An Observational Study of the Microbiological Quality of Bovine Colostrum Fed to Calves on Three Dairy Farms

• DOI: 10.20944/preprints202505.1169.v1
• Publication Date: 2025-05-16T03:11:12Z
• Authors: Flávio G. Silva; Marta Laranjo; Severiano R. Silva; Cristina Conceição; Joaquim L. Cerqueira

This study aimed to evaluate the microbiological quality of colostrum on three dairy farms with different colostrum management hygiene practices and to compare it with current colostrum quality guidelines. On farm A, colostrum was fed raw, while on farms B and C it was heat-treated. On farms A and B feeding equipment were cleaned manually, while on farm C an automated cleaning system was used. Samples were collected from the calf feeding equipment and submitted for microbial culture: total plate (TPC), total coliforms (TCC), E. coli, enterococci, staphylococci (STAP), and lactic acid bacteria counts; in addition, pH, aW, and Brix were analysed. Colostrum quality was defined as: good quality (GQ): TPC < 100,000, TCC < 10,000, STAP < 50,000 cfu/mL, and Brix ≥ 21%; or excellent quality (EQ): TPC < 20,000, TCC < 100, STAP < 5000 cfu/mL, and Brix ≥ 22%. Approximately 57 (GQ) and 38% (EQ) of samples met the defined criteria. Lower microbial counts were found on farm C. Colostrum from farm B had lower TPC, TCC, and E. coli counts than farm A. These results showed that a considerable proportion of calves were fed colostrum with suboptimal quality, especially when less rigorous hygiene practices were implemented.