Causes of neonatal calf diarrhea and mortality in pasture-based dairy herds in Uruguay: a farm-matched case-control study

• Published in: Brazilian journal of microbiology Vol. 52; no. 2; pp. 977 - 988
• Main Authors: Caffarena, Rubén Darío, Casaux, María Laura, Schild, Carlos Omar, Fraga, Martín, Castells, Matías, Colina, Rodney, Maya, Leticia, Corbellini, Luis Gustavo, Riet-Correa, Franklin, Giannitti, Federico
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.06.2021; Springer Nature B.V
• Subjects: Animals; Animals, Newborn; Antigens; Astroviridae - isolation & purification; Biomedical and Life Sciences; Calves; Case-Control Studies; Cattle; Cattle Diseases - etiology; Cattle Diseases - mortality; Colostrum; Coronaviruses; Cryptosporidiosis; Cryptosporidium; Cryptosporidium - isolation & purification; Dairy farming; Dairy farms; Dairy industry; Dairying - methods; Diarrhea; Diarrhea - etiology; Diarrhea - mortality; Diarrhea - veterinary; Diarrhea Viruses, Bovine Viral - isolation & purification; E coli; Enzyme-Linked Immunosorbent Assay - veterinary; Escherichia coli - isolation & purification; Farms; Feces - microbiology; Feces - parasitology; Feces - virology; Female; Food Microbiology; Immunity (passive); Immunization, Passive - veterinary; Infections; Life Sciences; Medical Microbiology; Microbial Ecology; Microbial Genetics and Genomics; Microbiology; Mortality; Mycology; Neonates; Pasture; Pathogens; Polymerase chain reaction; Real-Time Polymerase Chain Reaction - veterinary; Refractometry; Risk management; Rotavirus; Rotavirus - isolation & purification; Salmonella; Salmonella enterica - isolation & purification; Salmonellosis; Surveys and Questionnaires; Syndrome; Uruguay - epidemiology; Veterinary Microbiology - Research Paper; Viruses; Weaning; Uruguay; spp; Infectious diseases; Rotavirus; Mortality; Diarrhea; Dairy calves; Failure of transfer of passive immunity; Salmonella enterica; Cryptosporidium spp
• ISSN: 1517-8382; 1678-4405
• DOI: 10.1007/s42770-021-00440-3

Neonatal calf diarrhea (NCD) and mortality cause significant losses to the dairy industry. The preweaning dairy calf mortality risk in Uruguay is high (15.2%); however, causes for these losses are largely unknown. This study aimed to assess whether various pathogens were associated with NCD and death in Uruguayan dairy calves and whether these infections, diarrhea, or deaths were associated with the failure of transfer of passive immunity (FTPI). Contemporary diarrheic ( n = 264,) and non-diarrheic ( n = 271) 1- to 30-day-old calves from 27 farms were sampled. Feces were analyzed by antigen-capture ELISA for Cryptosporidium spp., rotavirus, bovine coronavirus, and Escherichia coli F5+, RT-PCR for bovine astrovirus (BoAstV), and bacterial cultures for Salmonella enterica . Blood/serum was analyzed by RT-PCR or antigen-capture ELISA for bovine viral diarrhea virus (BVDV). Serum of ≤ 8-day-old calves ( n = 95) was assessed by refractometry to determine the concention of serum total proteins (STP) as an indicator of FTPI. Whether the sampled calves died before weaning was recorded. At least one pathogen was detected in 65.4% of the calves, and this percentage was significantly higher in diarrheic (83.7%) versus non-diarrheic (47.6%) calves. Unlike the other pathogens, Cryptosporidium spp. and rotavirus were associated with NCD. Diarrheic calves, calves infected with any of the pathogens, and calves infected with rotavirus had significantly lower concentrations of STP. Diarrheic calves had higher chances of dying before weaning than non-diarrheic calves. Diarrheic calves infected with S. enterica were at increased risk of mortality. Controlling NCD, salmonellosis, cryptosporidiosis, and rotavirus infections, and improving colostrum management practices would help to reduce calf morbi-mortality in dairy farms in Uruguay.