23 April 2014

2 minute read

North America

A review of US studies into grain-fed and grass/forage fed beef has illustrated the complexity in characterising beef on health and eating grounds.

Grass-fed has been shown to be lower in fat than grain-finished beef but only lower in cholesterol in one study out of four.

This is according to Livestock specialist Dr Britt Hicks of Oklahoma Panhandle Research and Extension Centre who found it difficult to separate beef types.

He said both varieties provide omega-3 fatty acids mainly through linoleic acid and that both contribute to long-chain polyunsaturated fatty acids – linked with heart disease prevention.

Furthermore, both methods yield a product offering US consumers ‘a wide variety of important nutrients' which are both juicy and tender, although some studies favoured grain-fed for these attributes.

Where grass-fed beef fell short was in monosaturated fatty acids (MUFA), with 30-70 per cent less than grain-fed cattle.

MUFA is believed to increase ‘good’ cholesterol and that grass-fed beef could shift the ratio of MUFA and saturated fatty acids, compromising ‘good', cholesterol, Dr Hicks explained.

Polyunsaturated fatty acid (PUFA) percentage was found to lift 25 per cent on grass diets, although due to overall fat content being higher in grain-fed beef, PUFA in steak was greater in grain finished cattle.

Dr Hicks demanded more research be done to tie up remaining loose ends, adding that studies on global or European systems are not relevant for US beef.

Varieties in breed and forage variety/form are the main complicating factors, he added.

And while no concrete conclusions could be drawn on the merits of grass or grain, a study by a leading US beef company could have found the perfect sized carcass.

Yield grade three was optimum for returns per grain-fed beef animal in 2013, a study by US Premium Beef LLC has found.

Disregarding cattle fed Zilpaterol, the study found that carcass price/hundredweight and dollars per carass were:

• YG1 $193.75 and $1609
• YG2 $197.94 and $1684
• YG3 $201.04 and $1762
• YG4 $196.98 and $1783
• YG5 $189.45 and $1770

Yield grade four and five have a slightly higher total return but tended to be fatter carcasses, meaning less efficient with feed during finishing, the paper concluded.

Michael Priestley
News Team - Editor

Mainly production and market stories on ruminants sector. Works closely with sustainability consultants at FAI Farms