Housing conditions of dry cows: effects on teat contamination and somatic cells at the beginning of the subsequent lactation

Abstract

The study investigated the effects of housing conditions and temperature-humidity index (THI) during the dry period on total bacteria counts of bedding material, animal cleanliness, and teat bacterial contamination on 212 cows from three farms. Additionally, milk yield, quality, total somatic cells, and leucocyte fractions were evaluated in the subsequent lactation on a subgroup of 119 cows. The results showed a relationship between persistent high THI, teat bacterial contamination, and pathogens on teat skin. Somatic cell count (SCC) in milk at the beginning of the next lactation was not affected by THI during the dry period. Multiple correlation analysis revealed a relationship among high milk SCC, high percentage of neutrophils, high bacterial count of bedding during the dry period, and high milk production at dry-off. The study confirms that critical environmental conditions, such as high THI and poor bedding hygiene, during the dry period, can affect teat bacterial contamination and increase the risks for high SCC in the next lactation. High milk production at dry-off may be another risk factor.

HIGHLIGHTS

• Temperature and humidity in the barn during the dry period affect total bacterial and pathogen contamination on teats.

• Bedding bacterial count during dry period, milk production at dry-off, and post-calving somatic cell counts were positively associated.

Keywords:

• Temperature-humidity index
• hygiene
• bedding
• differential somatic cells
• milk

Acknowledgements

We thank the dairy farmers, technicians, and students for their participation and support in this study.

Ethical approval

Not required.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Data available on request from the corresponding author.

Additional information

Funding

The study was supported by Lombardy Region (PSR 2014–2020, operation 16.1.01 Gruppi Operativi PEI), project MAGA–Modelli aziendali per una gestione efficiente e sostenibile del periodo di asciutta and by the Agritech National Research Centre, and received funding from the European Union Next-GenerationEU (PIANO NAZIONALE DI RIPRESA E RESILIENZA (PNRR)–MISSIONE 4 COMPONENTE 2, INVESTIMENTO 1.4–D.D. 1032 17/06/2022, CN00000022). This manuscript reflects only the authors’ views and opinions, neither the European Union nor the European Commission can be considered responsible for them.