Facts about EBVs

In the last 10 years, EBVs have proven their benefit to NSIP breeders through documented improvements.

  • NSIP Polypay breeders have increased the breed average for pounds of lamb weaned per ewe by 13 pounds.
  • NSIP Suffolk breeders have increased the market weight of lambs at 120 days of age by 6 pounds per lamb while increasing loin eye muscle and reducing fat deposition.
  • NSIP Targhee breeders have increased the number of lambs born by 7%.
  • NSIP Katahdin breeders have increased weaning rate by 5% and are leading the national effort to develop resistance to internal parasites.
Understanding EBVs

Animals with higher EBVs for:

  • number of lambs born indicates that female progeny should conceive a higher percentage of lambs.
  • number of lambs weaned indicates females with stronger maternal traits which contribute to lamb survival, plus progeny with higher vitality and survivability.
  • maternal weaning (milk) weight indicates that lambs will be heavier at weaning due to a contribution of maternal traits, including milk production and mothering ability.
  • post weaning weight indicates that progeny that will be heavier at market/finished weight.
  • yearling grease fleece weight indicates that progeny should produce heavier fleece weights.
  • yearling staple length indicates progeny that should have longer stapled fleeces.
  • eye muscle depth indicates that lambs should have larger loin eye muscles. Increasing ultrasound-measured loin-muscle area one square inch should increase gross carcass value by approximately $10.

Animals with lower EBVs for:

  • yearling fiber diameter indicates progeny that should have finer fleeces.
  • yearling weight indicates progeny that have lower mature weights and therefore, less associated maintenance costs.
  • fecal egg count indicates progeny that resist parasitic infection, thereby reducing the need for deworming.
  • fat depth indicates progeny that will be leaner at market weight, but replacements ewes might also have lower reproductive capabilities

National Sheep Improvement Program
PO Box 1258 | Ames, IA 50014 | Phone: 515-708-8850 | info@nsip.org