Relationship between clinical lameness and somatic cell counts, and fat and protein contents in the milk of dairy cows

The aim of the study was to investigate the impact of clinical lameness on the somatic cell count (SCC) and percentage contents of fat and protein in cow's milk. Clinically lame cows (n = 12) were selected from a herd of 125 Polish Holstein-Friesian cows (located in the Wielkopolska region, Poland). The cows were housed in tie stalls with access to a pasture and a cow-yard throughout the year. Another group of 12 cows was included in the control on the basis of analogues (parity and stage of lactation). During the three weeks of the study one milk sample was collected from cows of both groups at weekly intervals (1 day after the assessment of locomotion in cows). Fat and protein contents in milk were determined with a MilkoScan device, SCC with a Fossomatic 90 apparatus. Somatic cell count values were transformed to a common logarithm (log SCC). Clinically lame cows and cows with a normal gait had a similar number of somatic cells (log SCC 5.58 and log SCC 5.63, respectively) and fat content (4.32% and 4.16%, respectively), but lower protein contents in milk (3.13% and 3.27%, respectively). It has been concluded that there were no statistically significant differences in SCC between clinically lame cows and healthy cows. The results of this study concerning of SCC, and fat and protein contents in milk of healthy and clinically lame cows should be treated as preliminary. Examinations should be repeated in large herds of cows taking into account interaction between the milk traits of cows (clinically lame and healthy) and parity, stage of lactation, as well as environment (housing system).