Genetic parameters for somatic cell count, logscc and somatic cell score of breeds: improved valachian, tsigai, lacaune and their crosses

Abstract

In the last few years there has been increasing emphasis on reducing milk somatic cell count to improve the milk quality in dairy ruminants. Genetic parameters for somatic cell count (SCC), LOGSCC and somatic cell score (SCS) were estimated. About 1193 measurements were included in the analysis for each character of 358 ewes of 9 genotypes. Nine breeds and genotypes were included in these experiments: purebred Improved Valachian (IV), Tsigai (T), Lacaune (LC) ewes, and IV and T crosses with a genetic portion of Lacaune and East Friesian (EF) - 25 %, 50 % and 75 %. Primary data were processed using restricted maximum likelihood (REML) methodology and the multi-trait animal model, using programs REMLF90 and VCE 4.0. Heritability coefficients for somatic cell count were low: h2=0.03, for LOGSCC h2= 0.08 and for somatic cell score h2=0.06. Somatic cell score can be considered for inclusion in a breeding program aimed at reducing somatic cell count and frequency of clinical mastitis in dairy sheep.

U poslednjih nekoliko godina postoji povećano interesovanje za smanjenje broja somatskih ćelija u mleku u cilju poboljšanja kvaliteta mleka kod preživara. Procenjivani su genetski parametri za broj somatskih ćelija (SCC), LOGSCC i skorovi somatskih ćelija (SCS). Obuhvaćeno je oko 1193 merenja u okviru analiza svakog od parametra i to kod 358 ovaca, u okviru 9 genotipova. Devet pasmina i genotipova obuhvaćeni su ovim ispitivanjem i to: čistokrvna poboljšana vlaška ovca (IV), cigaja (T), lakon (LC) ovce kao i ovce dobijene ukrštanjem IV i T sa genetskim primesama lakona i istočno-frizijske ovce – 25%, 50% i 75%. Preliminarni rezultati su obrađivani upotrebom restriktivne maksimalne verovatnoće (REML) primenom REMLF90 i VCE 4.0 programa. Nasledni koefi cijenti za broj somatskih ćelija bili su niski: h2=0.03, za LOGSCC h2=0.08 i za skor somatskih ćelija h2=0.06. Skor somatskih ćelija može da se uzme u obzir prilikom pravljenja programa ukrštanja, a u cilju redukcije broja somatskih ćelija i učestalosti klinički izraženih mastitisa kod muznih ovaca.