Abstract #55

Section: ARPAS Symposium
Session: ARPAS Symposium: Sustainable Dairy Production
Format: Oral
Day/Time: Monday 11:15 AM–12:00 PM
Location: Room 301 E
Recorded Presentation is being recorded
# 55
Modifications to the CNCPS related to environmental issues—Capability to evaluate greenhouse gasses, nitrogen and phosphorus excretion at the farm level.
Michael E. Van Amburgh*1, Larry E. Chase1, 1Cornell University, Ithaca, NY.

The Cornell Net Carbohydrate and Protein System (CNCPS) was developed to evaluate nutritional adequacy and predict nutrient supply and requirements in cattle under most management and environmental conditions. Evaluations of this capability have been published and the model is in continuous development (Tylutki et al., 2008; Van Amburgh et al., 2015). As model precision increases, the ability to develop or integrate extant equations to predict excretion of feces and urine and gasses from digestion also increases as those predictions are outcomes of predicting metabolizable energy and protein supply. For example, the ability to predict urinary and fecal nitrogen (N) was through evaluation of extant equations (feces) and development of a new equation that predicted urinary excretion (Higgs, et al., 2012). Implementation of this capability in 8 herds in NY was shown to reduce manure N excretion by 14% (22 kg/cow/yr) resulting in $163 increased income over feed costs (Chase, 2018). Greenhouse gas (GHG) production from cattle has been extensively studied and modeled as part of the development of DE, ME and NE equations, thus if the model is adequate at predicting those variables, predictions of GHG should be less complicated. Extant equations from Casper and Mertens, (2010) for CO2 and Mills et al. (2003) for methane were tested and adapted and were very robust at predicting GHG emissions. Total emission of CO2 per cow was positively related to total milk yield (R2 = 0.69). However, CO2 emissions per kilogram of milk as a function of milk yield (kg CO2/kg milk) resulted in a negative relationship, (R2 = 0.81). The average value of CO2 emission per unit of milk yield was 0.353 kg CO2/kg, with minimum and maximum values of 0.283 and 0.423 kg CO2/kg milk, respectively. Methane emissions per kg DMI ranged from 0.021 to 0.027 with a mean of 0.024 kg. Methane emissions were positively correlated with milk yield (slope = 0.004; R2 = 0.68) but negative correlated when expressed as a function of milk yield (slope = −0.26; R2 = 0.88) (Van Amburgh et al., 2015).

Key Words: environment, efficiency, CNCPS

Speaker Bio
Mike Van Amburgh is a Professor in the Department of Animal Science and a Stephen H. Weiss Presidential Fellow at Cornell University, where he has a dual appointment in teaching and research. His undergraduate degree is from The Ohio State University and his PhD is from Cornell University. He teaches multiple courses and leads the Cornell Dairy Fellows Program, advises approximately 50 undergraduate students, and is the advisor for the Cornell University Dairy Science Club. Mike currently leads development of the Cornell Net Carbohydrate and Protein System, a nutrition evaluation and formulation model used worldwide and through that effort is focused on enhancing the efficiency of nutrient use by ruminants to improve the environmental impact of animal food production. A significant focus of his current work is to understand whole animal and ruminal nitrogen metabolism and amino acid supply and requirements to enhance the development of the Cornell Net Carbohydrate and Protein System. Further, his group is active in developing methods to better describe the interaction between forage and feed chemistry, rumen function and nutrient supply to compliment the model. He has authored and co-authored over 70 journal articles and many conference proceedings and is the recipient of several awards including the ADSA Foundation Scholar Award, the Land O’Lakes Teaching and Mentoring Award from ADSA, the American Feed Ingredient Association Award for Research, the CALS Professor of Merit Award, and the CALS Distinguished Advisor Award. In 2016, he was named a Stephen H. Weiss Presidential Fellow, the highest teaching award given by Cornell University.