EVALUATION OF PROMISSORY TREE SPECIES FOR SHEEP FEEDING IN THE HIGHLANDS OF CHIAPAS, MEXICO

The main objective of this study consisted of evaluating the fodder po tential of the foliage of Buddleia cordata, Montanoa leucantha subsp. arborescens, Erythrina chiapasana, Quercus rugosa and Alnus acuminata var. arguta, tree species present in The Highlands of Chiapas, Mexico, in order to select the best fodder and carry out an evaluation of the species with greatest potential in sheep feeding. The chemical compos ition results on a dry matter basis were as follows: the crude protein (CP) content ranged from 8.4% in Q, rugosa to 27.7% in M. leucantha. Neutral detergent fiber (NDF) ranged from 39.0% in M. leucantha to 58. 3% in Q. rugosa and Acid detergent fiber (ADF) varied from 30.8% in M. leucantha to 56.8% in Q. rugosa; Gross energy (GE) contents were 3.0 kcal/g or even greater. Tannic acid was detected from 0.25 g/100 g in E. chiapasana to 1.1 g/ 100 g in Q. rugosa; there were no cyanogenic g lucosides detected in the samples, and no alkaloids were encountered i n Q. rugosa and A. acuminata, but E. chiapasana showed higher alkaloid content than the other trees. Q. rugosa had the highest foliage produ ction (6.9 kg DM/plant/cut), while E. chiapasana had the lowest produc tion (1.2 kg DM/plant/cut). In an in vivo intake and digestibility tri al, the leaves of M. leucantha fed as a sole diet for sheep had the be st composition values, higher (P < 0.05) in vivo dry matter intake (IV DMI-L) (628 g/day) and in vivo dry matter digestibility (IVDMD-L) (76% ) of the five evaluated species. Therefore, the foliage of M. leucanth a was included in the sheep's diet in a growth and digestion trial at 0%, 25% and 40% levels of inclusion replacing alfalfa (M. sativa); in vivo CP intake (IVCPI-D) (106.9 g/day), in vivo CP digestibility (IVCP D-D) (67.5%), and live weight gain (LWG) (75 g/day) were higher (P < 0 .05) in sheep fed with diets including M. leucantha leaves at 40% leve l of inclusion. In vivo DM intake (IVDMI-D), in vivo DE intake (IVDEI- D) and in vivo NDF intake (IVNDFI-D), as well as in vivo DM digestibil ity (IVDMD-D), in vivo DE digestibility (IVDED-D), in vivo NDF digesti bility (IVNDFD-D) and wool production (WP), were similar (P > 0.05) in diets including 0%, 25% and 40% of Montanoa leucantha leaves. (C) 199 8 Elsevier Science B.V.