Grouping Animals for Better Water Quality

What does grouping animals have to do with water quality?  Initially they may not seemed connected, but grouping animals can have big impacts on local water quality.  Cows can be grouped by age, pregnancy status, or stage of lactation.  Although all grouping strategies have benefits, grouping cows by stage of lactation is the most beneficial for water quality.

Cows at different stages of lactation have different levels of milk production.  When cows first calve their milk production is relatively low, but rapidly increases and peaks around 60 days post calving.  After that, milk production declines at a slower rate until the cows are dried off around 300 days post calving.  Because milk production is the main driver of feed and nutrient intake, cows at a similar stage of lactation will have similar nutrient requirements.  Therefore, if a herd is grouped based on stage of lactation rations can be created for each specific group that more closely matches the needs of that group.  

Rations are formulated based off of the average milk production of a group plus two standard deviations.  This is the best compromise to meet the requirements for the highest producing cows while decreasing the amount of overfeeding to the lower producing cows.  However, the tighter the range of milk production in a group of animals the lower the standard deviation and the more precisely the ration can be formulated to meet the needs of the group without overfeeding the lower producing cows in the group by such a degree.  The overfeeding of nutrients, specifically nitrogen and phosphorus, are major contributors to local water quality concerns because when more nitrogen and phosphorus is fed to the cow than she needs the extra is excreted in the feces and urine.

Grouping cows is generally more economical as well because feeds can be used most efficiently.  Larger dairy farms have been grouping cows for a while, but it is more difficult for smaller farmers to have enough animals in a certain stage of lactation and/or the facilities to group animals.  However, it can be done with some creativity and smaller farmers should consider grouping as a way to increase feed efficiency and reduce nitrogen and phosphorus loss from the farm.

Challenges to Implementing BMPs on a Farm

Why don't farmers implement certain best management practices (BMP) on their farms?  For those who are not farmers, it may seem obvious going onto a farm that a certain BMP should be implemented.  The farmer may even agree with you but yet there is no plan to implement that BMP on the farm.  The biggest reason BMPs are not implemented is the economy.  Farmers have no money to spare so even if there is cost sharing available there just aren't the matching funds from the farm perspective to make the BMP go forward.  Everyone has been hit by the overall economic crisis, but farmers were hit especially hard with low milk prices that will take many years to recover from.  In short, most farms are in survival mode and extras are just not going to happen.  Unfortunately there is no good solution to this issue until the milk price and the overall economy improve.

The other reason I see why farmers don't implement a specific BMP on their farm is that they don't know what to do. With limited funds they don't know what BMP would be most beneficial to them, and they may not be aware that some BMPs are actually required.  For example, farms in Pennsylvania have been required to have a conservation plan and a manure management plan since the 70's but there are many farmers that do not know that they are required to have these two plans on file.  If we want farmers to improve nutrient management and soil conservation on their farm we need to be very specific about what they need to do. 

The Miner Institute, A Great Resource

Miner Institute Dairy Facilities

The Miner Institute is a privately funded research institution located in Norther New York.  It has a working dairy farm and equine facilities that allows it to do a great deal of research in many different areas and one of those is environmental issues.  The institute also publishes an informative and entertaining monthly newsletter entitled the "Farm Report" on current topics and research updates.  

The October issue just came out and there are two interesting environmental focused articles related to manure application and the carbon footprint of milk.  The manure article emphasizes the importance of spreading manure as thin as possible to avoid environmental consequences.  The article also makes the point that in many situations traveling a little further to spread  manure instead of just going to the field next to the barn will pay off.  Many farms assume that the gas and time is not worth traveling further to spread manure, but the improved yields from those fields will offset the cost of travel in many situations.  

The other article of interest summarized a study published in Food and Nutrition Research that evaluated the carbon foot print of various drinks (milk, soft drinks, orange juice, beer, red wine, mineral water, soy drink, and oat drink) relative to the nutrients provided by those drinks.  The results of the article showed that milk had the lowest climate impact relative to the amount of nutrients provided.  Milk is a very nutrient dense product so what environmental impact it has is offset by the nutritive value of the product. 

I encourage everyone to check out the Miner Institute's Farm Report.  It will be well worth the time.