Longitudinal dynamics of the bovine udder microbiota

Abstract

Background In recent years, the number of studies concerning microbiota of the intramammary environment has increased rapidly due to the development of high-throughput sequencing technologies that allow mapping of microbiota without culturing. This has revealed that an environment previously thought to be sterile in fact harbours a microbial community. Since this discovery, many studies have investigated the microbiota of different parts of the udder in various conditions. However, few studies have followed the changes that occur in the udder microbiota over time. In this study, the temporal dynamics of the udder microbiota of 10 cows, five with a low somatic cell count (SCC, SCC < 100,000 cells/mL) and five with a high SCC (SCC > 100,000 cells/mL), were followed over 5 months to gather insights into this knowledge gap. Results Analysis of the temporal changes in the microbial composition of milk from udders with a low SCC revealed a dynamic and diverse microbiota. When an imbalance due to one dominating genus was recorded, the dominant genus quickly vanished, and the high diversity was restored. The genera dominating in the samples with a high SCC remained the dominant genera throughout the whole sampling period. These cows generally displayed a heightened SCC or an intramammary infection in at least one quarter though-out the sampling period. Conclusion Our results show that the bovine udder has a diverse microbiota, and that the composition and diversity of this community affects udder health with regards to SCC. Understanding what influences the composition and stability of this community has important implications for the understanding, control, and treatment of mastitis.

Metataxonomic analysis and host proteome response in dairy cows with high and low somatic cell count: a quarter level investigation

“…The four cows included in this project were defined as H-cows (SCC > 100,000 cells/mL) or L-cows (SCC < 100,000 cells/mL) based on a previous study conducted by Winther et al where the SCC were measured over three consecutive days at the start of the project [ 4 ]. The study revealed a difference in the stability and composition of the udder microbiota between H- and L-cows, where the H-cows displayed an imbalanced microbiota and a lower diversity over time compared to the L-cows.…”

“…One sample, JT24, contained blood. As no imbalance in the microbiota was detected in this sample, which is usually the case during a bacterial infection [ 3 , 4 ], the blood could be a result of a yeast infection or trauma to the udder [ 39 ].

Figure 1 Microbial composition of the 32 milk samples based on 16 S amplicon sequencing .

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“…Four Norwegian Red cows were selected from “The Livestock Production Research Centre” at the Norwegian University of Life Sciences based on a previous study by Winther et al [ 4 ]. The study categorized the cows as H- or L-cows based on high (>100 000 SCC/mL) or low (<100 000 SCC/mL) somatic cell count, respectively, at the start of the study as recorded by the automatic milking system (Delaval Online Cellcounter).…”

“…For analysis of microbiota in the milk samples, bacterial pellet was obtained and amplification and sequencing of the 16 S rRNA genes were performed as described previously [ 3 ]. The raw sequencing data were analyzed with the Dada2 algorithm as described by Winther et al [ 4 ].…”

Host DNA depletion methods and genome-centric metagenomics of bovine hindmilk microbiome

“…With the rapid advancement of high-throughput next-generation sequencing (NGS) technology and bioinformatics pipelines, culture-independent techniques have exponentially grown in use over the last few years to overcome some inherent limitations of cultivation methods ( 8 , 9 ). This has become evident due to the increased number of studies concerning the bovine milk microbiome, especially based on targeted approaches such as metataxonomic analyses ( 10 – 13 ).…”