Low protein feed for organic free-ranged sows

Feed with a low protein content can potentially reduce environment impact, minimize soy imports and improve the economy of organic pig farms.

By Linda Rosager Duve, Heidi Mai-Lis Andersen

Production results from a practical test and from a Danish experiment have shown that it is possible to reduce the protein content in concentrate feed for organic gestating sows to 60-65 g standard digestible crude protein per Feed Unit for sows (FUsow) when the sows have access to sufficient roughage.

The protein content can be reduced to 60-65 g standard digestible crude protein/ FUsow without having a negative effect on the sows' condition and the production results in the subsequent lactation. In fact, in the experiment, a positive effect on litter gain and weight on weaning was observed when feeding a concentrate with a reduced protein level (63 g standard digestible crude protein/ FUsow) compared to a standard concentrate (76 g standard digestible crude protein/ FUsow ).

Feed with a lower protein level has many potential benefits:

• Cheaper feed = better economy
• Reduced environmental impact – discharge of nitrogen is reduced
• Reduced climate impact - imports of protein feed from other continents is reduced

The protein content in roughage should be included

In addition to the concentrate, roughage also contributes protein. In the practical test and in the low protein experiment, the total amount allocated per sow per day was 260-270 g standard digestible crude protein. The protein contribution from the roughage varies greatly depending on the herd's feeding strategy, roughage type and quality and in the above-mentioned studies ranged between 10-50% of the allocated standard digestible crude protein. The highest proportion was in a herd using complete feed (mix of roughage and concentrate).

The protein content of the roughage should be accounted for in the feed ration to avoid oversupply of the sow and thus increased N loss to the environment.

Protein levels need to be adjusted in relation to:

• The herd's feeding strategy
• Type and quality of roughage
• The sows' intake of roughage and/or grass

The digestibility of crude protein in grass silage is 53% according to the feed component table. However, new results from Aarhus University indicate that the digestibility of silage is higher than the 53% stated in the Danish feed component table. It is therefore possible that the roughage contributes more protein than assumed.

Practical testing – read more here

The Innovation Centre for Organic Farming has tested the new low protein standards under practical conditions together with Vestjyllands Andel, Center for Frilandsdyr, Hestbjerg Økologi and Krarup Landbrug Økologi.

Hear about their experiences and the test at Krarup Landbrug Økologi in the video here.

The experiences from the two organic pig farms participated in the demonstration test can be seen in these videos. At Hestbjerg Økologi, at the same time as testing a concentrated feed with a low protein level, a resid-ual product was also being tested as roughage. The residual product is the press pulp from grass protein production.

Hear about their experiences and the test at Hestbjerg Økologi in the video here.