Which statement about a lactation curve is true?

• A. It shows the genetic lineage of the cow
• B. It shows milk yield over time after calving, typically rising to a peak then declining
• C. It measures feed intake only
• D. It is flat across lactation

Answer: (B)

A lactation curve represents how milk production changes over the course of a cow’s lactation after calving. It typically rises after calving to a peak and then gradually declines as lactation continues. This pattern happens because milk yield increases as the mammary gland becomes fully stimulated by lactation hormones and the cow’s energy and nutrients are allocated to milk production, but eventually the gland’s capacity and energy balance lead to a gradual drop in output. This curve is used to manage nutrition, milking schedules, and predict total lactation yield. The other statements don’t fit: pedigree describes ancestry, not milk production over time; measuring feed intake is a different metric from milk yield; and a flat curve would not reflect the natural rise and fall of lactation.