THE INFLUENCE OF THE FACTOR « GENETIC VALUE OF THE SIRE » ON THE IMPLEMENTATION OF THE GENETIC POTENTIAL OF THE INDICATOR « MILK PRODUCTION OF MAXIMUM LACTATION » OF THE YAROSLAVL BREED COWS

Dairy products are the main food elements of the man. Milk is the sole food for infants and it plays an important role in feeding of the sick, convalescent, and healthy adults. The Yaroslavl Region is a leading region of the Yaroslavl cattle breed. Therefore, the aim of our research was to determine the strength and reliability of the influence of the factor «genetic value of the sire» on productive characteristics of animals as a factor that helps to increase the productivity of animals. When we determine the strength of the influence of factors for statistical data we used the procedure of generalized linear models (General Linear Models GLM), and evaluation components of phenotypic variation attributes were analyzed by multivariate dispersive analysis. Our research has allowed to allocate bulls with genetic value which has the improving effect. Using the recommended lines the farmers of the Yaroslavl region may increase productive characteristics of animals and the profit of the farms and improve the efficiency of breeding.


Introduction
Accelerating the race of genetic improvement of the breed by breeding and productive indicators is possible by using bulls -improvers having high productive offspring (Mazepkin, 2000;Moskalenko and Konovalov, 2010).The impact of the productivity of daughters is decisive in the selection process.Improvement of cattle in sense of improvement of the genetic basis of the population of cattle for milk production, production of milk fat and content of milk fat in present conditions is done through bull sires and bull dams.By application of high quality breeding animals with proven genetic capacity (sons of bull dams and bull sires) production and reproduction traits of cattle population can be improved.(Petrovic et.al., 2006;Pantelic et.al., 2009, Petrovic et.al., 2012).Common genetic contribution of bulls in the genetic improvement of dairy cattle population is up to 95% (Mityukov, 2007;Moskalenko et. al., 2012).According to native and foreign scholars who study the impact of the factor «genetic value of the sire», 43-46% of the maximum possible selection effect is determined by selection of the bulls sires, 30-35% -by the selection of bulls mothers, 16-20% of cow sires and only 6% is due to the selection of cow mothers (76-78% of breeding progress is determined selection of bulls and only 22-24%by selection of cows).
Producers used in the herd influence not only on the growth and development of young animals, but also in the future -on productive characteristics of animals.This influence obeys the law: the offspring will be more productive if the difference between the productivity of the mother of the sire and mother of the daughter is small (Ovchinnikov, 2008).
We have a large number of literary sources devoted to the study of the environmental and genetic factors influencing on genetic potential and its realization.It is also given a great importance in the existing breeding programs.The Yaroslavl region is the leading district in breeding of the Yaroslavl cattle.Therefore, the aim of our research was to determine the strength and reliability of the impact of the factor «genetic value of the sire» on the implementation of the genetic potential of the indicator «Yield of maximum lactation» of the Yaroslavl cattle breed.

Material and methods
The object of the study were pure-bred cows of the Yaroslavl breed and crossbreed cows of the Holstein x Yaroslavl breed having different thoroughbredness of the Holstein breed, in the amount of 6230 cows, 4776 of them are leavers.
Material is prepared on the basis of the «Information database of the Yaroslavl cattle breed» (№ of the state registration is 2013620064), data of the program ARMZS (up to 2009 year) and ARMS -W (№ of the state registration is 2009613920 from 22.07.2009year), information software module «PAVKA».Farms of the Yaroslavl region with different keeping technology were selected for study: LLC breeding plant «Rodina» (Loose -boxed keeping of cows and equipment of «Westfalia» company), Joint Stock Company, breeding farm named after Dzerzhinsky (captive keeping with the use of installations of «DeLaval» company).
We determined the realization of the genetic potential estimated by Kuznetsovsks algorithm, 1983(Malyukova, 2012).The evaluation of components of phenotypic variability was performed using a multi-factorial dispersive analysis (Kuznetsov, 2000).

Results and discussion
In cattle herds Yaroslavl breed we determined the effect of the factor «genetic value of the sire» on the implementation of the genetic potential of the indicator «milk production of maximum lactation» (picture 1).Assessing the effects of the gradation of the factor «genetic value of the sire» on the studied characteristics of cattle is presented in the table 1.  Information shown in the picture 1and table 1reflect the results of the evaluation of the quality of bull's offspring.So the bull having nickname Zavetniy 159 has breeding category A3 with a bias toward neutral side, its rating falls in all farms.
The bull Jasmine 6218 (category A1B1) using in studied technologies (loose and captive keeping of cows) shows a high implementation of the genetic potential and genetic superiority (95.9-108.1%) of the indicator «milk production of maximum lactation».The bull Stinger 243 has a rating category A1 which has sufficiently manifested in the characteristics of the daughters using in studied technologies (his genetic superiority from 111.8 to 115.1 %).The daughters of the bulls 159 and 207 shows low implementation of genetic potential in the terms of the, breeding farm named after Dzerzhinsky on the variability of the indicator «milk production of maximum lactation».The effect of «genetic value of the sire» had a strong and significant influence (9.2%) on the variability of the indicator «milk production of maximum lactation».The analysis of factors effecting on productive traits were evaluated by Mazepkin (2000); Moskalenko and Konovalov (2010); Adediran et al., (2010).Hric and Pavlik (2012) in their research find that sire have significant effect on milk production of lactating cows.

Conclusion
Based on research and the results obtained, we can conclude the following: There is a significant genetic variability of the studied traits.The genetic merit of the sire had a strong influence on the variability of the indicator «milk production of maximum lactation».
Our studies has allowed to allocate bulls having genetic value which has the effect of improving on the productivity of the herds in which they are used.We recommend to use lines and their animal representatives to increase breeding efficiency in the cattle herds.