Animal Science Final Review: Genetics, Nutrition, and Husbandry

Genetics and Calculations of Estimated Breeding Value (EBV)

• Genetic Contribution Principles:     * Every parent contributes exactly half ($50\%$) of their DNA to their offspring.     * Example: If a sire has a weaning weight value of $+16\,lb$ and a dam has a value of $+6\,lb$, they each contribute their respective portions to the offspring calculation.

• EBV Calculation Formula and Procedure:     * A common mistake in calculations is performing the heritability ($h^2$) multiplication only once. To find the EBV, you must multiply by the heritability twice.     * Specific Example (585-Day Weight):         * Animal X Weight: $1031\,lb$         * Group Average (Population Weight): $963\,lb$         * Heritability ($h^2$) for 585-Day Weight: $0.6$         * Step 1 (Subtract Individual from Population): $1031 - 963 = 68\,lb$         * Step 2 (First Heritability Multiplication): $68 \times 0.6 = 40.8$         * Step 3 (Second Heritability Multiplication): $40.8 \times 0.6 = 24.48\,lb$         * Result: Animal X's EBV is approximately $+24.5\,lb$ heavier than the population average.     * Contextual Analysis: In a single breed population, differences should typically be within $\pm 5\,lb$ to $\pm 10\,lb$. A difference of $24.5\,lb$ suggests intense genetics, a different breed, or a crossbreed.

Nutrition and Feed Labeling Requirements

• The Nine Key Components of a Feed Label:     1. Purpose Statement: Identifies the species the feed is intended for and the specific life stage (e.g., lactating cows vs. lactating pigs; grower, finisher, or starter).     2. Product Name: The specific name of the feed (e.g., Superbowl Cattle Grower).     3. Net Weight: The total weight of the contents in the bag.     4. Guaranteed Analysis: Lists the guaranteed minimum and maximum amounts of nutrients, specifically Crude Protein, Crude Fat, and Crude Fiber.     5. Ingredient List: Essential for owners to identify potential allergens in case the animal has a reaction.     6. Feeding Directions: Detailed instructions on how much and how often to feed the animal (e.g., "Three pounds for a 100-pound dog").     7. Manufacturer Information: Name and address of the manufacturer so they can be contacted in the event of animal illness, death, or feed testing issues.     8. Medication Information: If the feed is medicated, it must list the active ingredients (e.g., Lasallopsid) and the withdrawal time. If the feed is not medicated, this section will be absent.     9. Lot Number and Date: Essential for tracking expiration and managing recalls. Expired feed loses nutritional value, becomes stale, or may develop mold.

Classes of Nutrients and Physiological Importance

• Water:     * Most overlooked but most critical nutrient.     * The body is made of $75\%$ to $80\%$ water.     * Consumption Ranges:         * Cold Weather: $1\,gal$ per $100\,lb$ of body weight per day.         * Hot Weather: $2\,gal$ per $100\,lb$ of body weight per day.     * Survival Limits: Animals can live up to $60$ days without food, but only $3$ to $7$ days without water. After $3$ to $4$ days, internal organs begin to shut down.     * Water Quality: Ideal pH is between $6.8$ and $7.5$. Poor quality leading to reduced intake results in diarrhea, poor feed conversion, and a "downhill spiral."

• Carbohydrates (Carbs):     * Should comprise $60\%$ to $70\%$ of the diet.     * Sourced from plants and other animals.     * Includes sugars, starches, and fiber.

• Proteins:     * Known as the "building blocks of life."     * Responsible for repairing tissues, forming enzymes and hormones, and supporting the immune system.     * Critical for the development and function of ruminant microbes.

• Fats:     * Classified as saturated or unsaturated.     * Transport fat-soluble vitamins (A, D, E, and K).

• Vitamins:     * Organic compounds. Specific vitamins are synthesized by bacteria in the rumen.

• Minerals:     * Inorganic compounds required for bone and tooth formation, nerve function, and metabolic processes.     * Divided into macrominerals (required in larger amounts) and microminerals.

Ration Factors and Operating Costs

• Factors Affecting Nutritional Rations:     * Age and species.     * Production status (e.g., pregnancy or lactation).     * Activity level (e.g., "animal athletes" require more protein and fat).     * Breeding Season Strain: Males (bucks, bulls) can lose significant weight due to activity. A buck may lose $20\,lb$ to $50\,lb$ during a heavy breeding season.
• Operating Costs: Feed is consistently the number one operating cost associated with raising any animal, regardless of species.

Feed Efficiency and Calculations

• Dry Matter (DM): Calculation of the feed weight minus the water content.
• Feed Conversion Ratio (FCR):     * Measures the amount of weight gained relative to the amount of feed consumed.     * Formula: $FCR = \frac{\text{Amount Consumed}}{\text{Weight Gained}}$.     * Example: If an animal consumes $60\,lb$ and gains $30\,lb$, the ratio is $2\,lb$ of feed for every $1\,lb$ of gain.

Methods and Principles of Restraint

• Restraint Hierarchy (Least to Greatest):     1. Verbal (e.g., sit, stay commands).     2. Physical (e.g., scruffing, halters).     3. Chemical (e.g., sedatives) or a combination of methods.

• Purpose of Restraint: To prevent injuries to the animal and the handler. The rule of thumb is "less is best," but safety is the number one priority.

• Animal Vision and Perception:     * Prey Animals (Cows, Sheep, Goats, Horses): Eyes are on the sides of the head for a wide field of view, but they have significant blind spots (e.g., directly behind them).     * Predators: Eyes are on the front of the face to provide depth perception for chasing.     * Blind Spots: Never approach an animal from behind without speaking first to avoid being kicked or bitten.     * Pigs: Have notoriously poor eyesight.

• Flight Zone:     * The animal's personal space. Entering the flight zone causes the animal to move away.     * Frequent handling reduces the flight zone. Unhandled cattle may have a flight zone of $30\,feet$.

• Types of Aggression: Pain-induced, paternal (maternal), territorial, fear-induced, intra-male (breeding), and dominance aggression.

Species-Specific Restraint Techniques

• Rodents (Rats/Mice): Use the scruff of the neck. Never pick them up by the tip of the tail for extended periods.
• Rabbits: NEVER pick up by the ears (can break cartilage). Grab by the scruff and always support the hindquarters.
• Goats: Do not scruff a goat; they will butt you.
• Pigs: Always have an exit strategy. If one pig is upset, the rest of the herd will come to its rescue.
• Exotics:     * Tortoises: Restrain on top of a toilet paper roll to prevent movement during X-rays.     * Lizards/Geckos: Do not grab by the tail. Pin front legs back along the body. Use gauze over the eyes to calm them.     * Arboreal Lizards: Feel more secure on a perch.     * Snakes: Use the "one handler for every four feet of snake" rule (e.g., a $12\,foot$ snake requires $3$ handlers). Use clear plastic tubes or paper towel rolls for restraint.

Veterinary Equipment and Injection Procedures

• The Five C’s of Drug Administration:     1. Correct Drug     2. Correct Dose     3. Correct Route     4. Correct Time of day     5. Correct Animal

• Injection Routes:     * Intramuscular (IM): Into the muscle.     * Intravenous (IV): Into the vein.     * Subcutaneous (SubQ/SQ): Under the skin.     * Intranasal (IN): Into the nose (always remove the needle before administration).

• Meat Animal IM Injections:     * Injections must be given in the neck to avoid ruining high-value meat cuts (loin, rump/round) with injection site lesions.     * Landmarks for Neck Triangle: Nuchal ligament (ligamentum nuchae), Scapula, and Cervical vertebrae.     * Volume Rule: If an injection is greater than $10\,mL$ ($10\,cc$), spread the injection sites out by one hand-width (approx. $5\,inches$).

• Blood and Veins:     * Venous Blood: Dark red/mahogany due to depleted oxygen and high $CO_2$.     * Arterial Blood: Bright fire-engine/cherry red due to high oxygen saturation.     * Common IV Sites: Jugular, saphenous vein, cephalic vein, tail vein, or milk vein.

Questions & Discussion

• Question: Are we supposed to bring the binders on Monday?
• Response: No. Lab notebooks/binders are due on the day of your final exam, which is next Wednesday.
• Question: Why don't we have class on Monday?
• Response: There is no class this coming Monday or Friday. Next week is strictly for final exams. You only show up for your scheduled final exam.
• Lab Materials: There was a brief discussion regarding initialing 92 items/labels and an issue with glitching/ordering in the digital system.