Study of the economic impact of cryptosporidiosis in calves after implementing good practices to manage the disease on dairy farms in Belgium, France, and the Netherlands

Progression of the faecal microbiome in preweaning dairy calves that develop cryptosporidiosis

BACKGROUND

Cryptosporidiosis is a diarrheal disease that commonly affects calves under 6 weeks old. The causative agent, Cryptosporidium parvum, has been associated with the abundance of specific taxa in the faecal microbiome during active infection. However, the long-term impact of these microbiome shifts, and potential effects on calf growth and health have not yet been explored in depth.

METHODS

Three hundred and forty-six (346) calves from three dairy farms had one faecal swab collected during the first week of life (W1). Thereafter, sampled calves were monitored for diarrhoeal disease and those that suffered a diarrhoea event were tested for C. parvum by lateral flow testing (LFT). Calves that experienced diarrhoea and tested positive for C. parvum by LFT were assigned to the Cryptosporidium-positive (Cp+) group (n = 32). Matched healthy (H) controls with no history of diarrhoea were selected from the remaining cohort (n = 33). The selected subset of calves (n = 65) was observed until weaning, collecting a faecal swab, at approximately Week 5 (W5) and Week 10 (W10) after birth, resulting in a total of 191 samples (W1; n = 65, W5; n = 64, W10; n = 62). 16S rRNA gene amplicon sequencing was performed on all extracted samples.

RESULTS

Analysis of the longitudinal microbiome showed significant changes in the microbial diversity and composition across all three time-points. Whilst Firmicutes were elevated in the Cp+ group at W5 compared to the H group, no other significant differences were detected between H and Cp+ groups. Whilst the core microbiota showed some taxa were exclusive to each group, the role of these taxa in health and disease has yet to be determined. Antibiotics were also found to have an impact on the relative abundance of some taxa. Though healthy calves received a significantly higher body condition score than Cp+ calves at W5, the difference did not reach significance at W10, suggesting that Cp+ calves may catch up to their healthy counterparts once the infection has resolved.

CONCLUSIONS

The findings of this study illustrated the changes in the microbial diversity and composition during the preweaning period in dairy calves. The results also indicated that the faecal microbiome is not predictive of cryptosporidiosis and implied that cryptosporidiosis doesn't cause long-term gut dysbiosis. This study furthered our understanding of the parasite-microbiome relationship and its impact on the bovine host.

The cow GUTBIOME CY study: investigating the composition of the cattle gut microbiome in health and infectious disease transmission in cyprus

BACKGROUND

Recent evidence suggests that the lower gut microbiome of ruminants presents roles in their health and environment, including the development of the mucosal immune system, milk production efficiency and quality and subsequent methane emissions. However, there are proportionately fewer studies on this complex microbial community in cattle and region-focus studies are non- existent.

METHODS

Herein, we present the research protocol of the GUTBIOME CY project pertaining to determine the composition of the lower gut microbiome in dairy cows situated in 37 farms across five districts of the island of Cyprus. Detailed questionnaires on animal husbandry and farming practices will be gathered from each farm. Faecal, milk (individual and bulk) and water samples will also be collected from cows and their offspring. Samples will be analysed using a combination of molecular biology and bioinformatics pipelines to define microbiome profiles and antimicrobial resistance (AMR). Information collected from the questionnaires will be used to test for associations between animal husbandry or farming practices and microbiome components and AMR.

DISCUSSION

Collected samples will establish the first dairy cattle biobank in the country for contributing substantially towards scientific advancements in microbiome research and providing insights to all stakeholders, tailored to the unique agricultural context of Cyprus.

Immediate dam-sourced colostrum provision reduces calf mortality - management practices and calf mortality in large dairy herds

BACKGROUND

Farm-specific management practices greatly impact calf mortality rates. This cross-sectional study aimed to analyse the association between calf mortality and management practices in large dairy farms. A total of 93 dairy farms were voluntarily included in the study. All farms reared their own youngstock, and all but one kept more than 100 dairy cows. From March 2017 to March 2018, calf management practices were monitored during a farm visit, and farm managers were surveyed regarding calving procedures, neonate management, and environmental factors. Data were collated and analysed in conjunction with the 2017 calf mortality rate, as determined for each farm by using data from the German database of animal origin and movement (HI-Tier). All variables from the topics of colostrum supply, calf feeding, housing, health related information and calving preparation of the cows that resulted in P ≤ 0.1 in the analysis of variance were assumed to be associated with the calf mortality rate and were considered for a general linear mixed regression model.

RESULTS

According to the data from the HI-Tier database of the 93 study herds from 2017, 54,474 calves were born alive and 3,790 calves died within the first six months of life. The calf mortality rate was lower on farms where calves were immediately provided with dam-sourced colostrum. Farm managers perceiving dust as the primary factor precipitating respiratory disease on the farm was positively associated with calf mortality. Regularly replacing bucket teats correlated with lower calf mortality rates compared to replacing them only upon detection of abrasion.

CONCLUSIONS

The study findings suggest that feeding calves with dam-sourced colostrum can potentially reduce overall calf mortality within the herd. This management practice holds comparable importance to ensuring successful passive transfer through timely and adequate colostrum feeding. Moreover, maintaining a low dust environment for the calves and consistently replacing bucket teats play significant roles in promoting better overall calf health.

Understanding the Cryptosporidium species and their challenges to animal health and livestock species for informed development of new, specific treatment strategies

Cryptosporidium species are parasitic organisms of vertebrates with a worldwide distribution. They have an important impact globally upon human and animal health, and livestock productivity. The life cycle of these species is complex and difficult to disrupt to improve human health, animal health, food security and economic growth. This may contribute to the fact that no new treatment strategy has been widely accepted or applied in livestock for years. Here we consider the natural history of these parasites, their biochemistry and economic impact. Using recent developments in understanding these parasites we then consider viable and affordable approaches to enhancing control of their effects on livestock. These are based on advances in drug discovery, omics research and artificial intelligence applications to human and veterinary medicine that indicate putative new therapeutic approaches.

Detection and Molecular Diversity of Cryptosporidium spp. and Giardia duodenalis in the Endangered Iberian Lynx (Lynx pardinus), Spain

Cryptosporidium spp. and Giardia duodenalis are the main non-viral causes of diarrhoea in humans and domestic animals globally. Comparatively, much less information is currently available in free-ranging carnivore species in general and in the endangered Iberian lynx (Lynx pardinus) in particular. Cryptosporidium spp. and G. duodenalis were investigated with molecular (PCR and Sanger sequencing) methods in individual faecal DNA samples of free-ranging and captive Iberian lynxes from the main population nuclei in Spain. Overall, Cryptosporidium spp. and G. duodenalis were detected in 2.4% (6/251) and 27.9% (70/251) of the animals examined, respectively. Positive animals to at least one of them were detected in each of the analysed population nuclei. The analysis of partial ssu rRNA gene sequences revealed the presence of rodent-adapted C. alticolis (n = 1) and C. occultus (n = 1), leporid-adapted C. cuniculus (n = 2), and zoonotic C. parvum (n = 2) within Cryptosporidium, and zoonotic assemblages A (n = 5) and B (n = 3) within G. duodenalis. Subgenotyping analyses allowed for the identification of genotype VaA19 in C. cuniculus (gp60 locus) and sub-assemblages AI and BIII/BIV in G. duodenalis (gdh, bg, and tpi loci). This study represents the first molecular description of Cryptosporidium spp. and G. duodenalis in the Iberian lynx in Spain. The presence of rodent/leporid-adapted Cryptosporidium species in the surveyed animals suggests spurious infections associated to the Iberian lynx's diet. The Iberian lynx seems a suitable host for zoonotic genetic variants of Cryptosporidium (C. parvum) and G. duodenalis (assemblages A and B), although the potential risk of human transmission is regarded as limited due to light parasite burdens and suspected low excretion of infective (oo)cysts to the environment by infected animals. More research should be conducted to ascertain the true impact of these protozoan parasites in the health status of the endangered Iberian lynx.