Relationships between LAMBPLAN EBVs for rams and post weaning performance of their crossbred progeny

LAMBPLAN calculates estimated breeding values (EBVs) for animals based on their measured performance and that of their relatives in industry flocks. Some 72 rams with LAMBPLAN EBVs were independently progeny tested in the Maternal sire Central Progeny Test (MCPT). Post weaning weight, carcase fat and eye muscle depth of their first cross progeny and second cross progeny of the first cross ewes were recorded. The correlations between the ram LAMBPLAN EBVs and their first cross progeny performance were positive and generally moderately high (0.5 – 0.6) for all traits and LAMBPLAN EBV analyses. The correlations for second cross progeny performance were positive although generally lower (0.3 – 0.5) than for first cross progeny. Regressions of progeny performance on LAMBPLAN EBVs quantified the possible response from selection and indicated higher than expected response in fat depth. The results clearly show that use of LAMBPLAN EBVs for selection of maternal sire rams will result in improved growth and carcase performance of crossbred progeny.