Animal Nutrition MCQs Set 2
26. Bone calcium to phosphorus ratio is:
A. 1:1
B. 1.5:1
C. 2:1
D. 3:1
Correct Answer: C. 2:1
Explanation: In mammalian bone, calcium and phosphorus are stored primarily as hydroxyapatite crystals. The biological ratio is approximately 2:1. Maintaining this ratio in the diet is crucial; an imbalance can lead to skeletal deformities or metabolic bone diseases.
27. Chromium is known as:
A. Lipotropic factor
B. Growth factor
C. Glucose tolerant factor
D. Anti-ketogenic factor
Correct Answer: C. Glucose tolerant factor
Explanation: Chromium is a key component of the Glucose Tolerance Factor (GTF). It works by enhancing the action of insulin, allowing cells to take up glucose more efficiently from the bloodstream.
28. Sheep are most susceptible to toxicity of:
A. Zinc
B. Copper
C. Iron
D. Selenium
Correct Answer: B. Copper
Explanation: Sheep have a limited capacity to excrete copper via bile. Even small dietary excesses can lead to a sudden “hemolytic crisis,” where accumulated copper in the liver is released into the blood, causing massive red blood cell destruction.
29. Piglet anemia is prevented by all EXCEPT:
A. Iron dextran injection
B. Teat painting with {FeSO}_4
C. Oral vitamin B_{12}
D. {FeSO}_4 drenching
Correct Answer: C. Oral vitamin B_{12}
Explanation: Piglet anemia is specifically an iron deficiency (hypochromic microcytic anemia) because sow’s milk is very low in iron. Vitamin B_{12} treats different types of anemia but does not resolve iron deficiency.
30. Nitrogen to sulfur ratio recommended for ruminants is:
A. 5:1
B. 8:1
C. 10:1
D. 12:1
Correct Answer: C. 10:1
Explanation: Rumen microbes require sulfur to synthesize sulfur-containing amino acids (methionine and cysteine). A ratio of 10:1 ensures that microbes have enough sulfur to utilize the available nitrogen effectively.
31. Normal blood calcium level in ruminants is:
A. 4–6 mg/dl
B. 6–8 mg/dl
C. 8–12 mg/dl
D. 12–16 mg/dl
Correct Answer: C. 8–12 mg/dl
Explanation: The body maintains serum calcium within a very narrow range (roughly 8.5–11.5 mg/dl). If it drops significantly below 8 mg/dl, the animal begins to show clinical signs of hypocalcemia (Milk Fever).
32. Feed containing moisture above _____% cannot be stored long-term:
A. 10
B. 12
C. 14
D. 18
Correct Answer: C. 14
Explanation: Grains and mixed feeds stored with more than 14% moisture are highly susceptible to mold growth (fungal spoilage) and the production of dangerous mycotoxins like Aflatoxin.
33. NFE is calculated by subtracting from:
A. Crude protein
B. Dry matter
C. Total ash
D. 100
Correct Answer: D. 100
Explanation: Nitrogen-Free Extract (NFE) represents the soluble carbohydrates. It is calculated by subtracting the percentages of Water, Ash, Crude Protein, Ether Extract, and Crude Fiber from 100.
34. Kjeldahl apparatus is used to estimate:
A. Fat
B. Fiber
C. Protein
D. Ash
Correct Answer: C. Protein
Explanation: The Kjeldahl method measures the total nitrogen in a sample. This nitrogen value is then multiplied by a factor (usually 6.25) to estimate the Crude Protein content.
35. True ketogenic amino acid is:
A. Valine
B. Isoleucine
C. Leucine
D. Lysine
Correct Answer: C. Leucine
Explanation: Leucine (and Lysine) are purely ketogenic; they are broken down directly into acetyl-CoA or acetoacetate and cannot be used to synthesize glucose.
36. Which vitamin content increases in hay due to sun drying?
A. Vitamin A
B. Vitamin B_{12}
C. Vitamin D
D. Vitamin K
Correct Answer: C. Vitamin D
Explanation: Ultraviolet (UV) radiation from the sun converts ergosterol in plant tissues into Vitamin D2 (Ergocalciferol). While sun drying destroys Vitamin A, it is the primary way hay becomes a source of Vitamin D.
37. Sorghum loses cyanide toxicity during hay making because of:
A. Oxidation of HCN
B. Denaturation of enzymes
C. Fermentation
D. Dilution effect
Correct Answer: B. Denaturation of enzymes
Explanation: In Sorghum, the enzyme \beta-glucosidase must react with dhurrin to release HCN (Cyanide). The drying process and heat involved in haymaking denature these enzymes, making the preserved forage safe for feeding.
38. Wastelage refers to:
A. Spoiled silage
B. Fermented crop residue
C. Anaerobically fermented animal waste
D. Low-quality hay
Correct Answer: C. Anaerobically fermented animal waste
Explanation: Wastelage is a specific type of silage made by mixing animal manure (usually poultry or cattle waste) with a dry forage like straw or hay and fermenting it anaerobically.
39. Which crop is rich in soluble sugars and most suitable for silage?
A. Wheat straw
B. Berseem
C. Maize
D. Rice straw
Correct Answer: C. Maize
Explanation: Maize (Corn) is considered the ideal silage crop because it has high levels of non-structural carbohydrates (sugars and starch) which are essential for lactic acid fermentation.
40. Addition of molasses during silage making is recommended when:
A. Crop has high protein
B. Crop has low soluble carbohydrates
C. Moisture is high
D. Silage pH is low
Correct Answer: B. Crop has low soluble carbohydrates
Explanation: Molasses provides a source of readily fermentable sugars. It is added to crops like legumes (which are low in sugar) to ensure the bacteria have enough “fuel” to produce lactic acid.
41. Urea and salt are added to cereal silage mainly to improve:
A. Energy content
B. Palatability and nitrogen content
C. Moisture retention
D. Acid production
Correct Answer: B. Palatability and nitrogen content
Explanation: Cereal crops are often low in protein. Adding urea increases the non-protein nitrogen (NPN) available to rumen microbes, while salt improves the taste and preservation.
42. Main route of phosphorus excretion in carnivores is:
A. Feces
B. Sweat
C. Urine
D. Milk
Correct Answer: C. Urine
Explanation: In carnivores, the kidneys are the primary route for phosphorus excretion. In contrast, ruminants excrete the majority of their phosphorus through their feces.
43. Vitamin that acts as a hormone is:
A. Vitamin A
B. Vitamin D
C. Vitamin E
D. Vitamin K
Correct Answer: B. Vitamin D
Explanation: Vitamin D is technically a pro-hormone. Once activated in the kidneys (as Calcitriol), it travels through the blood to act on the intestines and bones to regulate calcium levels.
44. Choline deficiency primarily leads to:
A. Milk fever
B. Fatty liver
C. Ketosis
D. Rickets
Correct Answer: B. Fatty liver
Explanation: Choline is essential for the synthesis of VLDL (Very Low-Density Lipoproteins), which transport fats out of the liver. Without choline, fats accumulate, leading to Fatty Liver Syndrome.
45. Perosis (slipped tendon) in poultry is NOT associated with deficiency of:
A. Manganese
B. Biotin
C. Vitamin C
D. Choline
Correct Answer: C. Vitamin C
Explanation: Perosis is a malformation of the hock joint. It is caused by deficiencies in Manganese, Biotin, Choline, or Folic Acid. Poultry can synthesize their own Vitamin C, so it is rarely a dietary concern.
46. Sheep are less prone to phosphorus deficiency because of:
A. Efficient absorption
B. High concentrate feeding
C. Selective grazing
D. Lower requirement
Correct Answer: C. Selective grazing
Explanation: Sheep are highly selective “concentrate selectors.” They tend to pick the youngest leaves and seed heads of plants, which contain much higher concentrations of phosphorus than the rest of the forage.
47. Piglets are most susceptible to iron deficiency anemia at age:
A. Birth–1 week
B. 2–4 weeks
C. 6–8 weeks
D. After weaning
Correct Answer: B. 2–4 weeks
Explanation: Newborn piglets have small iron stores that are depleted within the first week. By 2–4 weeks, their rapid growth rate outpaces the iron they receive from milk, leading to clinical anemia if not supplemented.
48. Sulfur-containing vitamin is:
A. Riboflavin
B. Thiamine
C. Niacin
D. Pyridoxine
Correct Answer: B. Thiamine
Explanation: Thiamine (Vitamin B1) and Biotin are the two B-vitamins that contain sulfur in their molecular structure.
49. Wool contains approximately how much sulfur?
A. 1%
B. 2%
C. 4%
D. 14%
Correct Answer: C. 4%
Explanation: Wool is rich in keratin, a protein with many disulfide bonds. This requires a significant amount of sulfur (approx. 4%), which is why sulfur supplementation is vital for wool production in sheep.
50. Major anion of intracellular fluid is:
A. Chloride
B. Bicarbonate
C. Phosphate
D. Sulfate
Correct Answer: C. Phosphate
Explanation: Inside the cell (intracellular), Phosphate and proteins are the primary anions. In the extracellular fluid (blood/lymph), the primary anion is Chloride.