Figure 5From: A missense mutation in growth differentiation factor 9 (GDF9) is strongly associated with litter size in sheepFrequency changes of GDF9 -alleles among the Norwegian White Sheep AI rams. Frequency change in the GDF9 allele c.1111A in NWS AI rams born in 1990-2009. The number of genotyped rams per birth year is presented by bars. The period 1983 – 1989 is omitted from the figure due to low numbers of rams per year (3 AI rams per year in average).Back to article page