Animal Nutrition Exam 3

What is a Least Cost Ration?

A diet that meets the animal’s needs at the cheapest price.

What are Nutrient Requirements?

The essential nutrients necessary for the maintenance, growth, reproduction, and health of an animal.

What does Total Digestible Nutrients (TDN) refer to?

A traditional method to express energy that does not account for energy losses in urine, methane, and heat.

What is Digestible Energy (DE)?

The amount of energy that is digestible and usable by an animal, particularly for equines.

What is Metabolizable Energy (ME)?

Energy available to an animal after accounting for energy losses through urine and methane, commonly used for pigs and poultry.

What is Net Energy (NE)?

The amount of energy available for maintenance and production, calculated as metabolizable energy minus heat increment.

What is Degradable Intake Protein (DIP)?

The fraction of dietary protein that is broken down by rumen microbes.

What is Undegradable Intake Protein (UIP)?

The fraction of dietary protein that is not degraded by rumen microbes and is absorbed in the small intestine.

What is Ration Formulation?

The process of creating a diet that meets all of an animal's nutrient requirements.

What is the National Research Council (NRC)?

An organization that publishes guidelines for nutrient requirements and feed composition every 7 to 10 years.

What are Energy Units in animal feeds?

Different measurements of energy needs and supplies in animal feeds.

Why is the Least Cost Ration important?

It covers 40 to 50% of production costs and is vital for efficient livestock operations.

What are some challenges in Ration Balancing?

Difficulty in balancing nutrients, especially vitamins and minerals, in animal diets.

What is the Maintenance Energy Requirement?

The amount of dietary energy needed to maintain an animal in zero energy balance.

What is Zero Energy Balance?

When the amount of energy consumed in feed equals the energy used by the animal.

What is Basal Metabolism?

The amount of heat produced by the body in a post-absorptive state with minimal physical activity.

What is the Basal Metabolic Rate (BMR)?

The lowest metabolic rate obtained while an animal is at complete physical and mental rest.

What are some Factors Influencing BMR?

Includes body size, species, age, previous level of nutrition, and climate.

How is Metabolic Body Weight calculated?

Calculated by taking the animal's absolute body weight (in kg) and raising it to the power of 0.75 to determine daily maintenance requirements.

What is Temperature Regulation?

The process whereby an animal expends energy to maintain its body temperature in response to environmental temperature changes.

How does Ambient Temperature affect energy requirements?

Cold temperatures require heat generation to maintain body temperature, while heat contributes to energy loss in warmer climates.

What is Muscular Work in terms of energy requirements?

Energy required for normal body functions like heart contraction and muscle tone maintenance.

What is the Maintenance Protein Requirement?

Amount of dietary protein needed to maintain an animal in zero nitrogen balance.

What is the Maintenance Calcium Requirement?

Amount of dietary calcium needed for an animal's bodily functions.

Do Young Animals have higher or lower maintenance requirements than older animals?

Young animals have higher energy needs than older animals due to growth and maintenance processes.

What are Species Constants?

Mathematical values used to relate heat production to body size across different species.

What is reproduction?

The process by which animals (and plants) give rise to offspring.

What is the optimal breeding age?

The age at which an animal reaches puberty and is ready to breed.

What is the fetal mortality rate?

The rate at which fetuses die before birth.

What is parturition?

The act of giving birth.

What is litter size?

The number of offspring produced at one time by a mammal.

How do you assess an animal for breeding?

Assessment involves evaluating the animal's nutritional status, often using a Body Condition Score (BCS), which is a scoring system based on its body fat.

What is flushing, and when and how is it used?

Flushing is a technique used to increase ovulation in production animals by enhancing nutrient availability before breeding.

What is gestation?

The period of development of the fetus from conception until birth.

What is a conceptus?

The embryo and its supporting structures, including the placenta.

What is malnutrition, and how does it affect pregnancy?

Malnutrition is faulty nutrition resulting from inadequate or unbalanced intake of nutrients, which can severely impair fetal development and maternal health during pregnancy.

What is the heat increment of pregnancy?

The additional heat loss experienced by the dam due to pregnancy-related metabolism.

What is nutrient transport?

The mechanism by which nutrients are moved from maternal to fetal circulation.

Which minerals are required at greater levels to support fetal skeletal development?

Calcium and Phosphorus.

What are trimesters, and how do nutrient requirements change during them?

Trimesters are the three phases of gestation, during which nutrient requirements change significantly, generally increasing as pregnancy progresses to support fetal growth and development.

What is an oocyte?

A female gamete involved in reproduction.

What factors can affect the time or age when an animal reaches puberty?

Factors such as nutrition, breed, environmental conditions, and individual health can influence when an animal reaches puberty and is ready to breed.

What are the key nutritional factors during pregnancy?

Key nutritional factors include adequate energy, protein, vitamins, and minerals (like calcium and phosphorus) to support maternal maintenance, fetal growth, and mammary development.

What is the historical significance of 1766 in the dairy industry?

It marks early developments in the dairy industry.

What percentage decrease in milk cow operations occurred from 2003 to 2012 in the United States?

33% decrease.

What was the approximate milk production in million pounds in the US in 2021?

Approximately 230,000 million pounds.

What is the typical increase in production per cow from 2013 to 2022?

10% increase.

Which technologies contributed to the dramatic increase in milk yield from 1940 to 1960?

Artificial insemination (AI) and improved genetics.

What is colostrum and why is it important?

Colostrum is the first milk, nutrient dense and provides maternal antibodies for offspring.

How does milk composition vary with species?

Each species has milk composition that meets the specific needs of its offspring.

Describe the relationship between milk yield, fat, and protein content.

Higher milk yield results in lower percentage of fat and protein.

What are the main duties of ruminants as milk producers?

Convert indigestible feeds into nutritionally valuable milk.

What are the primary components required for milk synthesis?

Water, vitamins, minerals, lactose, fat, and protein.

What hormone is used to increase milk production in lactating cows?

Somatotropin (bST or bGH).

What does a body condition score of 3.5 to 4 indicate for dairy cows before calving?

They should be physically fit and healthy.

What is a significant risk for lactating dairy cows during calving?

Metabolic diseases such as milk fever and ketosis.

What is a 'transition cow'?

A cow that has recently moved from pregnancy to lactation.

What are the critical nutrient needs for a fresh cow?

Energy requirements are high while appetite is declining.

How does feeding affect milk production?

Diet quality and nutrient concentration greatly influence milk yield.

What is the role of colostrum in calf nutrition?

It provides essential immunoglobulins to support the calf's immune system.

What conditions can occur if a cow has high urea nitrogen levels?

Impaired conception and embryonic development.

What condition follows reduced levels of blood calcium in lactating cows?

Milk fever or parturient paresis.

How does the lactation cycle affect nutrient requirements?

Nutritional needs change significantly from dry to lactating states.

What is growth?

The process of increasing in size and development throughout an animal's life.

What is postnatal growth?

The rapid growth and development that occurs in an animal immediately after birth.

What is colostrum?

The first milk produced by a mother after giving birth, rich in antibodies and nutrients essential for neonatal health.

What is the esophageal groove?

A physiological feature in ruminant neonates that directs milk from the esophagus directly to the abomasum, bypassing the rumen.

What is gut closure?

The process during which the intestinal epithelial cells of a neonate develop and lose the ability to absorb large immunoglobulin proteins.

What is creep feeding?

A management practice to supplement the diet of nursing young livestock, helping to transition them to solid food.

What is allometric growth?

Growth in which different parts of the body grow at different rates.

What is body composition?

The proportion of fat, muscle, and bone in an animal's body, crucial for determining the economic value in livestock production.

What is genetics?

The hereditary information that affects the growth potential and body composition of an animal.

What are maintenance requirements?

The necessary nutrients needed to maintain the basic metabolic functions of an animal before any growth can occur.

What is milk replacer?

A formulated substitute for whole milk, fed to young livestock when maternal milk is insufficient, unavailable, or to aid in early weaning.

What is weaning?

The process of gradually transitioning young animals from a milk-based diet to solid food and water, typically involving separation from the mother.

What are the factors influencing body composition?

The major determinants of an animal's proportion of fat, muscle, and bone, which include genetics, nutrition, environment, and physiological state.

What are the methods of body composition measurement?

Techniques used to assess body composition, categorized as direct (e.g., chemical analysis post-mortem) or indirect (e.g., ultrasound, CT scans, DEXA, visual appraisal, live animal weight and measurements).

What is the typical birth weight of a calf in beef cattle?

40-50 kg.

How often are beef cows expected to produce a calf?

Once per year.

What is the average gestation period for a cow?

9 months.

What percentage of the world's beef and veal is produced by the United States?

About 20%.

What type of operations are included in the beef industry structure?

Cow-calf, stocker/yearling, feedlot (finishing), and packing plant (slaughterhouse).

What is the postpartum period in cattle?

The 80-to-90-day period that begins at calving.

What nutritional requirements decrease during the first trimester of pregnancy in cows?

Energy requirements decrease by about 13% and protein needs by about 8%.

What is the most critical period for cows to have a body conditioning score of 3-4 before calving?

The third trimester (50 to 60 days before calving).

What must a newborn calf receive within the first 24 hours after birth?

Colostrum.

What is the primary feed given to cattle in feedlots to achieve market weight?

High-grain diet.

What complication can arise from a shift to a high concentrate diet in cattle?

Rumen acidosis.

What is grass tetany?

A condition resulting from low magnesium and calcium levels in forages.

What are clinical signs of grass tetany in cattle?

Nervousness, muscle twitching, staggering, muscle spasms, and convulsions.

What can help prevent bloat in cattle?

Slowly adapting cattle to grain-based diets and using tannin-rich forages.

What is a critical management guideline for cattle to avoid acidosis?

Introducing high concentrate feeds gradually over three to four weeks.

What condition occurs if blood glucose drops too low in cows?

Milk fever.

What are the benefits of Somatotropin (bST) in dairy cows?

Increases milk production; however, it is controversial.