J. MITEV, Zh. GERGOVSKA, Tch. MITEVA and T. PENEV
Trakia University, Agricultural Faculty, BG - 6000 Stara Zagora, Bulgaria
MITEV, J., Zh. GERGOVSKA, Tch. MITEVA and T. PENEV, 2011. Influence of lameness on daily milk yield, lactation curve and body condition score during lactation in Black-and White cows. Bulg. J. Agric. Sci., 17: 704-711
The study included 187 cows from the Bulgarian Black-and White cattle breed for a period of 3 years. Of the total number of cows, 10.2% suffered from lameness during the first month of lactation, with most of them (73.7%) had other illnesses during the same period. Test-day and peak lactation milk yields were lower by about 2 kg in cows that suffered from lameness only and lameness with co-morbidity, compared to healthy cows. Daily milk yield was the lowest in cows with lameness and ketosis at the same time - by 4.6 kg less compared to healthy animals, and by about 2 kg compared to groups of cows with other diseases. The strongest negative effect had the combination of lameness and ketosis. These cows had a lower peak lactation milk yield - by 6.15 kg than healthy cows, and by a little more than 3 kg than the other groups.No significant influence of the body condition score before calving on the groups with different health problems could be found, as well as a group effect on the mean BCS per lactation. Cows with the highest mean BCS before calving were the ones that suffered from lameness and ketosis simultaneously - a score of 3.95. The lowest BCS before calving was exhibited by cows that suffered only from lameness or other illnesses at the beginning of lactation. In cows affected only by lameness at the beginning of lactation, the effect of illness on milk yield was negative, yet it did not influence significantly the BCS of cows during lactation.