Evaluation of Nitrogen, Phosphorus, and Organic Matter Balance in the Feedlot as Affected by Nutrition

A steer finishing trial was conducted to evaluate level and source of dietary fiber on nitrogen, phosphorus, and organic matter excretion. One-hundred twenty steers were fed one of the following treatments: wet corn gluten feed (41.5% of diet DM), 7.5% roughage diet, and all concentrate diet. Nitrogen, phosphorus, and organic matter intake of steers fed wet corn gluten feed were greater than the other two treatments. Fecal nitrogen output was greatest with the wet corn gluten feed diet. All treatments lost about 50% of excreted nitrogen through volatilization. The all concentrate treatment had the highest percentage of phosphorus and organic matter in runoff compared to the other two treatments. All treatments had 65 to 78% of excreted phosphorus and 35 to 55% of excreted organic matter incorporated into the top three inches of the soil. The wet corn gluten feed treatment had the greatest percentage of excreted nitrogen, phosphorus, and organic matter removed from the pens when compared with the other treatments. Different diets can affect the amount of nutrients excreted and subsequently the retention or loss of nutrients from the waste