30 June 2000

Selecting best beef stock

Brazilian cattle breeding is relying more heavily on

technology. Emma Penny reports as part of an assignment

funded by Zenecas Young Agricultural

Journalist of the Year Award

CATTLE breeding in Brazil is a high-tech business, with producers embracing performance recording as a key means of selecting the best stock.

They also believe that selecting only the top stock from a large population will help boost genetic progress: That means that even producers with 12,000 cows will join breeding groups in an effort to increase selection pressure.

One of Brazils breeding groups, Connection Delta G, has 17 producer members, with a total cow population of tens of thousands covering Nelore, Braford and Hereford breeds.

Its mission is to breed cattle which are better beef animals – earlier maturing and with faster liveweight gain. Selection of superior animals is based almost exclusively on performance recording, with all progeny being recorded from birth to sale, and their sire and dam performance being recorded too – which means all stock are individually tagged.

Calves are weighed and individually tagged at birth, and then run with their dams at grass until weaning. At weaning, each animal is recorded for weight gain, days to gain 160kg from birth to weaning, conformation, early finishing, muscling, sheath angle and maternal ability.

These figures are used to produce EPDs, similar to the UKs EBV system but calculated on the number of days to reach a specific target. This is because the overall aim is to produce an animal which will reach sexual maturity earlier and will therefore finish more quickly. In a country where some cattle are not finished – or will not breed – until four-years-old, this is a vital requirement.

According to one group member, the Martins da Silva family at Estancia Sao Jose, Bage, who keep 1400 Braford cows and 600 Hereford cows on their 6500ha (16,000 acres), fewer than half the male progeny will be selected for a second recording after weaning EPD figures are received. Those not good enough are castrated and sold for finishing.

The best animals are kept on grass, under exactly the same conditions, then recorded again at 550 days. This includes weight gain from weaning to 550 days, days to gain 400kg from birth to 550 days, conformation, early maturity, muscling, sheath, scrotal perimeter – adjusted for age, and scrotal perimeter adjusted for weight and age.

Another Delta G member, Ian Hill, who runs 12,000 Nelore and Braford cows at Jacarezinho, Sao Paulo state, expects to have only 1000 bulls left after this second selection. "We will keep 150-200 of these to use in our own herd and sell them after use. About 15-20 of the top animals are used in progeny tests across the Delta G group via AI, and the rest are sold before they reach two years old, with 70% sold off the farm and about a third at auction."

Females are also under intense selection pressure, with the onus on early sexual maturity and breeding, says Mr Hill.

Delta G members select heifers for breeding based on their muscling and carcass scores, not weight, which Mr Hill says is a misguided selection tool as there is more correlation with good carcass characteristics and early breeding than weight. But early sexual maturity is also highly heritable.

At Jacarezinho, heifers meeting muscling and carcass targets were bulled at 17-months-old.

"Most Nelores calve at 26-40 months old, so theres huge scope to improve calving yield. Now we are bulling some heifers at 14-months-old; these genetics could really change the Brazilian cattle industry as most herds breed late because their genetics arent good enough," he says.

Heifers which dont fall pregnant when bulled early are grazed until 24-months-old, then AId with top Nelore bulls.

CATTLE breeding in Brazil is a high-tech business, with producers embracing performance recording as a key means of selecting the best stock.

They also believe that selecting only the top stock from a large population will help boost genetic progress: That means that even producers with 12,000 cows will join breeding groups in an effort to increase selection pressure.

One of Brazils breeding groups, Connection Delta G, has 17 producer members, with a total cow population of tens of thousands covering Nelore, Braford and Hereford breeds.

Its mission is to breed cattle which are better beef animals – earlier maturing and with faster liveweight gain. Selection of superior animals is based almost exclusively on performance recording, with all progeny being recorded from birth to sale, and their sire and dam performance being recorded too – which means all stock are individually tagged.

Calves are weighed and individually tagged at birth, and then run with their dams at grass until weaning. At weaning, each animal is recorded for weight gain, days to gain 160kg from birth to weaning, conformation, early finishing, muscling, sheath angle and maternal ability.

These figures are used to produce EPDs, similar to the UKs EBV system but calculated on the number of days to reach a specific target. This is because the overall aim is to produce an animal which will reach sexual maturity earlier and will therefore finish more quickly. In a country where some cattle are not finished – or will not breed – until four-years-old, this is a vital requirement.

According to one group member, the Martins da Silva family at Estancia Sao Jose, Bage, who keep 1400 Braford cows and 600 Hereford cows on their 6500ha (16,000 acres), fewer than half the male progeny will be selected for a second recording after weaning EPD figures are received. Those not good enough are castrated and sold for finishing.

The best animals are kept on grass, under exactly the same conditions, then recorded again at 550 days. This includes weight gain from weaning to 550 days, days to gain 400kg from birth to 550 days, conformation, early maturity, muscling, sheath, scrotal perimeter – adjusted for age, and scrotal perimeter adjusted for weight and age.

Another Delta G member, Ian Hill, who runs 12,000 Nelore and Braford cows at Jacarezinho, Sao Paulo state, expects to have only 1000 bulls left after this second selection. "We will keep 150-200 of these to use in our own herd and sell them after use. About 15-20 of the top animals are used in progeny tests across the Delta G group via AI, and the rest are sold before they reach two years old, with 70% sold off the farm and about a third at auction."

Females are also under intense selection pressure, with the onus on early sexual maturity and breeding, says Mr Hill.

Delta G members select heifers for breeding based on their muscling and carcass scores, not weight, which Mr Hill says is a misguided selection tool as there is more correlation with good carcass characteristics and early breeding than weight. But early sexual maturity is also highly heritable.

At Jacarezinho, heifers meeting muscling and carcass targets were bulled at 17-months-old.

"Most Nelores calve at 26-40 months old, so theres huge scope to improve calving yield. Now we are bulling some heifers at 14-months-old; these genetics could really change the Brazilian cattle industry as most herds breed late because their genetics arent good enough," he says.

Heifers which dont fall pregnant when bulled early are grazed until 24-months-old, then AId with top Nelore bulls.

BREEDINGSELECTION

&#8226 High selection pressure.

&#8226 Seeking early maturity.

&#8226 Progress being made.