Animal Science MCQ Multiple Choice Questions Answers for Practice
1. Which compartment of the ruminant stomach is known as the 'true stomach'?
Correct Answer is: Abomasum
Solution:
The abomasum secretes digestive enzymes and hydrochloric acid, making it functionally equivalent to the monogastric true stomach.
2. Which feedstuff is classified as a high-starch carbonaceous concentrate?
Correct Answer is: Corn grain
Solution:
Corn grain is high in starch and low in crude fiber, making it a primary energy source in animal feed.
3. What is the typical average gestation period for swine?
Correct Answer is: 114 days
Solution:
Swine gestation lasts about 114 days, commonly remembered as 3 months, 3 weeks, and 3 days.
4. Heterosis, or hybrid vigor, refers to which phenomenon in animal breeding?
Correct Answer is: Increased performance of crossbred offspring over parent averages
Solution:
Heterosis is the improved performance or trait expression in crossbred progeny compared to the average of their purebred parents.
5. Which gland produces luteinizing hormone (LH) and follicle-stimulating hormone (FSH)?
Correct Answer is: Anterior pituitary gland
Solution:
The anterior pituitary gland synthesizes and releases gonadotropins, including LH and FSH, into the bloodstream.
6. In laying hens, which section of the oviduct is responsible for forming the eggshell?
Correct Answer is: Uterus
Solution:
The uterus, also known as the shell gland, is where the egg spends approximately 20 hours depositing the calcium carbonate shell.
7. How do freshwater fish maintain osmotic balance in an environment hypoosmotic to their internal fluids?
Correct Answer is: Excreting large volumes of dilute urine
Solution:
Water continuously diffuses into freshwater fish, so they maintain homeostasis by excreting large volumes of dilute urine.
8. What are the primary volatile fatty acids (VFAs) produced by microbial fermentation in the ruminant stomach?
Correct Answer is: Acetate, propionate, and butyrate
Solution:
Rumen microbes ferment carbohydrates into short-chain fatty acids (acetate, propionate, and butyrate), providing the animal's primary energy.
9. What is the term for an animal's personal space that, when entered by a handler, causes the animal to move away?
Correct Answer is: Flight zone
Solution:
The flight zone is the area surrounding an animal that causes it to move away when a handler or predator enters it.
10. What is the first milk produced by a female mammal immediately following birth, which contains essential antibodies?
Correct Answer is: Colostrum
Solution:
Colostrum provides newborn animals with maternal immunoglobulins vital for passive immunity acquisition.
11. What is the management practice of removing wool from around the tail and breech area of a sheep to prevent flystrike?
Correct Answer is: Crutching
Solution:
Crutching involves shearing wool from around the tail and rear legs to reduce soilage and lower the risk of flystrike.
12. What term describes the proportion of phenotypic variation in a population that is attributable to genetic differences?
Correct Answer is: Heritability
Solution:
Heritability measures the proportion of observed variation in a trait among individuals in a population that is due to genetic variation.
13. Which muscle protein pigment is primarily responsible for the red color of raw meat?
Correct Answer is: Myoglobin
Solution:
Myoglobin is an iron-binding protein located in muscle tissue that binds oxygen and imparts a red color to meat.
14. What organ in the avian digestive tract serves as a temporary storage site for ingested food before it passes to the proventriculus?
Correct Answer is: Crop
Solution:
The crop is an expanded pouch in the avian esophagus used to store food prior to digestion.
15. In swine terminology, what is a male pig that was castrated before reaching sexual maturity called?
Correct Answer is: Barrow
Solution:
A barrow is a male pig that has been castrated before developing secondary sex characteristics.
16. What is the minimum temperature required for High-Temperature Short-Time (HTST) pasteurization of fluid milk for 15 seconds?
Correct Answer is: 161°F (72°C)
Solution:
HTST pasteurization requires heating milk to at least 161°F (72°C) for 15 seconds to eliminate pathogenic microorganisms.
17. A deficiency in which fat-soluble vitamin causes rickets, characterized by soft and malformed bones, in young growing livestock?
Correct Answer is: Vitamin D
Solution:
Vitamin D regulates calcium and phosphorus absorption; its deficiency leads to improper bone mineralization, causing rickets.
18. Which rubbery, V-shaped structure on the underside of a horse's hoof absorbs shock and assists in circulating blood back up the leg?
Correct Answer is: Frog
Solution:
The frog is a soft, V-shaped cushion that absorbs impact forces and aids venous blood return as the horse walks.
19. Frothy bloat in ruminants is primarily caused by the entrapment of fermentation gases within stable foam in which organ?
Correct Answer is: Rumen
Solution:
Frothy bloat occurs when stable foam traps fermentation gases inside the rumen, preventing normal eructation.
20. What term describes the recurrent period of sexual receptivity in female mammals during which ovulation typically occurs?
Correct Answer is: Estrus
Solution:
Estrus (or 'heat') is the period of sexual receptivity driven by high estrogen levels preceding ovulation.
21. What is the term for the visible intramuscular fat dispersed within the lean tissue of a cut of meat?
Correct Answer is: Marbling
Solution:
Marbling refers to intramuscular fat flecks within muscle tissue, which contribute to tenderness and flavor.
22. In female poultry, which ovary and oviduct typically develop fully and become functional for egg production?
Correct Answer is: Only the left
Solution:
In almost all bird species, including domestic chickens, only the left ovary and oviduct mature and become functional.
23. Which essential amino acid is typically the first limiting amino acid in corn-soybean diets for swine?
Correct Answer is: Lysine
Solution:
Lysine is the first limiting amino acid in standard swine diets based on corn and soybean meal, meaning its deficiency restricts overall protein synthesis.
24. Which specialized sensory system allows fish to detect movement, pressure changes, and vibrations in surrounding water?
Correct Answer is: Lateral line system
Solution:
The lateral line system consists of mechanoreceptive canals along the fish's body that sense pressure gradients and vibrations.
25. What is the proper livestock term for a castrated male sheep?
Correct Answer is: Wether
Solution:
A wether is a male sheep or goat that was castrated before reaching sexual maturity.
26. Which organism serves as the essential intermediate host in the life cycle of the common liver fluke (Fasciola hepatica)?
Correct Answer is: Freshwater snail
Solution:
Freshwater snails, particularly from the family Lymnaeidae, are required intermediate hosts where liver fluke larvae replicate.
27. What does the acronym EPD stand for in beef cattle genetic evaluation?
Correct Answer is: Expected Progeny Difference
Solution:
EPD stands for Expected Progeny Difference, predicting how future offspring are expected to perform relative to an average benchmark.
28. Which compartment of the ruminant stomach features an inner lining with a distinct honeycomb-like structure?
Correct Answer is: Reticulum
Solution:
The reticulum has a distinct honeycomb interior lining that traps foreign material and aids in regurgitation during rumination.
29. What type of rapid, irreversible learning occurs during a critical early period in an animal's life, forming a strong social attachment?
Correct Answer is: Imprinting
Solution:
Imprinting is a phase-sensitive learning process where young animals form immediate attachments to parents or caregivers.
30. Which dairy goat breed is easily recognized by its long, drooping ears and convex Roman nose profile?
Correct Answer is: Nubian
Solution:
Nubian (Anglo-Nubian) goats are distinguished by long pendulous ears, a convex facial profile, and milk high in butterfat.
