Outbreak of aflatoxicosis in a dairy herd induced depletion in milk yield and high abortion rate in Pakistan.

This case report investigated the outbreak of aflatoxicosis in a dairy herd in Pakistan, which resulted in 30 abortions of 40 confirmed (75%) pregnant cows in a period of 35 days and in 18.8% depression of farm average milk production for the entire herd. The analysis of the concentrate feed of the total mixed ration (TMR), using enzyme-linked immunosorbent assay (ELISA) procedures from two different local laboratories, indicated concentrations of 60 µg/kg dry matter (DM) of aflatoxin B1 (AFB1) and 100 µg/kg DM of total aflatoxins (AFs: sum of B1, B2, G1 and G2). Subsequently, a confirmatory analysis with a more sensitive and validated multi-metabolite liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was performed. This analysis detected a concentration of total AFs in the TMR of 166 µg/kg DM ± 3.5 (AFB1:134, AFB2:17.4 and AFM1:14.9 µg/kg DM). The concentrate feed (55% of the TMR DM) was confirmed as a source of contamination, presenting a concentration >29 times higher than the EU-maximum limit value (5.68 µg/kg DM). Additionally, the multi-mycotoxin analysis evidenced the co-occurrence of 81 other toxic and potentially toxic fungal metabolites in the fed TMR. After replacing the contaminated concentrate feed with feedstuffs of the same formulation but from a new charge of ingredients, the abortion episodes ceased, and milk production increased significantly. In conclusion, the data of this case report suggest that AFs may be associated with pregnancy losses in dairy cattle and milk production depression. From the public health perspective, the data also indicate the need for a more careful examination of dairy animal feed in Pakistan. Since the high concentration of AFB1 detected in feed and considering the literature-reported transfer rates (1-6%) of this toxin to AFM1 (carcinogen for humans) in milk, the milk produced during the outbreak period is expected to be contaminated with AFM1, which raises public health concerns.

ABORTION AND NEONATAL MORTALITY DUE TO TOXOPLASMA GONDII IN BIGHORN SHEEP (OVIS CANADENSIS).

Low lamb recruitment can be an obstacle to bighorn sheep (Ovis canadensis) conservation and restoration. Causes of abortion and neonate loss in bighorn sheep, which may affect recruitment, are poorly understood. Toxoplasma gondii is a major cause of abortion and stillbirth in domestic small ruminants worldwide, but no reports exist documenting abortion or neonatal death in bighorn sheep attributable to toxoplasmosis. Between March 2019 and May 2021, eight fetal and neonatal bighorn lamb cadavers from four western US states (Idaho, Montana, Nebraska, and Washington) were submitted to the Washington Animal Disease Diagnostic Laboratory for postmortem examination, histologic examination, and ancillary testing to determine the cause of abortion or neonatal death. Necrotizing encephalitis characteristic of toxoplasmosis was identified histologically in six of eight cases, and T. gondii infection was confirmed by PCR in five cases with characteristic lesions. Other lesions attributable to toxoplasmosis were pneumonia (3/5 cases) and myocarditis (2/5 cases). Protozoal cysts were identified histologically within brain, lung, heart, skeletal muscle, adipose tissue, or a combination of samples in all five sheep with PCR-confirmed T. gondii infections. Seroprevalence of T. gondii ranged from 40-81% of adult females sampled in the Washington population in October and November 2018-2021, confirming high rates of exposure before detection of Toxoplasma abortions in this study. Of 1,149 bighorn sheep postmortem samples submitted to Washington Animal Disease Diagnostic Laboratory between January 2000 and May 2021, 21 of which were from fetuses or neonates, a single case of chronic toxoplasmosis was diagnosed in one adult ewe. Recent identification of Toxoplasma abortions in bighorn sheep suggests that toxoplasmosis is an underappreciated cause of reproductive loss. Abortions and neonatal mortalities should be investigated through postmortem and histologic examination, particularly in herds that are chronically small, demographically stagnant, or exhibit reproductive rates lower than expected.

Detection of bovine gammaherpesvirus 6 in tissues of aborted fetuses from dairy cows concomitantly infected by Histophilus somni.

Bovine gammaherpesvirus 6 (BoGHV6), formerly known as bovine lymphotropic virus, is a member of the Macavirus genus, subfamily Gammaherpesvirinae, family Herpesviridae, that was initially associated with proliferative diseases in cattle. While the Macavirus genus contains agents, including alcelaphine gammaherpesvirus 1 (AlGHV1), ovine gammaherpesvirus 2 (OvGHV2), and caprine gammaherpesvirus-2 (CpGHV2), known to cause malignant catarrhal fever (MCF), and are collectively referred to as MCF virus (MCFV) group of organisms, diseases and/or clinical syndromes have not been associated with BoGHV6 and porcine lymphotropic herpesvirus (PLHV). This report investigated the occurrence of BoGHV6 in tissues of aborted dairy fetuses known to be infected by Histophilus somni to identify possible disease patterns associated with infection by this Macavirus. A nested-PCR (nPCR) assay was used to amplify the BoGHV6 polymerase gene from multiple tissues of 13 fetuses and the cow of one of these which were derived from seven dairy herds located in three geographical regions of Brazil. Direct sequencing confirmed the results of the nPCR assays. Additionally, all fetal tissues were previously investigated for the presence of H. somni, Listeria monocytogenes, Neospora caninum, Brucella abortus, Leptospira spp., bovine alphaherpesvirus 1, and bovine viral diarrhea virus (BVDV) by PCR and/or RT-PCR assays. The nPCR assay amplified BoGHV6 DNA from fetuses of most dairy herds (85.7%; 6/7) investigated, resulting in the amplification of BoGHV6 from 76.9% (10/13) of all fetuses evaluated from two geographical and important cattle-producing regions of Brazil. Furthermore, only BoGHV6 was identified in the spleen (n = 3), myocardium, and kidney (n = 2) of five fetuses, and BoGHV6 was the only agent associated with myocarditis in one of these. Nevertheless, dual, triple, and quadruple infections (including BVDV, B. abortus, and N. caninum) were identified in fetuses that were concomitantly infected by H. somni. Phylogenetic analysis revealed that the strain herein identified has 100% nucleotide (nt) sequence identity with wild type strains of BoGHV6 circulating in ruminants from Brazil and 99.8% nt identity with the reference strain of BoGHV6 but was 72.2-73.3% and 67.4-68.2% different from members of the MCFV group and PLHV, respectively. These results demonstrated that 76.9% of the fetuses evaluated were infected by BoGHV6, most likely via vertical infection resulting in transplacental transmission. Considering that most fetuses were concomitantly infected by BoGHV6 and H. somni the real impact of this viral infection cannot be efficiently determined. However, since BoGHV6 was the only pathogen identified in the myocardium of one fetus with myocarditis by histopathology, the possible participation of this Macavirus in the etiopathogenesis of the myocardial disease observed in this fetus cannot be ignored or discarded. However, the mere amplification of BoGHV6 DNA from the myocardium is not enough to establish a definite association between cause and effect, since in situ evaluations and experimental studies would be needed to confirm this agent in the etiopathogenesis of fetal diseases and/or abortions in cattle. Consequently, additional studies are needed to determine the exact role, if any, of BoGHV6 in the development of fetal disease, and possibly fetal mortality.

Epidemiologic and Public Health Significance of Toxoplasma gondii Infections in Venison: 2009-2020.

Toxoplasma gondii infections are common in humans and animals worldwide. The ingestion of food or water contaminated with oocysts excreted by infected cats or ingestion of uncooked or undercooked meat containing tissue cysts of T. gondii are the 2 major modes of transmission of T. gondii. Deer are a popular game. Recently, outbreaks of clinical toxoplasmosis were reported in humans in North America linked to ingestion of undercooked venison. Here, we review prevalence, persistence of infection, clinical disease, epidemiology, and public health risks of T. gondii infections in deer and other cervids for the past decade. Estimates of worldwide serological prevalence are summarized individually for each species of deer, elk, moose, and caribou. Genetic diversity of 112 viable isolates of T. gondii from cervids is discussed, including its public health significance. Prevalence of T. gondii in deer is very high. Any part of a deer, including liver, spleen, and muscles, should be cooked thoroughly before human consumption.

Seroprevalences of Toxoplasma gondii and Neospora caninum infections in Jordanian women who had a recent spontaneous abortion / Soroprevalências de infecções por Toxoplasma gondii e Neospora caninum em mulheres jordanianas que tiveram um aborto espontâneo recente

Abstract This cross-sectional study investigates Toxoplasma gondii and Neospora caninum among 445 recently spontaneously aborted (RSA) Jordanian women using ELISA and indirect fluorescent antibody (at a cut-off value of 1/200) tests, respectively. The type of hospital, age, cat and dog contacts, raw and barbecued meat and wild plant consumption, number of abortions, and stillbirths were tested as independent variables using univariate and multivariate logistic regression analyses. The true seroprevalences were 22.1% for T. gondii-IgG, 22.7% for N. caninum-IgG, 2.6% for T. gondii-IgM, 10.6% for N. caninum-IgM, 0% for T. gondii-IgG and IgM, 6.7% for N. caninum-IgG and IgM, and 4.6% and 0% for both parasite IgG and IgM, respectively. T. gondii-IgM-seropositivity was associated with the number of abortions with odds ratios (OR) of 2.4 and eating barbecued meat (OR = 0.12). N. caninum-IgG-seropositivity was associated with having a dog in the house (OR = 2.6), and with stillbirth (OR = 0.1). N. caninum-IgM was associated with visiting a private-hospital (OR = 2.7). RSA Jordanian women are equally exposed to both parasites with significantly (p < 0.05) higher seroprevalence of N. caninum-IgM compared to T. gondii-IgM suggestive of active infections among RSA women in Jordan.

Resumo Este é um estudo transversal, investigando Toxoplasma gondii e Neospora caninum entre 445 mulheres jordanianas recentemente abortadas espontaneamente (RSA), usando-se ELISA e testes de anticorpos fluorescentes indiretos (com valor de corte de 1/200), respectivamente. Tipo de hospital, idade, contato com o cão, consumo de carne, número de abortos foram testados como variáveis independentes, usando-se análises de regressão logística univariada e multivariada. As verdadeiras seroprevalências foram 22,1% para T. gondii-IgG; 22,7% para N. caninum-IgG; 2,6% para T. gondii-IgM; 10,6% para N. caninum-IgM, 0% para T. gondii-IgG e IgM, 6,7% para N. caninum-IgG e IgM, e 4,6% e 0% para ambos os parasitas IgG e IgM, respectivamente. A soropositividade para T. gondii-IgM foi associada ao número de abortos com "odds ratio" (OR) de 2,4 e ingestão de carne grelhada (OR = 0,12). A soropositividade para N. caninum-IgG foi associada à presença de cachorro em casa (OR = 2,6) e natimorto (OR = 0,1). N. caninum-IgM foi associada à visita a um hospital privado (OR = 2,7). Mulheres jordanianas com RSA estão igualmente expostas a ambos os parasitas com soroprevalência significativamente (p <0,05) maior de N. caninum-IgM, em comparação com T. gondii-IgM, sugestivo de infecções ativas entre mulheres com RSA na Jordânia.

Histopathological and Serological Analysis of Aborted Ewes and Neonatal Death with Toxoplasma gondii in Duhok City, Kurdistan-Iraq.

This study was carried out on seven flocks of ewes suffered from late abortion and neonatal mortality with the prevalence rate of infection reported as 13.95%. The blood and tissue samples were collected from the aborted ewes in several flocks of Duhok province, Kurdistan Region, Iraq. Serological analysis indicated that all the aborted ewes were confirmed positive for agglutination to Toxoplasma gondii (T. gondii)antibody. The investigation of the aborted fetuses showed the blood-stained fluid in the thoracic and abdominal cavity. Most of the aborted fetuses had also enlarged, congested, and friable livers and lungs. The placenta was swollen, reddish, and friable, and its cotyledons also spotted with whitish foci. T. gondii tachyzoites were also demonstrated in the placental sections of some aborted ewes. Severe congestion, necrosis, and infiltration of multinucleated cells were the most predominant histopathological changes of the aborted fetuses, as well as presented tissue cysts, tachyzoites, and bradyzoites in the liver, brain, heart, and lung. There were also several clusters of dark purple banana-shaped T. gondii tachyzoites within the brain and heart tissues in most of the examined aborted fetuses in different flocks. T. gondii tachyzoites were also detected from the peritoneal ascites of mice inoculated experimentally 12 days following the infection. Moreover, T. gondii tissue cysts were detected from the impression smears of the mice brains 32 days after the infection. Accordingly, the demonstration of T. gondii in Giemsa-stained impression smears associated with characteristic histopathological changes of different organs is a great fundamental method for the diagnosis of T. gondii in aborted cases.

An assessment of bovine herpes virus 4 as a causative agent in abortions and neonatal death.

Numerous viruses, including bovine viral diarrhoea virus (BVDV), bovine herpes virus 1 (BoHV-1) and bovine herpes virus 4 (BoHV-4), and other pathogens are the most common causes of reproductive disorders and are responsible for huge economic losses in livestock production. This study investigates the aetiological role of BoHV-4 in fertility problems such as abortions, stillbirth and birth with unviable calves. Retrospective samples from 38 animals, including 17 aborting cows, 17 aborted foetuses, three stillborn calves and one unviable newborn calf were analysed. The BoHV-4 genome was detected in 25 (65.7%) animals by polymerase chain reaction. In 14 of these infected animals, we detected co-infection with BVDV, while the co-presence of BoHV-1 was also detected in one animal. In addition to the high prevalence of BoHV-4 genome in materials related to fertility problems, isolation of BoHV-4 from the brain of one stillborn calf indicated a causal link between BoHV-4 and fertility problems, such as abortion, stillbirths or birth with unviable calves.

Association of Ureaplasma diversum with reproductive disease in cattle.

Aims: To examine the association between the detection of Ureaplasma diversum in vaginal swabs from dairy cows in north western Spain with the diagnosis of granular vulvovaginitis (GVV) and reproductive performance, and the association with subclinical endometritis (SE) in slaughterhouse material. The presence of this microorganism in cases of abortion was also investigated. Methods: From 106 dairy farms in the province of Lugo, 40 herds were randomly selected. Vaginal swabs were obtained from 10 randomly selected cows per farm, then pooled for analysis to detect the presence of U. diversum by quantitative real-time PCR (qPCR). In five of these herds samples from the 10 animals were individually tested for U. diversum, and the presence of GVV lesions and their reproductive efficiency (number of inseminations to achieve pregnancy over two subsequent pregnancies) were determined. Vaginal swabs from uteri of cattle obtained at a slaughterhouse (n = 100) were tested for U. diversum and the presence of SE, defined as >5% polymorphonuclear cells in cytobrush smears, was determined. Sixteen farms with abortion problems submitted samples for culture and PCR testing including for U. diversum. Results: Of the 40 herds, 39 (98%) tested positive for U. diversum. On the five farms, 25/50 (50%) cows tested positive for U. diversum, and more cows with GGV-lesions (16/25; 64%) tested positive than cows without lesions (9/25; 36%) (p = 0.047). There were more cows with poor reproductive efficacy that tested positive (8/11; 57%) than tested negative (3/17; 18%) for U. diversum (p = 0.029). Of the 100 uteri, five tested positive for U. diversum and there were more uteri with SE that tested positive (3/19; 16%) than uteri without SE (2/81; 2%) (p = 0.036). U. diversum was also diagnosed in 4/16 farms with abortion problems and liver appeared to be the best tissue for detecting U. diversum DNA in the fetuses analysed. Conclusions and Clinical Relevance: Infection with U. diversum was present in most of herds investigated and it was statistically associated with GVV, SE and poor reproductive performance. It was also detected in abortions and the liver may also be an additional tissue to be considered in the diagnosis of U. diversum abortion by PCR. The possible association with different diseases in the same area suggests that different presentations should be considered when studying the implications of U. diversum on the reproductive diseases of cattle.

Evaluation of abortions spontaneously induced by Neospora caninum and risk factors in dairy cattle from Lima, Peru / Avaliação de abortos induzidos espontaneamente por Neospora caninum e fatores de risco em bovinos leiteiros de Lima, Peru

Abstract Our objective was to identify the direct and indirect presence of Neospora caninum in dairy cattle and their aborted fetuses from Lima, Peru. A total 219 blood samples obtained from dairy cattle with records of spontaneous abortion were collected to detect antibodies against N. caninum in serum with indirect ELISA and search for risk-factor associations. 68 fetal aborted tissue samples of these cows were analyzed by PCR, indirect ELISA and histopathology assay to detect N. caninum presence. The prevalence ratio (PR) and 95% confidence intervals (CI) were estimated. Univariate analysis was performed using the chi-squared test. Among the 68 aborted fetuses collected, 10 (15%) were positive in at least two diagnostic tests. Among 219 serum samples, 46.6% (95% CI: 40.0%-53.3%) were positive. Cows with 4 years or older (PR: 7.10; 95% CI: 4.89-10.67) and multiparous (PR: 1.76; 95% CI: 1.11-2.80) were found to be more likely to possess N. caninum antibodies. This study detects presence of N. caninum in dairy cattle and their aborted fetus from Lima valley, suggesting biosecurity management improve to neosporosis control.

Resumo O objetivo do trabalho foi diagnosticar a presença direta e indireta de Neospora caninum em fetos abortados e de soros de bovinos leiteiros de Lima, Peru. Um total de 219 amostras de sangue obtido de vacas leiteiras, com registros de abortos espontâneos, foi coletado para detectar anticorpos contra N. caninum no soro (pelo ELISA indireto), e para estudar associações com fatores de risco. Foram examinadas 68 amostras de tecido fetal abortado das vacas soropositivas pela PCR, ELISA indireto e histopatologia para determinar a presença de N. caninum. A taxa de prevalência (PR) e o intervalo de confiança (CI) de 95% foram estimados. Análise univariada foi realizada usando o teste de Qui-quadrado. Entre os 68 fetos abortados, 10 (15%) foram positivos em pelo menos dois testes diagnósticos. Entre as 219 amostras de soro, 46,6% (95% IC: 40,0%-53,3%) foram positivas. Vacas com 4 anos ou mais de idade (RP: 7,10; 95% IC: 4,89-10,67) e multíparas (RP: 1,76; 95% IC: 1,11-2,80) apresentaram maior frequência de anticorpos contra N. caninum. Este estudo demonstrou a presença de N. caninum em bovinos leiteiros e em fetos abortados oriundos do vale de Lima, sugerindo a implementação de medidas de biossegurança, para o controle da neosporose.

Non-infectious causes that increase early and mid-to-late pregnancy loss rates in a crossbreed dairy herd.

High reproductive performance is an element factor for profitability in dairy herds; although, pregnancy loss of non-infectious nature during early and mid-to-late embryonic period is increasing in dairy cattle. Based on that, the present study aimed to determine the incidence of pregnancy loss before and after 60 days of insemination, and to identify some non-infectious causes that could enhance it. The herd was composed by 600 crossbred dairy cows and those with a corpus luteum (CL) were treated with prostaglandinF2α, then inseminated, on the other hand, those without a CL were submitted to a timed artificial insemination protocol (TAI). Pregnancy losses rates were analyzed by logistic regression by SAS, and differences were considered significant when P < 0.05. The overall pregnancy loss and mid-to-late pregnancy loss were not affected by animal category (P > 0.05); although, early pregnancy loss was higher in cows than in heifers (11.90 vs. 3.39%). The early pregnancy loss was higher in those cows that calved on spring/summer when compared to those calved on fall/winter (9.22% vs. 16.11%), moreover, those inseminated during spring/summer tended to have higher early pregnancy loss when compared to those inseminated on fall/winter (13.35% vs. 8.57%). In conclusion, when some of non-infectious causes were evaluated, it was observed that cows that calved on spring/summer had higher pregnancy loss. At this point, strategies should be developing to minimize pregnancy loss in dairy herds, as it could be considered an important reproductive problem.

Incidence and biomarkers of pregnancy, spontaneous abortion, and neonatal loss during an environmental stressor: Implications for female reproductive suppression in the cooperatively breeding meerkat.

Meerkats are group-living, insectivorous herpestids in which subordinate members provide extensive care for the dominant female's young. In contrast to some cooperative breeders, subordinate female meerkats are physiologically able to reproduce and occasionally do so successfully; their attempts are more frequently 'suppressed' via eviction or infanticide by the dominant female. Spontaneous abortion and neonatal loss occur with some regularity, further negatively impacting reproductive success. Here, we compared the reproductive outcomes and endocrine profiles, including of serum progesterone (P4), serum estradiol (E2), and fecal glucocorticoid metabolites (fGCm), of dominant and subordinate dams residing within their clans in the Kalahari Desert of South Africa. Our study spanned years of drought, which reduced insect abundance and represented a substantial environmental stressor. Meerkat pregnancies were identified at mid-term and culminated either in spontaneous abortions or full-term deliveries, after which pups were either lost prior to emergence from the natal den (usually within 2days of birth) or emerged at 2-3weeks. Neonatal loss exceeded fetal loss for all females, and contributed to narrowing the status-related disparity in female reproductive output seen during less arid periods. Although E2 concentrations were significantly lower in subordinate than dominant females, they were sufficient to support gestation. Absolute E2 concentrations may owe to androgenic precursors that also attain highest concentrations in dominant dams and may mediate aggression underlying female reproductive skew. Pregnancies terminating in fetal loss were marked by significantly lower P4 concentrations in mid-gestation and modestly lower E2 concentrations overall. Consistently high fGCm concentrations further increased across trimesters, particularly (but not consistently) in subordinates and in aborted pregnancies. Environmental stressors may modulate reproductive outcomes in meerkats through their influence on sex steroids and their effects on intragroup competition. The social and eco-physiological factors affecting intraspecific variation in reproductive output, even in obligate cooperative breeders, may be most apparent during extreme conditions, reflecting the benefits of long-term studies for assessing the impact of climate change.

Relationship between circulating progesterone at timed-AI and fertility in dairy cows subjected to GnRH-based protocols.

The objectives of this retrospective study were: 1) to investigate the effect of plasma progesterone (P4) concentrations at the time of timed-AI (TAI) on fertility, and 2) to examine risk factors associated with plasma P4 concentrations that impair fertility in lactating dairy cows subjected to GnRH-based protocols. Data from 872 lactating Holstein cows that had, or had not been presynchronized prior to a 7-day GnRH-based TAI protocol were examined. However, data from only those cows (n = 697; 79.9%) that ovulated after second GnRH were analyzed. Plasma P4 concentrations were determined using a solid-phase radioimmunoassay. Transrectal ultrasonography was used to determine cyclicity at first GnRH treatment, ovulation after first and second GnRH treatments, and pregnancy status at 32 and 60 d after TAI. Parity, days in milk (DIM) and BCS were also recorded. Plasma P4 concentrations at TAI ranged from 0.0 to 9.94 ng/mL (overall mean ± SEM, 0.32 ± 0.02 ng/mL) and 41 (5.9%) cows had P4 ≥ 1.0 ng/mL at TAI. The percentage of cows diagnosed pregnant at 32 and 60 d after TAI was 45.1 and 41.6%, respectively, and pregnancy loss from 32 to 60 d after TAI was 7.6%. Plasma P4 concentrations at TAI affected (P < 0.01) P/AI at 32 and 60 d, but did not affect (P > 0.1) pregnancy loss. No cows with plasma P4 concentrations >0.80 ng/mL became pregnant. However, ROC curve analysis revealed that the optimal P4 threshold at TAI for P/AI at 32 d was ≤0.50 ng/mL, with a sensitivity and specificity of 94.9 and 20.9, respectively. The percentage of cows with plasma P4 concentrations >0.50 ng/mL was 15.8% (110/697). Furthermore, a significant (P < 0.05) quadratic relationship between plasma P4 concentrations at TAI and P/AI at 32 d was observed. The maximum predicted probability of pregnancy was 0.54 at a P4 concentration of 0.26 ng/mL. Based on the odds ratios (OR), cows with P4 ≤ 6.2 ng/mL at PGF were 2.3 times less likely to have P4 > 0.50 ng/mL at TAI compared to cows with P4 > 6.2 ng/mL (OR = 0.44; 95% CI = 0.27 to 0.71; P < 0.01). Also, cyclic cows subjected to presynchronization were less likely to undergo luteal regression than non-presynchronized or acyclic cows (OR = 5.3; 95% CI = 1.77 to 16.27; P < 0.01). In summary, plasma P4 concentrations >0.50 ng/mL at TAI resulted in significantly reduced fertility. As elevated plasma P4 concentrations at TAI were more frequent in cows with lower P4 at PGF or those subjected to presynchronization, both groups are most likely to benefit from an additional PGF treatment prior to TAI.

Fertility of lactating dairy cows treated with gonadotropin-releasing hormone at AI, 5 days after AI, or both, during summer heat stress.

Objectives of this experiment were to evaluate pregnancy per AI (P/AI) and progesterone (P4) concentrations after AI of lactating dairy cows under heat stress conditions treated with 100 µg gonadotropin-releasing hormone (GnRH) at AI, 5 d after AI, or both. Lactating Holstein cows from two herds were enrolled in the study during summer. Cows detected in estrus based on tail paint removal were allocated to four treatments: (1) control (CON = 722); (2) GnRH treatment at AI (G0 = 739); (3) GnRH treatment 5 d post-AI (G5 = 697); or (4) GnRH treatment at AI and 5 d post-AI (G0+G5 = 697). Blood samples were collected from a subgroup of cows at AI (study d 0), study d 5 and 12 to determine P4 concentrations. Pregnancy diagnosis was conducted at study d 36 and 94. Temperature and relative humidity were collected from a meteorological station nearest the herds and temperature-humidity index (THI) was calculated. Average THI during study enrollment was 83.8 ± 0.1 and THI at study d 0 tended (P = 0.09) to be associated with P/AI at study d 36, but it was not (P = 0.33) associated with P/AI at study d 94. Treatment with GnRH at AI, 5 d after AI, or both, did not affect (P ≥ 0.64) P/AI at study d 36 or 94. An interaction, however, was detected (P = 0.06) between treatment and lactation number. Such an interaction was observed because, among ≥ third-lactation cows, P/AI was greater for G0+G5 (28.6%) and G5 (25.3%) than CON cows (17.3%) at study d 36. Pregnancy per AI of ≥ third-lactation G0 cows did not (P ≥ 0.11) differ from CON, G5, and G0+G5 cows. No differences in P/AI were detected among treatments in first- and second-lactation cows. Overall, treatments with GnRH at AI, 5 d after AI, or both were not (P = 0.94) associated with P4 concentrations on study d 0, 5 or 12. Among cows diagnosed pregnant at study d 36, progesterone concentration on d 5 was not affected (P ≥ 0.24) by treatments with GnRH at AI, 5 d after AI, or both, but progesterone concentration on d 12 was greater for cows treated with GnRH at AI and 5 d after AI compared with G0 cows. Lactating dairy cows in their third or greater lactation exposed to heat stress conditions with compromised fertility may have increased P/AI after treatment with GnRH 5 d after AI or the combined treatment of GnRH at AI and 5 d after AI because of reduced early embryonic loss.

Laboratory Findings Suggesting an Association Between BoHV-4 and Bovine Abortions in Southern Belgium.

Abortions cause heavy economic losses for the bovine sector. The use of a standardized panel of analyses covering a large spectrum of pathogens responsible of abortion in cattle allowed demonstrating the direct involvement of at least one pathogen in 57% of analysed abortions in the southern part of Belgium. This result suggests a margin of improvement in the diagnostic efficacy. In order to evaluate the interest to broaden the list of pathogens included in the panel of analyses, the implication of bovine herpesvirus 4 (BoHV-4) in abortion was assessed by two different studies. In the first study, coupled serology was performed after abortion on 714 dams to identify specific seroconversion against BoHV-4. The overall seroconversion in cows was 19.5%, with a higher frequency in primiparous compared to multiparous females. In addition, the type of breed (beef cattle) and the time period from the fourth quarter 2008 until the last quarter 2009 were significantly related to the seroconversion of cows. The second study investigated the virus ability to infect the foetus. In this study, 368 cases of bovine abortions were specifically tested for BoHV-4, using PCR on foetus tissues and ELISA on dam and foetus sera. The results showed a maternal seroprevalence of 64.7%, a foetal seroprevalence of 0.8% and a PCR prevalence in foetuses of 1.1%, demonstrating the ability of BoHV-4 to infect the foetus.

[Bovine herpesvirus 4 (BoHV-4): general aspects of the biology and status in Argentina]. / Herpesvirus bovino 4 (BoHV-4): aspectos generales de su biología y situación en la República Argentina.

Bovine herpesvirus 4 (BoHV-4) has been isolated from cattle with respiratory infections, vulvovaginitis, mastitis, abortions, endometritis and from apparently healthy animals throughout the world. Although it has not yet been established as causal agent of a specific disease entity, it is primarily associated with reproductive disorders of cattle. This virus can infect a wide range of species, either in vivo or in vitro. Two groups of prototype strains were originated from the first isolates: the DN599-type strains (American group) and the Movar-type strains (European group). In Argentina, BoHV-4 was isolated and characterized in 2007 from vaginal discharge samples taken from cows that had aborted. So far, more than 40 isolates, mainly associated with aborting bovine females have been registered in our country.

Neosporosis epidémica y endémica: descripción de dos eventos en bovinos para cría / Endemic and epidemic bovine neosporosis: description of two events in beef cattle

El objetivo de este trabajo es describir dos eventos producidos en la provincia de Buenos Aires en los cuales Neospora caninum estuvo asociado a la ocurrencia de abortos en bovinos de cría para carne. En uno de ellos se registraron 11 abortos en 57 vaquillonas durante 45 días, en este evento fue 5 veces más probable que una vaquillona que sufrió un aborto fuera seropositiva a N. caninum que una que no lo sufrió (odds ratio [OR] = 4,9 IC 1,2­19,9) (p<0,05). En el otro evento se registraron 14 abortos en 140 vacas, y no se observó asociación significativa entre los abortos y la seropositividad frente a N. caninum OR = 0,69 (0,06­7,31) (p>0,05). Se analizaron dos fetos de cada evento: estos resultaron negativos a otros patógenos de la reproducción, aunque presentaron anticuerpos específicos y lesiones histopatológicas compatibles con infecciones por N. caninum. Estos resultados sugieren dos posibles modalidades de presentación de abortos en bovinos causados por N. caninum: una epidémica, como la del primer evento aquí referido, y una endémica, como la del segundo

The aim of this study was to describe two events in which Neospora caninum was involved in bovine abortions in beef cattle. In the first event, 11 abortions in 57 heifers were recorded in 45 days. One aborted heifer was 5 times more likely to be seropositive than a non-aborted heifer (OR=4.9; IC 1.2­19.9) (p<0.05). In the second event, no association between serological results and abortions were observed (OR= 0,69; 0,06­7,31) (p>0.05). Neither antibodies nor isolation of other pathogens were achieved in any case. On the contrary, antibodies and pathognomonic histopathological lesions were observed in the four fetuses from both cases. Interestingly, the findings in the first event suggest the epidemic behavior of the disease. In contrast, in the second event it appears that few abortions were due to N. caninum, suggesting the presence of endemic neosporosis

Study on outbreak of Neospora caninum-associated abortion in dairy cows in Tabriz (Northwest Iran) by serological, molecular and histopathologic methods.

OBJECTIVE: To determine Neospora caninum (N. caninum) as a cause of bovine abortion in dairy cows by ELISA, PCR and Pathological methods in Tabriz, Northwest of Iran. METHODS: For study of outbreak of neosporosis, blood samples were collected from 76 Holstein aborted dairy cows in Tabriz (Northwest Iran). Antibodies to N. caninum were assayed by using a commercially ELISA kit (IDEXX, USA). IgG against N. caninum were found in 14 (18.4%) cases. Aborted fetuses of these seropositive dams were proposed for histopathological and molecular investigations. Brains, spinal cords and placentas of the fetuses were fixed in 10% buffered formalin for histopathology. Also 5-10 g of brain tissue was sampled for DNA extraction. In 6 out of 14 (42.8%) fetuses, brain tissue was positive in PCR. All dams of these fetuses were serologically seropositive in ELISA test. RESULTS: Histopathologically, the lesions consistent with N. caninum were observed in brains, spinal cords and placenta of all fetuses. Lesions in CNS included severe congestion, perivascular and perineuronal edema, status spongiosis, perivascular cuffing, focal gliosis, nourophagy and focal necrosis. There were some Neospora-like cysts in brain. In placentas, severe congestion, perivascular infiltration of mononuclear cells, vascular thrombosis, focal placentitis and necrotic foci in cotyledons were noticed. CONCLUSIONS: The results of present study agreed the results of similar studies about serological, histopathological and molecular results of other studies about neosporosis and it seems to support the outbreak of N. caninum-associated abortion in dairy cows in Tabriz (Northwest Iran).

Reproductive performance of dairy cows resynchronized after pregnancy diagnosis at 31 (±3 days) after artificial insemination (AI) compared with resynchronization at 31 (±3 days) after AI with pregnancy diagnosis at 38 (±3 days) after AI.

An important part of reproductive management programs on dairy farms is identification of nonpregnant cows and early re-insemination to achieve higher pregnancy rates. The objective of this study was to compare the effect on reproductive performance and pregnancy loss of 2 pregnancy diagnosis protocols: (1) pregnancy diagnosis performed 31±3 d after artificial insemination (AI) by ultrasonography (ULTRA), and (2) resynchronization started 31±3 d after AI but with pregnancy diagnosis performed 38±3 d after AI by palpation per rectum (PALP). Cows were randomly allocated into 1 of the 2 management programs. For cows enrolled in ULTRA, the initial pregnancy diagnosis (P1) was performed by transrectal ultrasonography at 31±3 d after AI, and nonpregnant cows were enrolled in the Ovsynch protocol for resynchronization of ovulation to receive timed AI (TAI). For cows enrolled in PALP, the Ovsynch protocol for resynchronization of ovulation to receive TAI was initiated at 31±3 d after AI regardless of pregnancy status, with the initial pregnancy diagnosis (P1) performed by palpation per rectum at 38±3 d after AI. For both groups, reconfirmation of pregnancy was performed by palpation per rectum at 63±3 d after AI (P2). Cows were inseminated after detection of estrus by use of activity monitors at any time during the study. Two levels of activity were used as a reference for cows AI after detection of estrus based on activity: an activity level of ≥2 when a cow was coded in DairyComp 305 (Valley Agricultural Software, Tulare, CA) as open (nonpregnant) and an activity level of ≥3 when the pregnancy status of the cow was unknown. Our findings showed that the odds of pregnancy loss cows in ULTRA was 2 times higher between P1 and P2 compared with that of cows in PALP. Furthermore, pregnancy diagnosis method (ULTRA vs. PALP) did not have a significant effect on the Cox proportional hazard of pregnancy at P2. The occurrence of assisted parturition, metritis, or retained placenta was associated with a reduced hazard of pregnancy at P2. An economic analysis was performed by simulating a 1,000-cow commercial dairy herd using a decision support tool to estimate the net present value (NPV; $/cow per yr) from using the 2 different pregnancy diagnosis methods. The analysis revealed minor differences in NPV between the programs, depending on the cost to perform ULTRA or PALP. In summary, we observed no difference in the reproductive performance and only a minor and fluctuating economic difference when using either PALP or ULTRA for pregnancy diagnosis of dairy cows.

Supplemental progesterone and timing of resynchronization on pregnancy outcomes in lactating dairy cows.

The objective was to determine the effect of exogenous progesterone (P4) in a timed artificial insemination (TAI) protocol initiated at 2 different times post-AI on pregnancies per AI (P/AI) in lactating dairy cows. Cows (n=1,982) in 5 dairy herds were assigned randomly at a nonpregnancy diagnosis 32 ± 3 d post-AI to 1 of 4 resynchronization (RES) treatments arranged in a 2 × 2 factorial design using the Ovsynch-56 (GnRH, 7d later PGF2α, 56 h later GnRH, 16 h later TAI) protocol. Treatments were as follows: cows initiating RES 32 ± 3 d after AI with no supplemental P4 (d 32 RES-CON; n=516); same as d 32 RES-CON plus a controlled internal drug release (CIDR) insert containing P4 at the onset of Ovsynch-56 (d 32 RES-CIDR; n=503); cows initiating RES 39 ± 3 d after AI (d 39 RES-CON; n=494); and same as d 39 RES-CON plus a CIDR (d 39 RES-CIDR; n=491). Cows were inseminated if observed in estrus before TAI. The P/AI was determined 32 and 60 d after TAI. In a subgroup of cows (n=1,152), blood samples were collected and ovarian structures examined by ultrasonography on the days of the first GnRH (G1) and PGF2α of Ovsynch-56. Percentage of cows with a corpus luteum (CL) at G1 was unaffected by timing of treatments, but percentage of cows with a CL at PGF2α was greater for d 32 than for d 39 cows (87.9 vs. 79.4%). In addition, percentage of cows with P4 ≥ 1 ng/mL at G1 was unaffected by timing of treatments, but was increased for d 32 compared with d 39 RES cows on the day of the PGF2α of the RES protocols (86.5 vs. 74.3%). Treatment did not affect ovulation to G1 or P/AI 32 d after RES TAI (d 32 RES-CON=30.1%, d 32 RES-CIDR=28.8%, d 39 RES-CON=27.5%, d 39 RES-CIDR=30.5%). A greater percentage of d 39 RES cows underwent premature luteolysis during the RES protocol compared with d 32 RES cows. An interaction was detected between day of RES initiation and CIDR treatment, in which the CIDR increased P/AI 60 d after TAI for d 39 (CON=23.7% vs. CIDR=28.0%), but not for d 32 (CON=26.9% and CIDR=24.2%) cows. Pregnancy loss was unaffected by treatment. In addition, cows had improved P/AI 60 d after TAI when they received a CIDR and did not have a CL (CON-CL=28.2%, CON-No CL=19.2%, CIDR-CL=27.0%, and CIDR-No CL=26.5%) or had P4 <1 ng/mL (CON-High P4=27.8%, CON-Low P4=15.0%, CIDR-High P4=25.0%, and CIDR-Low P4=29.4%) at G1, but not if a CL was present or P4 was ≥ 1 ng/mL at G1. In conclusion, addition of a CIDR insert to supplement P4 during the RES protocol increased P/AI for cows initiating RES 39 ± 3 d after AI but not 32 ± 3 d after AI.