Minerals, Vitamins & Feed Additives

• Genetic Basis of Heterosis (Hybrid Vigor):
• According to Falconer & Mackay's quantitative genetics framework:
• When two inbred parental lines differing in gene frequencies ($p_1$ and $p_2$, where $y = p_1 - p_2$) are crossed:
• The amount of heterosis observed in the $F_1$ generation (the deviation of $F_1$ from the mid-parent value) summed across all loci is:

where:

• $d$ = dominance deviation at the locus
• $y = p_1 - p_2$ = difference in allele frequency between the two parental populations
• Heterosis strictly depends on the presence of dominance ($d$) and genetic divergence ($y^2$) between parental lines.
• nalysis:
• (dy^2): Correct formula ($dy^2$, OCR recorded as dy).

Correct option: (2) dy

• Characteristics of High-Quality Silage:
• pH: $3.8 - 4.2$ (indicates rapid lactic acid fermentation suppressing clostridia).
• Lactic Acid: $3 - 8\%$ of dry matter (predominant organic acid).
• Ammoniacal / Volatile Nitrogen: $\lt 10\%$ of total nitrogen (reflects minimal proteolysis).
• Fungal growth: Absent / negative.
• Butyric Acid: Should be virtually absent or $\lt 0.1 - 0.2\%$ of dry matter.
• butyric acid level of $\gt 0.5\%$ signifies clostridial spoilage, extensive protein degradation, and putrefaction, which is characteristic of poor-quality silage.
• nalysis:
• (Butyric acid >0.5 %): Correct (this is a sign of spoiled silage, not good quality).

Correct option: (3) Butyric acid >0.5 %

• Principles of Haymaking:
• Statement 1: Finished cured hay should contain $\lt 12-15\%$ moisture to prevent mold growth and spontaneous heating (True).
• Statement 2: "Hay is dried more rapidly in the windrow than swath" (Incorrect / False):
• In the swath, the cut forage is spread out in a wide, thin, flat layer exposing maximum surface area to direct solar radiation and wind, drying substantially faster than in a gathered, compact windrow. Windrowing is done primarily after partial field drying to reduce leaf shatter.
• Statement 3: Rain on drying forage leaches soluble sugars and minerals (leaching loss) (True).
• Statement 4: Sun-curing converts ergosterol into Vitamin $D_2$ (ergocalciferol), making hay richer in Vitamin D than silage (True).
• nalysis:
• Statement 2 is incorrect, hence the correct answer.

• Himalayan Churpi:
• Churpi is a traditional indigenous dairy product prepared across high-altitude regions of Ladakh, Sikkim, Bhutan, and Nepal from the milk of the yak (Bos grunniens) or dzo.
• Skimmed yak milk is boiled, curdled with starter/lemon juice, pressed in wooden molds to express whey, and either consumed fresh (soft churpi) or sun-dried and smoke-cured for months into rock-hard blocks (hard churpi).
• It is classified technologically as an artisanal Cheese equivalent.
• nalysis:
• (Cheese): Correct.

Correct option: (4) Cheese