Influence of plant cover on dietary selection of transhumance goats on six rangelands in Southwest Mexico. FRANCO-GUERRA, FRANCISCO^*,1, MENDOZA, GERMAN², SÁNCHEZ, MANUEL, HERNÁNDEZ, JORGE³, PLATA, FERNANDO³, ¹ Escuela de Medicina Veterinaria y Zootecnia. Benemérita Universidad Autónoma de Puebla. 4 sur 304, Centro.C.P. 75480, Tecamachalco, Puebla, México² Colegio de Postgraduados, Programa de Ganadería, Montecillo, km 36.5 Carr. México-Texcoco., Montecillo, Estado de México, México³ Facultad de Veterinaria. Universidad de Córdoba. Departamento de Producción Animal. Campus de Rabanales, Córdoba, Comunidad Autónoma de Andalucia, España

ABSTRACT- This research was conducted to study grazing time and to determine the relationship between the vegetable cover (arboreal, shrubs) and degree of preference by transhumance goats in six rangelands in the Mixteca region of Oaxaca, Mexico. Grazing time and number of bites was registered by direct observation during summer, autumn and winter. Three preference levels of vegetable cover were established according to the Parker method. A total of 65 species were selected: 52% had a frequent consumption coinciding with abundance; and 48% were occasionally consumed related to low availability. Shrubs were the main plant preferred (57.2%), followed by forbs (40.5%), whereas trees had low intake (2.2%). There was a positive relationship between the degree of use and cover of the species in the rangelands (r = 0.703, P < 0.001). Plant cover, particularly from trees and shrubs, determines the degree of use by goats in the Mixteca rangelands. In general terms, in most of the ranges, legumes (Acacia, Leucaena, Mimosa, Pithecellobium) were present in the diet, which is important because its high protein content (Ramirez et al., 1990; Aganga et al., 1998). Goats are able to diversify their diet according to availability (Reed et al., 1990; Perevolotsky et al., 1998), increasing intake of forbs, particularly during winter. During summer and fall, shrubs contributed around 69% of the selected plants, whereas during winter, were reduced to 34%. Forbs were the second group increasing from 28% during summer and fall, up to 66% in winter. Trees were the minor component of the diet.

KEY WORDS: Arboreal, Vegetable covering, Shrubs, Free grazing transhumant