Naslov
Estimation of Population-Specific Genetic Parameters Important for Long-Term Optimum Contribution Selection—Case Study on a Dairy Istrian Sheep Breed

Autori
Kasap, Ante ; Ramljak, Jelena ; Špehar, Marija

Izvornik
Animals (2076-2615) 11 (2021), 8;

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
inbreeding ; effective population size ; connectedness ; sheep ; selection

Sažetak
The Istrian sheep breed has been subjected to selection for dairy traits for more than two decades. However, a detailed study of some important population-specific parameters such as effective population size (Ne) and connectedness between flocks has never been carried out. The aim of the study was to examine the above parameters in dairy Istrian sheep subjected to a national selection program. The Ne was estimated as the mean rate of increase in coancestry, and connectedness was determined using four different statistics. The Ne was estimated at 73 animals with pedigree constraints imposed on 4 equivalent generations and 3 full generations. Analysis of ∆Ne (“sliding window approach”) revealed a negative ∆Ne indicating a progressive loss of genetic variability (∆NeNEG≥4 = −6.6, p < 0.01 ; ∆NeNFG≥3 = −4.9, p > 0.05). The overall connectedness (r ~ 0.0001) was below the acceptable level for unbiased ranking of the animals belonging to different flocks (ri, j = 0.05). OCS appears to be the best option for the long-term survival (self- sufficiency) of the breed, but genetic links between flocks need to be strengthened to allow unbiased ranking of the animals based on the estimated breeding values.

Izvorni jezik
Engleski

Znanstvena područja
Poljoprivreda (agronomija)

POVEZANOST RADA