Any Animal exhibiting a superior characteristic, carries with it its heretibility(as estimated) regardless of the perfromance of its parents.

 

Objective: Using a standard environment of grassland production, build in those genes related to best possible economic return on beef.

Equation: The heritability of the traits x the selection differential ÷ the generation interval taken as five years using yearling bulls and heifers so selection for growth at 50% heritability using one bull that is 10 kilos above average in your herd and using yearling bulls and heifers = .5 x 10 ÷ 5 = 1.0 kilos per year

A programme should be built around this equation. Shortest possible generation Interval and highest possible Selection Differential

Method: Close herd. Select the best bulls representing those characteristics that you wish to improve, use them one year, replace with next year's best bulls.

To improve fertility, all females must conceive as a yearling and calve unassisted that year and every subsequent year.

Work at Trangie Research Station has demonstrated that some cows are twice as efficient as others (kilos of calf weaned to kilos of dry matter consumed).

By definition for the period that we have been selecting our own bulls out of closed herds - these bulls must have come from the most efficient cows, thus raising efficiency across the cow herds.

The advantages of having a closed herd: the breeder has complete control over the traits that he wishes to improve. As the period of time that the herd has been closed lengthens, recessive genes appear and can be eliminated. Improvement although slow, becomes fixed, additive and cumulative. Because sires are selected out of the best most efficient cows, both cows and bulls become more efficient.

The breeder's knowledge of background performance makes greater accuracy in selection. All stock have already performed under the farm's environment, making for better selection decisions.

As in-breeding levels rise, so does hybridisation when out-crossed. Cattle become constitutionally and structurally sound and free of genetic recessives.

I have been breeding Angus cattle since 1940. 20 years of buying bulls was very disappointing. After being closed since 1965 we have found that closed herd breeding is much more exciting and much more certain. Every year we await calving with great excitement. One more year on.

The advantages of outcrossing (buying in sires): Outcrossing disguises recessive genes, thus making progeny phenotypically sound but genotypically more variable. Also, every time you purchase an outside sire, you add all his genetic recessives plus problems from his herd.

Waigroup Breeding Objectives

• Fertility (every cow must calve every year)
• Calving ease (low birth weight, plus short gestation)
• Low birthweight
• Weaning weight
• Yearling weight
• Scanned for rib eye area
• Scanned for intermuscular fat