Naslov
Genotype by environment interaction for length of 1st inter lambing interval in sheep

Autori
Kasap, Ante ; Držaić, Valentino ; Mioč, Boro

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of Abstracts of the 69th Annual Meeting of the European Federation of Animal Science / EAAP Scientific Committee - Wageningen : Wageningen Academic Publishers, 2018, 590-590

ISBN
978-90-8686-323-5

Skup
69th Annual Meeting of the European Federation of Animal Science (EAAP)

Mjesto i datum
Dubrovnik, Hrvatska, 27.08.2018. - 31.08.2018

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
sheep, genotype, environment, interaction

Sažetak
Seasonal reproductive activity of ewes in temperate climates is a heritage of natural selection which favoured sheep giving birth at the most appropriate time of year in term of food availability. Short photoperiods stimulate pineal gland to synthesize more melatonin which triggers a series of hormonal reactions included in follicle maturation and ovulation. Melatonin exerts its function through specific MT1 G-protein receptor coded by MTNR1A gene (in sheep on 26th chromosome). Two polymorphic (bi- allelic) loci (606 and 612) on the 2nd exon of the gene have been associated with the seasonality. Presence of allele/s C-606 and G-612 have been mainly associated with whole-year breeding and shorter inter lambing period, but little has been known about genotype by environment interactions (GEI) on this issue. The aim of the study was to answer whether the same genotypes exhibit different phenotypes in different environments. The study was conducted on 277 natural-serviced ewes that were genotyped (MTNR1A – 606) and phenotyped in two different environments in Croatia (littoral=ENV1, n=157, continental=ENV2, n=120). The trait of interest was length of 1st inter lambing interval. In addition to the effect of interest (GEI), type of birth, season of lambing, and age at 1st lambing (covariate) were fitted in the ANCOVA statistical model to account for the available sources of phenotypic variability. Frequencies of genotypes CC, CT and TT in the ENV1 were 0.15‚ 0.55 and 0.30, and in the ENV2 0.26‚ 0.49‚ and 0.25, respectively. Estimates (LS means) of inter lambing intervals for CC, CT and TT in the ENV1 were 331.9, 355.4, and 371.3 days, and in the ENV2 363.5, 370.7, and 365.7 days, respectively. Results pertaining to ENV1 go in line with the majority of previous findings on this issue while those pertaining to ENV2 do not. The latter could be due to more intensive rearing system in ENV2 as compared to ENV1 which lead to weaker opportunity of the ewes to capture signals from the nature. Albeit determined re-ranking of genotypes across environments implicated existence of GEI, magnitudes of differences were too small, and intra class variances too high to detect statistical significance (F2, 265=0.95, P=0.39).

Izvorni jezik
Engleski

Znanstvena područja
Poljoprivreda (agronomija), Biotehnologija

POVEZANOST RADA