TNPSC Animal Husbandry & Veterinary Science (Degree Standard), Code 396 · India · Tamil Nadu Public Service Commission
Original practice questions written to the published syllabus · not past papersThe rumen and how to feed cattle, buffalo, sheep and goats through each stage of life, including ration formulation by the Pearson square and least-cost methods.
In the exams: ICAR AICE-JRF core group 05; ICAR AIEEA-PG 14 (Animal Nutrition)
How our questions for TNPSC Animal Husbandry & Veterinary Science, Code 396 spread across the units of Applied Animal Nutrition I: Ruminants. Difficulty: 23 easy, 9 medium, 0 hard.
| Feeding of lactating animals | 6 | |
| Area-specific mineral mixtures | 4 | |
| Nutrient requirements and feeding standards (ICAR 2013, NRC and NASEM) | 3 | |
| Ration formulation by the Pearson square | 3 | |
| Feeding of calves | 3 | |
| Evaluation of silage and hay | 3 | |
| Rumen ecosystem and function | 2 | |
| Rumen manipulation | 2 | |
| Feeding of heifers | 2 | |
| Feeding of dry animals | 2 | |
| Least-cost ration formulation | 1 | |
| Clinical nutrition | 1 |
Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.
On a predominantly forage diet, which volatile fatty acid is present in the rumen in the highest molar proportion?
A. Acetic acid, at roughly two-thirds of total VFA
Forage diets give about 65 to 70 percent acetate, 15 to 20 percent propionate and about 10 percent butyrate. Propionate rises with starch feeding, and lactic acid accumulates only in acidosis.
Further reading: Van Soest, Nutritional Ecology of the Ruminant, 2nd ed.
Which group of rumen microbes is most numerous per millilitre of rumen fluid?
C. Bacteria
Bacteria are commonly quoted at 10^10 to 10^11 per ml, against about 10^4 to 10^6 protozoa per ml. Protozoa are larger, so they can still form much of the microbial mass, which is a common source of confusion.
Further reading: McDonald et al., Animal Nutrition, 7th ed.
Using the Pearson square, what percentage of maize grain (9 percent CP) is needed with an oilseed cake (42 percent CP) to make a concentrate mixture with 18 percent CP?
A. 72.7%
Parts maize = 42 − 18 = 24; parts cake = 18 − 9 = 9; total 33. Maize = 24/33 = 72.7 percent. 27.3 percent is the cake share (the parts swapped); 50 percent assumes equal mixing; 42.9 percent is 18/42.
Further reading: McDonald et al., Animal Nutrition, 7th ed.
In a TMR, the usual target for feed refusals in a herd fed ad libitum is about:
C. 3 to 5 percent of feed offered
A small refusal of about 3 to 5 percent ensures cows are not limited, without excess waste. A clean bunk for long periods means cows run short; refusals of 15 percent or more waste money.
Further reading: NRC, Nutrient Requirements of Dairy Cattle, 2001; NASEM 2021
For large-breed dairy heifers in intensive systems, the commonly targeted age at first calving is:
C. 22 to 24 months
22 to 24 months balances rearing cost with heifer size. Indigenous cattle and buffalo under smallholder conditions often calve at 30 to 40 months or later, mostly because of poor feeding.
Further reading: NRC, Nutrient Requirements of Dairy Cattle, 2001; NASEM 2021
On a smallholder farm without a weighbridge, heifer growth is most practically monitored by:
A. heart girth tape measurement at regular intervals
Heart girth is well correlated with live weight and is used with breed-specific tables or formulas. Dentition gives age, not growth rate; temperature and dung colour do not measure growth.
Further reading: ICAR, Nutrient Requirements of Animals, 2013; Banerjee, A Textbook of Animal Husbandry
In Indian dairy practice, 'steaming up' refers to:
A. extra concentrate fed in late pregnancy before calving
Steaming up is the feeding of extra concentrate in the last weeks of pregnancy to meet foetal growth and prepare the rumen for the lactation ration. Steam-flaking is a grain processing method.
Further reading: ICAR, Nutrient Requirements of Animals, 2013; Banerjee, A Textbook of Animal Husbandry
In early lactation, the dairy cow is usually in negative energy balance because:
B. milk yield peaks before dry matter intake does
Milk peaks at about 6 to 8 weeks while DMI peaks later, so the cow mobilises body fat to fill the gap. Colostrum and early milk are not low in energy, and maintenance needs do not fall.
Further reading: NRC, Nutrient Requirements of Dairy Cattle, 2001; NASEM 2021
Silage with a strong rancid, putrid smell indicates:
B. clostridial fermentation producing butyric acid
A rancid, putrid smell comes from butyric acid and amines from clostridia, typical of wet, poorly fermented silage. Heat damage gives a tobacco or caramel smell; good lactic silage smells pleasantly acidic.
Further reading: McDonald et al., Animal Nutrition, 7th ed.
Safe practice limits urea in cattle rations to about:
A. 1 percent of total ration DM or one-third of total N
Urea is limited to about 1 percent of ration DM (or about one-third of total N), mixed well, introduced gradually and fed with fermentable energy; it is avoided in young calves. Higher levels risk ammonia toxicity.
Further reading: McDonald et al., Animal Nutrition, 7th ed.
Ten here, 32 in the app. The Laisha app has every practice question we have written to TNPSC Animal Husbandry & Veterinary Science, Code 396 in this subject, marked as you go, with timed papers, a jump-to-unanswered list and a certificate when you pass at 70 per cent.
Free for ten days, then one subscription of US$10 a month. We would rather say so here than have you find it later.
An AI operating system for agriculture: free guides, manuals and tools written for every country.