PROTEIN FROM GRASS AND GREEN LEAF TESTED IN FEEDS FOR PIG AND POULTRY
Schothorst Feed Research and Wageningen Livestock Research, together with partners from the animal feed chain, are looking to upgrade circular raw materials into valuable animal feeds. As part of this investigation, a press release has been distributed and has been adopted by various media.
Protein isolates from grass, red clover and alfalfa contain enough protein. However, digestibility for pigs and poultry is still on the low side. This is shown by research in the 'Circular Bio-economy' project. Schothorst Feed Research and Wageningen Livestock Research, together with partners from the animal feed chain, are looking for upgrading circular raw materials to valuable animal feeds.
Grass is a crop that is widely grown in Europe. The European area is approximately 238 million hectares. The yield can vary widely in practice and in the Netherlands amounts to an average of 10.8 tonnes of dry matter per hectare. The protein yield per hectare can vary widely from less than 1200 kilos to more than 2000 kilos per hectare.
Grass is mainly used in cattle rations and is not a common raw material for pigs and poultry, because one-stomach animals can only moderately digest intact grass and green leaves. The limited digestion is related to the high fiber content. Part of the protein is included in this fiber fraction and is poorly accessible to the digestive enzymes of pigs and poultry.
Research showed that pigs realized an improvement in protein digestibility from 40% to 63% when the grass was harvested at a younger stage and thus had a lower fiber content. This result offers prospects for the application of grass and green leaf refining, in which highly digestible proteins are separated from proteins that are bound in the fiber-rich fraction.
It is not yet known whether the protein that is released during the refining of grass and green leaves can be used as a protein source in the feeds of pigs and poultry. An initial exploration has been carried out with isolated protein from grass, red clover and alfalfa. Soybean meal was also examined as a reference. The digestibility has been analyzed in the laboratory by mimicking the protein breakdown with the help of acids and digestive enzymes.
All products had significant protein contents: soybean meal contained 48.9% crude protein and the high protein grass, red clover and alfalfa isolates contained 42.4%, 51.7% and 58.6% crude protein, respectively. The protein from soybean meal and alfalfa isolate was 97% and 79% digestible, respectively, while the protein digestibility of the red clover isolate was 60%. The follow-up research focuses on the economic and nutritional preconditions for the application of these protein isolates in the feeds of pigs and poultry.
Grass is mainly used in cattle rations and is not a common raw material for pigs and poultry, because one-stomach animals can only moderately digest intact grass and green leaves. The limited digestion is related to the high fiber content. Part of the protein is included in this fiber fraction and is poorly accessible to the digestive enzymes of pigs and poultry.
Research showed that pigs realized an improvement in protein digestibility from 40% to 63% when the grass was harvested at a younger stage and thus had a lower fiber content. This result offers prospects for the application of grass and green leaf refining, in which highly digestible proteins are separated from proteins that are bound in the fiber-rich fraction.
It is not yet known whether the protein that is released during the refining of grass and green leaves can be used as a protein source in the feeds of pigs and poultry. An initial exploration has been carried out with isolated protein from grass, red clover and alfalfa. Soybean meal was also examined as a reference. The digestibility has been analyzed in the laboratory by mimicking the protein breakdown with the help of acids and digestive enzymes.
All products had significant protein contents: soybean meal contained 48.9% crude protein and the high protein grass, red clover and alfalfa isolates contained 42.4%, 51.7% and 58.6% crude protein, respectively. The protein from soybean meal and alfalfa isolate was 97% and 79% digestible, respectively, while the protein digestibility of the red clover isolate was 60%. The follow-up research focuses on the economic and nutritional preconditions for the application of these protein isolates in the feeds of pigs and poultry.
Source: Wageningen University & Research, 01/12/2020