms; therefore, it is very important to select an accurate method for diagnosing early pregnancy. Besides traditional pregnancy diagnoses made by rectal palpation of the uterus from 40 to 60 days after AI and measuring the serum or milk progesterone concentration between 18 to 24 days after AI, there are several new possibilities to diagnose early pregnancy in dairy farms. However, it is very important to emphasize that before introducing any new diagnostic test, we need to make sure the accuracy of that particular test to be able to decrease the rate of iatrogenic pregnancy losses caused by prostaglandin or resynchronization treatments. This review focuses on the diagnostic possibilities and limitations of early pregnancy diagnosis in the field.One of the most recent techniques for the on-farm diagnosis of early pregnancy (EP) in cattle is B-mode ultrasonography. Under field conditions, acceptable results may be achieved with ultrasonography from Days 25 to 30 post-AI. The reliability of the test greatly depends on the frequency of the transducer used, the skill of the examiner, the criterion used for a positive pregnancy diagnosis (PD), and the position of the uterus in the pelvic inlet. Non-pregnant animals can be selected accurately by evaluating blood flow in the corpus luteum around Day 20 after AI, meaning we can substantially improve the reproductive efficiency of our herd. Pregnancy protein assays (PSPB, PAG-1, and PSP60 RIA, commercial ELISA or rapid visual ELISA tests) may provide an alternative method to ultrasonography for determining early pregnancy or late embryonic/early fetal mortality (LEM/EFM) in dairy cows. Although the early pregnancy factor is the earliest specific indicator of fertilization, at present, its detection is entirely dependent on the use of the rosette inhibition test; therefore, its use in the field needs further developments. Recently found biomarkers like interferon-tau stimulated genes or microRNAs may help us diagnose early pregnancy in dairy cows; however, these tests need further developments before their general use in the farms becomes possible.

Effects of sunlight hours and hormones on double ovulation, and singleton and twin pregnancies in mares

Equine twin pregnancies are almost exclusively dizygotic, without the application of advanced reproductive technologies, requiring 2ovulations in 1 estrous cycle. Breeding records were used to determine the effects of sunlight hours, prostaglandin F2α, human chorionicgonadotropin, deslorelin (a gonadotropin releasing hormone agonist), and progesterone and estradiol on double ovulation rates,and singleton and twin pregnancy rates. Breeding records of mares (n = 267) and their estrous cycles (n = 914) were analysed. Doubleovulations occurred in 10.5% (96/914) of estrous cycles. Twin pregnancies were observed in 42.7% (38/89) of mares that had doubleovulations. Overall, per estrous cycle pregnancy rate was 47.2% (405/858) and twin pregnancies was 4.4% (38/858). Double ovulationshad higher (p < 0.001) per cycle singleton pregnancy rate (69.7%; 62/89) than 1-ovulation cycles (44.6%; 343/769). Deslorelinincreased (p < 0.05; OR =1.24 95% CI) double ovulations and human chorionic gonadotropin tended (p = 0.089; OR =1.68; 95%CI) to increase double ovulations. Deslorelin use resulted in an odds ratio of 2.47 for a positive pregnancy (either singleton or twin)diagnosis compared to cycles without deslorelin use. None of the factors examined had a substantial impact on twin pregnancy rates.

Influence of Prednisone Treatment Before and During Pregnancy in Rats on Immunometabolic Biomarkers and Fetal Development

Prednisone is a glucocorticoid drug with free access and can negatively affect both the maternal immunometabolic profile and fetal development. The objective of this study was to evaluate the effects of prednisone treatment on the immunometabolic and reproductive profile, and maternal- fetal repercussions of rats. Adult female Wistar rats were distributed in groups: during no- pregnancy period (NPP), there were CONT group (n= 15, treated with vehicle) and PRED group (n=30, treated with 5mg/Kg prednisone). The treatment was oral and daily for 15 days. Following, the rats were mated, and with a positive pregnancy diagnosis, the pregnancy period (PP) was initiated (21 days), with CONT group (n=13, treated with vehicle), and the PRED group was subdivided: PRED1 group (n=14, treated with vehicle) and PRED 2 group (n=13, treated with 5mg/Kg prednisone). The body weight, food and water intake, oral glucose tolerance test (OGTT), serum immunometabolic parameters were measured, followed by maternal reproductive performance and fetal analyzes. The PRED2 group showed a glycemic drop at 60' of TOTG, IgG and leukocyte cells, in addition to an increase in triglycerides and aspartate aminotransferase. For reproductive indices, these rats showed a decrease in maternal weight gain and litter weight but increased placental efficiency and occurrences of skeletal and visceral anomalies. It is concluded that the administration of prednisone in both experimental periods induced changes in hepatic and metabolic functioning and maternal leukopenia, causing such changes to negatively influence to fetal development.

Postpartum uterine involution and ovarian follicular dynamics in crossbreed Anatolian water buffalo (Bubalus bubalis) during summer season

It was aimed to monitor postpartum (pp) uterine involution and follicular wave pattern by transrectal ultrasonography and detection of concentrations of milk progesterone (P4) in eleven water buffaloes during the summer season in Turkey. The data obtained from the first day of calving to positive pregnancy diagnosis were evaluated on a daily basis. Uterine position scores and nonechogenic material showed a decreasing grade pattern related to the time (P < 0.0001). A time effect was evident with uterine horn thickness (P < 0.05) or intercaruncular zone thickness (P < 0.01) and uterine horn lumen (P < 0.01). Uterine horn thickness showed a gravidity x time interaction (P < 0.05). Gravidity x time interaction was not evident in total uterine horn thickness but time effect was seen (P < 0.0001). Time effect was also evident for the thickness of uterine body (P < 0.0001) and cervix uteri (P < 0.01). The uterine body and horns were returned to previously nongravid state on day 26.00 ± 2.38 and the interval from calving to complete disappearance of uterine fluid was accomplished on day 31.44 ± 3.23 pp. The previously gravid and nongravid uterine horns, uterine body and cervix uteri involuted on day 31.42 ± 1.39, 28.37 ± 0.65, 29.37 ± 0.73 and 27.87 ± 0.47 pp, respectively. The interval from calving to first observation of dominant follicle of nonovulatory wave was 18.54 ± 6.91 days and on average 3.45 ± 1.91 nonovulatory waves were observed. Postpartum first ovulation occurred on day 64.45 ± 18.49. One and two wave models or combination of both waves were observed. The interval from calving to pregnancy was 72.36 ± 21.33 days. The maximum concentrations of milk P$_{4}$ during short or normal cycles and pregnancy were 0.62 ng/mL, 2.2 ng/mL, and 4.04 ng/mL, respectively. In conclusion, the presence of one or two waves should be considered when estrous synchronization programmes are planned in Anatolian water buffaloes during summer season.

Age-Dependent Effect of Foal Heat Breeding on Pregnancy and Embryo Mortality Rates in Thoroughbred Mares

The aim of the present study was to evaluate the correlation of age and heat cycle to determine reproductive efficiency in young and aged Thoroughbred mares bred on foal heat (FH) or on second heat (SH) after foaling. Embryo mortality (EmbM) was determined every time a mare was found open after a positive pregnancy diagnosis. Parturition to breeding interval, pregnancy rate (PregR) and EmbM rate were the dependent variables and the treatments were breeding on the FH or on SH. The cutoff age to obtain above-average probability for the EmbM was 10 years old. PregR in mares bred on FH was lower compared with SH (P < .01); however, it was neither affected by the age of mares (P > .05) nor by the age group of mares (P > .05). Regarding FH and SH, there was a difference in PregR in young mares (P < .01), unlike in aged mares (P > .05). EmbM rate was not different between mares bred on FH or SH (P > .05) although it was affected by age of mares (P < .01). EmbM was higher in oldest than young mares (P < .01). Aged mares bred on FH had a significantly higher EmbM rate compared with the young group also bred on FH (P < .01). In conclusion, the reproductive efficiency of Thoroughbred mares bred on FH is dependent of the age. Aged mares (≥10 years old) should be bred at their SH to reduce EmbM and improve reproductive performance.

Post-cervical compared with cervical insemination in gilts: Reproductive variable assessments

The aim with this study was to compare cervical (CAI; 3 × 109 spermatozoa/90 mL) and post-cervical (PCAI; 1.5 × 109 spermatozoa/45 mL) artificial insemination (AI) techniques for frequency of incidences (unsuccessful or difficult probe passage, backflow, metritis and bleeding), values for reproductive variables and duration of the procedure in gilts. There were 644 gilts (255–270 days old, weighing 150 ± 5 kg) randomly assigned to PCAI (n = 320) and CAI (n = 324) groups. In total, there were 957 and 958 artificial inseminations performed in the CAI and PCAI groups, respectively (2–4 AIs/gilt). The frequency of unsuccessful or difficult PCAI probe passage/AI was 14.6% (140/958), therefore, there was a 85.7% probe passage success/AI rate (818/958). The semen backflow frequency/AI was less with PCAI than CAI (4.3% compared with 8.2%, P < 0.001). With the PCAI group, there were only a few cases of bleeding (11/958: 1.1% /AI) with no difference between the CAI and PCAI groups (P = 0.224). In gilts (n = 72) where there was not passage of the PCAI probe (72/320; 22.5%) there was use of CAI, (M, mixed group). For the CAI, PCAI and M groups, there were similar values for positive pregnancy diagnosis, farrowing rates and prolificacy (P > 0.05). The average duration for AI was shorter in the PCAI (2.34 ± 0.809 min) than CAI (4.77 ± 1.059 min) group, and it was longer in the M group (7.48 ± 2.454 min; P < 0.050). The PCAI procedure, therefore, is recommended for AI of gilts.

Progesterone Supplementation During the Pre-implantation Period Influences Interferon-Stimulated Gene Expression in Lactating Dairy Cows

Abstract This study examined the effect of progesterone (P4) supplementation from Days 16 to 18 post-AI on interferon-stimulated gene (ISG) expression on Day 19 in high-producing dairy cows. Gene expression levels were measured in peripheral blood mononuclear cells. Possible relationships between ISG expression and the incidence of pregnancy failure were also investigated. Cows were alternately assigned on Day 16 post-AI to a control (C: n = 13) or treatment group (P4: n = 14). Out of 27 cows, 12 returned to oestrus before pregnancy diagnosis and 9 were diagnosed as pregnant on Day 28. ISG expression was assessed in all cows. Expression levels for the genes OAS1, ISG15, MX1 and MX2 were higher for pregnant than for non-pregnant cows (P=0.04; P&lt;0.001; P=0.02; P=0.045; respectively). A significant (P=0.01) interaction was observed between the treatment and positive pregnancy diagnosis groups on Day 28 post-AI for the probability of showing ISG expression. This interaction suggests that in cows not pregnant on Day 28, P4 supplementation may have led to increased ISG15 mRNA expression on Day 19. Lower ISG15 expression was detected for cows returning to oestrus than for pregnant cows (P&lt;0.001). However, cows with a negative pregnancy diagnosis showed intermediate values, differences being non-significant when compared to cows returning to oestrus or pregnant cows. Our results suggest that P4 supplementation during the pre-implantation period promotes conceptus signalling.

Pregnancy and stillbirth losses in dairy cows with singleton and twin pregnancies.

The aim of this study was to examine the effect of twin pregnancy, fetal laterality, the number of corpora lutea (CL) and cavitary CL on pregnancy losses in Holstein-Friesian cows with a positive pregnancy diagnosis based on ultrasonography between days 29-42 after AI. Pregnancy was confirmed by transrectal palpation between days 57-70 after AI and at the time of drying-off as well. Twin pregnancy rate was 8.4% at the time of the early pregnancy examination. Pregnancy loss did not differ between singleton- and twin-carrying animals either between days 57-70 of gestation or at drying-off. More losses occurred in singletons between days 29-42 and 57-70 in cows with cavitary than in cows with noncavitary CL (12.1% vs. 3.6%; P < 0.05) and in cows with double CL than in cows with single CL (7.3% vs. 3.6% %; P < 0.05). Between days 57-70 of gestation and drying-off this difference was still significant (20.7% vs. 3.7%; P < 0.001), while it was non-significant between cows with one CL (5.7%) vs. double CL (3.7%). Cavity occurrence was not affected by hormone therapy prior to AI (either PGF2α or OvSynch; 4.4% vs. 5.4%, respectively); however, the number of CL was reduced by the treatments (11.6 vs. 19.6%; P < 0.0005). In twin pregnancies there was no difference in the pregnancy losses between bilateral and unilateral pregnancies at any time point. The length of gestation was 278.2 ± 10.5 (singleton) and 267.4 ± 31.2 (twin) days, respectively (P < 0.01). The stillbirth ratio was higher in twin carriers than in singleton carriers (19.5% vs. 5.3%; P < 0.001).

Diagnostic échographique de grossesse arrêtée précoce : étude de la qualité des clichés

ObjectiveUltrasound examination plays a central role in case of suspected non-viable pregnancy. A wrong diagnosis might have major consequence in terms of inadequate care, especially in cases of false positive non-viable pregnancy diagnosis. Ultrasound criterions are today well defined. Our objective was to evaluate the feasibility and reproducibility of a novel image-quoting method of first-trimester non-viable pregnancy. MethodsThirty images of non-viable pregnancy were twice evaluated with blinded proofreading. Two quotations were evaluated: the first for the images of gestational sacs without embryo (gestational sac score), the second for the images with embryo (embryo score). ResultsThe ICC (interclass correlation coefficient) was>0.75 for inter- and intra-observer reproducibility both for the quotations of the gestational sac and for the embryo with a low variability. Reproducibility of quoting crown rump length measurements <5mm was low at first proofreading but after adjustment of the quoting modalities, ICC was also>0.75. ConclusionThe inter- and intra-observer reproducibility of our quoting methods is high with a low variability. They might be a useful tool in current practice in the future.

Risk Factors for Late Embryonic Mortality in Dairy Cows

We determined the risk factors for late embryonic mortality in dairy cows. We diagnosed pregnancy at 31 days and then confirmed the diagnosis at 45 days after artificial insemination (AI) via ultrasonography. The presence of an embryo with a heartbeat was the criterion for a positive pregnancy diagnosis. A diagnosis of late embryonic mortality was made when there was no positive sign of pregnancy in cows previously diagnosed as pregnant. The overall incidence of late embryonic mortality among 3,695 pregnancies was 6.9%. Logistic regression analysis revealed that herd size, AI month, synchronization protocol, and postpartum disease were important risk factors for late embryonic mortality. Herd size ＞ 100 (odds ratio [OR]: 0.66, p ＜ 0.05) and 50-100 lactating cows (OR: 0.63, p ＜ 0.01) had lower risks of late embryonic mortality than herd size ＜ 50 lactating cows. Cows inseminated during May-July had a higher risk (OR: 1.49, p ＜ 0.05) of late embryonic mortality than cows inseminated during February-April. Cows inseminated after estrus following PGF2α treatment also had a higher risk (OR: 1.77, p ＜ 0.001) of late embryonic mortality than cows inseminated following natural estrus. Lastly, cows with postpartum disease tended to have a higher risk (OR: 1.26, p ＜ 0.1) of late embryonic mortality than cows without postpartum disease. In conclusion, late embryonic mortality associated with the herd size, AI month, synchronization protocol, and postpartum disease in dairy cows.

Optimising the diagnosis of ectopic pregnancy

This retrospective cohort study reviewed the diagnosis of all ectopic pregnancies within a district general hospital over a 5-year period after the establishment of a dedicated Early Pregnancy Assessment Unit (EPAU). Of 215 ectopic pregnancies identified, notes were available for 208 (97%). Two-hundred and two cases were determined to have been diagnosed and managed as ectopic pregnancies. Six cases were excluded as they were pregnancies of unknown location managed as such. Overall, 91% were diagnosed by ultrasound scan, 5% were diagnosed clinically and 3% were diagnosed on serial human chorionic gonadotrophin (hCG) levels. This study found that the introduction of a dedicated, multi-professional, EPAU with a stable workforce improved ultrasound visualisation of ectopic pregnancies at first ultrasound scan from 22% prior to its commencement, to 61% over this period. The improvement in positive scan diagnosis of ectopic pregnancy was associated with a reduction in negative laparoscopy rate from 13% to 6%.

Evaluation of biochemical and reproductive biomarkers in pre and during gestational period in immunosuppressed Wistar rats with mycophelonate sodium

Materials and methods The rats were divided into three groups: rats treated with water (CONT=10) rats orally treated with MFS (20mg/ Kg) daily for 15 days until a positive diagnosis of pregnancy (MICO-1=10) and rats orally treated with MFS (20mg/Kg) daily for 15 days prior to and during 21 days of pregnancy (MICO-2=10). It was evaluated on the 17th day of pregnancy the Oral Tolerance Glucose Test (OGTT) and on day 21 the rats were anesthetized and killed by decapitation and thus measured reproductive parameters (Index fertility, childbirth, pregnancy and number of live births and resorption) and serum biomarkers (lipid parameters and liver transaminases) Statistical significance was p <0.05. Results In pregnancy period, there were no changes in glucose data during OGTT evaluation, although MICO-2 rats presented higher glycemia compared to other groups (CONT and MICO-1), with 170mg/dL. Furthermore, the MICO-2 rats presented other negative effects, including dead rats and total resorption of fetuses. The biochemical data presented decreasing of rates of serum lipid (cholesterol and lipoprotein fractions, triglycerides and alanine aminotransferase).

Evaluation on physiological biomarkers pre and during gestational period in immunosuppressed Wistar rats with mycophenolate sodium

Materials and methods The rats were divided into three groups: rats treated with water (CONT=10) rats orally treated with MFS (20mg/ Kg) daily for 15 days until a positive diagnosis of pregnancy (MICO-1=10) and rats orally treated with MFS (20mg/Kg) daily for 15 days prior to and during 21 days of pregnancy (MICO-2=10). It was weekly evaluated body weight, blood glucose, and water and food intake (before and during pregnancy). Statistical significance was p <0.05.

Effects of long-term vaccination against Coxiella burnetii on the fertility of high-producing dairy cows.

The impact of long-term vaccination against Coxiella burnetii on the fertility of cows was studied. Double vaccinations three weeks apart at the start of the third trimester of gestation in each of two consecutive pregnancies were applied. The final study population consisted of 410 cows after the first vaccination round. Based on the odds ratios, the likelihood of early fetal loss (pregnancy loss following a positive pregnancy diagnosis before Day 90 of gestation) was higher in control cows (OR = 1.42) than in vaccinated cows. The final study population consisted of 336 cows after the second round of vaccination. According to the odds ratios, vaccinated C. burnetii seronegative cows were less likely to be subfertile (> 3 AI) (OR = 0.4) compared to non-vaccinated seronegative animals, and the likelihood of early fetal loss was lower in vaccinated C. burnetii seropositive animals (OR = 0.3) compared to non-vaccinated seronegative cows. Seropositivity to C. burnetii was positively related to twin pregnancy after the two rounds of vaccination (OR = 2.1 and 3.5, respectively). These results indicate that two consecutive vaccination rounds against C. burnetii in advanced gestation reduce subfertility and early fetal loss in dairy cows.

Progesterone status, parity, body condition, and days postpartum before estrus or ovulation synchronization in suckled beef cattle influence artificial insemination pregnancy outcomes.

Our objective was to assess the effects of progesterone before initiating an estrus- or ovulation-synchronization program in addition to the influence of parity, BCS, and days postpartum on resulting pregnancy rates per AI. Experimental data were combined from 73 herd-year studies consisting of more than 8,500 suckled beef cows exposed to variants of the CO-Synch program. Blood was harvested from samples collected at 10 and 0 d before the onset of CO-Synch, and progesterone concentrations of the samples were determined. The progesterone environment preceding synchronization was assessed in 3 ways on the basis of progesterone concentrations measured in the 2 defined blood samples. All binomial logistic regression models used procedure GLIMMIX in SAS and included the fixed effects of program duration, inclusion of progesterone via an intravaginal insert, parity, days postpartum at AI, BCS, and appropriate interactions. In addition, model 1 included 3 categories of progesterone concentrations (low [<1 ng/mL], medium [1.00 to 3.99 ng/mL], and high [≥4.00 ng/mL] concentrations) at 10 and 0 d before synchronization and their interaction. Model 2 included 4 categories defining the stage of the estrous cycle (late diestrus, early diestrus, and proestrus-estrus-metestrus) or anestrus, at which cows started the synchronization program. Model 3 defined cows as cycling or noncycling at the onset of the program. Significant effects of progesterone supplementation, which hormone was used to initiate the timed AI program, parity, BCS, days postpartum, and progesterone status assessed in 3 ways were consistent in nearly all models. Progesterone status at the onset of synchronization was not important to pregnancy outcomes in multiparous cows, whereas pregnancy rate per AI was suppressed in primiparous cows that began in a low-progesterone environment (proestrus, estrus, metestrus, or anestrus). A significant 3-way interaction of parity, BCS, and days postpartum in 2 models reinforced the importance of these factors to AI pregnancy outcomes. Ancillary analyses identified the significant effects of cycling status and BCS as well as days postpartum on luteolytic response to PGF(2α). Pregnancy loss of 2.7% to 4.2% was detected to occur between a positive pregnancy diagnosis at 35 d post-AI and later stages of pregnancy. We concluded that progesterone status at the onset of the synchronization program is critical to pregnancy outcomes in primiparous but not multiparous cows.

Transrectal Ultrasonographic Monitoring of Early Pregnancy in Graded Murrah Buffalo Cows (Bubalus bubalis)

The objective of the present study was to evaluate the accuracy of transrectal ultrasonography as a method of pregnancy diagnosis at an early stage in graded murrah buffaloes. 30 inseminated buffaloes were utilized and pregnancy diagnosis was commenced on day 20, 25 and 30 post breeding. Positive diagnosis of pregnancy was based on the presence of an anechoic round area of varying size in the lumen of an echogenic uterine lumen representing the fluid filled allantoic cavity termed as the embryonic vesicle. The presence of an embryo within the embryonic vesicle was confirmed by observing an echogenic area with rhythmic pulsation representing heartbeats. The average lengths of embryonic vesicle on day 20, 25 and 30 were 0.415 ± 0.05, 1.116 ± 0.107 and 1.85 ± 0.068 cm, respectively and the average lengths of embryo on day 25 and 30 were 0.45 ± 0.064 and 1.05 ± 0.086 cm, respectively. Sensitivity was lower on day 20 and 25 being 50 and 75%, respectively when compared to day 30 which was 100%. The overall accuracy increased as the pregnancy advances and was observed to be 100% from day 30 onwards. It was confirmed that early pregnancy diagnosis using ultrasonography can be done effectively from day 25 post insemination.