Linseed meal (Linum usitatissimum)

Synonyms: Linum rubrum, Linum grandiflorum  var rubrum

Common name: Flax seed

Linseed meal is the residue remaining after extraction of linseed oil from linseed/flaxseed.

Nutritive value

 Linseed meal contains 32-37% CP and 70-85% TDN. It is unique among the oilseed residues in that it contains from 3-10% of mucilage. This is almost completely  indigestible  by  nonruminant  animals but  can be broken down  by  rumen microbes. It is readily dispersible in water forming a viscous slime. It is fed mostly to horses and young calves. Linseed meal has a fairly low protein content of approximately 35% and is severely deficient in lysine. For this reason it is a good source of protein for cattle, buffalo, sheep and swine but  is not  a good  source of protein  in the poultry  rations. Linseed meal is also low  in carotene and vitamin D. Linseed has the highest omega-3 fatty acids content of any oilseed and research has shown that feeding linseed in the ration of animal increases the omega-3 fatty acid content of milk and meat.

Deleterious factors

Linseed meal is laxative when fed in large amounts. It contains two types of toxic factors. One is  adipeptide  called  linatine  composed  of  glutamic  acid  and  l-  amino-D  -proline. The latter amino acid is an antagonist of pyridoxine  (vitamin B ). Thus, in nonruminants linseed meal may produce pyridoxine  toxicity. Immature linseed contains a small amount of cyanogenetic glycoside, linamarin and an associated enzyme linase which is capable of hydrolyzing it with the evolution of hydrogen cyanide which is extremely toxic. Death results from combination of the cyanide with cytochrome oxidase leading to immediate cessation of cellular respiration and anorexia. Low temperature removal of oil may produce a meal in which unchanged linamarin and linase persist. The cyanogenetic glycosides in linseed meal have protective effects against selenium toxicity.