Associations of the first occurrence of pathogen-specific clinical mastitis with milk yield and milk composition in dairy cows

Abstract

The aim of this study was to estimate the associations of the first occurrence of pathogen-specific clinical mastitis (CM) with milk yield and milk composition (somatic cell count (SCC), lactose, fat, protein content in milk and milk urea nitrogen (MUN)). We studied 3149 dairy cows in 31 Hokkaido dairy farms in Japan. Five pathogen groups were studied: Streptococcus spp.; Staphylococcus aureus (S. aureus); coagulase-negative staphylococci (CNS); coliforms; and fungi. Test-day milk data and clinical records were collected from June 2011 until February 2014. Mixed models with an autoregressive correlation structure were fitted to quantify the effects of CM and several other control variables (herd, calving season, parity, week of lactation, and other diseases). Primipara (first lactation) and multipara (second and later lactations) were analysed separately. All pathogens, particularly S. aureus and fungi, were associated with significant milk losses in multipara. In this study, S. aureus and CNS infections were not associated with significant milk loss in primipara. All pathogens, in particular S. aureus and fungi, significantly increased SCC in both parity groups. All pathogens, especially CNS (in primipara) and S. aureus (in multipara), decreased lactose content. All pathogen groups except for fungi were associated with significant changes in fat, protein and MUN. Some pathogens such as Streptococcus spp. and coliforms seemed to be associated with long-term fat, protein and MUN changes. These findings provide estimates that could be used to calculate precise costs of CM, and also provide better indicators of pathogen-specific mastitis.

Rumen and Hindgut Bacteria Are Potential Indicators for Mastitis of Mid-Lactating Holstein Dairy Cows

“…It is generally accepted that the SCC increases as soon as udder health deteriorates to boost the immune response for the invasion of pathogens [26]. In our study, lower milk yield, lactose percentage, and urea nitrogen in milk of the MA group were observed, indicating that the cows were indeed having mastitis due to the damage of milk-producing epithelial cells and the increase in the permeability of the blood mammary barrier [27][28][29]. Moreover, the urea nitrogen in milk was lower in the MA group while the ruminal ammonia concentration showed no difference between SC and MA groups, which was in accordance with our previous study [17].…”

Milk Lactose as a Biomarker of Subclinical Mastitis in Dairy Cows

“…Bobbo et al [51] found that milk produced by cows infected with mastitis pathogens had a lower lactose content, but statistical differences between contagious, environmental and opportunistic mastitis pathogens were not observed. A lower lactose content was also described in milk with coagulase-negative Staphylococcus [52,53], S. aureus [52,53], coliform bacteria [52,53] and fungal [53] infections. A great decrease in lactose content was also observed in milk samples with yeast infection.…”

Niacin Alleviates Dairy Cow Mastitis by Regulating the GPR109A/AMPK/NRF2 Signaling Pathway

“…A large number of studies have shown that mastitis can seriously affect the milk yield and milk quality of dairy cows [42], so alleviating mastitis is an important means to improve the milk yield and quality of dairy cows. In addition, some studies have shown that niacin can significantly increase milk yield and milk protein in dairy cows [43].…”