RE-THINKING DAIRY COW FEEDING IN LIGHT OF FOOD SECURITY

摘要

The competition for arable land to grow food, feeds, and biomass for fuel production (mostly from grain) has reached an all-time peak. Recent publications suggest that crop production would have to about double to keep up with the estimated demands resulting from population growth, dietary changes (especially meat consumption), and increasing bioenergy use, unless there are dramatic changes in agricultural consumption patterns (Foley et al., 2011). We have seen fundamental changes in the feeding of cattle over the last 50 years. Previously, cattle were fed almost exclusively feeds that were unsuitable for human consumption. The availability of cheap fossil energy for the production of mineral fertilizers and pesticides, the cultivation of land and long-distance shipping of crops has made it possible and even profitable to feed even ruminants enormous amounts of grain and pulses. As a result, highly intensive animal production systems have emerged. Grain and pulses, however, are potentially edible for humans. This means that these supposedly highly efficient animal production systems contribute to the increasing competition for arable land for crops. In dairy farming, to attain lactation of 10,000 kg/year and beyond, the amount of concentrates in the ration has to be maximized. Most of these concentrates are grain and pulse products. This kind of dairy cow feeding is not only contradictory to the evolutionary adaptation of cattle, which allows these animals to be able to digest fibrous plant substrate, but has also resulted in an increasingly unfavorable food balance (i.e. animal-derived food per unit of feed input potentially edible to humans). The potential of ruminants to efficiently convert forages from grasslands, pastures, and fiber-rich by-products from the processing of plant-derived foods into milk and meat will soon be of great significance, because arable land is becoming scarce and the demand for human food is growing. The use of highly productive arable land to produce animal feed results in a net loss for the potential global food supply.