May 16, 2011

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. 

May 9, 2011

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.   

April 26, 2011

Manure Runoff

Much of the country, including Pennsylvania, have received more rain this spring than the ground can absorb.  This has delayed planting and can also lead to increased manure runoff.  Although waiting to spread when there is not rain in the forecast is ideal, it may not be practical if a farm does not have any more storage.  If spreading during wet weather cannot be avoided then manure should be spread on fields with the least chance of runoff and sink holes should be avoided. Wisconsin has put out a nice public awareness radio address and the message in this address could apply to any number of states this spring.  Resources on manure spreading can be found at http://dnr.wi.gov/runoff/ag/manure.html

February 18, 2011

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.

February 10, 2011

Conewago Creek Stream Teams



This is a great program designed to get youth involved in improving local water quality.

February 2, 2011

Watershed Winds

There is a new newsletter available electronically through Penn State Water Resources website called Watershed Winds.  The goal of this newsletter is to disseminate strategies and practices to improve water quality that are working in one watershed to other areas of the state and country.  The articles range from agricultural practices to municipality programs to how to bring different organizations together.  There are a number of great example of how local watersheds have improved there water quality, and sharing how they managed to accomplish it is something that needs to be shared with others that are facing the same issue.  I encourage everyone to check out the newsletter and share what is working for them.