EBVs are critical in selection process

13 Mar, 2018 04:00 AM
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THE benefit of using estimated breeding values (EBVs) as part of the beef cattle selection process was highlighted to producers at a beef cattle field day run by WA Santa Gertrudis breeders at Cundarra, Gingin, recently.

Tropical Beef Technology Services technical officer Paul Williams, Rockhampton, Queensland, said an animal’s phenotype was a mix of genetics and environment.

Given genes were difficult to see, EBVs were used to estimate its breeding value, based on measured traits providing insight to the genetics independent of the environment.

Mr Williams said there were 18 different EBVs available including for birth, growth, fertility and carcase traits and things such as net feed intake, shear force which related to eating quality, structural soundness and flight times (related to temperament and ultimately potentially eating quality).

“Production and profitability is driven by the number of calves born by the weight (kilograms) of those calves and then the quality (c/kg) of those calves less the cost of production,” Mr Williams said.

“In trials that have been done we are seeing vast differences in the profitability of the top performing bulls relative to the lesser performers.

“A recent Brahman trial, run in conjunction with our BIN (Beef Information Nucleus) project, compared the top five bulls with the bottom five bulls and showed average differences in their progeny of 11kg for 200-day growth, 17kg for 400-day weight and 27kg for 600-day weight.”

Similarly in a Durham Shorthorn trial differences of 13.4kg for carcase weight, 0.6 per cent for IMF and 0.4pc for marbling were found, highlighting the importance of careful bull (and female) selection for maximising profitability.

“In the BIN trial the average carcase weight for progeny of the worst performing bull was 286kg compared to 340kg for the best performer which means a big difference in returns,” Mr Williams said.

“With regard to shear force or eating quality we have seen some Bos Indicus bulls perform just as well as the average Angus.”

And in relation to fertility Mr Williams said the best performing bull had most daughters cycling at 600 days, while the worst performer’s daughters were barely cycling at two years of age.

From a 94pc pregnancy rate from a 12-week mating the difference in calving due date was 4.5 weeks between the top and bottom sires.

The BIN project seeks to examine fertility in female progeny and analyse carcase and meat quality data from their steer counterparts for tropical beef breeds.

Another tropical cattle trial currently in play in northern Queensland was the five year MLA-funded Repronomics project.

Headed by David Johnston, beef cattle geneticist at the Animal Genetics and Breeding Unit (AGBU) at the University of New England, Armidale, New South Wales, its mission is enabling genetic improvement of reproduction in tropical beef breeds.

Since 2013, the project has seen almost 4000 females mated using 177 sires from 67 Brahman, Droughtmaster and Santa Gertrudis studs (not including Northern Territory) with 57 of these bulls considered link sires having progeny at more than one trial site.

Trial females are mated for 12 weeks with 3-4pc bulls.

Some early findings have shown big differences in eye muscle area, IMF (2 - 50pc) and in age at puberty between sires, with the latter also affected by seasonal factors resulting in a 700-day average in puberty in good seasons compared to an 1100 day average in drought conditions.

The MSA score also varied with Brahmans averaging 56, Droughmasters 57 and Santa Gertrudis 59, but when HGPs were introduced these figures dropped to about 48, although there was some benefit in carcase weight.

With regard to daily weight gain one steer achieved a daily gain of 2.6kg/day compared to the group average of 1.4kg/day.

Mr Williams said because of the increased accuracy of EBVs on the mating sires and the three breeds running together, the Repronomics project had brought the beef industry one step closer to developing a common Breedplan analysis across all breeds.

Live export buyer, feedlotter and station owner Dean Ryan, Central Stockcare, Bullsbrook, also spoke at the field day.

Mr Ryan, who has just clocked up 25 years working in the beef industry, provided some insight into the enterprise he runs with his wife Kate which includes a backgrounding property at Badgingarra, a feedlot at Gingin and Minnie Creek station in the Gascoyne, as well as a live export update.

He said cattle live export numbers had dropped 27.1pc in the past five years and were now similar to 2012/13 figures.

Overall the value of all livestock exported had dropped from $1.8 billion in the peak of 2015/16 to $1.4 billion now, but live exporters were feeling the pressure of rising cattle prices which had jumped from an average of $910/head in 2014/15, to $1270/head in 2016/17 and were now closer to $2000/head.

Mr Ryan said Indonesia remained a major market and there was still activity in Vietnam which had become a bit of a back door to China.

Fremantle was WA’s third largest cattle export port in 2017, shipping more than 100,000 head, behind Darwin, 350,000 head and Townsville, more than 150,000, but Mr Ryan predicted Townsville would be a growth port now that sea freight prices had dropped and with infrastructure improvements planned there.

Export destinations had their preferences for the type of cattle they bought with Indonesia currently focussing on high content Bos Indicus for feeders, while Vietnam preferred red cattle, especially bulls for slaughter and mid-range feeding.

Malaysia was price sensitive but preferred leaner cattle especially small pastoral heifers, MENA (Israel and Turkey) liked British breed cross milk teeth steers and bulls, Russia was chasing Angus and Hereford feeders and breeders and China wanted Bos Indicus types in the north and British breeds in the south.

Mr Ryan said challenges for live export included that profitability was on the decline and issues with ESCAS which had meant the loss of some markets and had added about $20/head in costs which ultimately would be transferred back to the producer.

“But in all that we do, whether for live export or local feedlotting consistency is the thing we want in cattle and we can afford to pay more for cattle that we know will be consistent in meeting specs,” Mr Ryan said.

“These are the types of cattle I can buy over the phone and know they are right.”

At Minnie Creek, the Ryans run a Santa Gertrudis/ Droughtmaster cross herd with calves generally trucked south to the family feedlot and sold to local butchers after 100 days on grain.

Given that WA is a heavily MSA driven market they also feed British/European crosses and are one of the major suppliers to Woolworths.

“We aim for feedlot entry weights of 300 - 400kg, prefer to buy backgrounded cattle and mix all our own rations using a fairly high percentage of lupins which seems to help meat colour,” Mr Ryan said.

Gabyon Pastoral’s Sally O’Brien, Irwin, followed her brother-in-law on to the speaker’s patch on the shady Cundarra verandah and provided an overview of the running of their 9600ha family-based operation.

Working with her brother Andrew Gillam and parents Rob and Ros Gillam, the family annually calve down 420 breeders, have 6500 breeding ewes with half mated to Merinos and half to Poll Dorsets and crop 3500ha to wheat, lupins and some canola.

Rather than increasing the size of their holding, the intention has been to “sweat their asset harder for greater profitability”.

In the cattle herd that means running 5/6 - 7/8 Santa Gertrudis females with some Shorthorn infusion mated predominantly to terminal sires including Charolais and Angus for maximum hybrid vigour.

“We love the maternal traits of the Santa cross female, their softness, that they get through the summer easier than some other crosses and that they clean up early in the coat so their calves really appeal,” Ms O’Brien said.

“In the past we tried keeping some of these crossbred calves as breeders but their mature cow weight meant too much maintenance and more hay required through summer.”

Changes at Gabyon, aimed at driving profit, have included the introduction of some perennial pastures in addition to existing Tagasaste.

“For the first time we planted it in rows in conjunction with tagasaste and our weaners have just done 0.7kg/day on it,” Ms O’Brien said.

“We have adopted better stockhandling techniques, more weaner education using dogs and daily handling and cull hard for temperament and fertility.

“We preg test everything and the policy is no calf, no stay, no exceptions plus we also cull any animal we have to assist calving or that doesn’t raise its calf.

“We have dabbled with AI but are now preferring to synchronise mate our heifers,” Ms O’Brien said.

“Good genetics are a big thing for us, but so too are the likes of using mineral licks and vaccinating, because if you don’t address all areas of the production system then you don’t get the full benefit of those good bulls you buy.

“We have been as specific as to customise our licks based on soil tests in individual paddocks and believe this is helping weaning weights, calf weight gaining ability and re-joining rates in females.”

This sort of attention to herd health was also championed by Dandaragan veterinarian Dr Jo Maguire who covered worming, vaccinations and dehorning.

Ms Maguire said some of the main diseases to inoculate against in WA were leptospirosis, vibriosis, enterotoxaemia (pulpy kidney) and botulism and good handling of vaccines was essential.

Things that could affect vaccine efficacy were incorrect storage, inefficient or contaminated guns and expired product (don’t buy in bulk).

For ease of management vaccinations could be given to calves at marking or weaning and should be given to introduced stock, growing stock going in to high quality feed and breeders and bulls annually, especially before mating.

“But remember it takes time for immunity to develop, usually from two weeks after the second booster is given,” Ms Maguire said.

“Vaccinations may seem like an expense but they are cheap insurance to protect against the risk of having a major issue which will affect your profitability far more.

“Similarly with worm burdens, if left untreated could affect an animal’s health and digestive efficiency for the rest of its life.

“Doing a faecal egg count to determine the type or types of worms present is the best policy to enable most effective treatment and in addition to this things like rotational grazing and using break crops can help,” Ms Maguire said.

The Gingin beef cattle field day was run by WA Santa Gertrudis breeders and sponsored by Santa Gertrudis Breeders Australia Association, Primaries, Elders, Landmark, S & C Livestock, Zoetis and Allflex.

FarmWeekly

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Live export needs to stop now. It's bad enough we're killing these animals, must we also torture
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Good to know that thousands of caring people in all walks of life oppose the cruel live animal
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Good to know that thousands of caring people in all walks of life oppose the cruel live animal