Morphological and functional traits and main disadvantages of the udder in cows of Black-and-White breed

Abstract

The object of research was the first-calf cows of Black-and-White breed. The groups were formed taking into account the part of blood of Holstein breed. The 1st group included animals with the part of blood than 50 % (an average of 37 % in the group), the 2nd with the part of blood of 50 % and the 3rd more than 50 % (an average of 63 % in the group). An increase in the part of blood in animals in the farm to 63 % had a positive effect on changing the shape of the udder. Thus, in the group of low the part of blood animals there were 78,2 % of cows with a cup-shaped shape and 21,8 % with a rounded one. Among half-blood cows with the cup-shaped udder accounted for 92,2 %, and with the rounded one it was 7,8 %, among the high part of blood it was 94,8 and 5,2 %%, respectively. In terms of udder length and depth measurements, cows with the high part of blood outperformed cows with the low part of blood by 2,5 cm (р < 0,01) and 2,1 cm (р < 0,01), respectively. In terms of udder decline, the difference between these groups of animals was 5,7 abs.% (р < 0,01) in favor of animals with the higher proportion of Holstein breed blood. First-calf cows with half part of blood and the high part of blood of Holstein breed were ahead of their herd mates with the low part of blood in terms of the rate of milk speed out the difference was 0,3 kg/min (р < 0,05) and 0,4 kg/min (р < 0,001), respectively. The most common udder defect (10 %)was narrow rear teats, while in the group with the high part of blood cows its occurrence was the lowest 6,7 %. The sum of the frequencies of udder defects in cows with the high part of blood was 16,7 % versus 23,3 % in the other two groups. We recommend to use purebred Holstein sires for mating with low-blood heifers and cows, and using sires with the part of blood of Holstein breed of 62 to 75 % or breeding “inter se” on heifers and cows with the higher proportion of blood of Holstein breed.