Abstract
Abstract The work aimed to establish the influence of udder parameters of Kazakh mares on their formation of dairy productivity and the growth rate of foals during the milk period. The cup-shaped udder is characterized by a large base (the udder circumference at the base is 70.3 cm), the symmetrical arrangement of both udder lobes, with well-developed cylindrical nipples, the nipples are widely spaced between the two lobes. The round shaped udder is instead characterized by conical and short nipples and a smaller udder volume. For four months of lactation, 1051 liters of commercial milk were produced from mares with cup-shaped udder, while 823.6 liters- with round-shaped udder.The observation results showed that foals from mares with the cup-shaped and round - shapedudders on the first day of life were 39.8 and 39.6 kg of live weight, respectively, then after a month, it doubles, reaching 82.5 and 79.5 kg. The highest indicators of absolute gain - 42.7 kg, average daily gain - 1.42 kg, and relative gain -107.3% were observed in offspring with a cup-shaped udder. In foals delivered from mares with a round-shaped udder, the gain rates (39.9; 1.33 kg and 100.7%, respectively) were slightly lower.