What makes a good female?

Start with identifying underlying poor genetics


Beef
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Identifying and selecting good genetics is more than simply culling the poor performers.

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RAISING a live calf to weaning and producing a calf that weighs well can be a major test for many breeding females, especially during the current conditions. 

Southern Beef Technology Services (SBTS) technical officer, Catriona Millen, says a good maternal cow should provide its calf with adequate nutrition to ensure the calf is weaned with a good weaning weight. 

The milk estimated breeding value (EBV) provides an estimation of the contribution of the cow to the 200-day weight of its progeny. 

“It is expressed as kilograms, so therefore indicates the expected difference in the calf weight due to maternal contribution,” she said. 

Chasing the highest milk figure may not be the right choice in all breeding systems, as it is important to remember the optimum Milk EBV depends on the production system and the environment. 

“Selection for increased milk production can be warranted where cows are run under good nutritional conditions, with for example improved pastures,” she said.

“Other poorer environments, for example scrub land, may not be able to support cows with a higher Milk EBVs. 

Producers with more scrubby, marginal country may prefer more moderate Milk EBVs.”

Higher milking females may not get back in calf as easy as lower milking cows.

Overall it is important to remember the optimum Milk EBV will depend on the individual production system and the environmental conditions. 

Are you keeping the right cows?

DROUGHT conditions are putting extra pressure on cattle breeding systems, with some producers wondering how they can identify their best breeders to ensure the right animals are retained. 

With females playing an important role in the herd, not only as they contribute 50 per cent of the genetics but because they have the job of raising a live calf to ensure a profit is made, it is crucial to make sure the most efficient cows are being kept. 

Southern Beef Technology Services’ (SBTS) winter edition said a maternal female should get in calf, give birth unassisted to a live calf, raise that calf to weaning and get back in calf, all while maintaining herself without having to consume copious amounts of feed.

SBTS technical officer, Catriona Millen, Armidale, said removing individuals based on performance does not eliminate the underlying poor genetics from the herd. 

“The parents and/or progeny aren’t culled and without making genetic improvements, the problem will simply repeat itself,” she said.

Apart from structural soundness, Miss Millen said it is important to look into genetics. “Genetics can be used to improve the percentage of females getting in calf,” she said. 

A number of Breedplan traits allow producers to make informed decisions about which animals offer the best maternal qualities, or how they can improve productivity by selecting for different traits. 

“Days to calving indicates the difference between animals in the time from the start of joining until calving. Lower, more negative figures are more desirable as they indicate females that conceive early in the joining period,” she said. 

“Scrotal size (SS) indicates fertility in the female herd as research indicates bulls with a higher SS tend to produce more early maturing heifers than those with a lower SS.”

The gestation length (GL) EBV (estimated breeding value) describes the genetic differences between animals in gestation length. 

“A lower, more negative GL figure indicate a shorter gestation length and is thus more desirable as it results in a smaller calf and gives the cow a longer period of time to re-breed,” she said. 

Given current feed costs producers need to consider the weight of their mature cows as it will have a major influence on net profitability. 

“Smaller lighter cows eat less therefore require less inputs. Conversely, with weight being a determinant in the value of cull cows, heavier cows provide higher returns at point of sale.”

“It is important to achieve an appropriate balance between feed requirements and her value as a cull cow.

“The mature cow weight EBV should be considered, and ideally a low to moderate EBV selected to reduce feed costs over a lifetime.”

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