Impact of clinical lameness, calving season, parity, and month of lactation on milk, fat, protein, and lactose yields during early lactation of dairy cows.

摘要

The aim of this paper was to investigate the impact of clinical lameness in Polish Holstein-Friesian dairy cows on milk yield as well as on fat, protein, and lactose yields during early lactation (120 d). The dataset includes 312 monthly test-day milk yields and milk composition records from 78 cows, which calved from October 2008 to April 2009. Twice a week, during the first 120 d postpartum, the cows were examined for lameness and they were scored fortnightly according to a 5-point locomotion scoring system. Factors affecting milk yield and milk components included calving season, parity, month of lactation, and degree of lameness. In cows, which were clinically lame for a month and which were clinically lame for more than a month (maximum per 2 months), the total mean reduction in milk yield per 120-d lactation was approximately 308 and 283 kg, respectively, as compared with cows, which were never lame in early lactation.