| Increasing the content of omega-3 fatty acids in the fatty acid profile of the animal products humans consume is becoming increasingly important as a way of promoting health and reducing the risk of disease. To achieve an improved fatty acid profile in milk and meat from dairy cows, it is necessary to feed the animals with high omega-3 fatty acid content feed. Flaxseed is a feed ingredient which may suffice these needs, however the nature of the omega-3 fatty acids present certain problems at the level of digestion - biohydrogenation in the rumen. Also, the extrusion method of producing a cooked flaxseed ingredient enhances the release of the oil from the flaxseed itself, but in turn increases the opportunity for oil loss during storage and transport. To limit oil loss, flaxseed was combined with three different absorbent materials (alfalfa, soy hulls, gluten) at three different ratios of absorbent to flaxseed for each absorbent (15:85, 20:80, 25:75) and the ability of the extruded samples to retain oil under compression was measured. Of the three absorbents, alfalfa performed the best (p < 0.0001) at a ratio of 25:75 (p = 0.0002). The samples were characterized in terms of the protein fractions -- soluble crude protein, neutral detergent insoluble crude protein (NDICP) and acid detergent insoluble crude protein (ADICP) -- and the digestibility of dry matter (DM) and crude protein (CP). The effect of extrusion, type of absorbent and the ratio of absorbent to flaxseed on the nutritional quality and some physical properties of the samples were ascertained. |
