NEW research has shown that farmers should be focusing on the reproductive performance of sheep, rather than fat and growth rates.
The importance of body reserves and condition score to provide ewes with a buffer against periods of poor nutrition and during pregnancy is widely recognised by breeders, however, Merino breeders are being urged to directly measure for reproduction and ewe condition when both factors are considered economically important traits – rather than selecting on the indirect traits of fat and/or muscle levels to improve reproductive efficiency.
A principal scientist at the Animal Genetics Breeding Unit, Dr Daniel Brown, said the impact of fat and muscling on many aspects of production had resulted in debate throughout the sheep industry as to the emphasis that breeding programs should place on these factors.
“The bottom line for sheep breeders is that selecting on fat is not a substitute for selecting directly for reproductive performance,” Dr Brown said.
“Due to the number of complex interactions between traits, the most important advice is for Merino breeders to measure directly the traits that contribute to their farm profitability.
“The best way to account for these interactions and achieve balanced genetic improvement is to use multiple trait selection indexes that consider the value of a range of individually measured traits.”