The dissertation is devoted to the research of economically important traits of cows of the Ukrainian black-and-white dairy breed with different types of body constitution. The primiparous were differentiated into low-, mid- and high-capacity types of body constitution (according to the method of O. M Chernenko) and friable-dense, delicate-rough, narrow-body - wide-body types of body constitution (according to the method of N. N. Kolesnik). Depending on the type of body constitution the features of growth, development, intensity of formation of live weight of heifers, exterior, milk productivity and reproductive capacity of primiparous have been studied. The features of cows with different types of body constitution have been studied according to the paternal origin.The economic efficiency of different types of cows according their body constitution has been calculated.
Heifers with low-capacity type of body constitution and dense, delicate and narrow-body types have been characterized by higher live weight, absolute, average daily gain and relative growth rate. The primiparous with high-capacity and friable types of body constitution were bigger, there were primarily characterized by larger measurements of the chest and body (Р < 0.05-0.001);cows of these types also had an advantage in udder measurements and indices.
Heifers with fast type of live weightformation compared withheifers of low typethe same age have been characterized by higher live weight at the age of 3-18 months, absolute and average daily gain at the age of 0-15 months, relative growth at the age of 0-6 months.
Analysis of the exterior of cows on a 9-point scale has shown that higher values of linear type traitsevaluation were observed in cows with high-capacity type of body constitution.According to the liner evaluation power of influence of low-, mid- and high-capacity types of body constitution on linear type traits ranged within 0,5-46,2 %, for cows with friable-dense type – 0,00-54,1 %, delicate-rough –0,00-46,3 %, narrow-body - wide-body types –0,00-32,1 %.According to a 100-point scale of exterior’s linear evaluation the primiparous of the studied types of body constitution have been rated as "good with a plus", except for low-capacity cows, which have been rated as "good".
The highest level of milk productivity was characteristic of mid-capacity cows and also dense, delicate and wide-body types of body constitution. The best results of reproductive capacity have been observed in cows with high-capacity type of body constitution, friable, rough and narrow-body types. Thus cowswith types of body constitution, which were characterized by lower milk productivity, had better reproductive capacity. There was a stronger influence of types of body constitution on the traits of milk productivity, determined by the method of O. M Chernenko, in particular, on milk yield per lactation (η2x = 24.5%; Р< 0.05), milk fat yield (η2x = 34.8 %; Р< 0.01) and milk protein yield (η2x = 26.0%; Р< 0.05). The highest 305-d milk yield, milk fat yield and milk protein yield were characterized of primiparous with a height of withers of 140 cm or more, depth of chest – 74 cm or more, oblique body length – 142-145 cm, chest girth – 186-193 cm. The greatest influence on the milk productivity of cows had the depth of chest and oblique body length (η2x = 20.2-37.6 %, Р < 0.05). The influence of the father origin on the formation of type of body constitution of the daughters was insignificant (η2x = 8.4-12.1%). The highest 305-day milk yield, proceeds, profit and profitableness have been received from the primiparous with mid-capacity type – 7395 kg, 75690 UAH, 8175 UAH. and 12–1% and from cows with delicate type of body constitution– 7304 kg, 75190 UAH, 8045 UAH and 12.0%, respectively.
