Seasonal variation of macro and trace mineral contents in 14 browse species that grow in northeastern Mexico

Leaves and twigs from shrub species consumed by range goats: Acacia berland ieri, Acacia farnesiana, Acacia greggii, Acacia rigidula, Celtis pallida, C ercidium macrum, Condalia obovata, Cordia boissieri, Desmanthus virgathus, Leucaena leucocephala, Leucophyllum texanum, Opuntia lindehimieri, Porlieri a angustifolia, Prosopis glandulosa, and Ziziphus obtusifolia were evaluate d for comparative seasonal contents of Ca, P, Mg K, Zn, Mn, Cu and Fe. Plan ts were collected in summer (September 12, 1992), fall (November 20, 1992), winter (February 20, 1993) and spring (May 22, 1993) in Marin, County, Nue vo Leon, Mexico. During spring and summer mineral concentrations were highe r in general. Only Ca. Mg, K, and Fe were in substantial amounts in all sea sons to meet adult goat requirements. With the exception of spring, shrubs had extremely low P concentrations. Manganese, Cu and Zn in most plants had low marginal levels to meet adult goat requirements. Moreover. potential i ntake of P, Mn, Cu and Zn in shrub species by goats weighing 50 kg BW consu ming 2.0 kg per day DM was low. However. plants such as D. virgathus, L. te xanum, P. glandulosa, L. leucocephala and C. macrum can be considered promi nent components in diets of range goats because of their high mineral conce ntrations. It appears that ration formulations for range goats in northeast ern Mexico should include P, Mn, Cu and Zn in all seasons of the year. (C) 2001 Elsevier Science B.V. All rights reserved.