Progress 10/01/06 to 09/30/09
Outputs
OUTPUTS: The results of this project have been disseminated in a number of ways. The revised fecal and urinary nitrogen excretion equations have been incorporated into the current version of the Cornell Net Carbohydrate and Protein System (CNCPS) model. This ration evaluation and formulation tool is used by feed industry personnel to do rations for individual dairy herds. These improved equations will be especially valuable as the tool is used in nutrient management planning. Results of this project have also been presented at a number of meetings. Presentations have been made at the Cornell Nutrition Conference. This meeting has about 400 participants from all segments of the feed industry. Presentations have also been made at our Feed Dealer Seminars. These are 7 regional meetings in New York with an attendance of about 200 individuals. These are the feed industry people that work on farms on a daily basis. Wriiten reports have also been provided. A recent article on the project was in the December issue of Eastern Dairy Business. This publication is mailed to more than 10,000 dairy producers. Two scientific journal papers and a series of Fact Sheets are also being prepared to further disseminate the results of this project. PARTICIPANTS: The following individuals were participants in this project. 1. One student conducting M.S. research. 2. 2 feed industry professionals were involved in the on-farm demonstration research portion of the project. 3. 2 dairy producers participated in the on-farm demonstration trial. 4. 9 feed industry professionals provided information on 14 dairy herds feeding lower crude protein rations. 5. 2 milk cooperatives participated by providing daily bulk tank milk urea nitrogen data an 1,245 dairy herds. There have been and continue to be training opportunities as a result of this project. Presentations have been given to Extension educators, dairy producers and feed industry professionals on the results of this project. We have also included this material in short courses for feed industry professionals. TARGET AUDIENCES: The primary target audiences for this project are: 1. Dairy producers 2. Feed industry professionals 3. Extensioin educators The primary efforts from this project are: 1. Dissemination of the results via presentations at meetings including dairy producers and feed industry professionals. 2. Distribution of written materials and articles to the target audience groups. A recent article in a popular press magazine went to more than 10,000 dairy producers. 3. This information has been incorporated into our dairy cattle nutrition course for undergradauate students. 4. This information has been used in feed industry short courses. This effort will continue. 5. Additional Fact Sheets and written materials will be developed. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
A number of approaches were used in this project to enhance the efficiency of nitrogen utilization by dairy cows. One was an evaluation and refinement of the nitrogen (N) excretion prediction equations in the Cornell Net Carbohydrate and Protein System model. Literature data was obtained from 32 papers containing 104 rations. The N excretion predicted by the CNCPS model was compared with the actual messured N excretion in these trials. Revised equations were then developed to predict total N, fecal N and urinary N excretions. The final r-squared value was 0.96 when the revised equations were tested against the experimental data. These equations have been incorporated in version 6.1 of the CNCPS model. A second approach was a field trial on 2 commercial dairy farms to lower ration crude protein (CP) levels. Rations were adjusted using the CNCPS model over an 8 month period. Milk production was not affected by the ration changes. In Herd A, ration CP levels were lowered from 17.5 to 16.6% during the trial. This is a decrease of 8% in daily N intake. Daily N excretion went down 12%. Income over purchased feed cost went up by 89 cents/cow/day. In Herd B, ration CP went from 17.7 to 16.9%. Daily N intake was 4% lower while N excretion decreased by 6%. Income over purchased feed cost incresed by 35 cents/cow/day. These results indicate that both N intake and excretion can be reduced in dairy cattle rations while maintaining milk production and improving profitability. A field survey of nutritionists was also conducted to identify dairy herds that are already feeding lower CP rations. Currently, data is available from 14 herds in 4 states. Ration CP levels range from 14.3 to 16.5% CP. These herds average greater than 80 pounds of milk per day so they represent higher producing herds. These herds have higher ration starch levels that would stimulate microbial protein production. The additional microbial protein is compensating for the lower levels of CP in the ration to provide adequate metabolizable protein to support milk production. These herds also had higher efficiences of converting feed N to milk N (range was 28 to 36%). A pilot study was also conducted to examine the variability in daily bulk tank milk urea nitrogen (MUN)levels. Daily data from 1,265 farms was provided by 2 milk cooperatives. The data for each herd covered a 3 month period. The standard deviation for daily MUN values on a monthly basis ranged from less than 0.5 to greater than 2 mg/dl. It is theorized that this variation could be used as an index of the variation that exists in daily feeding management practices on dairy farms. Additional work needs to be done to explore this possibility. The overall impact of this project is that both feed N intakes and daily N excretion can be reduced on dairy farms while milk production is maintained and profitability is increased. This benefits society by lowering the environmental impact of the dairy industry. Dairy producers benefit from the improved profitability.
Publications
- Higgs, R.J. 2009. Nitrogen use efficiency and sustainable nitrogen management in high producing dairy farms. M.S. thesis, Department of Animal Science, Cornell University.
- Chase, L.E., R.J. Higgs and M.E. Van Amburgh. 2009. Feeding low crude protein rations to dairy cows - opportunities and challenges. Proc. Cornell Nutr. Conf., Syracuse, NY. Pp:235-241.
- Chase, L.E. 2009. Opportunities to increase nitrogen utilization by feeding lower crude protein rations. Proc. Virginia State Feed Assoc. Conf., Roanoke, VA. Pp:86-91.
- Higgs, R.J., L.E. Chase and M/E. Van Amburgh. 2009. Assessing the ability of the Cornell Net Carbohydrate and Protein System to predict fecal and urinary nitrogen excretion in lactating dairy cows. J. Dairy Sci. 92(Supp. 1):479
- M.E. Van Amburgh, T.R. Overton, L.E. Chase, D.A. Ross and E.B. Recktenwald. 2009. The Cornell Net Carbohydrate and Protein System: Current and future approaches for balancing amino acids. Proc. Cornell Nutr. Conf., Syracuse, NY. Pp:29-38.
- Chase, L., R. Higgs and M. Van Amburgh. 2009. Lower ration crude protein has many benefits. Eastern Dairy Business. 1(12):22-23.
- Chase, L.E., R.J. Higgs and M.E. Van Amburgh. 2009. Feeding lower crude protein rations to dairy cows - Opportunities and challenges. Proc. Feed Dealer Seminars. Anim. Sci. Mimeo 238, Department of Animal Science, Cornell University Pp:1-7.
- Schmit, T.M., R.N. Boisvert, D. Enahoro and L.E. Chase. 2009. Optimal dairy farm adjustments to increased utilization of corn distillers dried grains with solubles. J. Dairy Sci. 92:6105-6115.
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Progress 10/01/07 to 09/30/08
Outputs
OUTPUTS: Milk urea nitrogen (MUN) is a tool that can be used to assess the efficiency of nitrogen (N) use in dairy cattle. MUN values are available to dairy producers from either the Dairy Herd Improvement (DHI) program or from bulk tank data provided by the milk cooperative. Two studies were done to assess MUN levels in dairy herds. DHI data for 872 dairy herds tested in July, 2008 was used. 48% of these herds had MUN values within the 8-12 mg/dl target range. About 4% of the herds had values < 8 mg/dl while the remaning herds (48%) had MUN values > 12 mg/dl. This indicates an opportunity to lower ration N levels and improve the efficiency of N use in these herds. A second data set was provided by 2 milk cooperatives that contained daily bulk tank MUN values over a 3 month period for 1,388 dairy herds. The objective was to assess the varaiation in MUN values within a month on dairy herds as a potential index of the daily consistency of the feeding program. The mean MUN value was 12.1 mg/dl with a standard deviation (SD) of 2.96. 38% of the herds had an SD of 0.5 - 0.9 while 40% had an SD of 1 - 1.4. 5% of the herds had an SD > 2 while 1.5% of the herds had an SD < 0.5. This initial evaluation does indicate that a significant amount of variability exists in daily bulk tank MUN values within herds. A study is planned to expand on these results. MUN can also be used to estimate urinary N excretion in dairy cattle. A number of prediction equations exist to predict daily urinary N excretion from MUN. A 100 cow dairy herd with an average MUN of 8 mg/dl would excrete about 31 pounds of urinary N per day. The calculated urinary N excretion would increase to 44 and 58 pounds per day for the same herd if average MUN values were 12 or 16 mg/dl. This is an increase of 42 and 87% in daily urinary N excretion compared to the base herd with a MUN value of 8 mg/dl. A field study using commercial dairy herds is in progress to evaluate the impact of lowering ration crude protein levels on feed cost, milk production, MUN and nutrient excretion. This trial is done in cooperation with the feed professional working with the farm on a routine basis. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The results of this work have been made available by 2 primary methods to date. A presemtation on the milk urea nitrogen (MUN) information was made at a series of 8 meetings in New York for feed industry professionals. There were about 200 total participants in these meetings. An article containing some of the MUN results was published in the Northeast Dairy Business magazine. This publication is sent to > 10,000 dairy producers in the Northeastern U.S.
Publications
- Chase, L.E., T.R. Overton and R. Higgs. 2008. Milk urea nitrogen - it's worth another look. Proc. 2008 Feed Dealer Seminars. Animal Science Mimeo 236. Dept. of Animal Science, Cornell University, Ithaca, NY. pgs. 4-8. Chase, L. and M. Van Amburgh. 2008. Are your rations environmentally friendly Northeast Dairy Business. 10(12):21.
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Progress 10/01/06 to 09/30/07
Outputs
The Cornell Net Carbohydrate and Protein System (CNCPS) model can be used to predict both nitrogen (N) and phosphorus (P) excretion by dairy cattle. Total daily N excretion is one of the outputs from this dairy ration evaluation program. In addition, the N excreted can be further divided into fecal and urinary N. The ability to predict urinary N excretion provides an index of ammonia emissions from dairy cattle. However, these predictions have not been validated with data from research trials containing total, fecal and urinary N data. This validation step is required before this tool can be applied to estimate N excretion in field situations. Two sets of data were obtained from published research trials in which N excretion was measured in total collection animal trials. One set was 12 diets fee to growing dairy heifers in 4 studies. The range in daily total N excretion in this set of data was 54 to 219grams. The correlation between the actual and predicted total N
excretion in the heifer data was 0.9493. Similar correlations for fecal and urinary N excretion were 0.9018 and 0.9002. This initial evaluation with growing dairy heifers indicated that the CNCPS model was doing a good job of predicting N excretion. A second set of data was 88 diets fed to lactating dairy cows in 24 published research trials. The total daily N intakes in these diets ranged from 256 to 889 grams. Total daily N excretion ranged between 173 and 638 grams. The correlation between actual and predicted total daily N excretion was 0.7167 in this set of data. The correlations for fecal and urinary N excretion were 0.8182 and 0.6131 in these diets. There was no screening of the data sets included for potential errors or losses in the N excretion data reported. It is normal that there will be some of the intake N that is not recovered and reported as excreted in total collection trials. This area needs to be further examined as the CNCPS model assumes that the entire N intake
needs to be accounted for in excretion via milk, feces or urine. These results indicate that the CNCPS model can be used to estimate N excretion in dairy cattle. However, these results also indicate that some additional refinement or improvement of the lactating dairy cow excretion model in the CNCPS program is needed.
Impacts
The results of using the CNCPS model to predict total, fecal and urinary N excretion will permit dairy rations to be fine tuned to decrease N excretion to the environment. This will be done primarily by improvimg the efficienmcy of N use in the rumen and decreasing the total grams of N fed to the animals. A the efficiency of N use is increased in the dairy cow both the total and urinary N excretions are reduced. The reduction in urinary N excretion will also result in less ammonia emissions from the animal. A 10% reduction in N excretion has been reported to decrease ammonia emissions by 15-20% in other studies.
Publications
- Ketterings, Q.M., E. Fenay, J.H. Cherney, K.J. Czymmek, S.D. Klausner, L. E. Chase and Y.H. Shukken. 2007. Application of manure to established stands of alfalfa and alfalfa-grass. Online. Forage and Grazinglands. dol:10.1094/FG-2007-0418-01-RV
- Wolfe, D.W., L. Ziska, C. Petzoldt, A. Seaman, L.E. Chase and K, Hayhoe. 2007. Projected change in climate thresholds in the Northeastern U.S.: implications for crops, pests, ;ivestock and farmers. Online. Mitigation and Adaptation Strategies for Global Change. Online. DOI:10.1007/s11027-007-9125-2
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