Effect of Streptococcus uberis infection on milk characteristics of
individual quarters
S.J. Lacy-Hulbert, M.W. Woolford, G. Nicholas and K. Stelwagen
Dairying Research Corporation, Private Bag 3123, Hamilton, New
Zealand.
Proceedings of the New Zealand Society of Animal Production, 1996,
56: 65-67
Composite 24 h milk samples were collected for detailed milk analysis
from each quarter of ten cows known to be free of intramammary infection.
Milk yield and concentration of lactose and serum albumin (BSA) were
significantly higher (P<0.001), and chloride ions significantly lower
(P<0.001), in hind compared with fore quarters. Four cows developed
clinical intramammary infection when subsequently challenged in the left
hind quarter with Streptococcus uberis. For all parameters measured, i.e.
protein, lactose, somatic cell count (SCC), BSA and immunoglobulins
(IgG), milk from the infected quarter differed significantly from the
uninfected quarters. No effect of infection was observed in quarters adjacent
to the infected quarter, except for SCC, which increased significantly
(P<0.001) in the uninfected hind quarter. Milk proteolytic activity in the
infected quarter increased significantly (P<0.001) due to increased
conversion of plasmin to plasminogen.
Keywords: NZSAPAB;
milk-composition; mastitis; Streptococcus-uberis; quarter-milk.
Download abstract in text format
Last Updated 18-03-1997
