Genetics

Seeking balancing breeding objectives in the north

Alice Greenup* 18/09/2018

THE fertility of the northern Australian beef herd is in the spotlight, and the need to improve it remains the focus of many operators.

Productivity in terms of kilograms weaned per cow mated is a function of the genetics for fertility and good nutrition.

Prominent northwestern Queensland beef cattle vets Ian Braithwaite and Sandi Jephcott each pregnancy-test tens of thousands of cattle each year.

They are at the forefront of the northern beef industry, observing what leading producers are doing in their business to stay at the top of the profit curve.

Dr Sandi Jephcott

Dr Jephcott has seen the changes over the decades and feels there is a day of reckoning coming.

“The Cash Cow research project proved that the large-framed cattle are less fertile than those with moderate frame. Excessively big-framed cattle have no place out here,” she said.

“Some of the beef businesses have lost sight of the nutritional constraints that their cattle herd experience. Using genetics is now seen as a panacea for profit building, rather than using a genetics package that is complimentary to good business management,” Dr Jephcott said.

For some of the ‘new-trending’ breeds to express desired market traits, they required good nutrition from the last trimester of pregnancy, right up until, as weaners they are transferred to backgrounding properties and as yearlings or older, they reach the required feedlot entry weight. But without good nutrition, they do not express their genetic potential and the product can be downgraded.

“Furthermore, some popular breeds may lack weight, so the cull bulls and cows are rejected from the meatworks – thereby missing out on a huge proportion of conventional income,” she said.

Dr Jephcott suggested Santa Gertrudis may be ideal for parts of northern Australia.

“The modern Santa is one that has objective measurements, has been bred for fertility, and is a moderate animal that can walk the distances away from waters to get maximum production in terms of weaners and weight gains,” she said.

“Unfortunately, the old types of Santas gave the breed a bad name, but there are really fertile Santa herds out there now and I would love to see them back up here (in northern Australia) in large numbers.”

Dr Jephcott said she used Santa bulls in her own operation near Roma, which targets the domestic feeder steer and heifer specs, prompting her to select bulls that have high 400-day Breedplan weights.

“I also select for BreedPlan fertility traits, such as Days to Calving and scrotal size. Once I have shortlisted the draft on objective data, I look at structure, temperament and general appearance,” she said.

“The Santa is adapted for this country, with a mix of Bos Taurus and Bos Indicus which have a combination of being adapted to the environment and meeting market specifications such as MSA.”

Ian Braithwaite

Dr Jephcott said the purebred Bos Taurus breeds being used in the dry tropics of Northern Australia were only walking up to a maximum of two kilometres from water, and this was “damaging the environment and worsening the nutritional profile” (by intensifying grazing pressure closer to waters).

Drs Jephcott and Braithwaite agree that the greatest progress they are seeing in the north is in those herds where the focus remains on productivity and adhering to those decisions.

“Ordinary things done consistently, produce extraordinary results,” Dr Braithwaite said.

“We have seen tremendous results with the herds up here, with a focus on selecting bulls with objective data for fertility.”

Criteria when selecting bulls

He said the criteria he recommended when buying bulls was to insist on a BBSE including semen morphology by a reputable vet, dam calving history and scrotal circumference above threshold size.

‘In Northern Australia about 90pc of production is underpinned by good nutrition. Fertility cannot be expressed without good body condition in the breeders,” Dr Braithwaite said.

“We think a minimum of 50pc Bos Indicus content is needed to adapt to walking large distances from water to feed in order to maintain body condition score in the breeders,” he said.

“Maiden heifers drive these new production systems and can make up to 30pc of the total breeder herd numbers. Using proven performance bulls (pedigree/BBSE) with the right nutrition, 85pc conception rates in these two-year-old heifers is very achievable. Large numbers of first round weaners from these matings have an enormous impact to the bottom profit line of the business.”

“We need fertility, but don’t need to get too complicated and we probably don’t want to be tied up focussing on single traits – even an excessive focus on days to calving may have implications down the track with shorter gestation lengths or other unforeseen implications,” Dr Braithwaite said.

“A good friend of mine, the late Dr Brain Burns described genetics is being like a balloon full of water – you push on one side and something else gives.”

Excessive attention to specific traits or numbers was fraught with unknown risks.

“We are breeding for survivability and productivity and I think we can get the balance right if we keep it simple with bulls selected on a BBSE incorporating semen morphology and above threshold scrotal circumferences, tropical adaptability, moderate frame size, and dam history.”

 

* Alice Greenup and her husband Rick operate Eidsvold Santa Gertrudis near Eidsvold in Central Queensland.

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