Impaired clotting ability of milk in dairy cows in the north of Scotland
Johnston, W.S.; Hopkins, G.F.; Maclachlan, G.K.
Veterinary Record 118(23): 637
1986
ISSN/ISBN: 0042-4900 PMID: 3739157 Document Number: 281035
Milk clotting times (MCT), estimated by the method of Johnston et al. [DSA 42, 4530], were normal in 38 of 63 samples from individual cows in 2 herds and in 1 of 26 group samples from up to 5 cows in 5 herds. Milk samples with delayed milk clotting ability were visibly normal and the cows from which they were obtained showed no clinical abnormality. Examination of 3 normal and 5 abnormal samples for mineral levels showed that all had normal total Ca levels but low levels of ultrafilterable Ca, especially in milks with increased MCT. Both total and ultrafilterable P levels were subnormal, with abnormal milks having the lowest levels. Total Mg but not ultrafilterable Mg levels in the abnormal milks were below normal. Citrate levels were low in all samples, especially in the abnormal milks. Delayed milk clotting did not appear to be seasonal. Problems in starting the cheesemaking process with this abnormal milk have been overcome by addition of calcium lactate.