Why do cattle guards work


Typical design of a cattle fence in the western United States
Cattle bars on a railroad in northeast New Mexico

Close up of the galong cattle fence

A Cattle bars - also known as Share grid in Australia; Cattle guard in American English; Vehicle passport, Texas Gate, or Stock gap in the southeastern United States;[1] and a Cattle stop in New Zealand English - is a type of obstacle used to prevent farm animals such as sheep, bees, pigs, horses, or mules from passing a road or railroad that penetrates the fence around an enclosed piece of land or a border. It consists of a recess in the street covered by a transverse grating of bars or pipes, usually made of metal, firmly attached to the ground on either side of the recess so that the gaps between them are large enough for your feet an animal can enter, but narrow enough so as not to obstruct a wheeled vehicle or a human foot. This provides an effective barrier for animals without hindering wheeled vehicles as the animals are reluctant to walk on the bars.


The modern cattle grille for roads used by automobiles is believed to have been independently invented several times between 1905 and 1915 in the Great Plains of the United States. Before that time, a similar device was in use for railways at least as early as 1836; A stone post was used in Great Britain as early as pre-Roman times.[2] An article in Texas monthly claims that the "first recorded non-rail cattle fence use" occurred in 1881 in Archer County, Texas, on the stagecoach route between Archer City and Henrietta.[3]

Cattle bars are typically installed on roads where they cross a fenceline, often on a border between public and private land. They are an alternative to erecting gates that would have to be opened and closed when overtaking a vehicle. They are common where roads cross open moorland, pasture land, or shared land by grazing, but separating fields is impractical. Cattle bars are also used when railroads that are otherwise unfenced cross a fenceline. Cattle bars are common around the world and widespread in countries such as Australia, the Scottish Highlands or the national parks of England and Wales. They are also common in the western United States and Canada. In the United States, they are widely used on Bureau of Land Management and Forest Service properties, as well as paved roads and interstate highway system entrances and exits in rural areas.

Variations [edit]

Almost all cattle bars are built around a bar. Most include a pit dug along a fence line, a base on which the trellis can rest, and wings to connect the guard to the fence. Since many guards were or are homemade and to some extent idiosyncratic, there are a variety of designs. The designs may vary depending on local conditions. The materials used to build a cattle fence depend in part on the weight it must support.[4]

An examination of the bars of traditional cattle grids in the Flint Hills of Kansas found that 80 percent was pipe, while smaller percent was railroad tracks, I-beams, planks, and other materials. The size of the bars varied from 1.5 to 6.5 inches (3.8 to 16.5 cm); The distances between the bars varied from 134 up to 4.4 to 20.3 cm; The number of bars per grid varied from 4 to 22. The length of the grid differed from 734 to 30 feet (2.4 to 9.1 m) and 40 to 120 inches (100 to 300 cm) in width, while the pits under the grids were 0 to 98 inches (0 to 249 cm) deep.[4]

Cattle bars, as they are called in the UK, Ireland and South Africa, are known by a variety of other names in other parts of the world. In the United States, they are cattle watchers. Mata Burro (“Donkey Killer”) is the preferred name in Brazil and Venezuela Guarda Ganado (“Cattle keepers”) they are called in Argentina. Alternatives in the United States include car intersection, car gate, cord gate, gap, cattle pass, run over, and many others. Canadians use the Pit Gate, Vehicle Pass, and Texas Gate, as well as the cattle guard, which in Canada mostly refers to guards on railroad lines.[5]


Since the 1940s there have been cattle bars made entirely or predominantly of concrete.[6] Individual ranchers often built their own, sometimes according to plans developed in the 1940s.[6] In the 21st century, a number of wood and concrete home improvement plans are available on the Missouri Alternatives Center website at the University of Missouri, USA.[7] Commercial precast concrete elements are also available. The Virginia-based Smith Cattleguard Company sold more than 15,000 units between 1960 and 1980.[6] Manufacturers also make commercial polyethylene molds with reinforcing bars. Placed in, or on the ground and filled, a finished livestock mesh with 28 MPa (4,000 pounds per square inch) reinforced concrete 5816 mm glass fiber reinforcement bars (GRP) can accommodate vehicle loads of up to 15 t per axle.[8]

Steel [edit]

University Lands, which manages land and mineral interests for a foundation that supports the University of Texas and Texas A&M University systems, publishes do-it-yourself manuals for three sizes of cattle grids with grids made of steel tubing. The manuals contain schematic drawings and accompanying instructions.[9] Commercial steel guards are also available from several companies.[10]

Virtual [edit]

Painted lines on the road can serve as sceuomorphs of cattle bars. The light-dark pattern of the lines on the sidewalk resembles the animals in a real cattle rail and believes that they are unable to cross. Using a virtual cattle fence is initially cheaper than a real cattle fence.[11] However, the cost of periodic repainting can potentially exceed the initial cost of a well-built metal guard.[12] A particular advantage of painted protective devices is that they are easy to drive over. In the United States, most are on federal or federal highways rather than private roads.[12]

Why they work is unclear, but it is most likely related to their visual system. Experts say that "a cow's perception of depth is such that it makes little or no difference between painted stripes on a dark background and bars over a pit."[13] Cattle may adopt the behavior of avoiding bars over pits either from individual experience or by imitating other cattle. However, it has been reported that painted grids with semi-wild cattle work without prior exposure to virtual grids.[13]

Cattle can sometimes defeat virtual guards. A rancher in Queensland, Australia told a reporter that after jumping over a painted grate, some of the old cops lost their fear of walking over it.[14] This is common; If one member of a herd finds it safe to step on the lines, others will follow suit. Other incentives that encourage cattle to test a virtual security guard include placing feed on the opposite side or using strong driving pressure to lead panicked cattle over a virtual grid.[11]

Electrical [edit]

Electric cattle bars use electricity to keep animals from crossing the fence line. There are different designs. High-strength wire is used that runs across the roadway, about 8 to 10 cm above the ground, and is attached to a power source on one side.[15] The main advantage is the cost and the ease of installation. Disadvantages include the need to spray the vegetation with herbicides to prevent weeds from shorting out the trellis when there is no barrier between the wires and the ground. In addition, some low-moving vehicles can catch and tear the wires out.[15]

James Hoy in The cattle guard discusses four types of electrical protection devices. One patented in Illinois in 1955 and another invented in New Zealand in 1979 is similar. each resembles "something like the frame of an old-fashioned metal bed" plugged into a battery or a powerful fence charger. They are easy to navigate but can pose a hazard to children or animals that get stuck in the station.[16] Another type was patented in two versions by an inventor from Oregon in 1956-57. It consisted of 20 live synthetic rubber strips mounted on a wooden frame. The invention was found to be highly effective in deterring all animals, including dogs, and was maintenance-free, easy to run over, and safe. However, the company that acquired the manufacturing rights ceased production in 1960.[16] A fourth type, homemade, consists of two sections of woven wire or steel plate laid on a concrete slab and separated on either side of a fenceline. The wire sections are then connected to an electric fence or a separate charger that is either conventional or solar powered.[16]

Effectiveness on Wildlife [edit]

A cow successfully crosses a cattle fence

While cattle bars are most effective on cattle, they can be used to keep deer and elk out.[17][18][19] Research has shown that deer can cross cattle bars with flat bars as opposed to rounded bars.[20] Sometimes a cattle fence is doubled to keep these animals out. A cattle fence that requires a 4.3 m (14 foot) horizontal jump is considered effective when combined with a deer fence.[21] Stripes are also painted on streets as a visual deterrent to deer, as in "virtual" cattle bars.[22]

Limitations and Risks [edit]

A cattle fence and stray sheep

While these barriers are usually effective for cattle,[23] You can fail because of ingenious animals. Sheep in search of food are known to jump over bars and carefully step into rooms[24] or walk along the side of bars that are eight feet wide.[25]

Wider grids are used where wildlife is to be confined. Some animals can jump over them, and a barrier to stop deer must be at least 5 m wide.[23]Bison, and bulls in particular, can easily jump over an 8-foot barrier and are known to jump widths of up to 14 feet (4.3 m).[26][27]

In areas with heavy snowfall and long periods of no thawing, snow can collect under a grate and allow animals to walk over it.

Horses are particularly susceptible to cattle rail injuries as their single-row hooves can slip between the bars and pinch their legs in a slightly broken position.[23] The same risk exists for kangaroos in the Australian outback, with an additional risk of entrapment.[28]

Cattle bars are generally unsuitable for holding goats.[23] However, a Texas Highway Department official reported that adding three 51 cm (20 in) painted stripes - arranged in yellow, white, and yellow - on the road in front of a cattle fence prevented goats from approaching or crossing the guard .[29]

Patents and standards [edit]

The US Patent and Trademark Office (US PTO) issued a patent US Patent 1125095A on January 15, 1915 to William J. Hickey, Reno, Nevada, for a cattle fence.[30]

There is a British standard for cattle fences: BS4008: 2006.[31] The US standards are set by the American Association of State Highway and Transportation Officials (AASHTO). AASHTO provides guidelines for the load-bearing capacity of cattle bars used on public roads in the United States. All cattle grids used on public roads in the United States must be certified by a qualified engineer that the grille meets AASHTO guidelines.[32]

See also [edit]

check Cattle bars in Wiktionary, the free dictionary.

References [edit]

  1. ^Brown, Robert A (March 1960). “Deceiving cattle with color”. Popular science. 176 (3): 228. Retrieved 2010-09-21.
  2. ^Hoy, James F. (2004), “Cattle Guards”, Encyclopedia of the Great Plains, by David J. Wishart, University of Nebraska Press, p. 292, ISBN
  3. ^Webre, Rodney (May 1984). "Texas Primer: The Cattle Guard". Texas monthly. Retrieved May 25, 2016.
  4. ^ abHoy, pp. 112-116
  5. ^Hoy, pp. 117-18
  6. ^ abcHoy, James F. (1982). The cattle guard: his story and lore. Lawrence: University of Kansas Press. Pp. 145-46. ISBN.
  7. ^University of Tennessee (2014) [1968]. “Fence and Cattle Guard Plans: Cattle Guard, Wooden Frames and Concrete”. University of Missouri. Retrieved June 4, 2016.
  8. ^Hendricks, Walt. “Animal protection forms”. Cattle Guards website. Ray Allen. Retrieved November 20, 2012.
  9. ^"Best Practices: Cattle Guards & Cattle Guard Specifications". University countries. 2011. Retrieved June 13, 2016.
  10. ^“Cattle guards and drive through gates” (PDF). University of Wisconsin Extension. Archived from the original (PDF) on September 19, 2015. Retrieved June 13, 2016.
  11. ^ abSheldrake, Rupert. "Cattle Deceived by Phoney Grids". sheldrake.org. Retrieved June 3, 2016.
  12. ^ abHoy, p. 153
  13. ^ abHoy, p. 154
  14. ^“Virtual cattle bars outsmart NT cattle”. Australian Broadcasting Company. July 28, 2005. Retrieved June 17, 2010.
  15. ^ abFord, Devlon (July 23, 2013). “Electrical livestock protection saves time”. Samuel Roberts Noble Foundation. Retrieved June 3, 2016.
  16. ^ abcHoy, p. 152
  17. ^Link, Russell (Maine DFW); Beausoleil, Rick; Spencer, Rocky (Washington DFW) (2005). "Wildlife-Human Issues: Living With Wildlife: Deer". Maine Inland Fisheries and Wildlife Department (adapted from Russell Link of the Washington State Department for Fish and Wildlife Living with Wildlife in the Pacific Northwest). Retrieved May 23, 2016.
  18. ^“Wildlife Crossings”. Backpacker. 37 (5): June 40, 2008. Retrieved May 27, 2016 - via Google Books.
  19. ^Ortega-Santos, José Alfonso; Fulbright, Timothy Edward (2013). White-tailed deer habitat: ecology and management on rangelands. Texas A&M University Press. p. 147. ISBN. Retrieved December 26, 2016 - via Google Books.
  20. ^Seamans, Thomas W .; Helon, David A. (2008), RM Timm; MB Madon (Ed.), “Comparison of electrified mats and cattle guards to control access of white-tailed deer (Odocoileus virginianus) through fences”, Proc. 23. Vertebr. Pest Conf., Univ. of Calif., Davis., pp. 206-209 - via the US Department of Agriculture,
  21. ^Soderstrom, Neil (2009), Deer Resistant Landscaping: Proven Advice and Strategies for Outwitting Deer and 20 Other Annoying Mammals, Rodale, p. 50, ISBN
  22. ^"Interstate 70 ramps between rifle, Canyon Creek to be affected by the fence project". Post Independent - Citizen Telegram. Gun, Colorado: Fast communication. July 31, 2013. Archived from the original on August 15, 2013. Retrieved May 23, 2016.
  23. ^ abcdRob (July 23, 2012). “Cattle guards can be dangerous for some animals”. Barn world. Retrieved June 5, 2016.
  24. ^Marchington, James (April 17, 2013). Sheep escape. Youtube. Retrieved June 5, 2016.
  25. ^“Crafty Sheep Conquer Cattle Grids”. BBC News. July 30, 2004. Retrieved October 3, 2014.
  26. ^Ballard, Jack (2013). bison. Guilford, Connecticut: Globe Pequot Press. p. 30. ISBN. Retrieved May 25, 2016.
  27. ^Lott, Dale F. (2002). American bison: a natural history. Berkeley: University of California Press. p. 42nd ISBN. Retrieved May 25, 2016.
  28. ^Hooper, Ben (August 1, 2016). “The Australian father pulls the upside down kangaroo out of the grate by the roadside”. United Press International. Retrieved December 26, 2016.
  29. ^Hoy, p. 155
  30. ^“Cattle Guard”. United States Patent and Trademark Office. January 19, 1915. Retrieved May 27, 2016 - via Google Patents.
  31. ^“Specification for Cattle Barriers”. British Standards Institution. April 28, 2006. Retrieved June 14, 2016.
  32. ^“Information on Cattle Guard”. Barn World Farm & Ranch Superstore. Retrieved June 17, 2010.