If you Google “five ways to,” you get a laundry list of how-to articles – five ways to channel your inner millionaire (it’s a joke, right?), five ways to kick the cable TV habit (does 26 hours a day constitute a habit?), five ways to do nothing and become more productive (sign me up), five ways to remove stripped screws (although it doesn’t list a burn pile, which works pretty well).
But astoundingly, it doesn’t list an article on five ways to feed forage in a dairy diet. It’s time to fix that. Here are five ways to evaluate the forage in your dairy cows’ diet – through corn silage, dry hay, haylage, pasture and green-chopped small grains.
Forage is the largest portion of a dairy diet and varies by reason of economics, availability, quality and quantity.
Corn silage-based systems
Characteristics
Dry matter (DM) content varies from 30 to 38 percent.
- 30 to 33 percent DM in bags, piles and bunkers
- 34 to 38 percent DM in conventional uprights
Advantages
Perhaps the biggest advantage for using corn silage in the dairy diet is because cows like it; hence, they tend to consume more of it. With increased DM intake, milk production will improve.
Corn silage fits well in a TMR because it has been pre-processed in the field and mixes easily with the TMR, increasing palatability. Other advantages include its high quality and consistency.
Extending the harvest window is another reason to choose silage. While alfalfa has a short harvest window (and the shorter the better), corn silage harvest can extend seven days to two weeks barring a killing frost or drought conditions. The harvest window can be further manipulated by changing corn maturity dates.
Disadvantages
Corn silage is moderately low in protein, which means purchasing supplemental proteins, which can be expensive. It also has low feed-buffering capacity, which means regularly adding sodium bicarb to the diet.
Because silage is very wet, it can become too wet, which will limit DM intake. A silage system also requires a greater investment in harvesting and handling equipment, and storage facilities. Silage feedout must also be closely managed, removing a certain amount from the face each day to keep the feed fresh and avoid secondary molding.
In addition, corn silage, like other wet products, is difficult to sell and transport because of the high water content and the cost to transport that water any significant distance. If silage must be moved, it is recommended to do this in cooler seasons and to accomplish it very rapidly with a moisture content of 65 percent to get good packing at the secondary site.
Recommendations
Cows need 5 pounds of long fiber, measuring over 0.75 to 1 inch in length. This is possible to achieve in corn silage if, when using the Penn State separator, we achieve 10 to 20 percent on the top box; however, it must be monitored carefully. Otherwise, baled hay or haylage must be added to maintain some length.
Research-based inoculants for silage are recommended at harvest and can increase DM recovery 3 percent and improve digestibility two or three units.
Hay-based systems
Characteristics
Dry matter content varies from 78 percent (at harvest) to 90 percent (coming out of storage).
Advantages
Hay packages come in all sizes – as light as 50 pounds in small squares or 1,000-pound bales. It’s easier to market and transport due to reduced moisture content and convenient packaging. Package size also facilitates feeding on an as-needed basis. It can be stored for long periods of time, even years, and provides an excellent source of long fiber that creates the rumen mat.
Disadvantages
Field losses can reach as high as 20 percent in a hay system due to rain, drought or other weather events, and it’s common to lose an entire crop from time to time. Although storage losses are usually minimal, there are further losses in the bunk as cows sort it and waste a portion.
It’s also difficult to add large amounts of baled hay (15 to 20 pounds per cow) to TMR mixers due to the mixing and shearing abilities of the mixers. Even if hay is processed first, as much as 2 percent crude protein is lost in the green dust cloud formed at processing, which is essentially created from the leaf portion, where most of the nutrient value is stored.
Putting up larger hay bales also creates denser packages. This requires baling at drier moisture levels to reduce mold growth, and field-drying hay can be a real challenge in some parts of the country.
Recommendations
Rations recommend 5 pounds of long fiber chopped to lengths of more than 1 inch, which hay easily provides. However, if functional fiber needs are met by other forages, then hay is not required.
Quality can be greatly improved in the field by cutting at the right maturity and handling drydown and storage correctly. Propionic acid can be used to minimize mold formation. Hay-based systems work well in smaller herds where large quantities of stored feeds are not required.
Haylage-based systems
Characteristics
We’ll define haylage to include alfalfa or legumes, grasses and any combination thereof. DM content varies from 35 to 65 percent:
- 35 to 40 percent DM in bags, piles, bunkers and baleage
- 45, 50, 55 percent DM in conventional upright silos
- 50 to 65 percent DM in oxygen-limiting structures
Advantages
Haylage is an acidic forage, making it well preserved and increasing its palatability. Cows like acidic feeds. Optimal particle size can be achieved to aid rumen digestion and hay mat formation, and it fits well into a TMR mixer. Since the feed has already been processed, it mixes very uniformly and quickly.
Since there is less field drying required (as opposed to a dry hay system), higher quality can be preserved and chopping can be accomplished for longer periods during the day and night. A higher DM intake would be expected with a little higher rate of passage due to a shorter particle size with less sorting.
Disadvantages
Field losses vary from 5 to 15 percent. Higher storage losses are also a possibility because of fermentation, especially if feed is too dry or too mature and heat damage occurs. Harvesting equipment expenses could be higher, requiring a chopper, collection wagons, blowers and packing tractors, depending on how it’s stored.
Recommendations
It would take a larger herd to justify the cost in extra equipment and added labor. Also, at feedout a minimum amount should be taken from the face, so if herd size doesn’t consume what needs to come off the storage face every day, then quality loss can shoot up. If haylage isn’t fed with the TMR correctly, then cows will leave the TMR and eat only the haylage, lowering nutrient intake and losing milk production.
It’s also not recommended that haylage be transferred from one storage unit to another. While haylage is fairly low in acid content, a move to a secondary facility can result in secondary fermentation.
Pasture-based systems
Advantages
Pasture systems, if managed properly, can produce some of the highest-quality forage available. Secondly, there are no costs in machinery for harvesting or distributing manure. Cow comfort improves, as does hoof and leg conditioning, thus reducing veterinary costs.
Disadvantages
While production costs are low in a pasture system, milk production is also lower by about 14 percent. Secondly, the physically effective fiber needed to maintain good rumen function is not as high in a pasture-based system (about 50 percent) compared to baled hay (which can exceed 92 to 96 percent).
In addition, New Zealand research in pasture systems indicates a general rumen pH under 5.5 because of high quality, high rate of passage and high digestibility.
Crude protein can also be very high, of which about 80 percent is rumen-degradable (breaking down to ammonia), and we have to balance the ration with carbohydrates to capture that without reducing rumen pH any lower. How do we monitor that?
Watch for yellow burnt areas where cows are urinating in the grass. This would indicate higher levels of nitrogen excretion rather than capturing it as microbial protein. Cows consuming high levels of pasture may also have fecal scores less than 2.5, another indication of excess nitrogen loss.
Finally, DM intake can be limiting, as cows can only consume so much pasture.
Recommendations
Really high-producing cows can’t eat enough pasture to support higher milk yields (based on an average eight-hour grazing day x 60 to 65 bites per minute); therefore, DM has to be supplemented to maintain higher production levels.
A pasture system could be expected to support 50 to 60 pounds of milk production, but no more. The guideline for Penn State indicates about 1 pound of additional grain supplement for every 4 to 5 pounds of milk after the pasture nutrient supply has become limiting.
Pastures are not nutritionally balanced, so it’s important to work with a nutritionist or consultant to achieve a more balanced feeding program depending on the level of milk production.
Small-grains systems
Characteristics
Crops include wheat, barley, oats, rye and triticale, harvesting at boot stage for high-quality forage (high in moisture and difficult to field-dry for hay production). Harvesting at milk to dough stage achieves average quality forage with higher yields. DM content should be about the same as haylage values.
Advantages
When harvested and ensiled correctly, small-grain forages make a very palatable feed, and it can be high in quality. It’s an early crop, so if you’re short on forage, it’s a good forage extender. It works well in a double-crop system and will utilize some manure application and the excess nitrogen.
Disadvantages
Quality of small grains is extremely variable, depending on harvest conditions. A wet spring can keep us from getting into the field at the right time, narrowing the harvest window. We usually only have two to four days leeway between harvesting a super crop to having dry-cow feed. Yield is just as variable.
Recommendations
It is critical to have a good inoculant on this crop. This crop will also be low in soluble carbohydrates (compared to corn silage). Small grains love potassium, so if soil levels are high in potassium, the crop can be as high as 4.5 to 5 percent potassium, which is detrimental to a close-up dry cow program.
Storage principles would be similar to the haylage crop. With varying nutritional value, it’s important to determine the value of the harvested crop and match it correctly to the animal needs (not feeding average quality to a high-producing herd, for instance).
Summary
There isn’t any one forage system that is “the best” system, because economics, availability, available quantity and quality all play a part in the decision. Only fair evaluations of all systems will reveal the best option for your operation.
And there you have it. The “five ways to” Google search will now be complete. If I can find somebody to pay me for this, I will have finally channeled my inner millionaire. Score! PD
Lynn Jaynes
Editor
Progressive Dairyman
