What We Have Learned from Feeding Less Protein
Feed less protein and still maintain milk production. That’s one of the many benefits of implementing precision feed management on your dairy. Other benefits include less nitrogen and phosphorus excretion, a decrease of purchased feeds, improved efficiency of nutrient use and even improved profitability.
Precision feed management (PFM) can help you achieve all of these benefits, explains Larry Chase, professor emeritus of dairy nutrition at Cornell University. What exactly is PFM? “The continual process of providing adequate, but not excess, nutrients to the animal and deriving a majority of nutrients from homegrown feeds through the integration of feeding and forage management for the purpose of maintaining environmental and economic sustainability.”
PFM is a process. It doesn’t happen overnight. It requires a team approach from the dairy producer, key dairy employees and feed and crop advisors with one goal: To provide a consistent ration with minimal variation in order to improve the efficiency of nutrient use, maintain or grow milk production and minimize the dairy’s environmental impact. Ration formulation, feed purchasing decisions, feed and forage analysis, feeding management practices, forage production and even forage storage all play a role in achieving positive results.
So what is the potential impact? Chase uses the example of a lactating dairy cow that weighs 1,450 lbs, produces 70 lbs of milk per day and consumes 47 lbs of dry matter per day. If the percent of crude protein in her ration is reduced by one unit, it cuts the amount of nitrogen she excretes by 27.5 lbs/year. If the ration phosphorus is reduced by 0.05% the result is 8.5 lbs less phosphorus excreted by the cow each year, he explains. Multiply these results by 1,000 cows and the difference becomes 27,500 lbs less nitrogen and 8,500 lbs less phosphorus excreted as waste. Given the increasing pressure animal agriculture faces about environmental concerns and regulations, if you can reduce the amount of nutrients excreted as waste and still maintain or grow milk production, it’s a win-win that should be considered.
During the last decade the PFM Working Group has conducted multiple projects with commercial dairies of all sizes to understand how best to implement PFM, measure results and demonstrate its benefits. Cerosaltetti (2012), in a report to the U.S. Army Corps of Engineers, reported results for 34 herds enrolled in the PFM program between 2008 and 2011 in Delaware County, N.Y. These herds decreased purchased grain by about 2 lbs/cow/day and increased forage in the ration from 59 to 65.4%. The amount of phosphorus and nitrogen excreted in manure decreased by 18.6% and 9.8%, respectively. In addition, milk income over purchased feed cost increased by 50 cents/cow/day.
A 2017 report by Cerosaletti and Dewing and submitted to the NYC Watershed Agricultural Program showed that by implementing PFM 8 dairies were able to decrease phosphorus and nitrogen in manure by 23% and 7% respectively and milk income over purchased feed cost increased by 46 cents/cow/day. In an eight-month study by Higgs et al. (2012) 2 western New York dairies were able to lower ration crude protein by 1.7 units, milk urea nitrogen decreased by 2 mg/dl and milk production was maintained in these herds. The amount of nitrogen excreted in manure decreased by 6% on one dairy and 17.8% on the other dairy. Total daily feed cost at the 2 dairies decreased by 21 and 72 cents/cow/day, and income over purchased feed cost increased by $0.27 and $1.27 dollars/cow/day.
Cornell Cooperative Extension conducted a three-year study with 8 dairies that fed concentrates and forages. During the project, each dairy was able to reduce the amount of crude protein in the diet and decrease the amount of nitrogen excreted in manure. Reduction in crude protein ranged from 0.7 to 4.5%, and the decrease in nitrogen in manure ranged from 5.2 to 29%. All dairies saw an increase in income over feed cost. The average income over total feed cost was $147/cow/year, and the average income over purchased feed cost was $158/cow/year.
A five-year trial on a commercial dairy was reported in The Professional Animal Scientist (Tylutki et al., 2004). The 500-cow dairy incorporated changes in the ration, feed management procedures, forage production and forage storage to meet the goals of the PFM program. During that time, total animal numbers increased by 23%, total milk shipped per day increased by 45%, daily feed cost decreased by 34% and the amount of phosphorus and nitrogen excreted in manure decreased by 28% and 17%, respectively.
The PFM Working Group has developed a set of benchmarks to evaluate dairies at the beginning of a project and to track their progress toward goals. These benchmarks are the foundation used to build precision feed management programs on dairies.
New York PFM Benchmarks
|Forage NDF intake, % of BW||≥0.9|
|Forage DM, % of total ration DM||≥60|
|Homegrown feed, % of total ration DM||≥60|
|Ration P, % of NRC requirement||<110|
|Ration CP, %||<16.5|
|Milk urea nitrogen, mg/dl||8-12|
|Cows dead or culled <60 days in milk, %||<8|
Work to date indicates that the development and implementation of precision feed management plans on dairies is a win-win for the farm and for the environment, says Chase. The results from these studies, and from on farm use, consistently demonstrates that when dairies implement PFM practices it yields positive results. The dairies purchase less feed and therefore import less phosphorus and nitrogen, have improved nutrient efficiency, are able to at least maintain or increase milk production and reduce the amount of nitrogen and phosphorus excreted into the environment. All of these factors combined can help improve dairy profitability and sustainability.