TY - JOUR AU - S. Pischan AU - L. Lytvyschenko AU - A. Gonchar PY - 1970/01/01 Y2 - 2024/03/28 TI - THE SERVICE PERIOD AND LEVEL OF MILK PRODUCTIVITY OF HOLSTEIN COWS FOR 305 DAYS OF LACTATION JF - Theoretical and Applied Veterinary Medicine JA - TAVM VL - 4 IS - 1 SE - Animal Science DO - UR - https://bulletin-biosafety.com/index.php/journal/article/view/121 AB - The aim of research was to determine the effect of high productivity and dominant lactation on the length of service period purebred Holstein breed cows by the balanced feeding in the industrial complex. Research has found, that live weight of animals for five lactations of exploitation in an industrial complex has a dynamic character, which increases from the first productive use (586 kg), acquires its maximum in the third lactation (690 kg), and steadily declining in the fifth lactation and is about 583 kg. Proved that during exploitation of cows on industrial complex, the highest daily level of milk yield increases to third lactation, then decrease, that indicate a physiological exhaustion of organism.  However, the dynamics of the highest daily milk yield is not always adequate changes live weight lactating animals  for exploitation of in an industrial complex.  If in firstborn highest daily milk yield is high enough, although it does not exceed an average of 44,4 kg, in animals of second lactation – it comes to index 48,4 kg, the live weight during this period increased by an average of 7,9%, while the increase in milk yield does not exceed 6,9%. Instead, with the growth of live weight of cows of the third lactating at 8,9% increasing milk yield is only by 3,05%. In the fourth lactation the index of highest daily milk yield is decreased, and inferior to indexes third lactation by 3,5%, as live weight decreased by 8,5%. If live weight of cows in the fifth lactation decreased by 15,7 %, the index of milk yield decreased  in relation to the third lactation at 5,7%. Found that the length of service period at 65,8 days, the level of milk production in terms of 305 days of lactation cows first to fifth lactation is an average of 10687,5 kg physical or 10785,6 kg 4% milk. At the same time the animals of the same age, but with a service period of 542,8 days, productivity indicators was only slightly higher: accordingly 11237,2 and 10893,4 kg of milk. If the difference in terms of service period is 8,3 times, then by level of milk yield milk physical  it does not exceed 4,9%. The analysis of productivity due to the length of service period indicates that in effective fertilization the dominant of lactation does not play a decisive role. ER -