SmallRuminant Reseanzh zyxwvutsr ELSEVIER Small Ruminant Research 27 (1998) 19-23 Biodiverse and biosustainable production system with goats in Mexico: importance of a forage bank M.A. Galina aqbTc, * , D.C. Puga b,c, A. Hernhdez ‘, G.F.W. Haenlein d zyxwvutsrqponm a Facultad de Estudios Superiores Cuautitlan, UNAM, Cuautitlan, 54,000 Mexico b Posgrado Interinstitucional en Ciencias Pecuarias, Universidad de Colima, Colima, 28,000 M&co ’ Puma Ranch, Municipio de1 Marques, Queretaro, Mexico d Department of Animal and Food Sciences, University of Delaware, Newark, DE 19717-1303, USA Accepted 15 January 1997 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONM Abstract A l-year study was conducted to measure the forage volume necessary to maintain a goat herd in the semiarid zone of Mexico in terms of economic feasibility and seasonal grazing to conserve range land. The average weight of the adult females was 53 f 5 kg and yearlings weighed 40 k 3 kg at first kidding. Average milk production was 400 + 67 kg in 210 days. A concentrate of 2.9 Meal ME and 16% CP was offered twice a day. Average voluntary feed intake was 1.880 kg DM day-’ with an annual total of 686.3 kg; of those, 248.7 kg DM was provided by alfalfa hay from a forage bank corresponding to 36.2% of the total feed intake; 210.9 kg or 30.7% of the diet was concentrate and 226.6 kg or 33.0% was from the range land (grasses, shrubs and tree leaves). Alfalfa hay varied greatly in price during the year, being cheapest during October to December. Therefore to make most economic use of alfalfa as a forage bank for the rest of the year total supply of alfalfa had to be purchased during that time. Under the system of this study, alfalfa use was greatest during the time of zero grazing which was from February to April to avoid overgrazing and maintain biosustainability of the range land. From July through September grazing was the main source of nutrient supply because of the previous rain, thereby saving alfalfa hay and supplement feeding which diminished cost of production. 0 1998 Published by Elsevier Science Ltd. Keywords: Goats; Tropical grazing; Forage bank; Biosustainability 1. Intrtiduction The theory of the INRA French system of fill units intake (CVA) as a tool to calculate the volun- tary feed intake of ruminants has been discussed (Galina et al., 1991, 1995). Other studies have been done also in total confinement and feeding agricul- * Corresponding author at: AP 22, Colima, Colima, 28,000 Mexico. Tel.: (331) 411-33; fax: (331) 275 81; e-mail: galina@cgic.ucol.mx tural by-products (Galina et al., 1991, Galina, 1994). The CVA of goats was measured in a total confine- ment system when the goats were fed alfalfa and concentrates and all forage was weighed (Morales, 1986). A second study with another goat flock man- aged with known levels of supplement and unknown levels of forage including by-products, brush and Italian rye grass (L.&urn perenne). The CVA was measured and nutrient requirements determined for the different levels of production during the year (Galina et al., 1993). Measurements were collected 00921.4488/98/$19.00 0 1998 Published by Elsevier Science Ltd. All rights reserved. PZI SO921-4488(97)00023-O