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SUMMARYSpecific soil fertility and water retention constraints limit increased crop production in the subsistence-oriented farming systems of Burkina Faso. Previous attempts to introduce apparently promising technologies based on research that had not directly involved the fanner and that had not benefited from farmer-feedback have been largely unsuccessful. Active farmer involvement can help to identify relevant constraints to production and to identify and modify technologies to make them viable. Formal and informal farmer surveys and farmer participation in field experiments have led to the development of potentially useful cropping practices involving the complementary use of mechanical tied ridge and fertilizer-based technology.

The comment by Griffith and Meilke (GM) on the paper by Furtan, Nagy, and Storey (FNS) relates to (a) the lack of an endogenous soybean sector and (b) the single period nature of the FNS model. The GM model is a large econometric model of both the rapeseed and soybean sectors in six regions. The FNS model is a spatial-equilibrium quadratic-programming model of four regions and three commodities: rapeseed, rapeseed oil, and rapeseed meal. The conclusions drawn from the two models are somewhat different and are not surprisingly so as the models used are based on different assumptions. It is the exogenous nature of the soybean, soybean oil and meal sector that makes the GM model different from the FNS model. This however, is not likely the reason for the different conclusions found between GM and FNS on the removal of the Japanese tariff on imported rapeseed oil. There are two key assumptions that are different in the GM and FNS model. First, GM allow for the EC to export rapeseed into the Japanese market, whereas FNS considered the EC as an import region only. Second, the conversion of rapeseed into rapeseed oil and meal is a fixed parameter in the FNS model, while it is stochastic in the GM model. It is these assumptions that explain the different conclusions found. The FNS model uses fixed input-output coefficients for converting rapeseed into oil and meal. The Canadian plants are newer and supposedly more efficient than the Japanese plants, which gives the Canadians a comparative advantage. Thus, when all market restrictions are removed, the crushing of rapeseed moves to Canada because of the comparative advantage. The GM model uses a somewhat different procedure to estimate the supply of oil and meal, and thus they get different answers-given in the first period after the tariff is removed. The GM model is a potential improvement over the FNS model in that it endogenizes the EC market. GM found that after the Japanese rapeseed oil tariff was removed, imports of rape oil into Japan increased, not from Canada as found by FNS, but from the EC. This GM claim is the major difference in the conclusions of the two studies, and they attribute this to the fact that the GM model

The sizes of stomach compartments relative to total body weight and carcass weight were compared among roe (Capreolus capreolus), red (Cervus elaphus), and fallow deer (Cervus dama) collected in Hungary. The relative rumen-reticulum tissue weight as a percentage of body weight was similar for all three species. As the body size of the species increased, the relative weight of omasal tissue increased, and abomasum tissue decreased. J. WILDL. MANAGE. 39(3):621-624 Capacities of the different stomach compartments of the digestive tract have important implications in the nutrition of ruminant animals. The rumen capacity in relation to body weight influences the retention time of food in the rumen. Animals with a smaller rumen must have a higher turnover rate to secure their nutrient needs, whereas animals with a large rumen can retain ingesta for a longer time and consequently digest more fiber (Hungate 1966: 414). The food habits of ruminant animals are influenced to some degree by rumen capacity. Animals with a small rumen must select forage lower in fiber and higher in digestibility than animals with a large rumen in order to satisfy energy needs. The relationships of rumen contents weight and rumen volume to total body weight have been reported for sheep by Purser and Moir (1966), for mule deer (Odocoileus hemionus) by Short et al. (1965), and for white-tailed deer (0. virginianus) by Short et al. (1969). The purpose of this paper is to report the size of the various organs of the digestive tract in relation to animal weight for three species of wild European ruminants: roe, fallow, and red deer. This research was made possible through a cooperative agreement between the Hungarian Academy of Sciences and the U.S. National Academy of Sciences. Thanks are extended for the cooperation, helpful suggestions, and actual work contributed by L. Bencze, A. Bleier, K. Boroczky, T. Fodor, J. Hopp, G. Nagy, L. Sugar, S. Toth, and many other Hungarian game managers who helped throughout the study. Special thanks are due to the two daughters of the senior author who helped prepare the materials for study.