We may have touched on this before but I just read a synopsis in Hoards Dairyman and thought it was pretty interesting. Fertility has decreased in dairy cattle over the past 20 years (worldwide, actually). This decrease in fertility is believed to be related to single trait selection - ie production over fertility (must admit this single trait selection is very reminiscent of what we are seeing in certain circles of the beef world).
SOrry, I digress - anyhow researchers from U of Wisc have discovered a defective gene (for knabe it is a SNP in a transcription factor gene) that is associated with reduced survival of embryos in cattle. Death of embryos homozygous for this defect (GG) occurs much earlier than previously recognized.
They then took sperm from homozygyous normal (CC) and heterozygous (GC) bulls and did in vitro fertilization resulting in 772 IVF embryos. Survival was measured at different times and found that 2 copies of the normal C gene (CC) lead to much better survival. In otherwords embryos of the CC genotype survived better than either CG or GG....food for thought when selecting traits
SOrry, I digress - anyhow researchers from U of Wisc have discovered a defective gene (for knabe it is a SNP in a transcription factor gene) that is associated with reduced survival of embryos in cattle. Death of embryos homozygous for this defect (GG) occurs much earlier than previously recognized.
They then took sperm from homozygyous normal (CC) and heterozygous (GC) bulls and did in vitro fertilization resulting in 772 IVF embryos. Survival was measured at different times and found that 2 copies of the normal C gene (CC) lead to much better survival. In otherwords embryos of the CC genotype survived better than either CG or GG....food for thought when selecting traits