Effects on milk yield, somatic cell count and milk conductivity of short-term non-milking of lactating quarters of cows.
Compensatory changes in daily milk production between quarters within an udder were investigated, together with related changes in cell count and electrical conductivity of fore milk samples. Two quarters per cow were left unmilked for 2 d (Group 1, four cows) or for 4 d (Group 2, four cows), and then all quarters of all cows were milked twice daily for a further period of 16 d. The mean daily yield per cow fell 50% during the period of milking two quarters. Daily yield for cows in Group 1 decreased significantly only during the treatment period and the first post-treatment period of 4 d, whereas the daily yield for Group 2 was significantly reduced during the whole post-treatment period. The cell count for all continuously milked (control) quarters was stable during the experiment, but increased in the treated quarters during the first 4 d of the post-treatment period. Non-milking was accompanied by a significant increase in fore milk conductivity which persisted for an additional 4 d after the resumption of normal milking. Throughout the last 12 d of the post-treatment period milk from both control and treated quarters had significantly decreased conductivity levels compared with the pretreatment values.
Institut für Hygiene, Bundesanstalt für Milchforschung, Kiel, Deutschland.
J
J
Hamann
P
P
Gyodi
D000818:Animals; D002417:Cattle / Q000502:physiology*; D002452:Cell Count; D004553:Electric Conductivity; D005260:Female; D007774:Lactation / Q000502:physiology*; D008321:Mammary Glands, Animal / Q000502:physiology; D008892:Milk / Q000166:cytology* / Q000502:physiology*; D013997:Time Factors