• Pullet Output of Commercial Layer Parent Stock:
• single female parent breeder (dam) of commercial egg-type stock (e.g., BV-300, Bovans, Hy-Line) produces approximately $280\text{ to }300\text{ total eggs}$ up to 72 weeks of age.
• With $90\%$ settable eggs, $85\%$ hatchability of fertile eggs, and a $50:50$ sex ratio at vent sexing:

Correct option: (3) 135

• Atmospheric Ammonia ($NH_3$) Threshold in Poultry Housing:
• According to poultry health and welfare guidelines:
• The maximum permissible ambient ammonia concentration in a poultry house is $25\text{ ppm}$ (ideal level $\lt 10\text{--}15\text{ ppm}$).
• Concentrations exceeding $25\text{ ppm}$ paralyze respiratory cilia, damage the tracheal mucosa, and predispose birds to airsacculitis and Newcastle disease / infectious bronchitis; levels above $50\text{ ppm}$ cause blindness (keratoconjunctivitis) and growth depression.

Correct option: (3) 25 ppm

• Prebiotics in Poultry Nutrition:
• Prebiotics: Non-digestible carbohydrate oligosaccharides that selectively stimulate the growth and metabolic activity of beneficial gut bacteria (Bifidobacterium, Lactobacillus).
• Common prebiotic sources include chicory (inulin/FOS), yeast cell walls (MOS), cello-oligosaccharides, and plant tannins.
• Aspergillus species: Fungi (Aspergillus niger, A. oryzae) are sources of exogenous feed enzymes (xylanase, phytase) or direct-fed microbials, not prebiotics.

Correct option: (4) Aspergillus sps