Forage shrubs in North Island hill country 4. Chemical composition and conclusions

摘要

A range of shrubs was evaluated as potential sources of forage for grazing animals. Shrubs were established in rows in hill pastures near Woodville.Nine #x201C;true#x201D; shrubs, and two erect grasses, pampas grass (Cortaderia selloana) and toetoe (C. fulvida) were evaluated. The true shrubs were:Chamaecytisus palmensis, tagasaste;Medicago arborea, tree medic;Ulex europaeus, gorse (two variants: wildgorse and short-spined gorse);Cytisus scoparius, broom;Robinia pseudoacacia, black locust;Leptospermum scoparium, manuka;Cassinia leptophylla, tauhinu; andCeanothus griseus, ceanothus. Nitrogen, and in most instances macro-and micro-element, concentrations of leaf were higher than those of stem. Foliage of manuka, tauhinu, pampas, and toetoe was not an adequate nitrogen source for lactating ewes, and all species were deficient in phosphorus. Tauhinu, pampas, and toetoe were magnesium-deficient, and tagasaste, broom, black locust, and ceanothus were sodium-deficient. Leaf material consistently had lower neutral-detergent-fibre and acid-detergent-fibre concentrations than stem. On average, leaf also had lower lignin concentrations but this was not consistent across species. Toetoe, pampas, hay, both gorses, and manuka had particularly high fibre levels in the foliage, and the gorses, manuka, and ceanothus had high lignin concentrations.