Rnking Sires Between Environments

[Mike]

Re-Ranking of Sires For Weaning Weight In Good & Poor Environments




Previous research revealed that heritability estimates for maternal weaning wt. have been shown to be higher in environments with restricted cow feed intake as opposed to environments with less limiting feed resources. Consequently, it may be possible for sires evaluated in good environments to rank differently in poor environments.



The objective of this Colorado State Univ. study was to determine the magnitude of sire re-rankings when accounting for different heritabilities in different environments. Data were obtained from the Red Angus Assoc. of America. It consisted of 91,061 cow weights and 23,243 calf weaning weights. Calf weights were classified as occurring in either a good or poor environment. Whether the environment was classified as good or poor depended upon the dam's weight change since the previous year. The study involved the 50 most accurate sires in the Red Angus breed.



Rank correlations (0.96 to 0.99) for sires in this study showed that changes in ranking of sires between good and poor environments were insignificant (Speidel et al. 2006. Proc. Western Sec. ASAS. 57:82).



Source: Dr. Rick Rasby, Professor of Animal Science, Animal Science, University of Nebraska - Lincoln, Lincoln, NE

 

[Jason]

The ability of cattle to work in different environments is a real strong point, but also a weakness.

If this research proves correct, maybe more than milk is different for the same genetics in different environments.

 

[Red Robin]

If this research proves correct, maybe more than milk is different for the same genetics in different environments.

I've said that for years. Fescue will show you that not all cattle are equal. Some can take it , some can't . Same with high starch diets, low quality forage inputs, cold, hot, etc.

 

[andybob]

I was in a testing program that compared our cattle by breed within the environment in which we ranched, as I sold bulls locally or to similar bushveld environments, the results meant more to my buyers than feed testing at the central testing station, and all bulls were sold in 'working condition' including those selected for export. Cross referencing between other breeds in the area, or the same breed in other areas was available, if anyone needed the information. My new herd here in N.C. is to be selected with the same criteria in mind, and I have several future buyers keen to utilise my bulls in their commercial herds to produce low maintenance F1 heifers in their herds.