Cattle (Bos taurus) have long been a major source of meat in the traditional diet of American people. The first cattle in America were the buffalo (Bison bison), which freely grazed the plains of North America. They were tough, hardy, and adapted to live under harsh natural conditions. After the discovery of North America, colonists shipped British and European breeds over to the Americas.
A breed is a group of animals that have certain characteristics that differentiate them from other groups within that species. Most distinguishing of breed characteristics are their coat color patterns which are essential tools for identifying a breed. Reproductive efficiency, growth rate, carcass desirability, and/or high tolerances may differ greatly within a breed, so these traits may not be consistent within a breed to aid in the identifications of a certain animal
Definitions:
Dual Purpose Breed-- breed used for either draft and milk production or milk production and carcass quality.
Triple Purpose Breed-- breed used for draft, milk production, and carcass quality.
Crossbreeding Program-- a breeding selection program in which breeders try to produce a superior commercial beef cattle herd with high carcass desirability, quick growth rate, hybrid vigor, and reproductive efficiency.
Hybrid Vigor-- (Heterosis) a trait breeders try too manifest in crossbred cattle such as high tolerances to climate, insects, disease, etc.
Dam Breed-- cows selected from a certain breed for a crossbreeding program because of their ease in calving, high milking ability, and maternal instincts.
Sire Breed-- bulls of certain breeds that are used in a crossbreeding program
Rotational Sire Breed-- sire used in ;rotation with others to produce the cows that will be used as the dams for the next cross breeding program.
Terminal Sire Breed-- sire used as the last cross of a breeding program to produce commercial beef cattle. The terminal sire is selected for high carcass quality, fast growth rate, and large amounts of muscling.
Two Way Breed-- Used as both a dam and sire breed in crossbreeding programs.
Although traits such as reproductive efficiency, high tolerances, carcass quality, quick growth rate are not generally specific to a breed they are common to many individuals and can therefore be used to produce a commonality within a herd. Culling a herd is the general procedure for breeding out undesirable traits in a crossbreed program. For example: A rancher wants a herd to have the heat tolerance of a local bull. After rotating the sire into the herd for a season the F1 generation will receive heterosis from the cross with the bull of heat tolerance. All animals that do not show the heat tolerance will be taken from the herd and sent to market , leaving only those that show this trait.
British Breeds
Angus:
Origin-- Aberdeen region of Scotland
Brought to the United States in 1873.
Characteristics-- Black hair coat and pigment. The Angus breed has a recessive gene for a red coloration of hair. The Red Angus has its own breed association. Angus are homozygously polled.
Size-- Medium with moderate muscling
Bulls 1700-2400lbs
Cows 1000-1500lbs
Usage-- Due to their good milking ability and maternal instincts, Angus cows are often used as a dam breed in crossbreeding programs.
Origin- Hereford Shire, England.
Brought to the United States in 1817.
One of the most numerous breeds in the US.
Characteristics- The Hereford breed has a very distinguishing red and white coloring pattern. For general purposes the face, chest, and belly are usually white. In most cases the lower leg will have stockings (white up to hock). If there is not any white coloration over the shoulders of the animal then it is referred to as a "Redneck". Herefords may either be polled or horned.
Size- Medium to moderate muscling.
Cows weigh approximately 1300lbs.
Bulls weigh approximately 2300lbs.
Usage- Herefords have more subcutaneous fat than is desired in a carcass, but this aids in survival where temperatures are low. Also the Hereford breed as a whole show high fertility which makes them desirable to run as sire breeds. Some problems occur with Herefords due to their lack of black pigmentation around the eye. This leads to a susceptibility to pink eye and other cancerous eye diseases.
Origin- England
The Shorthorn was imported to the United States in 1783. This breed is categorized into three different types: milking, beef, and polled.
Characteristics- Colors range in red, white, and roan, and they can be either polled or horned.
Size- Medium with moderate muscling.
Cows weigh approximately 1300lbs.
Bulls weigh approximately 2000lbs.
Usage- Shorthorns have excellent maternal traits such as milk production, which producers utilize in crossbreeding programs.
Continental or European Breeds
Charolais:
Origin-- France
Imported to Mexico in 1930 and from Mexico to the King Ranch in 1936.
Characteristics-- White, golden wheat, or straw in coloring. They are naturally horned but there are polled strains of this breed. They are feed efficient and can gain rapidly on feed or grain.
Size- Large and heavily muscled.
Cows approximately 1800-2000lbs.
Bulls approximately 2600-3000lbs.
Usage- Used as a rotational or terminal sire breed, but it works well either way in a crossbreeding program.
Origin- Italy
Semen imported to the United States in 1971.
Characteristics- White to steel gray, white being recessive with black pigmentation. Chianina's are noted for their strong and correct legs with hard hooves.
Size- Largest breed in the world.
Cows approximately 2200lbs, standing as tall as 60-68 inches at the withers.
Bulls approximately 3500, standing as tall as 65-72 inches at the withers.
Usage- Chianina's work well as rotational or terminal sire because of their large size. Past usage of the Chianina was as a draft animal in Italy.
Origin- France
Characteristics- Reddish golden in color.
Size- Medium with thick muscling.
Cows weigh approximately 1300lbs.
Bulls weigh approximately 2400lbs.
Usage- Limousin are noted for high carcass quality making them a good terminal sire breed to improve muscling and carcass quality in a crossbreeding program.
Main-Anjou:
Origin- France.
Characteristics- Dark red with white markings on head, body, underline, tail, and rear legs.
Size- Large
Cows weigh approximately 1700-2000lbs.
Bulls weigh approximately 2700-3000lbs.
Usage- In France the Main-Anjou is used as a dual purpose breed, but in the United States it is commonly used as a terminal sire breed to increase size of the calf crop.
Origin- Switzerland
Semen was shipped to the United States in 1967.
Characteristics- Color can be yellowish brown to red with the head, underline, breast, legs, and switch being white. The Simmental breed is horned.
Size- Second largest breed being long bodied and well muscled in the hind quarters.
Cows weigh approximately 1600lbs.
Bulls weigh approximately 2600lbs.
Usage- The Simmental breed has been used as a triple purpose breed, and then was used more efficiently as a dual purpose breed. In the United States the main purpose for this breed is to increase milk production, weight, and growth rate when used as a rotational sire or terminal sire.
American Breeds
Beefmaster:
Origin-- Falfurrias, Texas
Breed Developer-- Tom Lasater
Early Development-- Mr. Lasater practiced a strict culling of his cattle herd. If a cow did not calve by a certain date, had a low birth wight, or if they required assistance during birth, he would send that cow to market and replace it with another. Since such culling techniques are not practiced much today, the Beefmaster has lost a small portion of its original desirability.
Characteristics-- Red is generally the dominant color with not distinct color pattern. Most of the Beefmaster breed is horned, but they can be polled. The beefmaster breed was created form crossing the Brahman, Shorthorn, and Hereford breeds. Roughly this crossing ratio is considered to be � Brahman, � Shorthorn, and � Hereford.
Size-- Medium sized breed
Bulls approximately 2100lbs
Cows approximately 1300lbs
Usage-- The Beefmaster breed was created to have high fertility, square conformation, high milk production, hardiness, quick weight gain, and a good disposition. They work well as dam breeds.
Origin-- Oklahoma
Breed Development-- The Brangus breed was first developed about 1912. Further development took place in the 1940s. The Brangus cattle are composed of Angus and Brahman. This ratio is obtained by breeding a � Brahman and � Angus with a full blood Angus.
Characteristics-- Black pigmented with black hair coloring. As with the Angus, Brangus also have a recessive gene for red hair coloring. All Brangus are polled. They are noted for their good heat tolerance, insect resistance, and mothering ability.
Size- Medium with moderate muscling
Cows approximately 1100-1500lbs
Bulls approximately 1850-2200lbs
Usage-- The Brangus is used for a dam breed and either a rotational or terminal sire breed. They are classified as a two way breed.
Origin- King Ranch, Kingsville, Texas.
Breed Developement- The breeding program for this breed began in 1910, and the Santa Gertrudis became a breed in 1940. The basis of this breed is Brahman and Shorthorn.
Characteristics- Solid cherry red and can be polled or horned. Large ears and loose skin with excess around the dulap portray this breed.
Size- Large with adequate muscling.
Cows weigh approximately 1600lbs.
Bulls weigh approximately 2000lbs.
Usage- the most common usage of the Santa Gertrudis is as a two way breed.
Origin- Texas and Mexico
Characteristics- Longhorns may have any color with any color pattern. The most acute characteristic among them is their long widespread horns.
Size- Medium build with flat muscling.
Usage- Longhorns are noted for their easy rustling ability, strong legs, adaptability, excellent maternal traits, and ease of calving. All of these traits add durability to any herd in a crossbreeding program.
Origin-- India
Imported to the United States in 1849.
History-- The Brahman breed are also known as Zebu cattle which means "of Tibet". Most people of India believe that cattle are sacred so they are not considered to be a food source for the population. Consequently, Brahman cattle suffer from small growth rate, low reproductive efficiency, and they have a tougher meat than other breeds. The main use of Brahman cattle is in crossbreeding programs. They produce hybrid vigor when crossed with Bos taurus breeds that results in better heat tolerance due to the Brahman having more sweat glands. Furthermore the increased sweat production provides the individual with more insect resistance.
Characteristics-- Black pigmented skin with a hair coloring of gray, red brown, black, white, or spotted. Loose skin, pendulous sheaths, droopy ears, sloping rumps, and a prominent hump over the shoulders.
Size-- Medium with moderate muscling.
Bulls 1600-2200lbs
Cows 1000-1600lbs
Usage-- The major use of the Brahman breed is to produce a hybrid vigor in a crossbreeding program. Brahman cattle are also known for reaching sexual maturity earlier than other breeds with excellent maternal instincts needed for a dam breed .
Swine Breeds
American Landrace:
Origin
Size
Usage
Characteristics
Berkshire:
Origin
Size
Usage
Characteristics
Chester White:
Origin
Size
Usage
Characteristics
Duroc:
Origin
Size
Usage
Characteristics
Hampshire:
Origin
Size
Usage
Characteristics
Poland China:
Origin
Size
Usage
Characteristics
Spotted:
Origin
Size
Usage
Characteristics
Yorkshire:
Origin
Size
Usage
Characteristics
Horse Breeds
A. 25,000 years ago, hunted for meat
B. 4,500BC -- 2,500BC domesticated in China and Mesopotamia
C. 1,000BC domestication of horse spread to almost every part of Europe, Asia, and N. Africa
III. Horses in America
A. 1,500's Spaniards brought horses to America
B. 1,600's Spanish missions well established and well supplied with horses
C. 1,650-- 1,750 Spanish horses were dispersed over W. Plains, and horse culture developed by Indians
D. 1,800's vast herds of mustangs roamed west (Feral-- undomesticated)
E. 1918 21 million horses in U.S.-- mostly draft
F. 1950 2 million horses in U.S.-- due to tractor and automobile
G. Present-- estimates from 5.2-- 10 million head of horses, mostly used for pleasure
IV. Horse Breeds
A. Arabian
1. Influenced development of other breeds more than any other
2. Imported to U.S. shortly before Revolutionary War
3. General purpose-- light riding horse, unsurpassed for endurance
4. Common Characteristic-- Dish Faced
B. Spanish Barb
1. Spanish brought to U.S.
2. Formed basis for feral horses (Mustangs)
C. Thoroughbred
1. Provided foundation stock for Quarterhorse, Standardbred, American Saddlebred, Morgan
2. Native English breed-- bred to Spanish, Turkish, and Italian mares
a. Then bred to Arabian, Turkish, and S. Barb to increase speed of breed
b. Three main sires can be traced to the beginning of this breed-- Byerly Turk, Herod, and Godolphin Arab
3. Generally long legged and bodied, tall, sleek muscled, known for speed at distances (6 furlong races [3/4mi] to 1 1/2mi)
D. Quarterhorse
1. Developed in U.S. beginning in colonial times (known as quarter milers)
2. Many breeds contributed to ancestry including mustangs, Morgans, and thoroughbreds
3. Important sires-- Janus, PeterMcCue, Traveler
4. 2 types-- racer and stock horse
5. 1950's AQHA established
E. Appaloosa
1. Spanish horses formed basis
2. Nez Percé Indians of Palouse Valley
a. 1877-- Chief Joseph surrendered, nearly wiped out the breed
b. 1938-- Appaloosa Horse Club formed to preserve breed
3. Known for colorful markings
a. Eye encircled with white
b. Skin mottled black and white
c. Hooves striped vertically (black and white)
F. Morgan
1. Original sire owned by Justin Morgan
a. Believed to be out of Arab-type mare and Thoroughbred stud
b. Used to establish Quarterhorse, Standardbred, and American Saddlebred
c. Morgan Registry established 1894
G. Paint
1. Many registries would not register horses with excessive white, so APHA was established in 1965
2. Two basic color patterns
a. Overo-- colored with white spots, white does not cross back, one or more legs are dark, spots are irregular, and tail is usually one color
b. Tobiano-- White with colored spots, white crosses back, legs white below knee or hock, body spots regular, oval and distinct, one or both flanks are dark
H. Standardbred
1. American trotting horse
2. Ancestors-- Throroughbred, Norfolk Trotter, Barb, Morgan, and Canadian Pacers
3. Trot-- 2 beat diagnol gait
4. Pace-- 2 beat lateral gait
I. American Saddle Horse
1. Origin-- Kentucky, ASHA established in 1891
2. Easy riding horse with high lifted gaits
3. 3 or 5 gaited
a. Walk 4b
b. Trot 2b
c. Canter 3b
d. High walk 4b
e. Rack 4b trot with no pacing
J. Tennessee Walker
1. General Purpose riding horse
2. Ancestors-- Thoroughbred, Standardbred, American Saddle Horse, Morgan, Canadian Pacers
3. Naturally overstrides (up to 51in)
4. TWHBA established 1935
K. Draft Breeds
1. Percheron
a. Imported to U.S. in 1839
b. Most popular draft breed in U.S.
c. PHAA established 1876
d. High knee action, speed at walk, no feathering of fetlock
2. Belgian
a. 1910-- 1930 more popular than Percheron
b. BDHCA established in 1887
c. Slow, no fancy leg action, docile and feathered at the fetlock
3. Clydesdale
a. Lighter than other draft breeds
b. Flexion of knee and hock
c. Extensive white markings
d. Heavily feathered
e. More nervous than other breeds
Animal Nutrition
Nutrition is defined as the process of which an organism takes in and digests food for the growth and replacement of bodily tissues. Within the field of animal science, studies of two types of digestive tracts will be discussed. Monogastric animals (horses, dogs, humans, swine, etc.) have simple, one compartment stomachs. Ruminant animals (cattle, sheep, goats, etc.) have complex anaerobic stomachs. The rumen is divided into four compartments: rumen, reticulum, abomasum, and omasum. Within the ruminant stomach microbes effectively breakdown ingested food for their own nourishment and as the first step of digestion for the host animal.
Monogastric Stomach:
Ruminant Stomach:
Further progression through the digestive system past the stomach is the small intestine. This is the major site of nutrient absorption into the blood stream. The small intestine is divided into three sections: the duodenum, the jejunum, and the ileum. Within the small intestine bile and pancreatic fluids mix with the ingested nutrients, degrading them for absorption through the mesenteric artery.
Small Intestine:
Further and final digestion takes place within the large intestine. This is also divided into three different sections: the cecum, the small colon, and the rectum. The majority of absorption from the large intestine is that of water. After the water is removed from the nutrients then the contents are prepared for excretion.
Large Intestine:
Ingested Nutrients:
Carbohydrates:
Proteins:
1. Composed of amino acids specifically linked in a specific order.
2. Required for the building of bodily tissues.
3. There are twenty amino acids needed by organisms for tissue construction, they are classified into two different categories:
| Essential Amino Acids | Non-essential Amino Acids |
| Arginine | Alanine |
| Histidine | Asparagine |
| Isoleucine | Tyrosine |
| Leucine | Cysteine |
| Lysine | Cystine |
| Methionine | Serine |
| Phenylalanine | Glutamine |
| Threonine | Glycine |
| Tryptophan | Hydroxproline |
| Valine | Proline |
Lipids:
1. Formed from long carbon chained fatty acids.
2. Insoluble in water.
3. Lipids are easily broken down to form energy for organisms. Degradation of fats for energy requires less energy than energy formed from carbohydrates
Suggested Experiments:
Ration Formulation
As an understanding of the gastro-intestinal tract and ingested nutrients are needed to produce high quality animals, so is knowledge on the feed stuffs presented to the animal. According to what type of growth of an animal is desired, feedstuffs should be catered to fit these guidelines.
For example: Feeder steers are grown to produce muscle tissue that is harvested for human consumption. Protein is fed to stimulate muscle tissue growth. How is a high protein diet derived? The first step in this process is understanding what minimum amount of energy a feeder steer needs to maintain normal bodily processes and then to add in an amount of protein that will succeed in muscle tissue growth and production.
Hypothetically a diet of 16% energy and 22% protein will succeed in giving us the adequate amounts of both energy and protein. Within a mill are various components to make a feed stuff that will equal to the percentages needed.
|
Mill Contents | ||
| Component | % Crude Protein | % Energy |
| Soybean Meal | 26% | 16% |
| Crushed Corn | 14% | 16% |
| Blood Meal | 35% | 10% |
| Sorghum | 17% | 19% |
Calculation of a ration is formulated by using a Pearson square:
1. Choose a component with a
number larger than the target
number and place it at position
A.
2. Choose a component with a number smaller than the target number and place it in position B.
3. A -- TN= X
4. B -- TN = Y
5. Use the sum of X and Y as the denominator of both X and Y giving you percentages of each component to make the ration.
1. 26 -- 22 = 4
2. 22 -- 14 = 8
3. Denominator = 12 (8 + 4)
4. The ration just formulated has 22% crude protein. The composition of this ration is 67% soybean meal (8/12=0.67 or 67%) and 33% crushed corn (4/12=0.33 or 33%).
Since both components have 16% energy there is no need to calculate for energy, the requirement is already met.
The luxury of having two ration components with the same amount of a needed nutrient is rare. Under these circumstances a formulation of mix must be made first.
Example 2: A ration is needed that will supply a high energy diet to a race horse. Supplemental protein is a secondary concern. Therefore the diet must contain a minimum of 20% energy and 15% crude protein. Like any typical expensive race horse, this one is finicky upon what it will eat. Among sources for a feed stuff this race horse will eat:
|
Ration Components | ||
| Component | % Energy | % Crude Protein |
| Molasses | 28% | 8% |
| Oats | 14% | 12% |
| Crushed Corn | 14% | 16% |
| Sorghum | 17% | 19% |
| Soybean Meal | 20% | 19% |
| Cotton Seed Meal | 15% | 12% |
1. Solve for the necessary amounts
of energy.
2. Composition of Mix 1 is 43% Molasses (6/14=0.428 or 43%) and 57% Oats (8/14=0.572 or 57%)
3. Calculation of Mix 1's crude protein percentage is step two.
4. Molasses 43% * 0.08 = 3.44
Oats 57% * 0.12 = 6.84
Crude Protein percentage of Mix
1 is 10.28%.
1. Ration is 54% (4.72/8.72=0.541 or 54%) sorghum and 46% (4/8.72=0.458 or 46%) Mix 1.
2. The final calculation is to figure the amount of each of the components of Mix 1.
3. 43% * 46% = 20% molasses
57% * 46% = 26% oats
4. The final composition of this ration is 54% sorghum, 26% oats, and 20% molasses.
Lab Reports
Hypothesis:
Section of the lab report of which a theory is proposed. The theory is noted as the alternative hypothesis (HA), and control is stated as the null hypothesis (HO).
Example:
HO: High protein feeds will not yield higher digestibility of proteins.
HA: High protein feeds will yield higher digestibility of proteins.
Review:
Within this section a brief description of what the experiment is being conducted is written. Included in this section is a short history on major components of the experiment. Why this experiment is being conducted, and the importance of the results. For example, if the experiment is being conducted on the gastro-intestinal tract, a short description of how the digestive tract is composed would be appropriate. Also, if certain nutrients are being examined a description detailing their importance to the body would also be important.
Example:
Dietary phosphorus occurs as both inorganic phosphates and organic phosphoproteins, phosphorylated sugars, and phospholipids. Amounts of inorganic and organic phosphorus will vary depending on the complete diet of the animal, though most of the phosphorus that is absorbed is in its inorganic form. Organically bound phosphorus is hydrolyzed enzymatically in the lumen of the small intestine and released as an inorganic phosphate.
Procedure:
In this section the procedure is illustrated in the order of which the experiment is carried out. If equipment is used, a brief explanation of what the equipment does is expected to be noted at the point where the equipment is used. Reagents that are used in the experiment are spelled out and then noted in parenthesis. Later in the results and discussion parts of the report the abbreviations are used.
Example:
25mL of hydrochloric acid (HCl) was used to ionically reduce the phosphorus (P) within the soil sample.
Results:
This section is where the results from the experiment are written. Results are usually outlined within the text and illustrations are used to graphically detailed. Graphs are the most commonly used illustration. Effects can clearly be seen through a bar or line graph.
Example:
Digestion of phosphorus was higher in the juvenile swine and mature sows than in the mature boars.
Discussion:
This is perhaps the most complex of all sections of the lab report. In this section an evaluation of the results must be made in comparison to results from literature that has been researched. Does the literature contradict the results of the experiment, or does the literature verify the results? Furthermore discrepancies that may have occurred during the experimental procedure are detailed.
A Successful Lab Report Needs:
Phosphorus Digestion Experiment
Sample Collection:
An appropriate size sample of both the feed ration and fecal material will be needed for this analysis. Collection will be made and then the sample will be stored in an air-tight container and frozen so that the nutrients will not degrade.
Forming of the Extract:
Before the sample can be analyzed by the spectrophotometer, an extract must be formed. The molybdate method, as outlined by the AOAC, will be used in forming an extract. 5g of the sample will be mixed with a solution of 0.93N hydrochloric acid (HCl) and 1.5N ammonium acetate. One teaspoon of activating charcoal will be added to the extract. This extract must be stirred for approximately 30 minutes without a stopper. The solution must then be filtered to produce the final extract.
Testing for the Amount of Phosphorus:
After the extract has been formed, the use of a reagent to activate the phosphorus within the extract is added. Next, the extract is transferred to the "spec tubes" and inserted into the spectrophotometer and the amount of phosphorus is computed.
** Don't forget to zero out the spec before measuring the samples.
Calculations:
The final section of this experiment is to calculate the percent of phosphorus utilized by the animal.
Animal Genetics
Genetics is the study of the passing of inheritence from parents to offspring. Genetics can be divided into three branches: (1) Mendelian genetics, (2) molecular genetics, and (3) population gentics.
Mendelian genetics- study of transmission of traits from parents to offspring.
molecular genetics- study of the structure of genes and what interactions they have at the molecular level.
population genetics- study of genetics throughout populations using their genotypic and phenotypic similarities and dissimilarities.
phenotype- observable genetic trait.
genotype- the allelic makeup of an individual.
allele- one of several different forms of a gene.
Mitosis:
Heredity is passed from cell to cell through a process of cell division called mitosis. Mitosis consists of four different phases: (1) prophase, (2) metaphase, (3) anaphase, and (4) telophase.
Prophase- Chromosomes will condense into two sister chromatids that will be visible under a light microscope. Furthermore, the largest orgenelle, the nucleolus will disappear wile the nuclear membrane dissipates. Finally, during the end of prophase the spindle fibers start of appear.
Metaphase- The nuclear membrane is fully dissipated and the chromosomes are freely flowing within the cytoplasm. The spindle fibers attach to the centromeres of the chromosomes and gradually start changing their alignment to the equatorial plane.
Anaphase- The spindle fibers pull the centromeres apart while towing one chromatid to each pole of the cell.
Telophase- The two sets of chromatids start to uncoil and the nuclear membrane reappears, separating the two different sets. Towards the end of telophase the cell membrane splits down the center forming two "daughter cells".
Population Genetics:
What is population genetics? Simply put, population genetics is the area of genetics that studies the patterns of genetic variation with natural populations. One of the major factors in determining genetic variation between populations of the same species is natural selection. This ideology dates back to the 1859 published work of Charles Darwin, On the Origin of Species by Means of Natural Selection.
The basic principles of Mendelian genetics help to increase the understanding of any one populations' genetic composition. Based on a populations' segregation from other populations of the same species, we can identify certain traits that are unique to that population. Furthermore, that unique trait is part of the population's gene pool.
Gene pool- a total of the variety of alleles within a given populaion.
Population- a group of the same species that coincide together and are capable of reproduction.
Inbreeding- nonrandom mating that occurs between closely related individuals of a population.
Animal Reproduction
A general knowledge of animal reproduction is vital to any animal related business. Income in the cattle business is directly related to the reproductive efficiency of a cow-calf operation. If birth rates are low and calf mortality rates are low then a animal manager must be able to identify the problem and define a solution.
In addition, a general understanding of genetics is needed for a manager to breed out traits he or the industry considers undesirable and be able to introduce traits that are desirable.
Following is a set of examples of undesirable traits for each individual animal operation.
1. Low maternal instincts
2. High mortality rates
3. Slow weight gain
4. Small bone structures
5. Lack of milk high milk production
M. Sheep/Goats:
1. Low mohair/wool grade
2. Slow weight gain
N. Swine:
1. Slow weight gain
2. Incorrect conformation
O. Equine:
1. Slow or stunted growth
2. Incorrect conformation
3. Lack of muscle structure
4. Lack of sexual characteristics
In order to have a greater understanding of reproductive efficiency a animal manager must understand the physiology of the male and female reproductive organs.
Male Reproductive Organs:
A. Testes-- primary male sexual organ
1. Production of sperm cells
2. Production of testosterone
B. Epididymis-- area where spermatozoa mature and are stored
C. Vas Deferens-- a tube that transports spermatozoa for temporary storage in anticipation for ejaculation
D. Prostate Gland-- secretes nourishment for sperm and stimulates activity
E.
Vesicular Glands-- neutralizes urine and stimulates sperm activity.
F. Urethra-- a long passageway extending through the penis that originates at the bladder. The urethra is transports both urine and sperm through the penis.
G. Penis-- organ through which sperm is transported to the vagina during copulation and urine is excreted.
Illustration of male reproductive organs
Female Reproductive Organs:
A. Ovary-- produces eggs, estrogen, and progesterone.
B. Follicle-- germ cell surrounded by a layer of cells. Follicles have the potential to mature into and egg. The majority of follicles die and are absorbed by the ovary and replaced.
C. Corpus luteum-- (yellow body) produces progesterone to maintain pregnancy.
D. Oviducts-- site of fertilization.
E. Uterus-- site of fetal development.
F. Cervix-- organ the connects the uterus to the vagina.
G. Vagina-- site of copulation within the female, also birth canal and connected to the bladder.
H. Clitoris-- sensitive organ on the lower tip of the vagina.
I. Vulva-- external genital material.
Explanation of Sexual Hormones:
Testosterone-- produced within the testicles in the interstitial cells. Testosterone stimulates growth of the male reproductive track, sperm, social dominance, horns, etc.
Estrogen-- produced from the follicles. Estrogen is stimulates the development of the uterus for pregnancy and increases the motility of the oviducts and uterus during esterus.
Progesterone-- produced by the corpus luteum and this hormone prevents ovulation during pregnancy and maintains pregnancy. Progesterone also increases the development of milk producing tissues.
Suggested Experiments: Palpation, AI, Stallion or bull collection
Animal Health Care
Management of livestock reproduction and nutrition are two key components that help prevent sickness among a herd or remuda. However complete disease free herds are unlikely. Many common afflictions such as hardware disease, bloat, colic, etc. infiltrate even the most cared for groups. In this section common livestock afflictions will be described along with their symptoms and signs.
Colic:
1. Symptoms
a. Looking or biting at flank.
b. Horse stretches for urination but does not urinate.
c. Increase in temperature and sweat.
d. As condition becomes more acute, the horse will lie down and roll over.
e. Final condition, horse will begin throwing himself towards the ground.
2. Causes
a. Failure of foals to pass muconium at birth.
b. Parasites within the GI tract.
c. Quick changes in feed stuffs.
3. Treatments
a. Walking the animal.
b. Introduction of a pain killer.
c. Dosage of 1 gallon of mineral oil per 1,000lbs of body weight.
d. Sugary if material is not passed within 12 hours from sign of first symptoms.
Pink Eye:
1. Symptoms
a. Area surrounding eye is swollen.
b. Secretion of pus from eye.
2. Causes
a. Mechanical trauma introduced to the eye (thorns, wire, etc.).
b. Infections transferred by parasites.
3. Treatments
a. Precautionary methods of spraying areas of heavy livestock traffic (feedlots, rustling pens, etc.) and use of vaccinations.
b. Treat with antibiotics and ointments.
Rumen Impaction:
1. Symptoms
a. Ruminant animal sluggish and slow, low activity cycle.
2. Causes
a. Animal gets loose and ingests a large amount of supplemental feed stuffs that lower the pH of the rumen.
3. Treatments
a. Introduction of mineral oil at 1 gallon per 1,000lbs of body weight.
b. Administration of IV glucose and a gluconeogenic medicine.
c. Change diet to small amounts of supplements and large amounts of grass hay.
Traumatic Pericarditis:
1. Symptoms
a. Ruminant animal with little or no appetite.
b. Swollen brisket area.
c. Noticeable jugular pulse.
d. Standing position of an arched back and front feet widely spread.
2. Causes
a. Ingestion of metal objects (nails, wire, etc.). These ingested objects could possibly rupture the reticulum and enter the cardiac region and pierce the heart.
3. Treatments
a. Prevention measures can be taken by orally administering 1-2 magnets periodically.
b. Surgery to remove the ingested object.
Bloat:
1. Symptoms
a. Distended abdomen region.
b. Animal has a difficult time breathing.
2. Causes
a. Dry Bloat-- excess feeding of supplemental concentrates
b. Foamy Bloat-- excess feeding of green legumes (alfalfa).
3. Treatments
a. Walking the animal.
b. Standing the animal uphill.
c. Tie a stick into mouth.
d. Passing a stomach tube so that the gas may pass.
e. Oral administration of a commercial product that will breakdown the gas and 1 gallon of mineral oil per 1,000lbs of body weight to help pass the wastes.
f. Puncturing the rumen (needle, knife, trochar).
Founder:
1. Symptoms
a. Disfigurement of the hoof.
2. Causes
a. Consumption of moldy or sour feed stuffs.
b. Toxins become lodged within the lowest portion of the horse (hoof) and begin destroying capillaries.
c. Cooling a horse too quickly accompanied by large intakes of water.
d. Post symptom of a severe infection.
3. Treatments
a. Submerge feet in water.
b. Administer cortisone, antibiotics, Vitamin C and B12.
c. Allow horse to have lots of fluids.
Slaughter and Processing
The final step within the industry of livestock production is the slaughter and processing of carcasses for human consumption. With the exception of horses, most livestock will eventually either become pets, used for recreation, or sent to a feedlot for the first step in the processing line. Within the feedlot most animals are fed a diet that will quickly increase weight and stimulate muscle growth. From here animals are sent to a processing plant where they are humanely slaughtered.
Slaughter Process:
1. Immobilization or Stunning
a. Mechanical (stun gun, pistol, or hammer)
b. Electrical
c. Chemical (Carbon Dioxide Chamber)
2. Bleeding
a. Severing the jugular artery and allowing the blood to be removed.
3. Head Removal
a. The head is removed at the atlas joint.
4. Skin Removal
a. Cattle-- skin is removed with a knife or hide remover.
b. Sheep-- use the fist to remove the hide on the exterior side of the fell membrane. This term is known as "Fisting".
c. Swine-- The hair is removed by a scalder that removes 95% of the hair. The remaining 5% is removed by hand.
5. Removal of Feet
a. Cattle-- removed at the hock and knee.
b. Sheep-- removed at the lower metacarpal.
6. Evisceration
a. An incision is made in the abdominal and ventral cavities of the animal and the GI tract, respiratory and circulatory organs are removed.
7. Splitting
a. The carcasses of cattle and swine are cut dorsally into two halves.
8. Washing
a. Spraying of the carcasses removes bone, dirt, and some microbes with a minimum of 125psi.
9. Inspection
a. Various local, state, and federal agencies inspect the carcass to make sure it is qualified for sale within the country.
10. Cooling
a. This is done to remove the last amounts of body heat and to prepare the carcass for shipping and processing into choice cuts.
Terms Associated With The Meat Industry:
1. Amount
2. Texture
3. Distribution
References:
Chapter on Animal Nutrition
Pendergraft, Jeff S. Lecture Notes: Advanced Animal Nutrition. 1997. Sul Ross State University.
Jurgens, Marshall H. Animal Feeding and Nutrition (6th ed.). Kendall/Hunt Publishing Co.
Chapter on Reproduction
Ramsey, C. Boyd. Animal Science 1301: Spring 1997. Texas Tech University.
Skaggs. ANSC 108: Fall 1993. Texas A&M University.
Chapter on Animal Health
Weyerts, Paul. Lecture Notes: Livestock Management. 1997. Sul Ross State University.
Chapter on Carcass Processing
Skaggs. ANSC 108: Fall 1993. Texas A&M University.