Milk Quality and Mastitis
The udder health of dairy cows has great impact on the quality of the raw milk. During mastitis, i.e. inflammation in the mammary gland, the composition of the milk will be negatively affected, with economical consequences for the dairy farmer as well as the dairy industry.
To be able to verify the quality of the milk delivered to the dairy, offer the farmer fair payment in relation to the raw milk quality and contribute to preventive work concerning udder health problems, specific and sensitive biomarkers indicating raw milk quality are needed.
During mastitis, the most severe production disease among dairy cows, the composition of the milk will be impaired but also the prospective to produce high quality dairy products. As a consequence of the administration of antibiotic drugs to cure the infection, the risk to find antibiotic residues is higher in milk from cows with mastitis.
Authorities as well as dairy companies are working to optimise analytical methods and control systems for detection of drug residues in milk. Due to injuries in the secretory tissue, synthesis of specific components in the milk will be impaired. Moreover, components from blood will enter the milk as a result of the increased permeability between blood and milk.
Changes in milk protein composition and increased enzymatic degradation of casein, the most important milk protein for the dairies, will result in a lower cheese yield, taste and texture deficiencies and reduced shelf life for dairy products.
The number of white blood cells (somatic cell count) is presently the most common marker used to diagnose mastitis in udder quarter milk samples, but it is also used as an indirect milk quality trait. In bulk tank milk samples, the relationship between somatic cell count and quality parameters is poor, and in our research we are investigating new, alternative markers for milk quality in relation to udder health.
Research group:
Åse Sternesjö, professor
Maria Åkerstedt, Agr Dr
Monika Johansson, PhD
Lotta Wall, laboratory technician
Projects:
Antibiotic residues in milk
Markers for milk quality
Mastitis bacteria and milk quality