Nitrogen intake and subsequent excretion were decreased with steers fed the experimental treatment. During the summer more N was removed from pens on the experimental treatment since OM excretion was greater which led to decreased N volatilization. With the concentration of the feedlot industry into fewer acres and fewer producers, waste management is becoming an increasingly important issue. Feedlot design has advanced to handle the nutrient concentration from manure in these feedlots, particularly surface runoff and leaching. From a cost perspective, minimizing total manure production and removal time is advantageous.
N needs to be applied to optimize crop yields.
Increasing the N or decreasing the P will add value to the manure relative to crop needs. From an environmental perspective, decreasing total N and P excretion would be advantageous to improve the sustainability of the industry. The animal's requirement changes with age and time on feed. Calves have a higher requirement for MP than yearlings. At the same time, calves require less MP at the end of the finishing period than at the beginning.