melatonin receptor 1A	(MTNR1A)
Arylalkylamine N-acetyltransferase	(AA-NAT)
PCR restriction fragment length polymorphism	(RFLP)
single nucleotide polymorphism	(SNP)
quantitative trait loci	(QTL)
marker-assisted selection	(MAS)
age at first lambing	(AFL)
lambing interval	(LI)
litter size	(LS)
early favorable	(EF)
late favorable	(LF)
unfavorable	(UF)