Bos taurus
Description
A member of the family Bovidae, the species Bos taurus (B. taurus) is comprised of several hundred different breeds and makes up the majority of domestic beef and dairy cattle found through out the Americas and Europe. Of these numerous breeds several of the most common, including Holsteins and Ayrshires, are found in Wisconsin. Features common to this family include: a paraxonic toe arrangement, fused metapodials (canon bone), the presence of true horns, a four chambered stomach, lack of upper incisors and canines, and an overall hypsodont tooth morphology common to grazers (Feldhammer 1999).
Due to the amount of variation present among breeds, specific morphological characteristics must be presented as approximations. An attempt was made to focus on breeds found within Wisconsin, primarily the Holstein, and the resulting data may not accurately describe all breeds of B. taurus.
According to data presented by the Ontario Ministry of Agriculture and Food (2003), the average height at rump and length from nose to tail recorded for Holstein cattle surveyed was 58-59 in and 95-102 in respectively. Weights averaged 1500-1900 lbs, though significant variation was seen among females during the various stages of lactation. Numerous color variations exist between species, with common patterns made of black or tan and white. Color patterns are unique for each individual which allows for easy identification.
Distribution in Wisconsin
Found throughout all of Wisconsin’s 72 counties, B. taurus is the most widely distributed domestic animal in the state, with a population of approximately 1.3 million individuals located on 17,711 farms (Jesse 2002). Population densities are greatest in the east central portion of the state, with somewhat lesser densities in the southwest (Jesse 2002).
Ontogeny and Reproduction
Sexually mature at approximately 13 months of age, members of B. taurus generally breed at 13-26 months (Holstein Association USA 2002). In natural settings polygyny is observed, with dominant males competing for chances to breed with available females. Following fertilization, the gestation period is approximately 9 months, with a healthy calf weighing approximately 90 lbs soon after birth (Holstein Association USA 2002).
Natural life spans of domestic B. taurus are generally not fulfilled, with an average productive life being 3-4 years, at which time the animal is typically sold for beef production.
Behavior and Ecology
Due to the process of domestication it is difficult to describe the natural behavior and ecology of B. taurus. Individuals occurring in Wisconsin are exclusively a domestic species and thus behavior and ecology must be described in these terms.
A gregarious animal, B. taurus occurs in herds of with an average size of 24-52 individuals (Jesse 2002). In wild settings, herding behavior provided such benefits as increased safety from predators and chances for mating, however in modern herds it is primarily a function of a domestication and human manipulation. Herds are generally comprised of females and juveniles, with adult males being separated and used primarily for stud purposes. This system produces a form of unnatural polygyny where access to the available females is restricted, with only certain males being allowed to breed with multiple females. This planned manipulation eliminates competition and fighting between males and significantly alters the natural breeding behavior of B. taurus in an attempt to control reproduction and improve domestic stocks.
Feeding habits could be described as bulk grazing with a focus on fresh grasses and other succulent vegetation (Feldhammer 1999). As is typical of most grazers a herd will feed in a particular area until the preferred or available food sources are depleted at which time it will move on in search of more vegetation. In a domestic setting various grazing rotation systems have been developed in an attempt to mimic nature and maintain a constant food source while preventing damage to the vegetation through over grazing. This involves continually moving the herd to various different enclosures as the vegetation regenerates in the previously grazed areas. The ecological impacts of these practices have been observed and include such things as the alteration of vegetation composition, age class, and structure as well as the indirect production of habitat for numerous other animal species (Warren 2002, Kazmaier 2001).
In addition to their ecological interactions with the environment, B. taurus is also affected by interactions with native animal species, predominantly predators. As a general rule, grazers and their young are often the focus of predators due to their abundance and tendency to come together in large herds. Also as part of the domestication process species are often breed to be placid and less wary than their wild relatives. This combination often produces a situation were the cattle become easy targets for predators which have discovered their vulnerable nature. Predation events by Gray wolves (Canis lupes) have increased in recent years as wolf populations have continued to grow. The majority of cases, approximately 17 each year, have come from the northern third of the state where a large portion of the current wolf population, approximately 355 individuals, is located (Wisconsin wolf advisory committee 2003).
Remarks on domestication
As reported by Feldhammer (1999) the domestication of cattle most likely occurred approximately 8000 years ago at sites in eastern Europe and western Asia. It is believed that modern cattle arose from a species of giant wild oxen called an auroch (Bos primigenius), which stood 6 ft at the shoulder. Through selective breeding early farmers were able to alter the characteristics of the auroch and create various breeds which better suited their needs and were easier to control. Today cattle are the most abundant, and thus economically important, livestock species in the world, with approximately 1,351,792,140 individuals distributed across every continent except Antarctica.
The success of cattle as a domestic animal, as compared to animals not successfully domesticated, can be traced to several behavioral and life history characteristics. According to Diamond (2002) there are 6 characteristics that an animal can possess which will hinder or prevent domestication. They are: 1.) lack of follow-the-leader dominance hierarchies, 2.) nasty disposition, 3.) reluctance to breed in captivity, 4.) diet not easily meet by people, 5.) slow growth rate and long birth spacing, 6.) tendency to panic in enclosures. Species such as zebras, elephants, and panda bears all fall into one or more of these categories. Cattle on the other hand seem to be generally well suited for domestication. They possess a dominance hierarchy which humans can exploit. They breed well in captivity, their birth spacing and development is not excessive, and there diets are relatively easily meet. Lastly they have a relatively placid disposition and have taken well to enclosures of various sizes, from milking stalls to fenced in fields. However, one must ask the question, “how did the auroch compare to what we know as modern cattle”? Was it a docile giant that was relatively easy to domesticate or did it take hundreds of years and gradual changes in the auroch’s behavior? This portion of the domestication of cattle is unclear and it is uncertain how the auroch was initially domesticated.
The domestication of cattle, as well as other species of live stock has shaped the world in untold ways and may be the most important development in human history in the past 13,000 years (Diamond 2002). Combined with the domestication of plants it has allowed for the development of permanent settlements and a system of division of labor. Throughout history it has allowed for the development of whole classes of artists, solders, and inventors, all of whom played huge roles in the shaping of our history. All told domestication has, and continues to alter the lives of people all cross the world. Not only does it provide food for billions of people every day but it effects our history, health, and future. Culturally it is an important part of life in the state of Wisconsin and provides a livelihood for thousands. The domestic cow has been recognized as the state domestic animal in Wisconsin since 1971 (SHG Resources 2003) and continues to be a large part of Wisconsin’s economic and cultural identity.
Literature cited:
Anderson, N. 2003. Sizing Holstein Cows, Ontario Ministry of Agriculture and Food webpage 2003. <http://www.gov.on.ca/OMAFRA/english/livestock/ceptor/2003/mar03a4.htm>. Accessed 4 December 2003.
Diamond, J. 2002. Evolution, consequences and future of plant and animal domestication. Nature 418, 700-707.
Feldhamer, G.A., L.C. Drickamer, S.H. Vessey, J.F. Merritt.1999. Mammalogy: Adaptation, Diversity, Ecology. McGraw-Hill, Boston, Massachusetts, USA.
Holstein Association USA. 2003. Origins of the breed, webpage 2003. <http://www.holsteinusa.com/html/thecow1.html>. Accessed 24 November 2003
Jesse, E.V. 2002 June. Rethinking dairyland, report from 2002. <http://www.aae.wisc.edu/www/pub/>. Accessed 6 December 2003.
Kazmaier, R.T., E.C. Hellgren, D.C. Ruthven, D.R. Synatzske. 2001. Effects of grazing on the demography and growth of the Texas tortoise. Conservation Biology, 15(4): 1091-1101.
SHG Resources. 2003 December. Dairy cow domestic symbol, webpage 2003. <http://www.statehousegirls.net/wi/symbols/animaldomestic/>. Accessed 4 November 2003.
Warren, J.M., J.L. Rotella. 2002. The effects of cattle grazing on duck and shorebird production in the Aspen Parkland ecoregion. Intermountain Journal of Science 8(4): 268.
Wisconsin wolf advisory committee. 1999 October. Wisconsin Wolf Management Plan, 1999. < http://www.dnr.state.wi.us/org/land/er/factsheet/mammals/wolf.htm>. Accessed 4 December 2003.
Reference written by Sean Roedl, Biol 378: Edited by Chris Yahnke. Page last updated 4-5-05.
