TY - JOUR AU - O. Chernenko AU - O. Chernenko PY - 2018/11/30 Y2 - 2024/03/28 TI - Economic trait of cows with different duration of prenatal growth period JF - Theoretical and Applied Veterinary Medicine JA - TAVM VL - 6 IS - 3 SE - Articles DO - 10.32819/2018.63005 UR - https://bulletin-biosafety.com/index.php/journal/article/view/193 AB - The study presents the research of prenatal growth period duration of Ukrainian red dairy breed and explains the relation of this process to the productive and reproductive qualities. Experimental animals have been divided into three groups depending on the duration of their prenatal period: less than 274 days is short (Group I); 274–284 days is average (Group II) and longer than 284 days is extended (Group III). The boundaries between the groups have been determined on the basis of the standard deviation in the variation in the number of signs: short duration of prenatal period is less than –0,5σ; average – from – 0,5σ to +0,5σ; extended – more than +0,5σ. It has been found out that the most significant difference according to the live weight among the studied groups of animals is at the age of 6 and 12 months. During these periods, it was statistically significant in favor of animals with short and medium duration of the prenatal period (P > 0.95). In animals of all groups, the period of intensive growth was the first six months of life, which are characterized by the highest absolute, daily average and relative growth. However, heifers with an extended period of prenatal growth were inferior to animals with a short and average duration of these signs, respectively: 11.4 kg (9.1%) for P > 0.99, 63.4 g (9.2%) for P > 0.999, 6.0% for P > 0.95 and 9.3 kg (7.4%) for P > 0.99, 51.9 g (7.6%) for P > 0.999 and 4.2% for P> 0.95. At the age from 12 to 18 months, heifers with an extended period of prenatal period grew more intensively than those of the same age who had a short and medium duration. Between the specified groups of animals, a statistically significant difference has been established according to the growth rates of live weight (P > 0.99). The body measurements of the firstlings of all groups were typical of dairy cattle livestock production. There was no significant difference in these qualities between experimental animal groups. Animals of all experimental groups after the first calving had a higher body mass compared to the standard for Ukrainian red breed (470 kg). But a significantly higher live weight was observed in firstlings of a short period of prenatal growth compared to those who had an extended duration, the difference is statistically significant and is 37 kg (7.7%) for P > 0.99. For 305 days of the first three complete lactation periods, the advantage over the diets and the yield of the resulting milk fat belongs to animals with a short duration of prenatal growth period compared to animals who had extended period with a statistically significant difference (P > 0.95–0.999). There are no differences between experimental groups of animals for fatty milk. Herd mates with an average duration of prenatal period took the intermediate position. It has been found out that in animals of the Group 1, the age of the first insemination and calving, in comparison with the herd mates of the Group III, was earlier, respectively: 5.9 and 11.4 days. Although all experimental groups of animals are showed satisfactory reproductive qualities, there is still a tendency to better values of these characteristics in animals with short duration of prenatal period. ER -