Genetic parameters of some productive and reproductive traits in sheep from the Bulgarian dairy synthetic population (BDSP) and its crosses with Lacaune and Assaf

Georgi Kalaydzhiev

doi:10.2298/bah2104263k

Abstract

Dominating in recent years in Bulgaria are the sheep from the Bulgarian Dairy Synthetic Population (BDSP) and its crosses with other dairy breeds. This in turn leads to significant, scientifically based genetic and phenotypic diversity and different levels of productivity. The aim of the study is to research and characterize the genotypic parameters of the main productive and reproductive traits in sheep from the Bulgarian dairy synthetic population and its crosses with the breeds Lacaune and Assaf. The study includes a total of 3212 ewes reared in 15 farms, as from Bulgarian dairy synthetic population - 1114 ewes, BDSP crosses with Assaf - 1052 ewes and BDSP crosses with Lacaune - 1046 ewes, born in the period from 2014 to 2019 including. Studied trait were: milk yield for a standard 120-day period of I, II and III lactation, biological fertility of the 1st, 2nd and 3rd lambing and the trait - live weight of different age categories. The statistical model used was based on the model of animal /Animalmodel /, using the software product VCE and PEST (Groeneveld). Heritability in the main selection trait milk yield of the 1st, 2nd and 3rd lactation reaches from low to moderate and medium values. The lowest level of genetic diversity is in BDSP - h? varies from 0.125 to 0.157, in BDSP x Assaf from 0.131 to 0.202, and with the highest genetic diversity in the studied trait are ewes BDSP x Lacaune, respectively from 0.342 to 0.397. The rates of fertility in all three studied groups were from low to moderate h? - in BDSP from 0.133 to 0.156, in BDSP x Lacaune - from 0.040 to 0.112 and in BDSP x Assaf - from 0.100 to 0.122.

Highlights

Dairy sheep are the most numerous part of the population in the country, which determines their main place in the structure of the national gene pool
The study includes a total of 3212 ewes reared in 15 farms, as from Bulgarian dairy synthetic population - 1114 ewes, Bulgarian Dairy Synthetic Population (BDSP) crosses with Assaf - 1052 ewes and BDSP crosses with Lacaune - 1046 ewes, born in the period from 2014 to 2019 including
A total of 3212 ewes reared in 15 farms, constitute of Bulgarian dairy synthetic population - 1114 ewes, BDSP crosses with Assaf - 1052 ewes, and BDSP crosses with Lacaune - 1046 ewes, born in the period from 2014 to 2019

Summary

Introduction

Dairy sheep are the most numerous part of the population in the country, which determines their main place in the structure of the national gene pool. The main directions of selection in this productive direction are increase of milk yield and fertility, improvement of the suitability of the udders for machine milking, increase of the resistance to the climatic factors and optimal utilization of the feed. The competitiveness and economic sustainability of productive systems in sheep breeding are a key factor for the successful business of farmers today This explains their desire to genetically renew their herds faster than is possible through purebred breeding. The method of creating the population allows in its intrabreed structure to use an "open nucleus" - it is characterized by an open system of selection This allows, in addition to the main purebred breeding, in some cases to periodically apply ennobling crossbreeding with breeding material from the breeds involved in the creation of BDSP and from other world famous dairy breeds (Stancheva et al, 2014)

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Conclusion