Dynamics of correlations of phenotypic features of individual development of young animals of different genealogical lines of gray cattle of Ukrainian breed

Abstract

The results of the research of indicators of individual development of young cattle of gray Ukrainian breed of different genealogical lines are given. Based on the obtained data, the strength and direction of correlations between traits are calculated. The study was conducted at the Polyvanovka Research Farm and the Livestock Laboratory of the State Institution "Institute of Grain Crops of NAAS". The work was performed according to the research program №31 "Genetic improvement of farm animals, their reproduction and conservation of biodiversity. (Genetics, conservation and reproduction of bioresources in animal husbandry), tasks "Identify population and genetic patterns of biological diversity of the isolated gene pool of indigenous gray Ukrainian cattle".
 Evaluation of animals by indicators of individual development was carried out taking into account the following characteristics: live weight at birth, at 7-, 12-, 15- and 18-month-old age, absolute, average daily and relative live weight gain was calculated in the following periods: from birth to 7 -month age; from birth to 12 months of age; from birth to 15 months of age and from birth to 18 months of age. Biometric processing of research results was performed according to the methods of Kovalenko V. P. etc. (2010).
 It is established that repair heifers in different age periods exceed the minimum requirements for the live weight of the elite class by +0.28 - +7.67 %. The difference between the actual live weight of repair heifers at 12 months of age and the data of the Instructions for grading beef cattle is – 13.6 kg or – 4.94 %. Repair heifers of the Shamrin HU-41 line outperform their peers of the Petushok 191-U line in terms of the absolute increase in live weight during the growing period from birth to 12–15 months of age by 12.0–7.3 kg, respectively.
 However, the difference is not significant. The difference between the groups of experimental animals on the indicator "Absolute increase in live weight during the period of rearing from birth to 18 months of age, g" and "Index" intensity of formation (Δt), points "is 0.9 kg (td = 0.08; P> 0.05) and 0.039 points (td = 1.14; P> 0.05). The relative increase in live weight of heifers of the gray Ukrainian breed line Petushok 191-U and Shamrin HU-41 for the period of rearing from birth to 18 months of age is at the level of 148.2 – 175.0 %. The results of correlation analysis show that the number of reliable indicators is 90.0 %. This indicates the effectiveness of the use of indicators of absolute, average and relative gains in live weight for the period of rearing from birth to 18 months of age, as well as the index "formation intensity" (Δt) for early forecasting of gray animals in the early genesis.