27 March 2012

3 minute read

Feed efficiency is crucial, Dr Basarab said, when you consider that 50-70 per cent of production costs, whether it be for the cow-calf herd or in the feedlot are associated with feeding. In fact two thirds of the energy that cows consume is used only on maintenance.

Is it possible to reduce this maintenance need, he asked.

No Improvements in Efficiency to Date

"Genetic improvement in feed efficiency is estimated to be valued at $50-100 million annually to Alberta's beef cattle industry."

However, increasing average daily gain is not increasing feed efficiency, Dr Basarab said.

Over the last 100 years, no improvements have been made in maintenance requirements. In the 70's cattle weights increased, however maintenance requirements remained the same.

Whilst other livestock industries have reduced their greenhouse gas emissions and global warning potential through genetic improvement, Mr Basarab pointed out that beef cattle have made no improvements since 1988.

Other livestock industries have actively increased feed efficiency. Poultry produces 1.9-2.9 kg CO2 emissions per kg of chicken, whereas cattle produce 18-36 kg CO2 emissions per kg of beef produced.

Dr Basarab noted that carbon footprint per kilogram of beef varies by region and beef production system. A US calf/ year-fed implanted feedlot system has half the carbon footprint of a long fed Brazil fed with deforestation system.

Breeding for Residual Feed Intake (RFI)

RFI is the key for measuring feed efficiency, Dr Basarab said. It reflects an animals energy requirement for maintenance.

The lower the RFI the more efficient the animal. If an animal has a high RFI this suggests that the animal consumes more feed than required.

There can be a $36 difference per head between animals. This is a significant cost saving and must be captured in genetics, he said.

Selecting for low RFI has no affect on average daily gain (ADG) or animal size, he said.

It can also lead to feed conversion rate (FCR) improvements between nine to 15 per cent, and reduce feed intake by 10-12 per cent.

RFI must be adjusted for fatness, to demonstrate that there is no effect on carcase fat, Dr Basarab explained.

Dr Basarab discussed research carried out at the University of Alberta which looked at the effects of low RFI on body composition and carcase fat.

He said all in all, animals selected for RFI were much more efficient, also emitting less heat as the animal retained energy for feeding or liveweight gain.

He said that these improvements in feed efficiency can lower methane emissions between 15-30 per cent, and manure production by 15-20 per cent.

"Higher RFI animals have higher methane emissions," Dr Basarab said.

One interesting thing that Dr Basarab noted was that efficient dams had a higher calf survival rate. This he suggests is due to more efficient cattle being able to respond better to stress.

"Lower maintenance animals may have more nutrients available to better look after their progeny and provide a healthy uterus environment.

In conclusion, selecting for RFI can:

• Reduce feed intake by 10-12 per cent
• Improve FCR by 9-15 per cent
• Lower methane production by 20-30 per cent
• Reduce feed costs by up to $55/ head
• Reduce net energy required for maintenance
• Positive effect on body fat and weights
• No negative effects on carcase yield/ quality grade/ growth/ body weight/ calving pattern/ pregnancy/ calving or weaning.