Barnyards Need Attention

Barnyards are in need of attention on many dairies and future regulations are aiming to make sure that attention is paid.  The new Pennsylvania Manure Manual has not yet been released by the Department of Environmental Protection, but all indications are that barnyards are going to receive greater attention than they have in the past.  Future regulations on manure management and cropping practices have been discussed previously, but barnyards are a major concern of environmental regulators.  Barnyards are often areas that are not suited for cropping, get too much traffic for a ground cover to really take hold, and are just not a priority for maintenance or improvement on most farms.  However, from and environmental standpoint, barnyards are a major source of manure runoff to streams.  Heavy rains can easily flush manure from barnyards into local streams if there is not a system in place to prevent this.  Also, from an animal health standpoint, improperly maintained or designed barnyards can contribute to mastitis and hoof health problems.  

Barnyards can be dirt lots or paved areas.  Barnyards that are dirt can quickly become mud pits.  Standing in wet conditions, like a muddy barnyard, can soften hooves leading to hoof problems and lameness that can negatively impact milk production.  Also, if animals are left in barnyards long enough during the day they will eventually lay down exposing the teats to environmental mastitis pathogens.  Although environmental mastitis is generally easier to treat compared with contagious mastitis it can still lead to a great deal of lost production and income before it is controlled.  Lastly, the cleaner the barnyard is kept the cleaner the cows will be at milking, which means less cleanup at milking.  

Concrete barnyards can be better than dirt barnyards, but only if maintained.  Uneven concrete can lead to injury and hoof problems.  Also, unless concrete is poured so that there is good drainage it can become just as wet and sloppy as a dirt barnyard.

There is cost share money available for barnyard improvements through Natural Resources Conservation Service, county Conservation Districts, and private groups.  The following are some areas to consider about your own barnyard.

• Is the barnyard cleaned regularly?  Scraping barnyards weekly will prevent hoof problems and eliminate the potential runoff of manure from the barnyard.
• Are there curbs on the concrete barnyard?  Curbs keep manure from running off the barnyard into local waterways. 
• Is there a system to collect runoff from the barnyard?  If the barnyard is curbed, there needs to be a drain so that the barnyard doesn’t become a pool.  However, the collection of rain water and other material from the barnyard needs to be treated as any other manure laden runoff and should be run through some type of filtration or storage system.
• Is excess rainwater running into the barnyard?  Roof gutters and down spouts should be designed to divert rainwater away from the barnyard into a filtration area.

In short, proper design of rain gutters and downspouts to divert rain water away from the barnyard, a proper filtration or storage system for collection of runoff from the barnyard, and scraping the barnyard to keep manure from building up will protect local waterways and prevent herd health issues.  For more information on this issue visit the Penn State Agriculture and Environment Center at www.aec.cas.psu.edu to watch a webinar on barnyards, exercise lots and water quality.

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. 

Nitrates in Well Water

Nitrates are found in fertilizers, manure and liquid waste, and naturally occurring soil bacteria can convert other forms of nitrogen to nitrate.  The water quality standard in Pennsylvania for nitrates is 10 parts per million (ppm).  However, there are no state regulations on private wells in Pennsylvania so the responsibility of monitoring water quality of private wells is up to the home owner.  Lancaster County is known to have high nitrate levels with 10-20% of wells having nitrate levels above the 10 ppm limit with 30-60% of wells in limestone areas measuring high in nitrates.  

The health concerns with nitrates apply to both humans and animals.  Nitrate is converted to nitrite by bacteria in the digestive track of people and animals.  Once the nitrite form is absorbed it decreases the ability of red blood cells to carry oxygen.  The higher the nitrate level in the water the more dangerous it becomes.  Babies are especially vulnerable because they do not produce a lot of acid in their stomachs; therefore, nitrate to nitrite converting bacteria can grow in the stomach and produce more nitrite compared to a more acidic stomach.  Adults, with their highly acidic stomachs, do not have nitrate to nitrite converting bacteria in their stomachs so nitrate is only converted to nitrite once it reaches the large intestine at which point there is less opportunity for absorption before it is excreted.

Ruminant are the most susceptible group of animals on the farm due to the bacteria population in the rumen that converts nitrates to nitrites.  Nitrites are then absorbed across the rumen wall and inhibit oxygen transport.  Nitrates are found naturally in ruminant feed so high nitrate water may push them past the toxicity level.  Acute toxicity can be treated and animals can recover well if caught early, but there is some concern about chronic impacts of slightly high nitrate levels.  A University of Wisconsin study showed that, over time, the services per conception were higher in cows given high nitrate water versus cows given water with no nitrates.  

Although there are ways to treat high nitrate wells, preventing nitrate contamination of the well in the first place is the best option.  Careful manure application is the best way to prevent nitrate contamination of well water.  Manure contains nitrogen in the form of ammonia, nitrates, and organic nitrogen.  Ammonia can be converted to nitrates by soil bacteria.  Nitrates are associated with the water in the soil and leach down through the soil if not utilized by the crop.  Once the nitrates are below the root zone they are no longer available to the plants and will continue down through the soil until they reach ground water.  Once in ground water nitrates remain unchanged and can build up over time.  Therefore, applying nitrogen to meet the demands of the crop without over applying is important to prevent nitrate leaching into ground water.  Spreading of manure near shallow wells, poorly sealed or constructed wells, and wells that draw from shallow aquifers should be avoided as these wells are at greatest risk for nitrate contamination because the path for manure nitrate to the ground water is the least restricted.  Also, wells should be located away from sources of contamination like barnyards, fields that receive manure, septic fields, etc.  Wells should also be sealed properly to prevent contamination from surface water.   

Freeboard Requirements

Manure storage facilities need to be designed and constructed to accommodate the amount of manure produced on the farm, the length of time storage will be needed for, and there needs to be a safety net space.  This safety net space is referred to as "freeboard".  Freeboard becomes especially important for rainy weather because uncovered manure storage facilities can fill up with rain water quickly, and during the spring when facilities are filled with manure that was stored all winter rain water can quickly cause an overflow.  The following are the rules for freeboard requirements in Pennsylvania.

For a liquid or semisolid manure storage facility, the following minimum freeboard requirements apply and shall be maintained:

     1.  For an agricultural operation with over 1,000 AEUs that was a new or expanded operation after January 29, 2000, a minimum 24-inch freeboard, except for enclosed facilities that are not exposed to rainfall, which must have a minimum freeboard of 6 inches.

     2.  For all other facilities, a minimum 12-inch freeboard for manure storage facilities that are ponds, and a minimum 6-inch freeboard for all other manure storage facilities.