• Rumen Metabolite Concentrations Across Ruminants: The concentration of total Volatile Fatty Acids (VFA) and ruminal ammonia ($NH_3\text{-N}$) is highest in goats compared to buffaloes, sheep, and cattle.
• Physiological Reasons:
• Goats are intermediate / concentrate selectors (browsers) possessing a smaller rumen capacity relative to metabolic body weight, higher salivary secretion rate with greater buffering capacity, and higher fermentation rate per unit rumen volume.
• Rapid microbial turnover and intense fermentation kinetics in goats lead to elevated peak VFA ($\gt 120\text{--}150\text{ mmol/L}$) and ammonia levels.

Correct option: (1) Goat