To analyze fluctuation of indexes of consist and quality of milk of black and white and red-spotted cows during different months and seasons of lactation. The work was performed in Lithuanian Academy of Veterinary, department of stockbreeding as well as public enterprise Pieno Tyrimai during Master studies 2005-2007. During the analysis, data of controlled cows’ productivity was analyzed according to accounting information of cattle breeding. During the analysis we evaluated 98 Lithuanian black and white cows, Lithuanian red-spotted cows, as well as Ayrshire cows. Milk yield of Lithuanian black and white cows was 1160 kg of milk more than Ayrshire and 252 kg of milk more than Lithuanian red-spotted. Average milk yield of Ayrshire cows was 92 kg more than Lithuanian red-spotted. There was 0.53–0.83% of fat in milk of Lithuanian black and white cows, protein was 0.24–0.25% less than in Ayrshire or Lithuanian red-spotted. Lithuanian black and white cows had 1.0–15.0 kg of milk fat (or 0.3 –4.8%), milk protein – 23.0–25.0 kg (or 11.2–9.4%) more than in Ayrshire or Lithuanian red-spotted. During all periods of lactation most milk fat were found in milk of Ayrshire cows (5.05%), least in Lithuanian black and white cows (4.21%). Milk fat of Lithuanian black and white and Lithuanian red-spotted was less in comparison with Ayrshire cows. During all months of lactation most amount of protein was found in Lithuanian red-spotted and Ayrshire (3.69-3.68%), and least – in Lithuanian black... [to full text]

The aim of Master work is to valuate Lithuanian black and white cows productivity and milk composition considering the blood dimensions of holstein breed. All data had been made through statistical analysis by EXCEL computation as well as by statistical package „R“ (http://www.r-project.org) in the LVA Laboratory of Animals Research of Breeding Worth and Selection. It was stated that the average of the Holsteinization grade of the researched cows in stock was 79,38 percent, and only 7,1 percent of the researched cows average of the Holsteinization grade didn’t reach 50 percent. Intermediate correlation between the milk productivity and milk protein was found an unfavourable but statistical reliable coherence (r=-0,346, p<0,001) The highest milk productivity was by cows with Holsteinization grade of 87,5-98,5 percent, the best milk fat consistence in percent 62,5-74,0 percent of Holsteinization grade cows, and the best milk protein consistence was by cows with Holsteinization grade reaching up to 50 percent. Having developed holsteinization grade in a stock, the percent of cows productivity was set the little statistical reliable coherence (r=0,224, p<0,01). The greatest number of somatic cells (532,7 thousand/ml.) was found in milk of cows which had the holsteinization grade to 50 and 50,0-62,4 percent.