The leaves ofthe agave plant are left in the field after harvesting the heads for tequila production. Different types ofagave leaves were isolated, classified, and their content in the total plant determined. The usable fractions were collected and their properties determined. Of the total wet weight of the agave plant, 54% corresponds to the agave head, 32% corresponds to materials which could be usable for sugar and fiber production which leaves 14% ofthe wet plant without apparent utility. The fractions with higher total reducing sugars (TRS) content were the fresh fraction of partially dry leaves stuck to the head and the leaf bases with a TRS content of 16.1% and 13.1%, respectively. The highest TRS concentration (16-28%) is in the agave head which is used for tequila production. Theleaves are 90-120 cm longand 8-12 cmwide andcontain fiberbundles that are 23-52cm long and 0.6-13mm wide. The ultimate fiber length is approximately 1.6 mm with an average width of25 µm. There are several types ofleaffibers that can be utilized depending on what part ofthe plant they come from and what product is desired. Agave leaffibers were pulped using a soda pulping process and the pulp was hand formed into test sheets. Test sheets made from pulped agave leaffibers had a breaking length comparable to paper made from both pine and eucalyptus fibers, but the tear index and burst index were lower than the other two papers.

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Iiiiguez-Covarrubias, G., F'ranco-G6mez, Ma, de J. and AndradeMaldonado, Gpe. del R. 1994. Biodegradation of swine waste by house fly larvae and evaluation of their protein quality in rats. J.

This work presents the results that were obtained in a commercial composting plant where food (149,690 kg) and yard wastes (144,520 kg) were used as raw materials for its stabilization under the aerated static pile (ASP) method as an alternative to the mechanically mixed windrow method to solve problems of flies and odor nuisance complaints. In a pile of approximately 498 m 3 , the change in temperature was the main parameter that was evaluated during 49 days of positive forced aeration. Subsequently, a part of the material of the ASP (62 m 3 ) was subjected to a curing period for 44 days recording changes in temperature and humidity. The results of carbon dioxide and volatile ammonia emissions analyses (NH 3 ) and of a bioassay to screen for the presence of phytotoxic conditions showed a very mature compost with an emergence > 90% and a seedling vigor > 95%.