2.8- Summary of the nutritional value of pastures: Print

The pea family (Leguminosae) (clovers, trefoils, vetches...) is a good source of protein (20% of weight or more), minerals (iron-Fe, copper-Cu, phosphorus-P and calcium-Ca, for example), fibre (11-25% of weight) and vitamins (carotenoids, B1, niacin, folic acid). It is also beneficial for soils as plants from this family fix nitrogen due to the action of certain bacteria in nodules on their roots. Both wild and sown members of the pea family are present in the fields on the Vista Alegre farm. The disadvantages of the pea family include the lower carbohydrate content of some species (less energy), low vitamin C content which is only present in any quantity of interest during germination or when “green” and the diseases that can be caused by depending exclusively or too much on Leguminosae.

Examples of the nutritional composition of some members of the pea family:

Alfalfa (Medicago sativa)
Protein: high content
Vitamins:Betacarotene (precursor vit A), C, D, E y K
Minerals: Ca, K, Fe, P,
Carbohydrates: low content

Clovers (Trifolium sp.)
Protein: high content
Vitamins: A, B2, B3, C, E
Minerals: Ca, Mg, K,
Carbohydrates: low content

red clover

Common bird’s-foot-trefoil (Lotus pedunculatus)
Protein:high content
Vitamins:high content
Minerals:Zn, Cu, Mg, Co, Se
Carbohydrate:low content

Grasses, on the other hand, have a higher carbohydrate content and thus provide energy, whilst they are poorer in proteins. They generally contain acceptable levels of calcium, magnesium and potassium, but are in poor in phosphorus

Hainbat gramineoren elikadura-osaeraren adibidea:

Perennial rye-grass (Lolium perenne)
Protein:low to medium average content (11% dry matter)
Minerals:Ca, Mg
Energy content:very high

Fescues (Festuca sp).
Protein:low to medium average content (13% dry matter)
Energy content: very high

Cocksfoot (Dactulis glomerata)
Protein:medium value (15% DM)
Energy content: high

In general, the species belonging to other families present on Vista Alegre farmland are of lower nutritional value (lower forage value), usually because they contain less quantities of each element. They generally contain few fatty acids but many vitamins. However, the value of these species is not only related to their contribution in nutritional terms, but also to other functions within the context of agroecology and food sovereignty (Section 3).

Examples of the nutritional composition of some species from other families:

Dandelion (Taraxacum officinale): leaf nutrients
Vitamins:A, B, C, D y E
Minerals:Ca, Fe, S, Mg, Mn, P and potassium salts
Bitter glucosides
Folic acid, carotenoids, flavonoids

Chickweed (Stellaria media)
Minerals:Cu, Fe, P, Ca, K

Fat hen (Chenopodium alba): leaf nutrients
Vitamins:A, B (thiamine, riboflavin and niacin), C
Minerals:Fe, Ca, K, P

Mallow (Malva sylvestris)

Vitamins: A, B, C

Common mallow

Yarrow (Achillea millefolium)

Plantains (Plantago sp.)
Vitamins:A, C

As the data offered suggests, certain plant families and some plant species in fields and grazing lands offer some of the nutrition requirements of cows, whilst other families and species provide others. Agroecological dairy farming implies supplying forage (grazed or harvested) containing a variety of families and species to balance all the needs of cows on the basis of the biodiversity offered in each area. In general pastures made up of between 50-60% of grasses, 25-30% Leguminosae and between 20% and 25% of species belonging to other families are considered to be well balanced in terms of achieving acceptable nutrition from forage. Additionally, however, and as is mentioned in Section 3, such species’ composition also permits attainment of other objectives of animal nutrition in the context of agroecology and food sovereignty.