Cows are supposed to be eco-friendly

"the course of animal test! Unauthorized access prohibited!", warns a note on the door of the research stall of the AgroVet-Strickhof in Lindau, ZH. Behind the thick, shiny steel doors Finn, Franz, Fritz and Bruno are on a bit of straw in high-tech chambers with artificial light and a permanent supply of fresh air. Round-the-clock, the four young cattle are monitored with video cameras, and their respiratory gases as well as methane from the digestive tract with Sensors measured. For 48 hours, without interruption.

The Muni have their temporary accommodations before, during training exercises already learned to know and seem to care only for something: for lining. Three of them receive, in addition to the Grass - and corn silage is a feed that contains either pumpkin seed cake, and the cyanobacteria Spirulina or beans as a protein carrier.

"you have to immediately eat started and to keep trotting out," says Magdalena Kurrig, a PhD student at the Institute of agricultural Sciences at ETH Zurich. Two cattle had already in the first half hour. Another positive sign that things are going well.

a screen from the control room, the cattle can see their neighbors through large Windows on the sides observed Kurrig. The agricultural scientist is researching possible feeding strategies for eco-friendly and efficient generation of high-quality beef.

"We're looking at this trying to find a replacement for soy in order to be less dependent," says Michael Kreuzer, a Professor of animal nutrition at the ETH. Because of the worldwide increasing consumption of animal products increase the demand for high-protein animal feed, and in the limited areas under cultivation, this increasing the competition with food production.

methane from the rumen

In contrast to chickens, are ruminants, however, fiber-rich, to utilize edible biomass and to Refine into high-quality animal products. In addition, cattle and sheep graze in hilly and mountainous regions, the country can economically be hardly used otherwise. The disadvantage is that It is the greenhouse gas methane, which is 25 times the climate is effective as carbon dioxide is produced during the digestion.

The Gas forms in the rumen. Bacteria and scourge little animals on the columns of the fibers of the grasses and produce hydrogen. To dispose of "this will convert micro-organisms it into methane," says Kreuzer, whose Team also tests feed additives to reduce the emissions of methane. This was not simply because the digestive system in ruminants is very complex, and the digestibility of the forage and the productivity of the animals should not be adversely affected.

image to enlarge

the World comes, according to the world food organization FAO, roughly one-seventh of all greenhouse gases produced by farm animals from the agriculture , especially of cattle. "In the case of the calculation of the deforested rainforest that has been taken into account in the Amazon region, for example, for soybean cultivation, or for the recovery of grazing areas," says Daniel Bretscher of the research Institute agroscope, the each year the greenhouse gas inventory of Swiss agriculture.

Up to the year 2050 are expected to be the agricultural greenhouse gas emissions compared to 1990 by at least a third lowered. "The animal husbandry accounts for about 85 percent of them," says Bretscher. In a comparison of various farm animals dairy cows are the largest issuers. Therefore, it is necessary to take various measures for a reduction in consideration – for example, in animal breeding through selection of cows that produce less methane than others. Also effective in an extended lifespan of the animals, or feed additives such as tannins or flax seed.

In the Swiss agriculture is already in use is the high-quality, methane-inflammatory Oilseed flax seed, which has at the same time also has a positive effect on the fatty acid composition in the milk. "But this can only be a limited framework to implement", says Kreuzer. Due to the low yields per Hectare, you would have to replant otherwise, almost half the agricultural area of Switzerland with Flax, if you wanted to import everything. Add to this that from as yet unexplained reasons, the effectiveness against the methane emissions fluctuate greatly. to explore

in order To further the possibilities for more environmentally-friendly cows, examined leaves the group of cruisers to the effect of chopped Hazelnuts, which contain efficient tannins. The particular Suitability of the hazel, has been discovered in the laboratory using rumen juice, and then with the measurements on the animal in the respiration chamber confirmed. The Team at the ETH in the last year, reports in the journal "Scientific Reports", that in the case of sheep, the daily emissions of methane by up to 30 percent to reduce. The nitrogen excretion with urine decreased thanks to the hazel-leaves-Pellets of up to two-thirds. This is likely to lead to out of the Manure less the air pollutant ammonia.

to get A urinal for cows

the ammonia is a Problem in other ways in the handle, has been developed by the Dutchman Henk Hanskamp of a cow-the toilet, which should come in well over a year on the market. It is a sort urinal for cattle, the fields, the urine separately. For this purpose, a movable bowl stimulates the Central band, the nerve between the base of the tail and udder. Due to the induced voiding reflex, the cow immediately the water that can be collected. The Trick also veterinarians turn to when they need urine samples of cattle.

A cow leaves, on average, up to 30Liter the urine per day. Cows eat young, succulent Grass, especially a lot of urinary nitrogen. Usually, the urine is mixed in the stable relatively quickly with Extension, so that due to an enzymatic reaction resulting in the pungent-smelling Gas, ammonia developed. Later, the liquid and solid excrements of the animals are scattered on the field and in the pasture, the manure is applied in addition of the potent greenhouse gas nitrous oxide.

in the World, a seventh of all greenhouse gases produced by farm animals. Photo: Keystone

"A separation of urine and feces in the barn is in principle a good approach," says the ammonia-expert Christof Ammann of Agroscope, his colleagues in the attempt to stall Tänikon are also looking for solutions for ammonia reductions, for example through the use of urine collection trays. Mainly because of the organic farmer uses no synthetic fertilizers and manure needs, he would have to make a large part of the collected urine to the fields, but may then be more precisely metered.

"to Me, but it is still not clear whether you can train at the Dutch model, in fact, all the cows so that they leave voluntarily through targeted food rations in a fenced area to do their business," says Ammann. The development of methods for emission reduction is important, because currently, 90 percent of ammonia emissions come from agriculture.

Less meat

"The farmers are often in a vicious circle," says the ETH-Zurich researchers cruisers. Because food won't get paid what you are worth. If the price drops, they produce often more, to be able to have the income. This leads to the fact that, despite the rising power of much less animals. to achieve

"the greenhouse gas reduction target of at least a third, it would take a fundamental change in the agricultural structures, as well as our food consumption to more plant-based foods," says Bretscher agroscope. This is the most sustainable and most efficient.

The young Muni are now back in their group in the barn. "Happy and cheerful", says the ETH researcher Kurrig that all four know each other very well. Every day she looks up to Finn, Fritz, Franz, and Bruno, to which it has established from the beginning of a relationship. But in principle, they, too, are ordinary calves of the stall, the life of only one to one and a half years – fed with special feed.

(editing Tamedia)

Created: 12.02.2019, 18:43 PM