During silage making, nutrients such as protein and fatty acid fractions are subjected to changes that lower their quality to some extent. The protein fraction is exposed to enzymatic degradation that results in its conversion to simple nitrogenous compounds. The fatty acid fraction is altered in a way that has repercussions for meat quality. It has been shown that the meat from grazing animals has a more positive fatty acid composition for humans than the meat from stall-fed animals.
Forage to dairy and beef
Improving the nutritional value
Project responsible: Rolf Spörndly, Department of Animal Nutrition and Management, SLU
Project group: Torsten Eriksson and Martin Knícky, Department of Animal Nutrition and Management, SLU
Forage ley is the crop occupying the greatest area in Sweden, 49% of agricultural land (16% grazing and 33% harvested ley). It is the largest feed ingredient in the diet of dairy and beef cattle, sheep, goats and horses.
During silage making the crop is first cut and then allowed to dry (wilt) from approx. 20% DM to 30-60% DM. The crop is then transported to air-tight silos of various designs. In Sweden, silage is made in tower silos, plane silos, round bales or tubes.
Wilting can take anything from a few hours to several days depending on the weather and the methods used for harvesting. Different methods for handling the newly cut silage can speed up the process. The actual mechanical treatment can also be expected to have an effect on the degree of decomposition that occurs in the cut crop and during the ensiling process.
The study aims to determine in a systematic way how the protein and fatty acid fractions are altered during wilting and to characterise various quality parameters. This is essential for future technical development of harvesting systems that maintain quality during forage conservation.
In the first year, the effects of wilting and DM content will be studied in a red clover-timothy ley according to the timetable below.
In the second year the study will continue with fewer variables but with additional plant material in the form of:
- white clover
- birdsfoot trefoil
- meadow fescue
Knicky, M., Eriksson, T. and Spörndly, R. 2012. Effects of different wilting regimes and DM contents on fatty acid profile of fresh forage. In: Udén et al (Ed) Proceedings of the 3rd Nordic Feed Science Conference, Uppsala, Sweden. Report 280. Department of Animal Nutrition and Management. Swedish University of Agricultural Sciences, pp 49-52.
Eriksson, T., Knicky, M. and Spörndly, R. 2012. Ammonia-N and α-amino-N in silage determined on either water extracts or solubilized freeze-dried samples . In Kuoppala, K. et al (Ed) Proceedings of the XVI International Silage Conference, Hämennlinna, Finland. MTT Agrifood Research, University of Helsinki, Finland, pp 264-265.
Knicky, M., Eriksson, T. and Spörndly, R. 2012. Fatty acid composition of a variety of forages before and after ensiling. In Kuoppala, K. et al (Ed) Proceedings of the XVI International Silage Conference, Hämennlinna, Finland. MTT Agrifood Research, University of Helsinki, Finland, pp 250-251.
T. Eriksson, R. Spörndly, and M. Knicky. 2009. The effects of wilting time and dry matter on proteolysis and lipolysis in silage. In: Broderick G.A., Adesogan A.T., Bocher L.W., Bolsen K.K., Contreras-Govea F.E., Harrison J.H. and Muck R.E. (eds) Proceedings of XV International Silage Conference, Madison, USA, 2009, pp. 215–216. Madison, WI: U.S. Dairy Forage Research Center, USDA-Agricultural Research Service and University of Wisconsin-Madison, College of Agricultural and Life Sciences.