IMPROVEMENT OF SELECTION METHODS OF EVALUATION OF THE PRODUCING COMPOSITION OF THE ROMANOV SHEEP BREED
Authors: Herman Y. I. , Herman A. I. 
Published: May 2019

In order for Roman breed sheep to meet modern requirements, remain competitive and in demand in specific breeding conditions at sheep breeding enterprises of various forms of ownership and departmental affiliation, it is necessary at this stage of selection and breeding to develop and implement a new scale for assessment of breeding sheep.

The aim of research was to improve and approbate the assessment methods for a set of breeding traits of sheep of the Roman breed in Belarus for further development of breeding value indices.

The research subject was rams and ewes of RUE “Vitebsk breeding enterprise” of Vitebsk region and individual sheep-breeding enterprises with various forms of ownership in the amount of 370 animals. Expert assessment was carried out according to two or more ewes lambing according to the method of assessment and selection of sheep according to set of traits for breeding use of the Romanov breed. Analysis and data processing were carried out in the laboratory for horse breeding, fur farming and small animal breeding at the Republican Unitary Enterprise “Research and Production Center of the National Academy of Sciences of Belarus for Animal Breeding” in accordance with methodological recommendations for study of performance and biological traits of sheep of breeds and groups few in number.

Due to possibility of taking into account different number of evaluated traits, there is flexibility and objectivity in evaluation of sheep in scores, followed by ranking to: the best, valuable, useful and not recommended for breeding, which, in turn, correspond to a specific integrated index of an animal’s breeding value in percent.

Research results. In the course scientific research, it was determined that, depending on scores received and the planned breeding value index, producing rams get the following purpose:

– rams for self-repair purpose – over 9.0 scores or BVI 101% and above;

– rams for breeding purpose – 8 scores or BVI 85–100%;

– rams for market production purpose – 7 scores or BVI 65–84%.

The obtained evaluation indicators for each animal are summarized and the average score for all producing rams is calculated, and comprehensive index of breeding value is determined. It’s worse noting that in the future studies are planned with the most comprehensive and reliable method, which is based on determining the results of expert evaluations of the offspring according to set of traits with the subsequent ranking of producers by this trait.

Depending on the scores received and the breeding value index, ewes get the following purpose:

– ewes for self-repair purpose – over 8.0 scores or BVI 101% and over;

– ewes for breeding purpose – 8–7 scores or BVI 85–100%;

– ewes for market production purpose – 7–6 scores or BVI 65–84%;

– other – 6–5 scores or BVI up to 50–64%.

The ranking scales for producing rams and ewes developed by us include the assessment of animals by origin, typicality, measurements, exterior, fur-coat traits, and queens additionally by fertility rate, which is taken into account for at least 2 lambs. Due to possibility of taking into account different number of evaluated traits, there is flexibility and objectivity in evaluation of sheep in scores, followed by ranking according to time scale to: best, valuable, useful and not recommended for breeding, which, in turn, correspond to a specific integrated index of an animal’s breeding value in percent.

It should be noted that this development (assessment scale) allows livestock breeders at sheep farms applying it in practice without additional training when evaluating sheep, it is an intermediate link in transition to an index assessment of animals’ breeding value.

Conclusion. In the future, the developed scales for rams and ewes ranking will allow developing individual breeding value indices and planned comprehensive index for evaluating sheep of the fur-coat direction of productivity, which will contribute to more objective and rapid differentiation of the breed quality, increase efficiency of the breeding work and predictability of results.