Animal Science
Animal Science

Animal Science

Lead Author(s): Maria Haag, Jason Scheffler, Robert Dove

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An introduction to the field of Animal Science, focusing on the basic physiological principles and the basic production of various species.

Chapter 1: Introduction

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Introduction

Animals have been a part of human existence since the dawn of time. The study of animals, particularly behavior, began long before animals were domesticated. The hunter-gathers studied animal behaviors and patterns to learn how to have the most successful hunt, while avoiding being hunted by the animals. Animals of various species have become a part of the day to day life of most humans. Animal Science is the study of domesticated animals. The study of Animal Science helps to improve the lives of animals as well as helping animals improve the lives of humans. Over time, Animal Science has evolved into the study of all aspects of an animal’s life, including nutrition, reproduction, genetics, behavior, health, physiology and a multitude of other topics. 

Domestication

Domestication of animals began over 15,000 years ago with the domestication of the dog. The dog offered man companionship and protection, while man offered the dog food and protection. Domestication of any species takes many generations and over time the dog became a faithful companion. The domestication of livestock began around 10,000 years ago in southwest Asia with the domestication of goats, sheep and pigs. Early domestication involved restricting the foraging area of the animals to make it easier to hunt and in some case feeding them. In time, breeding programs were started to replace the animals that were used for food. The domestication of animals along with the cultivation of crops eliminated the need for humans to be constantly on the move hunting and gathering and allowed them to develop an agrarian society that allowed groups to remain in one location. The domestication of animals has had a profound impact on the development of civilizations. The domestication of animals has led to the development of robust economies, aided in exploration and development of new lands, provided protection and altered the outcome of numerous wars. Ownership of animals are symbols of wealth and status in many societies. 

Table 1.1 The Domestication of Animals:

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Question 1

The first species of animal domesticated was the ?

A

Cat

B

Pig

C

Chicken

D

Dog

E

None of the above


Agriculture 

The propagation of food and fiber from plants and animals became known as Agriculture. The word agriculture is derived from the Latin words agri (field) and cultura (cultivation). It is estimated that there were 7.6 billion people in the world in 2017 and that there were 2.6 billion (37%) of the world population working in agriculture. The challenge of the 37% of the population that works in agriculture is to feed the remaining 63% of the population. It is estimated that by 2050 there will be almost 10 billion people in the world. The ever increasing world population puts significant demands on agriculture to improve efficiency and find new production methods to feed the world. The percent of the population working in agriculture is not distributed equally around the world. In developed countries like the United States, Germany, Australia, Japan and the United Kingdom, less than 4% of the population works in agriculture. In other parts of the world the number of agriculture worker is much higher. In Kenya, approximately 70% of the population works in agriculture, while in China, 59% of the population is involved in agriculture. In general the more developed the agriculture system is in a country, the lower the percentage of people working in Agriculture. (USDA/FAO). 

Question 2

Highly developed countries have a higher percentage of the population working in agriculture than do lesser developed countries.

A

True

B

False


Agriculture in the U.S. 

Agriculture and related industries are very important to the United States, contributing almost a trillion dollars to the gross domestic product (GDP) and providing over 21.4 million jobs. This was about 5.5% of the total U.S. GDP and about 11% of the total U.S employment in 2015. Farm production was almost 137 billion dollars or about 1% of the U.S. GDP. 

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In the United States there are about 2 million farms, with an average size of 440 acres. The amount of land used for farming in the United States has decreased since the 1950s, while farm productivity has increased dramatically. Advances in technology and mechanization have allowed for increased farm sizes while requiring fewer people to work on the farm. Over 90% of the farms in the United States are still owned by individuals or families. 

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The increase in agriculture productivity has kept food prices very low for American consumers. It is estimated that the average American household spends less than 7% of their household income on food consumed at home and under 13% of their household income on total food purchases including food eaten away from home. This makes food prices as a percentage of income in the United States some of the lowest priced food in the world. 


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The percentage of income spent on food eaten away from home has increased over time, a reflection of the changes in lifestyles that have occurred over the past several decades.  Expenditures on total food purchases account for over 12% of the household expenses, ranking 3rd behind expenditures for housing (33%) and transportation (15.8%). 

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Historically Livestock enterprises and crop enterprises have made up about equal parts of the total gross agriculture income in the United States. In recent years, crop income has exceeded livestock income, with livestock income representing 42-45% of the total value of agriculture production. One of the main reasons that crop values have increased is the increased use of corn to make ethanol to be added to gasoline. The amount of corn used to produce ethanol is equivalent to the amount of corn used for livestock feed (35-40% of total production). This has significantly increased the demand for corn and therefore the price of corn. 

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Question 3

Approximately what percentage of the average household spend on food eaten at home.

A

5%

B

7%

C

9%

D

11%


Livestock Enterprises in the U.S. 

Within the livestock enterprises in the United States, the sale of beef accounts for 39% of the cash receipts for livestock. Poultry and eggs account for 24%, dairy accounts for 21%, and swine for about 10% of the total livestock sales. Beef is the only commodity whose price has increased on a per hundredweight basis over the past 10 years, when corrected for inflation. During this time period, poultry and pork production have increased, while beef production has decreased due to a number of factors.  The dramatic increase in poultry production is a result of improved production technologies and increased demand for poultry products. 

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In 2015 the per capita availability in the United States of boneless chicken was 62 pounds per person, compared to 51 pounds of beef and 48 pounds of pork. Chicken consumption continues to increase on a yearly basis due to both the price of the commodity and the creative marketing by the poultry industry to promote their product as a healthy food. 

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Even with the abundance of food in the United States, over 12% of households report being food insecure. Food insecurity is defined as not having reliable access to sufficient quantities of affordable, nutritious food to support healthy, active lifestyles for all members of the household. Food insecurity occurs in all areas of the country and is particularly prevalent in low income, elderly and single parent households where an unexpected expense or life event can significantly decrease the ability to secure food. Through advances in Animal Science, improved production practices can be developed to help decrease food insecurity in the United States and around the world. Advances in nutrition, genetics, reproduction and herd health will lead to more efficient and economical production of meat making it more affordable to all. 

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Question 4

Which meat commodity has the highest per capita availability on a yearly basis?

A

Beef

B

Chicken

C

Lamb

D

Pork


Careers in Animal Science

Animal science is a diverse field with many different areas of specialization. Careers in veterinary medicine are the most commonly associated options, but there are many other opportunities. People with degrees in animal science can work for different species organizations including breed associations. They can take sales jobs or research and development jobs with animal product companies. They can work as managers on production operations. They can attend graduate school for careers in research and academia. They can become zookeepers and animal trainers. They can even work as handlers for police or groups like TSA. The unique and diverse perspectives one gains from an animal science degree prepares students for a variety of careers. 

Agricultural Research

A significant portion of the knowledge that we have generated over the past 200 years to improve production efficiency, food safety and sustainability has been the result of the land grant university system. The Morrill Act of 1862 gave states land to be used to establish colleges of agriculture. Each state determined how to use the funds to develop a college in their state. Today, every state has a land grand university that conducts agricultural research. The Hatch Act of 1887 established Experiment Stations, often associated with land grand universities to do agriculture, solar energy, home economics, and rural energy research and to encourage application of those technologies. The Smith-Lever Act of 1914 provided extension funds to land grant universities to disseminate research findings and practical information to farmers and consumers.  For more information on the development of the land grand universities, please see appendix 1.  

Important Terms

Like any field of study, Animal Science has its own jargon. It is important for animal scientists to know and apply the correct terms when speaking about livestock. Growth performance is one of the ways that producers determine how an animal is growing.  Changes in growth performance can indicate that the animal is stressed or ill. Some of the basic growth performance terms are:

Average Daily Gain: (ADG) This is a measure of how many pounds or kilograms an animal grows each day. During the growth phase animals are often weighed on a schedule and the weight gained is divided by the number of days between weighing to determine the average gain during that time period. During the growth phase animals will gain more weight per day as they get larger. In some cases animals are weighed individually weekly, while in other cases groups of animals are weighed when the group enters the farm and when it leaves the farm. 

Average Daily Feed Intake: (ADFI or ADF) This is a measure of how many pounds or kilograms of feed disappears from the feeder each day. It is assumed that the animal(s) ate the feed, although a small percentage is routinely wasted. Feed intake is normally determined at the same intervals as when the animal is weighed. Feed intake is calculated as the difference between what was delivered to the feeder minus what is left in the feeder divided by the number of days since feed was first added to the feeder. It is a measure of how much an animal or group of animals is eating each day. 

Gain:Feed: (G:F) This is a measure of efficiency. It calculates how many pound or kilograms an animal gains per pound or kilogram of feed intake (ADG/ADFI). G:F will always be less than 1, but the closer the number is to 1 the more efficient the animal is. Young chickens and pigs may have a G:F close to 1, while older animals may have a G:F of .3-.7.

Feed:Gain: (F:G) This is the inverse measure of G:F. It calculates how much feed is required for each unit of gain (ADFI/ADG). F:G will always be greater than one, but the smaller the number the more efficient the animal. 

Each species has its own descriptive terms for gender, reproduction and grouping. These can be found in table 1.2. 

Table 1.2 General terms by species.

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Conclusion

Animal Science is a very diverse field of study that encompasses all aspects of animal production and how animals interact with the environment. Advances in animal science help to maintain a safe, sustainable food supply and continued research will help feed the ever increasing human population. The development of cutting edge technologies to improve animal efficiency and productivity will insure that animal agriculture continues to play a vital role in the health and nutrition of the human population.  

Question 5

Which piece of legislation established the land grant univeristies?

A

Hatch Act

B

Smith-Lever Act

C

Morrill Act

D

Lincoln Act

References

Image Credits

[1] Foal: image courtesy of vimesogmbh under CC0 1.0 via Pixabay. Chicks: image courtesy of Detonator under CC0 1.0 via Pixabay. Calf: image courtesy of Capri23auto under CC0 1.0 via Pixabay. Lamb: image courtesy of PublicDomainPictures under CC0 1.0 via Pixabay. Piglets: image courtesy of aitoff under CC0 1.0 via Pixabay. Collage created by author.

[2] Table created and provided by author in Microsoft Office.

[3] Image courtesy of the United States Department of Agriculture Economic Research Service in the public domain.

[4] Image courtesy of the United States Department of Agriculture Economic Research Service in the public domain.

[5] Image courtesy of the United States Department of Agriculture Economic Research Service in the public domain.

[6] Image courtesy of the United States Department of Agriculture Economic Research Service in the public domain.

[7] Image courtesy of the United States Department of Agriculture Economic Research Service in the public domain.

[8] Image courtesy of the United States Department of Agriculture Economic Research Service in the public domain.

[9] Image courtesy of the United States Department of Agriculture Census of Agriculture in the public domain.

[10] Image courtesy of the United States Department of Agriculture Economic Research Service in the public domain.

[11] Image courtesy of the United States Department of Agriculture Economic Research Service in the public domain.

[12] Image courtesy of the United States Department of Agriculture Economic Research Service in the public domain.

[13] Image courtesy of the United States Department of Agriculture Economic Research Service in the public domain.

[14] Image courtesy of the United States Department of Agriculture Economic Research Service in the public domain.

[15] Image courtesy of the United States Department of Agriculture Economic Research Service in the public domain.

[16] Table created and provided by author in Microsoft Office.