Untitled Flashcards Set

Gene

A segment of DNA that contains the instructions for making a specific protein or set of proteins.

Shape of DNA

Double helix.

Mutation

A change in a gene that leads to a different outcome, such as in Polled Hereford.

Genetic Blueprint

The complete set of genetic instructions for an organism.

Genetic Variation from Sire

Much more genetic change occurs from the sire due to the influence of male genetics on offspring.

Breeding Technologies Examples

Artificial insemination and embryo transfer.

Selection in Animal Breeding

To improve desirable traits in livestock.

Types of Selection

Phenotypic selection, genotypic selection, and molecular selection.

Homozygous Allele Example

AA or aa.

Heterozygous Allele Example

Aa.

Dominance

When one allele masks the expression of another (e.g., black fur dominant over brown).

Over-Dominance

The heterozygote has a higher fitness than either homozygote.

Co-Dominance

Both alleles are expressed equally in the phenotype.

Heterosis

Hybrid vigor, where hybrid offspring exhibit improved or increased function.

Qualitative Traits Examples

Color, coat type, horned/polled status, disease resistance, and conformational traits.

Environmental Impact on Phenotype

Nutrition, housing conditions, and social interactions can affect a calf's development.

Highly Heritable Trait Example

Milk production.

Lowly Heritable Trait Example

Reproductive performance.

Hyperplasia

Increase in cell number.

Hypertrophy

Increase in cell size.

Precocial Young

Young that are born in an advanced state and are relatively mature.

Altricial Young

Young that are born in a more undeveloped state and require significant parental care.

Compensatory Gain

Increased growth rate after a period of underfeeding.

Law of Diminishing Returns

Increased input will eventually yield lower returns.

Cellular Organization Levels

Cell, tissue, organ, system, organism.

Nutrient Partitioning

Prioritization of nutrient use for maintenance, growth, reproduction, and lactation.

Animal Management During Finishing

Proper feeding and care to maximize weight gain.

Factors That Increase Growth

Nutrition, genetics, and environment.

Economically Important Tissues

Muscle, adipose, bone.

Physiologically Important Tissues

Nervous, circulatory, respiratory.

Nutrient Delivery to Fetus

Increase blood flow and oxygen supply.

Order of Fat Deposition

Internal, subcutaneous, intramuscular.

Slaughter Weights for Livestock

Cattle: 1100-1300 lbs; Sheep: 100-120 lbs; Swine: 240-280 lbs; Goats: 70-90 lbs.

Growth Hormone Fluctuation

Varies throughout the animal's life, peaking during growth stages.

Fitness

The ability of an organism to survive and reproduce.

Polyestrus

Animals that exhibit multiple estrous cycles throughout the year.

Seasonal Polyestrus

Animals that have estrous cycles during certain seasons.

Monoestrus

Animals that have one estrous cycle per year.

Estrous

The recurrent physiological changes that are induced by reproductive hormones.

Estrus

The period of sexual receptivity in female mammals.

Gestation

The period of development of the embryo or fetus in the womb.

Parturition

The act of giving birth.

Estrous Synchronization

Methods used to control the timing of estrus cycles.

Artificial Insemination

A reproductive technology used to impregnate females by manually depositing sperm.

Embryo Transfer

The process of transferring an embryo from one female to another.

In-Vitro Fertilization

The fertilization of an egg outside the body.

Intracytoplasmic Sperm Injection

A specialized IVF technique where a single sperm is injected directly into an egg.

Sexed Semen

Semen that is sorted to contain only male or female sperm.

Cloning

The process of producing genetically identical individuals.

Vestibule vs Vagina

The vestibule is the passageway leading to the vagina; the vagina is the muscular canal.

Cervical Anatomy Dependent on Species

Cervix structure varies to accommodate species-specific reproductive physiology.

Uterine Layers Function

Endometrium: supports fetal development; Myometrium: aids contractions; Perimetrium: protective outer layer.

Site of Fertilization

Fallopian tubes.

Graafian Follicle

A mature ovarian follicle containing a developing egg.

Seminal Plasma Function

Provides nutrients and a medium for sperm survival.

Sertoli Cells Function

Support and nourish developing sperm cells.

Leydig Cells Function

Produce testosterone.

Seminiferous Tubules Function

Site of sperm production.

Tunica Dartos Function

Regulates testicular temperature.

Cremaster Muscle Function

Lifts and lowers the testes.

Pampiniform Plexus Function

Regulates temperature of arterial blood to the testes.

Inner Cell Mass Function

Develops into the embryo.

Trophoblast Function

Forms the outer layer of the embryo and develops into the placenta.

Placenta Function

Facilitates nutrient and gas exchange between mother and fetus.

Hormone During Follicular Phase

Estrogen.

Hormone During Luteal Phase

Progesterone.

Average Estrus Length for Livestock

Cow: 18 hours; Ewe: 30 hours; Mare: 5-7 days; Sow: 48-72 hours; Doe: 24-36 hours.

Zygote

The fertilized egg formed by the union of sperm and egg.

Embryonic Period of Gestation

First 8 weeks of gestation.

Fetal Period of Gestation

From week 8 to birth.

Placenta Type in Livestock

Cow: cotyledonary; Ewe: cotyledonary; Mare: diffuse; Sow: diffuse; Doe: cotyledonary.

Artificial Insemination Use

To increase genetic diversity and improve breeding efficiency.

Easiest Way to Assess Animal Potential

Observe productivity and performance metrics.

Digestive Tract Functions

Ingestion, digestion, absorption, and excretion.

Types of Digestion Examples

Mechanical (chewing), chemical (enzymes breaking down food), microbial (fermentation in ruminants).

Absorption Definition

The process of taking in nutrients into the bloodstream, which occurs primarily in the intestines.

Chickens Physical Digestion Location

In the gizzard.

Reptiles Primary Digestive Type

Chemical digestion.

Cattle Digestive Tract Type

Ruminant.

Sheep Digestive Tract Type

Ruminant.

Goats Digestive Tract Type

Ruminant.

Swine Digestive Tract Type

Monogastric.

Horses Digestive Tract Type

Non-ruminant herbivore.

Saliva Function

Moistens food and begins the digestive process.

Epiglottis Function

Prevents food from entering the trachea during swallowing.

Ruminant Stomach Chambers

Rumen (fermentation), Reticulum (filtering), Omasum (water absorption), Abomasum (true stomach).

Microbial Fermentation By-Product

Volatile fatty acids (VFAs).

Three VFAs

Acetic acid, propionic acid, butyric acid.

Animal with Esophageal Groove

Calves, to direct milk to the rumen.

Small Intestine Sections and Functions

Duodenum (digestion), Jejunum (absorption), Ileum (final absorption).

Protein Hormones Activation

They must be activated to exert biological effects.

Bile Production and Storage

Produced in the liver, stored in the gallbladder.

Cecum Function

Fermentation site and absorption of water and nutrients.

Highest Cost in Livestock Production

Feed.

Feedstuff Definition

Any material that can be used as feed for animals.

Diet Definition

The mix of feedstuffs consumed by an animal.

Ration Definition

The daily allowance of feed for an animal.

Nutrient Definition

A substance that provides nourishment essential for growth and the maintenance of life.

Building Blocks Definition

Basic components from which nutrients are formed.

Essential AA Definition

Amino acids that must be obtained from the diet.