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| Johnson, D. Gale. |
| The increase in world grain production in the past half-century was unparalleled in the history of the world. In that same period, the absolute increase in the world's population exceeded that of all previous history--it more than doubled. The supply of grain more than kept up with the rapid growth of demand--the per capita supply of calories in developing countries increased by 27 percent between the early 1960s and the early 1990s while the real price of grain in international markets declined by at least a third. The expansion of grain production since 1960 has been largely achieved through higher yields--the substitution of other inputs for land. Consequently the roles of land and the diminishing returns to land have been significantly attenuated by... |
| Tipo: Working or Discussion Paper |
Palavras-chave: World grain; Comparative advantage; Diminishing returns; Price variability; International Relations/Trade; F1. |
| Ano: 1997 |
URL: http://purl.umn.edu/29177 |
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| Almeida,TW; Silva,AL; Saccomani,AP; Muñoz,JA; Silva,RT; Franca,NV; Faria,DE; Faria Filho,DE. |
| ABSTRACT Feed formulation using linear programming consists of determining the mixture of feedstuffs required to meet pre-established animal nutritional requirements at the lowest cost. On the other hand, with the use of non-linear programming, it is possible to define nutritional requirements at the time of formulation, aiming at maximum profit. The objective of the present study was to compare feeds formulated using linear and non-linear programming in terms of live performance and internal and external egg quality of commercial laying hens. A total of 288 Hisex® White laying hens, 1.540 ± 0.128 g body weight, were evaluated from 33 to 45 weeks of age. Hens were distributed in a completely randomized block design, including six treatments with six... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Diminishing returns; Linear programming; Mathematical modeling; Meta-analysis; Profit.. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2019000300313 |
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