Cattle feeding

From Wikipedia, the free encyclopedia

Cow eating grass
Cow eating grass

Different cattle feeding production systems have separate advantages and disadvantages. Most cows have a diet that is composed of at least some forage (grass, legumes, or silage). In fact most beef cattle are raised on pasture from birth in the spring until fall (7 to 9 months). Then for pasture-fed animals, grass is the forage that composes all or at least the great majority of their diet. Cattle fattened in feedlots are fed small amounts of hay or straw supplemented with grain, soy and other ingredients in order to increase the energy density of the diet. The debate is whether cattle should be raised on diets primarily composed of pasture (grass) or a concentrated diet of grain, soy and other supplements. The issue is often complicated by the political interests and confusion between labels such as "free range", "organic", or "natural". Cattle raised on a primarily forage diet are termed grass-fed or pasture-raised; for example meat or milk may be called grass-fed beef or pasture-raised dairy. However, the term "pasture-raised" can lead to confusion with the term "free range", which does not describe exactly what the animals eat.

In the United States, cattle in concentrated animal feeding operations (CAFOs) are typically fed corn, soy and other types of feed that can include "by-product feedstuff". As a high-starch, high-energy food, corn decreases the time to fatten cattle and increases yield from dairy cattle. These cattle are called corn-fed or grain-fed. In the United States, most grass fed cattle are raised for beef production. Dairy cattle are usually supplemented with grain to increase the efficiency of production and reduce the area needed to support the energy requirements of the herd. A growing number of health and environmental proponents in the United States such as the Union of Concerned Scientists advocate raising cattle on pasture and other forage. Some claim that the adoption of a grass-fed beef production system would dramatically increase the amount of land needed to raise beef.

Grass-fed cattle at a Walcha, NSW sale.
Grass-fed cattle at a Walcha, NSW sale.

Contents

[edit] Health and Nutrition

[edit] Fats

Most grass-fed cattle are leaner than feedlot beef, lacking marbling, which lowers the fat content and caloric level of the meat. Meat from grass-fed cattle also have higher levels of Conjugated Linoleic Acid (CLA) and the Omega-3 fatty acids ALA, EPA, and DHA.[1] While the research on CLA is unclear with regard to humans, it has shown many positive effects in animals in the areas of heart disease, cancer, and the immune system.

[edit] Antibiotics

Less intense population density is sometimes cited as a reason for decreased antibiotic usage in grass-fed animals. However, bovine respiratory disease, the most common cause for antibiotic therapy has risk factors common in both forms of production (feedlot and pasture finished).[2]

In dairy herds, grazed cattle typically have a reduced need for antibiotics relative to grain-fed cattle, simply because the grazed herds are less productive. A high-energy feedlot diet greatly increases milk output, measured in pounds or kilograms of milk per head per day, but it also increases animal physiological stress, which in turn causes a higher incidence of mastitis and other infectious disease, which frequently requires antibiotic therapy.

Antibiotics are routinely added to grain feed as a growth stimulant. Cattle consume 70% of the antiobiotics in the United States.[3] This practice widely contributes to the rise of antibiotic-resistant bacteria, including MRSA.[4] Where MRSA once was contained to rare cases in hospitals, it is now becoming community-acquired due to its emergence in the feedlot. This poses a major public health threat.

[edit] Disease

[edit] E. coli

Escherichia coli , although considered normal flora for many mammals including humans, has many strains. Strain E. coli 0157:H7 is associated with human illness and death as a foodborne illness. A study by Cornell University has determined that grass-fed animals have far fewer E. coli (approx. 300 times less) than their grain fed counterparts. Also in the same study, the amount of E. coli they do have is much less likely to survive our first line defense against infection, stomach acid. This is because feeding cattle grain makes their digestive tract abnormally acid, and over time, the 'bad E. coli' has become acid-resistant . So if we ingest them in our food a large number of them can potentially survive our stomach acid and go on to grow in our gut, causing an infection. [5] Since the Cornell study in 1998 many groups have tried to contest the results. A study by the USDA Meat and Animal Research Center in Lincoln Nebraska(2000) has confirmed the Cornell research.[6]

[edit] Mad Cow Disease

Meat and bone meal can be a risk factor for bovine spongiform encephalopathy (BSE), when healthy animals consume tainted tissues from infected animals. People concerned about Creutzfeld-Jacob disease (CJD), which is also a spongiform encephalopathy, may favor grass-fed cattle for this reason. In the United States, this risk is relatively low as feeding of protein sources from any ruminant to another ruminant has been banned since 1997.[7] The problem becomes more complicated as other feed stuffs containing animal by-products are still allowed to be fed to other non-ruminants (chickens, cats, dogs, horses, pigs, etc.). Therefore, at a feed mill mixing feed for pigs, for instance, there is still the possibility of cross-contamination of feed going to cattle. Since only a tiny amount of the contaminating prion begins the cascading brain infection, any amount of mixed feed could cause many animals to become infected. This was the only traceable link among the cattle with BSE in Canada that led to the recent US embargo of Canadian beef. BSE does not occur in Australia.

Soybean meal is cheap and plentiful in the United States. As a result, the use of animal byproduct feeds was never common, as it was in Europe. However, U.S. regulations only partially prohibit the use of animal byproducts in feed. In 1997, regulations prohibited the feeding of mammalian byproducts to ruminants such as cows and goats. However, the byproducts of ruminants can still be legally fed to pets or other livestock such as pigs and poultry such as chickens. In addition, it is legal for ruminants to be fed byproducts from some of these animals. [3] A proposal to end the use of cow blood, restaurant scraps, and poultry litter (fecal matter, feathers)[8] in January 2004 has yet to be implemented [4], despite the efforts of some advocates of such a policy, who cite the fact that cows are herbivores, and that blood and fecal matter could potentially carry BSE.

In February 2001, the USGAO reported that the FDA, which is responsible for regulating feed, had not adequately policed the various bans. [5] Compliance with the regulations was shown to be extremely poor before the discovery of the Washington cow, but industry representatives report that compliance is now 100%. Even so, critics call the partial prohibitions insufficient. Indeed, US meat producer Creekstone Farms alleges that the USDA is preventing BSE testing from being conducted [6].

[edit] Campylobacter

Campylobacter, a bacterium that can cause another foodborne illness resulting in nausea, vomiting, fever, abdominal pain, headache and muscle pain was found by Australian researchers to be carried by 58% of cattle raised in feed lots versus only 2% of pasture raised and finished cattle.[9]

[edit] Environmental concerns

In arid climates such as the Southwestern United States, livestock grazing has severely degraded riparian areas, the wetland environment adjacent to rivers or streams. People have long recognized that riparian zones and rivers are the lifeblood of the western landscape, being more productive and home to more plants and animals than any other type of habitat. Scientists refer to riparian zones as hotspots of biodiversity, a characterization that is particularly apparent in arid and semiarid environments, where such zones may be the only tree-dominated ecosystems in the landscape. The presence of water, increased productivity, favorable microclimate, and periodic flood events combine to create a disproportionately higher biological diversity than that of the surrounding uplands.[10]

[edit] Taste

The cow's diet affects the flavor of the resultant meat and milk. A 2003 Colorado State University study found that 80% of consumers in the Denver-Colorado area preferred the taste of United States corn-fed beef to Australian grass-fed beef, and negligible difference in taste preference compared to Canadian barley-fed beef.[11]

Kobe beef herds, which are prized for their marbling, are traditionally fed beer to stimulate their appetite during hot weather, and maximize fat content, producing a very rich flavor.

Grass-fed beef is not standardized. Most is leaner than conventional feedlot beef, but some is equally marbled due to carefully managed grazing, excellent pastures, and improved genetics. Another technique for producing well-marbled grass-fed cattle is to keep the animals on pasture for two years or more. (Feedlot cattle can be ready for market in as few as 14 months due to the high-energy feed and the use of growth-promoting hormones and antibiotics[citation needed].) Most pasture-based ranchers dry-age the beef for 7-21 days, enhancing the flavor and tenderness of the meat. Currently, feedlot cattle are taken to slaughter at 14-18 months and cut, boxed and shipped in a matter of hours.[citation needed]

[edit] USDA label

The United States Department of Agriculture's Agricultural Marketing Service (AMS) released a revised proposal for a grass fed meat label claim for its process-verified labeling program in May 2006. [12] The Union of Concerned Scientists, which in general supports the labeling proposal, claims that the current revision, which contains the clause "consumption of ... grain in the immature stage is acceptable", allows for "feed harvesting or stockpiling methods that might include significant amounts of grain" because the term "immature" is not clearly defined. [13]

On October 15, 2007 the USDA established a standard definition for the "grass fed" claim which requires continuous access to pasture and prevents animals from being fed grain or grain-based products.[14]

[edit] See also

[edit] References

  1. ^ http://www.ucsusa.org/assets/documents/food_and_environment/greener-pastures.pdf, p. 58
  2. ^ The medicine and epidemiology of bovine respiratory disease in feedlots. Australian veterinary journal Cusack 2003 vol:81 iss:8 pg:480-487 [1]
  3. ^ Mellon, M et al. (2001) Hogging It!: Estimates of Antimicrobial Abuse in Livestock, 1st ed. Cambridge, MA: Union of Concerned Scientists.
  4. ^ Our Decrepit Food Factories. New York Times Pollan December 16, 2007 [2]
  5. ^ Russel, J.B., F. Diez-Gonzalez, and G. N. Jarvis, "Potential Effect of Cattle Diets on Transmission of Pathogenic Eschericia Coli to Humans" Microbes Infect 2, No.1 (2000) :45-53
  6. ^ Tony Scott Klopfenstein, T., et al. 2000 Nebraska Beef Report,:39-41 PFD at eatwild.com
  7. ^ 2004.01.26: Expanded "Mad Cow" Safeguards Announced To Strengthen Existing Firewalls Against BSE Transmission
  8. ^ The term "chicken litter" also includes spilled chicken feed as well as fecal matter and feathers. It is still legal in the United States to use ruminant protein to feed chickens. Thus, ruminant protein can get into the food chain of cattle in this round about way.
  9. ^ Bailey,G. D.,B. A. Vanselow,et al.(2003). "A study of the Food Borne Pathogens: Campylobacter, Listeria and Yersinia, in faeces from slaughter-age cattle and sheep in Australia." Commun Dis Intell 27(2):249-57
  10. ^ Kauffman,, J. Boone, Ph.D.. Lifeblood of the West. Retrieved on 2007-08-08.
  11. ^ Wendy Umberger, Dawn Thilmany and Amanda Ziehl, Department of Agricultural & Resource Economicse, Colorado State University. 2003. "Consumer Tastes & Preferences: What Research Indicates". http://dare.agsci.colostate.edu/aft/curriculum/3.1_cons_prefs.ppt
  12. ^ Agricultural Marketing Service, USDA (May 12, 2006). United States Standard for Livestock and Meat Marketing Claim, Grass (Forage) Fed Claim. The Federal Register. Retrieved on 2006-08-02.
  13. ^ Clancy, Kate (presumably 2006-08-02). What's At Stake?. Union of Concerned Scientists. Retrieved on 2006-08-02.
  14. ^ 178-07