Laboratory Technical Assistant — Livestock Management / Poultry Husbandry — VHSE — 2015 — Official Paper — Kerala PSC PYQ Practice with Answers

Correct answer (Option B):\nInfectious Bursal Disease (IBD), also known as Gumboro disease, is a highly contagious viral disease that attacks the bursa of Fabricius in young chickens. This organ is crucial for B-lymphocyte development, leading to severe immunosuppression and leaving birds vulnerable to secondary infections. Option B is correct.\n\nWhy others are wrong:\nOption A causes bacterial enteritis. Option C (Ranikhet Disease) is a acute systemic respiratory virus. Option D is a parasitic protozoan disease.\n\nStudy tip:\nIBD primarily affects young chicks between 3 to 6 weeks of age when the bursa is at its peak development.

Correct answer (Option C):\nBleaching refers to the natural loss of yellow pigment (carotenoid) from the skin, beak, shanks, and vent of a laying hen as she produces eggs. The pigment is diverted to the egg yolk, indicating high productivity over time. Option C is correct.\n\nWhy others are wrong:\nOption A is the shedding and renewal of feathers. Option B is the physical extraction of feathers after slaughter. Option D is a non-standard generic term.\n\nStudy tip:\nBleaching follows a strict biological sequence: vent fades first, followed by the eye-rings, earlobes, beak, and finally the shanks.

Correct answer (Option B):\nFumigation using formaldehyde gas is the standard commercial practice to disinfect hatching eggs. It kills surface pathogens before they can penetrate the porous eggshell, preventing microbial contamination inside the incubator. Option B is correct.\n\nWhy others are wrong:\nOption A is an old, non-commercial preservation method. Option C is a diagnostic technique using light to check internal egg quality or embryo development, not a method for chemical disinfection.\n\nStudy tip:\nEgg fumigation is ideally done within two hours of collection or prior to setting inside the setter compartments.

Correct answer (Option A):\nFormaldehyde gas is generated by a chemical reaction between Potassium Permanganate (KMNO₄) crystals and liquid Formalin solution. This combination yields a wide-spectrum gas capable of eliminating bacteria and mold spores from egg surfaces. Option A is correct.\n\nWhy others are wrong:\nOptions B, C, and D utilize sodium chloride, sodium carbonate, or hydrochloric acid, which do not generate the essential disinfectant formaldehyde gas required for sanitizing facilities.\n\nStudy tip:\nStandard single-strength (1X) fumigation typically uses 20 g of Potassium Permanganate mixed into 40 mL of Formalin for every 100 cubic feet of space.

Correct answer (Option C):\nFiloplumes are tiny, hair-like feathers that possess a very thin shaft with a few small barbs at the apex. They remain embedded in the skin of the carcass after the main feathers have been removed during processing. Option C is correct.\n\nWhy others are wrong:\nOption A describes the outer body plumage that defines a bird's external shape. Option B denotes fluffy down feathers providing thermal insulation. Option D refers to the long curved tail ornaments found on adult roosters.\n\nStudy tip:\nSingeing is the mechanical processing operation used specifically to burn off leftover filoplumes from the bird's carcass.