school energy&environment

Water employed for breeding

By 2025 more than 60% of the world population will live in water-stressed conditions.
The zootechnical sector substantially contributes to water consumption and its pollution both directly and indirectly: 8% of world hydric consumption concerns the zootechnical sector that employs water mainly to irrigate fields farmed to produce fodder.
Just think that 15 thousand litres of water are required to produce 1 k of beef!
To produce 1 kg of chicken we need 3,500 litres of water whereas the production of cereals requires less water, that is 3,400 litres for rice, 2 thousand for soy, 1,400 for wheat, 900 for corn and 500 for potatoes.
Animal production represents, moreover, one of the major sources of pollution of waters that entails: eutrophication that alters the balance of acquatic ecosystems; pollution of aquifers by nitrogen and phosphorus, organic and antibiotic micro-polluting agents with consequent risks for human and environmental health.
Eutrophication is generated by zootechnical waste, chemical pollution of aquifers is caused by excessive use of fertilizers and pesticides in crops used to feed cattle.
Liquid and semi-liquid cattle shedding contain levels of phosphorus and nitrogen above the average because animals can absorb only a small part of the amount of these substances contained in their fodder, the rest is released through their faeces.
When animal manure filters in water flows, nitrogen and phosphorus contained in it in excess, alter water quality and damage acquatic ecosystems in damp areas.
Just think that up to 70-80% of nitrogen provided to bovines, pigs and laying hens through nutrition and 60% of nitrogen given to broilers is eliminated through faeces and urine and ends in water flows and underground aquifers.
Think that an adult pig produces 4 times as many faeces as a human being and that in an industrial plant can live about 50 thousand pigs with a very high production of daily shedding!
When agriculture and breeding are balanced (as occurred before intensive breeding and partly still takes place), a cycle is created in which agricultural production is limited by the amount of manure needed to fertilize fields and manure in turn depends on how much fodder is available to feed animals.
The coming of chemical fertilizers has allowed to free agriculture from breeding and the rhythms of industrial production create so much manure that farmed fields aren’t sufficient to absorb it all: for this reason, shedding in excess must be disposed as waste.
Finally, we shouldn’t forget that zootechnology prevents water from playing its crucial role of penetrating into land and reuniting with underground waters (that are drawn by humans) as this activity compacts soil, reduces infiltration capacity, dries damp areas and deforests to introduce crops.