Producción sustentable. Calidad y leche orgánica. Luis García y Luis Brunett (coord). Universidad Autónoma Metropolitana y Universidad Autónoma Del Estado De México. México, 2009

Abstract

Until virtually the ninth decade of the 20th
Century, the main preoccupation of different
agents related to the food sector was to
provide enough food for a growing world population.
To achieve this objective, on one hand, marginal
areas and others where there was previously forest
and rainforest were incorporated into cultivation
and livestock production, and, on the other hand,
increasing the amount of product per unit through
technological development was sought.
The latter was achieved through intensification
of production systems and the use of agro-chemicals
(fertilizers, herbicides and pesticides, primarily)
and improved seeds in the case of agriculture and,
in general terms, genetic improvement, changes in
animal nutrition and development of new antibiotics
for veterinary use in the case of livestock production.
An example of the increase in productivity, for the
case of milk production, is the one that García points
out in Chapter 1 of the book reviewed here; the
U.S.A., between 1950 and 2000, went from having an
approximate stock of 22 million heads that produced
52 000 million tons of milk per year to 9.2 million
heads from which 75 000 million tons of milk were
obtained in the year 2000. From the optic of animal
unit, in 1940 an average cow in the U.S.A. produced
2086 kilograms of milk and by the year 2007, the
average yield per animal was already greater than
9000 kilograms.