Studies on Mastitis Caused by Translocated-Bacterial Components in Ruminants

概要

Milk is secretion obtained from healthy animals, such as cows, goats, sheep, and buffalo.
Milk and dairy products are an integral part of human nutrition since they carry biological value
nutrients that are highly significant for several biochemical and physiological functions. The
range of milk production worldwide varies significantly among countries, depending on dietary
habits, milk processing technologies available, market demand, and social and cultural
circumstances. The per capita consumption of milk and milk products is higher in developed
countries.
In Japan, the per capita milk consumption ranges from 30 to 150 kg/capita/year (FAO,
2020), with 7,290 million tons of milk production and 729,500 lactating cows in 2019 (Ministry
of Agriculture, Forestry and Fisheries (MAFF), 2020). According to MAFF, this milk
production has dropped 15% since 1998, while the decline in dairy cows number has been less
precipitous due to increasing herd sizes which reaches 88.8 head per farm in 2019 (up to 5%
from the previous year). Meanwhile, the number of dairy farming households nationwide has
also dropped by almost 60% in the last 20 years. The reasons for the decline include a harsh
working environment that allows a few days off and a lack of willing successors. Furthermore,
the increase in milk production is often associated with a greater risk of certain diseases. Milk
secretion in the dairy cow has a high metabolic priority and is maintained at the cost of
reproductive and metabolic processes. As a result, diseases may develop (Fleischer et al., 2001).
The prevalence of clinical mastitis, peracute mastitis, metabolic disorders, and prepartum
disorders in dairy cows in the temperate zone of Japan has been raised to 28.0, 13.3, 3.7, and
4.0%, respectively (Fukushima et al., 2020).
Importance of good dairy farming practice is required to ensure the quality of milk
under generally acceptable conditions, whereas animal health is one of the areas that needed
good practice. Mastitis is of considerable interest because its occurrence harms animal wellbeing and farm profitability. For decades, researchers worked to identify mechanisms of
infection, define the clinical and subclinical states of the disease, discover appropriate
screening tests, identify pathogen-specific characteristics, and develop effective milking
procedures to develop successful control programs. Even tremendous significant advances in
mastitis control have been made during the last century, mastitis remains an important subject
of future research because of its complexity. ...

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