As markets fluctuate and producers are deciding how and what to include in their rations to optimize their production goals, now is the time to invest in forages more than ever.

No matter what ration is being put together, forages are the backbone that hold the animal and rumen health together. The rest fills in the pieces to meet your production goals. The most efficient protein and energy the cow can harness, is produced by her rumen microbial population. Whether by the microbial protein synthesized or the volatile fatty acids produced during rumen fermentation that the cow absorbs for energy, both are the most efficiently utilized by the dairy cow.
 
Neutral detergent fiber and the digestibility (NDFD) of that nutrient within forages will tell you how much energy she can potentially obtain from forages. Routinely through near-infrared spectroscopy (NIR), nutritionist obtain the breakdown of fiber and starch as main carbohydrates to see how they will behave in the rumen and the quality and amount of energy. For example, two corn silages (A and B) may have 36% NDF, but A is 65% digestible compared to B at 70% digestible. Research has determined for every unit increase in NDFD animals increase dry matter intake (DMI) by 0.37 pounds per day. In this example, that equates to 1.85 pounds greater DMI. Assuming a 1.5 pounds milk to 1 pound DMI conversion, this is 2.8 lbs of potential milk. The difference could be differences in harvest time or condition, or differences in genetics.
 
What forages fit for your nutrition program is a great conversation to have between your nutritionist and agronomist to make sure both goals from either are aligned. On the corn silage varieties, producers are adopting brown mid-rib varieties to get maximum fiber digestibility and starch. Alfalfa varieties that include the low-lignin traits are other examples of technologies in agronomy that support greater digestibility.
 
Other measurements of quality will tell you how much energy is available. These include pH, fermentation acids relating to feed stability. Table 1 and 2 lay out the typical corn silage and alfalfa haylage fermentation profiles. Some of these measurements relate back to how forages were preserved on-farm. Whether bunker, silage, pile, or bag, knowing your quality based on nutrient analysis, packing density, and antinutritional factors such as molds, yeasts, mycotoxin, silage alcohols and other toxins. All of these can negatively impact your dairy system depending on what is present from heifers to lactating cows. To identify if a problem exists, the total diet can be analyzed initially to determine what is present. Poor preservation and secondary fermentation can contribute to up to 30% shrink.
 
Table 1. Typical Corn Silage Fermentation:

	Sil-All Activate (homofermentative product)	Biotal Buchneri 500 (heterofermentative product)
pH	< 4.0	< 4.0
Lactic Acid	5.0-10.0	4.0-6.0
Acetic Acid	1.0-3.0	2.0-4.0
Propionic Acid	<0.1	<0.1
Buytric Acid	<0.1	<0.1

 
 
Table 2. Typical Alfalfa Silage Fermentation:

	Sil-All Activate (homofermentative product)	Biotal Buchneri 500 (heterofermentative product)
pH	< 4.8	< 4.8
Lactic Acid	4.0-6.0	3.0-5.0
Acetic Acid	0.5-2.5	1.5-3.0
Propionic Acid	<0.25	<0.25
Buytric Acid	<0.1	<0.1

 
While proper harvest, storage and feedout are the most important for quality forages, inoculants can assist in preserving a plant’s nutrients when fed in unison to good forage management. All of this relates back to quality and how to get as much out of your forages as possible. With any preservative, you are only as good as your harvest and storage quality. Based on the dry matter of forages, storage conditions, will impact what inoculant is right for you. If you have not done so consider having your forages evaluated to see what inoculant, preservative or enzymes will complement the on-farm forages.


By Lizzy French, PhD, PAS