Te Mania bulls graphic example of genetic progress

12-05-2010 | Sandra Taylor

When Te Mania's Frank Wilding was selling bulls back in the 1960s a good bull weighed 600kg.

Today the Te Mania bulls go under the hammer at 750kg and are sold as 20-month-old animals rather than as two-year-olds as they were back then.

For Te Mania's stud manager John Harrington, this illustrates the rapid rate of genetic progress stud breeders have made, particularly in recent years through the use of estimated breeding values (EBVs) and Breedplan.

For Harrington, EBVs are a measuring tool and he doesn't believe genetic improvements can be monitored unless they are being measured.

Through the use of these tools, studs such as Te Mania have been able to make selections based on objective measurements rather than just phentotype.

"We have to go past looking at animals just on phenotype; what we want is the genotype or the genetics tied up in the animal," Harrington says.

"The biggest bull is not necessarily the best breeder.

"We want structurally sound animals. They need to be able to harvest grass, but they don't need the biggest head and jaw. They need to be functional."

For Harrington, phenotypic selection, without knowing the multigenerational history of a bull, can be damaging and result in unfavourable genetics that can impact on the cow herd for many years.

Cattle breeding is a slow job and the wrong genetics can do a lot of damage.

"There is too much unknown."

Unlike commercial farmers, large-scale stud breeders are able to put population pressure on their bulls by running them in big contemporary groupings. The animals sort themselves out, Harrington says, and the cream invariably rises to the top. It is these superior animals that are used in their breeding programmes.

Improvements in carcase characteristics are a good example of the progress that can be made through selecting on objective measurements rather than phenotype.

Te Mania was one of the first to carry out carcase evaluations. These types of evaluations have enabled stud breeders to make big in-roads into improving the musculature, and therefore the yield, of beef cattle.

Harrington says animals today are more efficient and have better carcase attributes and he believes much of this progress can be attributed to Breedplan and the information it generates. This is particularly evident in Te Mania's herd graphs which show significant progress since they have been using EBVs.

Through artificial breeding programmes, stud breeders are able to source proven genetics from anywhere in the world, and for Harrington, using proven genetics, or sires with a high degree of predictability, is critical.

Having many years' worth of data allows stud breeders to see which breed lines work for them and which don't; this is the sort of information that underpins the genetic progress that commercial farmers are able to benefit from.

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