Economies of scale in the production of swine manure Economias de escala na produção de dejetos de suínos

Manure production on grower/finisher swine operations in the United States was examined using data from 184 grower/finisher swine operations that participated in the United States National Animal Health Monitoring System's 1995 National Swine Study. Two methods were used: one, assuming that pigs produced 8.4% of their body weight in manure each day; another using the difference between feed fed and weight gained as a proxy variable to study manure production. Using this latter approach, a production function was developed. The function exhibited diminishing returns to scale when food waste was not fed to pigs, but constant returns to scale when food waste was included in their diets. The difference between feed fed and weight gained was lower on operations that restricted entry to employees only.<br>A produção de dejetos em granjas de crescimento e terminação de suínos nos Estados Unidos foi avaliada utilizando dados de 184 granjas participantes de um estudo nacional de 1995 do "United States National Animal Health Monitoring System". Dois métodos foram usados: um considerando que suínos produzem 8,4% do seu peso corporal de dejetos por dia e o outro usando a diferença entre o alimento ingerido e o ganho de peso como um indicador para o estudo da produção de esterco. Através desse último procedimento, desenvolveu-se uma função de produção

Comparison of the reactions K±p→Q±p at incident momentum 8.25 GeV/c

In this paper a comparison of the general features of the reactions K±p→Q±p (1) at incident momentum 8.25 GeV/c is presented. The relevant data derive from events yielding four-constraint fits to the reactions K±p→K±π+π-p in exposures of the CERN 2m HBC to RF-separated K+ and K- beams. The (Kππ) effective mass distributions, production angular distributions in the Q region (1.2≤M(Kππ)≤1.5 GeV) and corresponding decay angular distributions are exhibited, and background effects due to N* and Δ production are systematically studied. In particular, it is found that the distributions dσ/dt′ and dσ/dt for reactions (1) are adequately described by exponential functions over the interval 0.05-0.35 GeV2, and exhibit a cross-over effect for momentum transfer squared -0.1 GeV2. For both reactions a flattening of dσ/dt′ for t′ < 0.05 GeV2 is observed. By studying the Chew-Low plots and the effects of the different cuts it was found that this flattening cannot be attributed to amplitudes with net s-channel helicity flip different from zero, at least at these energies. © 1976.SCOPUS: ar.jinfo:eu-repo/semantics/publishe