Economically sustainable shade design for feedlot cattle

Area of Science:

• Animal Science
• Agricultural Engineering
• Environmental Science

Background:

• Heat stress negatively impacts feedlot cattle welfare and productivity.
• Existing literature lacks comprehensive economic data on shade implementation.
• Novel shade designs can mitigate heat load and improve animal conditions.

Purpose of the Study:

• To evaluate the economic impact of a novel shade structure on feedlot cattle.
• To assess the effects of shade on animal welfare and productive performance.
• To introduce and validate a new shade design for optimal solar radiation protection and resilience.

Main Methods:

• Eight hundred crossbred bulls were assigned to pens with or without galvanized steel-roof shade structures.
• Performance metrics (body weight gain, feed intake, carcass weight) and heat stress indicators (body temperature, respiration rate, water intake) were monitored.
• Economic analysis used net present value, and meteorological data informed the InComfort Index (InCI).

Main Results:

• Shade structures reduced radiant heat load, with 80% of cattle using shade on hot days (InCI > 0.6).
• Shaded cattle exhibited lower water intake (3.4 L/animal), body temperature (5°C), subcutaneous temperature (1°C), and respiration rate (10 breaths/min).
• Hot carcass weight increased by 8 kg/animal, despite similar dry matter intake, indicating improved feed efficiency.

Conclusions:

• The novel shade design is economically profitable, with an estimated 4-cycle payback period ($90/animal investment).
• Implementation of shade structures enhances animal welfare and productive performance in feedlot cattle.
• This study confirms the financial viability and benefits of improved shade design for sustainable cattle production.