The interrelationships between milkability traits and subclinical mastitis in cows.
The investigation was conducted during 2005-2006 on 4010 dairy cows. Having performed statistical data analysis, we determined that the lowest somatic cell count (SCC) in Red and Red-White cow population was obtained when the milking time was 5-6 min., milking speed was higher than 1.5 kg/min., high milk flow was from 2.51 to 4 kg/min., and in Black-White cow population having a milking time was higher than 7 min., milking speed was from 1.01 to 2 kg/min., a high milk flow --from 2.01 to 4 kg/min. (p<0.001). In Red and Red-White cow population with subclinical mastitis, milking time was longer and milking speed was slower than in healthy cows. High milk flow values were least in healthy Black-White cow population. This determines a more equal milk flow which is desired in milking cows mechanically. Most sensitive to udder infection are 1st lactation cows which have a higher milk flow. A larger phenotype correlation coefficient in Red and Red-White cow population was between the SCC and milking time (-0.089, p<0.01) and between high milk flow (0.086, p<0.01) and milk yield (-0.071, p<0.05). However in Black-White cow population, correlation was found between SCC and milk yield (-0.117, p<0.01) and milking speed (-0.110, p<0.01). Contagious mastitis pathogens were identified in Red and Red-White cow milk samples primarily from productive cows having a milking speed of 1.01-1.5 kg/min., and in Black-White cow population having a milking speed of 1.51-2.0 kg/min.
Japertiene
R
R
Lithuanian Veterinary Academy, Department of Animal Breeding and Genetics, Tilzes 18, Kaunas, LT-47181, Lithuania. biometrija@lva.lt
Juozaitiene
V
V
Kriauziene
J
J
Rudejeviene
J
J
Japertas
S
S
D000818:Animals; D002417:Cattle; D002452:Cell Count; D003612:Dairying; D005260:Female; D007774:Lactation / Q000502:physiology*; D008414:Mastitis, Bovine / Q000175:diagnosis*; D008892:Milk / Q000166:cytology; D013997:Time Factors