There are many benefits to feeding high-forage rations to dairy cows. Doing so successfully takes planning and forethought. In review of our own feeding trials along with work conducted by Dr. Larry Chase of Cornell University, here are some points to consider and reference guidelines of forage quality and ration parameters.
What we are considering high-forage rations are those rations with nearly 60 percent forage or higher, fed to high-production cows, more than 100 lbs milk.
The benefits of higher-forage rations include the following, as noted in a survey of producers feeding high-forage rations conducted by Dr. Chase:
• Improved milk components
• Improved $IOFC
• Fewer metabolic disorders, less acidosis
• Fewer foot problems
• Increased cow longevity
• Less purchased grain
• Lower vet costs
• Improved whole-farm nutrient balance: less imported nutrients (P)
The standard nutritional guideline of high-production cows consuming 1.2 percent of their bodyweight as NDF is far exceeded with highly digestible forages.
With highly digestible forage, consumption of 1.5 percent of bodyweight as NDF is common in high-production cows, with even higher values for low cows. With high-quality forage, more needs to be fed in order to maintain rumen health and not simply allow more grain to be consumed as part of total TMR intake.
High-quality forages required
In our experience, 24-hour NDF digestibility of total TMR needs to be more than 60 percent. The individual forages both CS as BMR and grass silage were more than 55 percent NDFD24.
Stage of plant maturity is the single greatest factor determining quality; grasses at vegetative/boot stage with NDF less than 52 percent, legumes at bud NDF 40 to 45 percent.
Corn varieties selected for high fiber and/or high starch digestibility. Next is preservation, pack density more than 45 lbs per cubic foot at a minimum, the tighter the better. Forage harvested too mature, too dry, too wet or loosely packed, will not work in high-forage rations.
Farm management considerations
Feeding high-forage rations and maintaining high milk production is possible. It takes planning and the proper mindset of producer and nutritionist. Forage quality needs to be consistent, as it becomes a higher proportion of the diet; variable quality will have greater effect on intake and digestion.
Forage inventory needs to be increased 15 to 30 percent or more and requires segregated storage space based on quality/NDFD; not all cows need or will respond to the higher-quality forage (i.e. tail-enders). Is the TMR mixer big enough to mix bulkier loads?
In the summer, aerobic stability of the TMR will need to be monitored. Consider the need for crop acres, storage space and time to build forage inventory. Old ways of harvest may need to change to get the amount and quality of forage required.
Best wishes for 2013. It is not too soon to start planning for higher-forage rations. PD
References omitted due to space but are available upon request. Click here to email an editor.
—Excerpts from Miner Institute Farm Report, January 2013
Kurt Cotanch
Forage Lab Director Miner Institute
