Monitoring Dry Matter Intake

Dry matter intake (DMI) is the biggest driver of milk production so it only makes sense that it should be monitored as closely as milk production.  Dry matter intake is a measure of what is presented to the cows minus what is remaining when the next feeding is provided.  It can be impacted by a number of factors, but unless you have a good idea as what the true DMI on your farm is it will be very hard to trouble shoot when a problem does arise.

In order to track DMI the dry matter of the ration and the refusals need to be monitored regularly.  If the herd is fed using a component feeding system then the dry matter of the individual ingredients also need to be tracked.  Like any type of analysis, getting a good representative sample is the first and most important step to the process.  Sampling a total mixed ration can be difficult, but taking a sample right at the mixer is one of the best ways to get a good sample.  A refusal sample should be taken from the refusal collection from the entire herd, not just what was in front of a couple of animals.  Once the sample is taken it is dried in either a Koster tester or a microwave oven until the weight of the sample no longer changes.  The dried weight is then divided by the wet weight to determine the dry matter percent.  Although there will be fluctuations in dry matter from week to week, if there are big changes then mixing of the total mixed ration should be investigated to make sure it is being done properly.  

The other aspect of monitoring DMI requires that the amount of feed being presented to the cows is known.  Mixing and delivering the ration as close to what is on the feed sheet should always be the goal.  Scales that are not calibrated correctly or not working well can significantly change what is being presented to the cow.  Therefore, checking the scales every week is a good practice to get into and does not take a lot of time.  A less precise way to monitor mixing of the ration is to track feed inventory on the farm.  If grain bins are getting empty faster or slower than would be expected based on the formulated ration this indicates a problem.  Either there is a problem with mixing the proper amount of each ingredient, or pests (birds/rodents) are eating the feed from the storage area.  Pests can also eat the feed once it is in front of the cow, which can make DMI look greater than it actually is.  Pests will not only impact feed inventories and DMI, but they can also spread disease so trying to eliminate them should be a priority.

Lastly, in order to get the full picture of DMI on the farm, the refusals from each group of animals needs to be weighed.  Depending on the feeding situation on the farm this job will be easier for some than others.  However, it is worth the effort because simply eye-balling it is not always the best method of estimating how much the cows are not eating because gradual changes in intake may go undetected until they reach a significant threshold.  If problems in intake are detected early it may be possible to correct them before they lead to big changes in milk production.  Therefore, taking the time and effort to weigh back refusals a least a few times a month will keep the eyeballing method honest and may head off some bigger problems. 

Feed Efficiency

Feed efficiency is something that has been extensively used by beef, swine, and poultry producers for years, but dairy farmers have not utilized it to the degree that it could be.  Feed efficiency reflects how well the cows convert feed into milk.  It is one of the most basic production measures on the farm and will directly impact of bottom line of the farm.  The more milk that can be gained for each pound of feed consumed equates to greater income on the farm, but you cannot improve on something you are not tracking to begin with. 

Feed efficiency is defined as pounds of 3.5% fat corrected milk per pounds of dry matter intake.  It is a simple calculation that should be tracked on every farm.  Fat corrected milk is not a value that dairy farmers deal with regularly but the following is the equation for calculating it:  3.5% fat corrected milk = 0.432 x milk (lb) + 16.23 x fat (lb).

So what is the goal?  For a one group herd at 150 to 225 days in milk we would expect a feed efficiency of between 1.4 and 1.6 lb 3.5% fat corrected milk per pound of feed.  However, goals for specific groups will depend on the diet as well as the cows themselves.  Cows that are fewer days in milk will have higher feed efficiency, which means they put more feed into milk and less into weight gain.  This is obvious to many farmers, but understanding that this is the case can also be a good motivation to get cows bred in a more timely manner so that the average days in milk is lower and there are more cows with higher feed efficiency on the farm.  Also, older cows will tend to be more efficient than heifers because heifers are still growing and some of their intake is going into growth and not into milk production.  There is not much that can be done to correct this, but it is good to understand that heifers will be less efficient.  Lastly, pregnant animals are less efficient than non-pregnant animals because some of the nutrients in the feed are going towards supporting the fetus instead of all of it going to milk production.  Again, there is not much to be done about this because we need cows to be pregnant, but it is good to recognize this.  

From a feeding standpoint, anything that increases the digestibility of the diet will increase feed efficiency because the cows will be able to get more out of the feed than they will out of less digestible feeds.  Forages are one of the main ingredients in the ration and the most variable in terms of digestibility.  In general, forages that are lower in neutral detergent fiber and lignin are more digestible and will be utilized to a greater extent by the cow than forages with higher fiber content.  

Grains are the other main ingredient in many rations and how well they are processed will impact how efficiently they are used.  Processing corn silage so that kernels are broken down into at least quarters will increase the utilization of the starch in the kernels. The more the kernels are broken the more access the rumen microbes have to the starch and the more they can utilize the starch.  This is the same reason why fine grinding of shell corn is recommended.

Improving feed efficiency has economic benefits, but the environmental benefit is if more of the feed is broken down and utilized for milk production than there will be less manure to deal with on the back end. 

Feed Management Plans Being Embraced

Pennsylvania’s NRCS (Natural Resources Conservation Service) set a goal of 40 feed management plan applications this year and they have already received 43 applications! This is a great start to a program that has so much potential to help farmers and the environment. The overall goal of the program is to adjust rations and feeding procedures on the farm in order to reduce the amount of nitrogen and phosphorus in the feed. When less of these nutrients are fed to the animals less ends up in the manure. Therefore, if the manure does happen to make its way to a local water way it will have less of an impact on local water quality and the Chesapeake Bay overall. The plan is written by a certified nutritionists and that nutritionist then has to follow up with the farm quarterly to make sure the plan is being implemented and make any adjustments to the plan.

Although there are a lot of environmental benefits to having a feed management plan there are also economic benefits to the farmer. The first year of the contract a farmer can get $2,000 per group of animals and they can have up to five groups on the farm so that farm could receive $10,000 the first year to cover the cost of the plan writing and implementation. There is also money available for the second and third year of the contract, although the most money is allocated for the first year. Also, it has been shown that farmers that follow a reduced nitrogen and phosphorus ration tend to have lower feed costs and if implemented correctly the cows can actually produce more milk than they did on a conventional ration.

So why aren’t more than 43 farmers involved in this program? For one, it is a new program that many farmers don’t even know exists so there is still a lot of work to do to bring attention to it. Two, the fear of losing milk production is always a concern when rations are adjusted. Lastly, this type of plan takes a consistently high level of management to implement well on a farm. It takes attention to the details every day, which can be a big change to some producers. However, I think a plan could be developed to work into any farm situation and the benefits of a few small adjustments could be great.

Dietary Phosphorus and Water Quality

cattle-manager.com

Phosphorus (P) is a very important mineral for both cows and their rumen microbes.  It is involved in almost all metabolic reactions so being deficient can be very detrimental.  However, it is also a very important element in almost all metabolic reactions in plants.  Therefore, as cows eat plants and plant materials they are getting enough P to meet their requirements.  Grains tend to be higher in P compared with forages, and byproducts (distiller’s grains, corn gluten feed, and wheat midds) tend to be the highest.  Because it is so prevalent in plants supplemental P is almost never needed.  

What is the big deal about P?  The issue with P is that, like animals and plants on land, algae also need P to grow.   When too much P gets into waterways either through manure contamination or soil erosion algae grows uncontrollably.  Too much algae in the water blocks out the light killing aquatic plants, which serve as habitat and food supply of higher level organisms.  When this algae bloom finally dies the decomposition of the algae draws oxygen out of the water making it impossible for fish and other aquatic organisms (fish, shellfish, etc.) to survive.  

So how much is too much?  Like the level of any nutrient, the level of P required for the cow depends on her milk production and how available the P in the feed is.  However, in most cases a P concentration of 0.35% to 0.38% of ration dry matter will be enough to meet the needs of the cow.  In the “Reducing Dietary Phosphorus in the Dairy Herd” publication by Zhiguo Wu and Virginia Ishler with Penn State University there is a nice example of how overfeeding P in the ration contributes to higher levels in the manure.  For a cow milking 75 lbs and eating 50 lbs of dry matter, a dietary P content of 0.35% of ration dry matter will result in 1.9 lbs/ton of P in the manure where as a dietary P content of 0.48% of ration dry matter will result in 2.9 lbs/ton of P in the manure.  Because P fed above the level that the cow needs will just be excreted going from a recommended P level of 0.35% to a high level of 0.48% results in the significant increase in manure P levels.  

Higher manure P means that there may be limitations as to where that manure can be spread.  Another calculation from this publication shows that when a cow is fed a 0.48% P diet compared with a 0.38% P diet an additional 12.2 pounds of manure P is excreted over a 305 day lactation.  This higher P diet would require an additional 0.31 acres to spread the manure on compared with the low P diet.  If additional land was not available P would be applied at 14.5 lbs/acre in excess of what the crop could remove and would result in an increase in the soil P test over time. 

Although many have reduced the level of P in their rations, there are still a few that throw in a little extra for good measure.  This is not only bad for the environment, but it is also represents an unnecessary cost.  Deficiency issues are not seen until you get around 0.3% P, and a dietary level of 0.3% P is hard to create using normal feedstuffs.  Therefore, concerns about loss of milk production or reproductive performance due too little P are unwarranted.  

Phosphorus, has, and will continue to, receive a lot of attention, but the positive side is that it is something that can be easily controlled at the farm level.

Feed Management

Feed Management is an excellent program that all dairy farmers should be taking advantage of.  It is a Natural Resources Conservation Service program that is available nationwide, but is receiving a great deal of attention in Pennsylvania.  When farmers apply for this program they can receive $2,000/group per for the first year, $1,500/group per for the second year, and $1,100/group for the third year of the contract.  A group can be the high producing cows, low producing cows, heifer groups, etc.  Farmers can apply for up to five groups on their farm so that can be a good amount of money.  There has been $1 million set aside in Pennsylvania to cover new plan applications so there is plenty of funding available for anyone who is interested.   The payments are to cover the cost of having a feed management plan written by a certified plan writer and the quarterly follow-up that the plan writer needs to do.  In Pennsylvania, the plan writers are trained by Penn State Cooperative Extension and state extension specialists.  The goal of a feed management program is to reduce nitrogen and/or phosphorus excretion by the cows through ration alterations and/or feed management changes on the farm.  These plans are very flexible and tailored to every individual farm, and are designed to be things that the farmer is capable and willing to implement on the farm.  If you are interested in learning more about this program contact your local NRCS office.

Front End Solutions to Back End Problems

Photo by Dan McFarland

Precision feeding of dairy cows is a great way to address water quality concerns in local waterways and the Chesapeake Bay.  So what is precision feeding?  It is feeding dairy cows to most precisely meet their nutrient requirements based on their level of production.  Because precision feeding depends on the level of milk production it is a very farm specific practice that can be difficult to identify without evaluating more than just the nitrogen and phosphorus content of the ration.  

However, the ration is the first place to start when implementing precision feeding and we will start there with more specifically defining precision feeding.  Phosphorus is a required nutrient for the cow, but it can be supplied in the ration at levels greater than what she needs.  Any excess phosphorus is excreted in the manure and provides no benefit to the cow.  In general, a phosphorus level of 0.37% of the ration is enough to meet the needs of most animals. Supplementation of phosphorus in dairy rations is rarely needed and is a quick ration adjustment to make.  Many farms are doing better at feeding a lower phosphorus diet, but byproducts (brewer’s grains, distiller’s grains, etc.) tend to be a cheaper feed alternative to more traditional feedstuffs, but they are also high in phosphorus.  Therefore, incorporating byproducts into a ration can lead to higher phosphorus diets than would be recommended.

Nitrogen is the other nutrient we are most concerned with and, like phosphorus, excess nitrogen above what the cow needs for her level of milk production will be excreted in the urine.  However, unlike phosphorus, nitrogen cannot simply be reduced in the ration without potential negative impacts.  The amount of energy in the ration along with a number of other factors greatly impacts how efficiently nitrogen is utilized by the cow and how much needs to be included in the ration.  If other aspects of the ration are not balanced correctly or there is a problem with how feed is managed on the farm reducing the protein content of the ration could potentially lead to a loss of milk production.

When done correctly precision feeding will not only benefit local water ways, but will also increase the profitability of the dairy farm by reducing feed costs, but if implementing improperly it can lead to a loss of milk production.  Therefore, implementation of precision feeding requires that the nutritionists and the farmer be educated on this practice before it should be implemented on the farm. 

Penn State University along with other organizations have, and continue to, provide education to farmers and nutrition consults on how to best implement precision feeding on a farm.

Here is a link to the Penn State Extension website with more information on feeding dairy cattle. http://www.das.psu.edu/research-extension/dairy/nutrition

What is in Manure?

Manure can be both a blessing and a curse on many farms.  It is a great fertilizer for the crops, but it also has to be managed diligently from when it comes out of the cow to when it is spread on the field to ensure that it is all ending up where it should.  From collections systems to storage and spreading there are many things to consider about manure management, but one benefit to manure is often overlooked.  It is a great indicator of the health of your cows and how well they are utilizing the diet that is being fed to them.

There is a great deal of effort put into creating a well balanced ration and presenting it to the cow, but after that the cow and her rumen microbes are in control and do we really know what is happening in there?  Yes, we know a great deal about how feeds are digested and utilized, but every farm and every cow are different.  Therefore, the only way to determine how cows on your farm are utilizing your diet is to look at the manure.  Many producers look for loose manure as an indicator that there might be too much protein in the ration or too many concentrates in general.  Some even look at whether there are corn kernels in the manure.  Identifiable corn in the manure is a good sign that not all the corn in the ration is being utilized for milk production.  

However, not many look beyond the looseness of the manure or whether there is corn in it.  There is more that can be learned from the manure and it requires that a manure sample be taken and sent to a lab for analysis.  Manure analysis do not need to be done as often as forage analysis, but looking at it once or twice a year might yield some surprising information.  From an environmental perspective looking at the phosphorus content of the manure will give you a good idea as to whether the diet is providing the right amount of phosphorus to the cow.  Manure phosphorus levels should be between 0.55% and 0.7% in a diet that is meeting the phosphorus requirements of the cow without providing too much.  Manure can also be analyzed for neutral detergent fiber to determine how well the fiber portion of the ration is being utilized.  Starch is also a great thing to measure because it will quantify how much of the starch from the corn in the manure is being excreted.  

In order for manure analysis results to be useful they first need to be taken properly.  The general rule is that 15% of a specific group or up to 20 cows should be sampled.  The sample should be of fresh manure, which means palpating cows or obtaining samples from piles that have recently hit the floor and are not contaminated with feed or bedding.  As with any sampling, it is important that the sample is representative of the entire group.  Samples from all the cows in a group are mixed together and sub-sampled.   The sub-sample is placed in a well sealed container and shipped overnight to a lab that performs manure analysis, or should be frozen if not mailed immediately.  This analysis can take two to three weeks to perform.  The results need to be interpreted relative to the ration that specific group was eating at the time of the sampling.

Having done many manure analysis I understand that it is not something that folks are eager to do, but it is another tool that can be utilized on the farm to help ensure that the ration is being utilized as efficiently as possible.

Tracking MUNs to Limit Ammonia Emissions

Milk urea nitrogen (MUN) is an affective and easy tool for farmers to track how well their cows are utilizing nitrogen from the feed, but it can also be a tool to evaluate air quality on farms. 

Milk urea nitrogen on well managed farms ranges from 8 mg/dl up to 12 mg/dl.  Values higher than 12 indicates that there is nitrogen being wasted and the ration formulation needs to be evaluated.  There are two things that should be looked at in the ration when MUNs are running high.  The first is the amount of protein in the ration.  If the cow is fed more protein than she needs that protein will first be converted to ammonia in the rumen.  Ammonia is then absorbed into the blood stream where it is converted to urea due to the toxicity of ammonia to the cow.  Much of this urea is then excreted as a waste product in the urine, but some will also go into the milk.  Therefore, MUN is a good indicator of how much urea is excreted in the urine.  The other thing to look at in the ration is the amount of available energy.  If there isn't enough energy for the level of protein the protein will be broken down without subsequent microbial protein production and ammonia will be formed.

From a farmer perspective high MUNs indicate that money is being wasted on protein that is not being used for milk production.  From an environmental perspective urea that is excreted in the urine is quickly converted back to ammonia by the urease enzyme found in the feces.  This ammonia creates air quality concerns for the farm and the surrounding area.  It is estimated that 25% of the nitrogen that ends up in the Chesapeake Bay comes from the air as ammonia. 

Protein Utilization on Pasture

Although we tend to worry about cows getting too much protein from the pasture during the lush spring months, the fall bump can also lead to too much protein intake on pasture. Good quality pastures tend to provide more protein than energy in general, but during the spring and fall growing seasons that ratio tilts even further towards protein. Therefore, supplementing either grain, corn silage, or a total mixed ration (TMR) is usually necessary to improve production in grazing herds and increase the utilization of protein from the pasture.

The energy component of the diet can greatly influence how the protein from the pasture is digested. This is because when a cow eats she is not only eating to support her own needs, but also the needs of the microbes in her rumen. When there is energy and protein available at the same time these microbes break down the feed (energy and protein) and use the end products to produce more of themselves (microbial protein). They then pass out of the rumen serving as a protein source for the cow. However, if there isn’t enough energy available, as is the case on pasture, the protein in the pasture will still be broken down, but instead of being converted to microbial protein, feed protein is broken down to ammonia. Ammonia is absorbed into the blood where it is converted to urea. This urea in the blood is the source of milk urea nitrogen (MUN) and urea nitrogen in the urine. Since MUN is coming from the same blood urea nitrogen pool as urea in the urine it is a good indicator of urea excretion and utilization. Excessive urea production and excretion in urine can lead to water and air quality concerns.

Also, from the cow’s standpoint, the production and excretion of excess urea takes energy. There is a paper out of Penn State by Kolver and Muller that estimated excess urea excretion cost the cow almost 4 lbs of milk/day! This is because it takes energy for the cow to convert the absorbed ammonia, which came from excess protein supply in the rumen, to urea. Ammonia is toxic to the cow so this conversion to urea is a necessary energy utilizing process, which cannot be eliminated, but can be reduced through lower protein rations and appropriately matching ration protein and energy concentrations. Are you willing to leave 4 lbs of milk on the table knowing that not only did you lose milk production, but you also lost feed efficiency and it could have been prevented if MUN had been tracked and maintained within the recommended 8-12 mg/dl?

One way to improve nitrogen efficiency from the pasture and decrease MUN is to supplement the pasture with a partial TMR. A study from Penn State supplemented pasture with a partial TMR and saw an 8 lb/day increase in milk production and a 3 mg/dl decrease in MUN compared with pasture supplemented with 19 lb of concentrate. Supplementing with a grain mix or corn silage are also options, but a mixture is usually better at providing digestible energy that is not too fermentable in the rumen.

Although the pasture may be supplying a large portion of the dry matter, supplementing the pasture is necessary to maximize its full potential. Total mixed ration supplementation of pasture allows for better capture of protein from the pasture the nitrogen utilization will be increased, which can be tracked though MUN values. For all the effort that goes into developing and maintaining high quality pastures lets be sure we are getting all we can out of these efforts.

eXtension - A Great Resource

eXtension is a website that was developed within the last 5 years and is turning into a great resources on a number of issues.  All the material on the website is peer reviewed and comes from reputable research institutions and extension professionals so it can be trusted.  It has information on the following general topic areas:

• Community - master gardening and entrepreneurship
• Disaster Issues - floods, oil spill, wildfires, and agrosecurity
• Energy - farm and home 
• Family - child care, food and fitness, care giving, food safety, parenting, and personal finance
• Farm - manure management, bee health, beef cattle, dairy cattle, corn and soybean production, cotton, goats,  horses, organic, and small meat processors
• Pest Management 
• Youth   

Hidden under the "manure management" sub-section of the "Farm" tab is a great page on environmental regulations related to livestock and poultry operations.  This explains both water and air quality regulations that are enforced at the national level.  There are many state and local regulations that farmers will also need to follow which aren't discussed on this page, but it is still a great resource for the national laws.  On other pages is a dearth of information on environmental tools and management strategies that can be employed on varies types of farms.

Grazers Impacted by New Chesapeake Bay Regulations

A draft of the guidance strategy for federal agricultural lands in the Chesapeake Bay watershed (Guidance for Federal Land Management in the Chesapeake Bay Watershed) was released in March, and although the title implies that these suggestions are only relative to agriculture on federal lands the content implies otherwise.  It is suggested in the first few paragraphs of this 246-page document that these suggestions should be taken into consideration by states and other agencies in the development of the local watershed implementation plans.   There are twenty implementation measures outlined in this guidance, but the focus of this column will be on the three measures that would most directly impact grazers.

The one that has, and will continue to get, the most attention states:  “Exclude livestock form streams and streambanks and provide alternative watering facilities and stream crossings to reduce nutrient inputs, streambank erosion, and sediment inputs and to improve animal health.”  This push has been coming from the federal, state, and local level for some time and there will continue to be pressure on this issue.  Research has shown that when cattle are fenced out of the streams there are significant reductions in fecal coliforms, total nitrogen, total phosphorus, and total solids in the streams.  Also, from the cow standpoint, hoof health and udder health are generally better in cows that are not allowed to stand in water.  This guidance does not specify a suggested buffer zone width, but even a simple poly wire along the bank can have benefits for water quality and animal health.

The other measure that relates directly to grazing operations states:  “Minimize nutrient and soil loss from pasture land by maintaining uniform livestock distribution, keeping livestock away from riparian areas, and managing stocking rates and vegetation to prevent pollutant losses through erosion and runoff.”  Many well managed grazing operations are already implementing practices that would address these issues as too high a stocking density without proper rotation will decrease pasture quality and intake.  This measure also suggests that the streambank buffers, mentioned previously, should not be grazed except under specific circumstances. 

The last measure directly addressing grazing operation states:  “Manage runoff from livestock production areas under grazing and pasture to minimize off-farm transport of nutrients and sediment.”  With properly managed pastures the vegetation should reduce and prevent a great deal of runoff, but high traffic areas and compacted soils can facilitate runoff from pasture areas.  It is unclear how sacrifice lots/paddocks fit into these regulations, but the goal of all of these measures is to eliminate as much as possible all runoff from agricultural operations and that includes cultivated fields, barnyards, pastures, and sacrifice lots. 

It is unclear how these specific measures will play out in Pennsylvania, but it is clear that more regulations are coming and they will impact everyone.

Pasture walks scheduled:  Below are three pasture walks I will be involved with and presenting some of this information and how these new Chesapeake Bay regulations might impact you.

June 29^th  Amos Ebersol at 590 Red Hill Rd, Narvon, PA.  A conventional jersey operation with a thriving direct marketing business.  Karl Dallefield of Midwestern Bio-Ag will be speaking.  Lunch will be provided.

June 30^th  Roman Stoltzfus at 1143 Gap Rd, Kinzers, PA.  A highly diversified organic dairy grazing operation.  Karl Dallefield of Midwestern Bio-Ag will be speaking.  Lunch will be provided.

July 21^st  Stephen T. Stoltzfus at 5268 Amish Rd, Kinzers, PA.  An organic dairy operation.  Dr. Gregory Martin of Penn State Extension will be speaking on fly control.  Lunch will be sponsored by Beitzel’s Spraying.