Protein content in dairy cattle diets affects ammonia losses and fertilizer nitrogen value

• Published in: Journal of environmental quality 1998-05, Vol.27 (3), p.528-534
• Main Authors: Paul, J.W. (Agriculture and Agri-Food Canada, Agassiz, British Columbia, Canada.), Dinn, N.E, Kannangara, T, Fisher, L.J
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; ALIMENTACION DE LOS ANIMALES; ALIMENTATION DES ANIMAUX; AMMONIA; AMMONIAC; AMONIACO; ANIMAL FEEDING; Biological and medical sciences; BOVIN; BOVIN LAITIER; CATTLE; CONTENIDO PROTEICO; DAIRY CATTLE; DAIRY INDUSTRY; DECHET; DESECHOS; DIET; DIETA; EMISSION; ESTIERCOL; FARMYARD MANURE; FUMIER; Fundamental and applied biological sciences. Psychology; GANADO BOVINO; GANADO DE LECHE; INDUSTRIA LECHERA; INDUSTRIE LAITIERE; PROTEIN CONTENT; REGIME ALIMENTAIRE; Soil and water pollution; Soil science; TENEUR EN PROTEINES; WASTES
• ISSN: 0047-2425; 1537-2537
• DOI: 10.2134/jeq1998.00472425002700030008x

Altering feeding strategies for dairy cattle (Bos taurus) may reduce manure N excretion and NH3 emission from the manure. We determined the effect of dietary formulation on NH3 emission immediately following manure excretion and the availability of manure N for plant growth. Manure (urine and feces) was collected from dairy cattle fed diets containing crude protein levels of 16.4% (T1High), 15.3% (T1Med), and 12.3% (T1Low) in trial 1, and 18.3% (T2High), 16.7% (T2Med), and 15.3% (T2Low) in trial 2. Ammonia emission was measured in the laboratory for up to 48 h. Emissions during the first 24 h following manure excretion were 38 and 23% of the total manure N from Diets T1High and T1Low, and 22, and 15% of the total manure N from Diets T2High and T2Low. Manure NH4+ concentration and pH were positively related to the dietary crude protein level. Manure from cattle-fed diets T1Med and T1Low were applied to soil at two rates to determine short-term N availability for three plantings of corn (Zea mays L.) grown for 30 d each in the greenhouse. The recovery of manure and fertilizer N in the plants and the soil for the first two plantings was 48, 31, and 103% for the T1Med, T1Low, and inorganic N treatments, respectively. Whole farm N utilization for diets T2High and T2Low were estimated at 18 and 23%, respectively. Feeding diets lower in crude protein increases efficiency of N on the dairy farm, decreases NH3 emissions following excretion but also decreases the short-term N availability of the manure