Coxiella burnetii and Reproductive Disorders in Cattle: A Systematic Review.

Coxiellosis or Q fever is an infectious zoonotic disease caused by the bacterium Coxiella burnetii. A systematic review using bibliographic research was carried out, and the focus was the relationship between C. burnetii infection and reproductive disorders in cattle [abortion/stillbirth/perinatal morality/weak calves (ASPW complex); retained foetal membranes (RFMs); metritis/endometritis; and infertility/sub-fertility]. The bibliographical search yielded 443 results from databases, but only 61 were deemed eligible. For each disorder, summary tables were prepared, and a scientific evidence score was calculated for each study based on four criteria to help assess the level of evidence for the impact of C. burnetii on the reproductive disorders assessed: type of publication (peer-reviewed or other); type of study (case-control/cohort or other); type of C. burnetii test (direct or indirect); and comparative statistical analysis (yes or no). In addition, summary tables also included information on the study population, country, authors and year of publication, key findings and an assessment of the evidence for an association. For the ASPW complex, RFMs, metritis/endometritis and infertility/sub-fertility, 43, 9, 8 and 19 studies provided data, respectively. On a scale of four, nearly 50% of all study citations had evidence scores of three or four. For ASPW, RFMs and infertility/sub-fertility, there is a significant body of evidence to support a deleterious role for Q fever. In contrast, for metritis/endometritis, the evidence is unclear. It is concluded that there is a substantial need for further research, particularly involving larger animal populations in more controlled settings. To provide more consistency, it is recommended that authors follow more precise definitions of reproductive parameters and more robust diagnostic methodologies.

Current Insights in the Repeat Breeder Cow Syndrome.

Cows can have difficulties becoming pregnant, and in certain cases, these reproductive failures do not have an evident cause. Furthermore, when these failures are repeated three or more times with estrous cycles of normal duration and in the absence of evident clinical signs, it is considered repeat breeder cow (RBC) syndrome. A substantive incidence of RBC syndrome has been reported all over the world, which severely affects the farm economy. This paper reviews those studies particularly focused on RBC syndrome from 2000 to 2023 but also includes consolidated information until this date. Hormonal imbalances, undetectable oviductal or uterine defects, or poor oocyte or embryo quality have been reported as causes of RBC syndrome, while subclinical endometritis has been considered a relevant causal agent. However, it is unresolved why this condition is recurrent in certain animals, despite the implementation of corrective management actions or treatments. Recent studies evaluate the putative role of certain genes, factors, hormones, or proteins in the pathogenesis of RBC syndrome. Numerous risk factors contribute to the appearance of this syndrome, and some of them could be mitigated to partially prevent this infertility, while others cannot be changed. Due to the complexity of this syndrome, it is important to increase knowledge about the mechanisms involved, develop new diagnostic tools to differentiate causal agents, and implement new treatments to restore fertility. There is consensus about the huge repercussions of this syndrome on farm profitability, but further studies are now needed to describe its economic impact.

Benchmarking welfare indicators in 73 free-stall dairy farms in north-western Spain.

The aim of this study was to describe the status of body condition score (BCS), hock injuries prevalence, locomotion and body hygiene score as animal welfare measures in 73 free-stall dairy cattle farms in Lugo (Spain). A benchmarking process was established across farms: (1) the animal-based indicators were ordered from low to high values; (2) The farms were classified into three categories based on the number of indicators within less than the 25th percentile, 25th to 75th percentile and above the 75th percentile. The median prevalence of unsuitable BCS, hock injuries and clinical lameness was (median (range)) 51.7 per cent (13.3 to 89.5 per cent), 40.0 per cent (7.0per cent to 100 per cent) and 9.0 per cent (0per cent to 60.0 per cent) respectively. The dirtiness of the cow's coat had a high prevalence (73.0 per cent (37.5per cent to 100 per cent)). Most farms did not display consistently good or poor animal-based indicators and each farm had its own set of strong and weak points. Moreover, facilities design and management practices were described to understand source of the observations made of the cows. The incidence of overstocking was 31.5 per cent for stalls and 26.0 per cent for headlocks. The front lunge space was reduced (<90 cm) on most dairies (90.4 per cent). Signs of poor natural ventilation (cobwebs or humidity on the roof) and ammonia odour were observed on 32.8 per cent and 85.0 per cent of the barns totally closed or with a side openingless than 50 per cent of the wall height. The milking parlour was designed with two or more turns more than 90° (9.3 per cent), and failed to allow cows to see the parlour before entering (45.2 per cent). On 52.0 per cent of dairies, more than 15 per cent of the cows had to be forcefully moved into the milking parlour. In conclusion, there was a big variation in the animal welfare levels within and across farms and they could benefit from others by changing management practices related to facilities and herds.

Oestrus synchronisation in postpartum dairy cows using repetitive prostaglandin doses: Comparison between D-cloprostenol and dinoprost.

This trial evaluated the reproductive performance in an early routine oestrus induction programme using two different PGF2α preparations in dairy cattle. D-cloprostenol sodium (n = 192; Group A) or dinoprost (n = 187; Group B) was administered between days 35 and 42 post partum. Also, a group of non-treated cows (n = 135; Group C) was included as control. Pedometers were used to detect oestrus, and also secondary oestrous signs and vaginal mucus quality were assessed prior to artificial insemination (AI). When oestrus was not detected for 14 days after PGF2α administration, the treatment was repeated, up to a maximum of three times. There were no differences between the study groups in oestrus detection (A = 73.48%, B = 73.01%, C = 79.26%; P = 0.428), good mucus quality (A = 96.45%, B = 91.30%, C = 93.45%; P = 0.203) and the presence of mounting lesions (A = 98.58, B = 94.93%, C = 98.13; P = 0.414). First-service pregnancy rates were 19.78%, 15.64% and 32.03% in Groups A, B and C, respectively (P = 0.003). There were no inter-group differences for the interval from parturition to first AI. However, a significantly shorter interval from parturition to conception (92.17 days, 99.45 days, 118.93 days; P = 0.002) and significantly less services per conception (2.12, 2.18, 2.66; P = 0.003) were observed in Groups A and B in comparison with Group C. The use of PGF2α resulted in better fertility in a repetitive, routine postpartum programme, although no differences between Dcloprostenol and dinoprost were detected.