ABSTRACT
244Photoperiod manipulation, also known as long-day lighting (LDL), is the management practice of using a designed lighting system to artificially extend the duration of light that a lactating cow is exposed to light with the goal of increasing milk production. Photoperiod manipulation has gained much wide span industry interest.4 Appropriate lighting can improve productivity and safety on a dairy farm. On average, lighting represents 17% of total dairy farm electrical energy use. Optimal lighting conditions may increase milk productivity and conserve energy consumption. Factors that contribute to increased milk production include: the type of light, the amount of light provided per watt, the temperature of the work area, the height of the ceilings, and the length of the lighting period. By making these changes, along with other improvements, the dairy operation and lighting system will be more energy efficient. 245This can lead to improved farm productivity and increased revenue, while lowering energy costs.
