Buckeye Dairy News: Volume 5 Issue 3

Dr. Normand St-Pierre, Dairy Specialist, Ohio State University 

The cost of major nutrients remains high. The average cost per megacalorie (Mcal) of net energy lactation (NEL) has steadily gone up over the last 6 to 8 months. As of May 2003, NEL was costing an Ohio dairy producer an average of 7.5 cents per Mcal, a figure which is historically high. Effective fiber (e-NDF) is also relatively expensive at 9.7 cents/lb. Fortunately, these are counter-balanced by reasonable (rumen degradable protein, RDP at 3.3 cents/lb) to low prices (digestible rumen undegradable protein, D-RUP at 16.7 cents/lb; non-effective fiber, ne-NDF at -3.1 cents/lb) for other nutrients. This indicates that proper ration balancing, especially for energy and effective fiber, is currently an important factor in controlling feed costs in our dairy herds.

Table 1. Estimates of nutrient unit costs.

- A blank means that the nutrient unit cost is likely equal to zero.
- ~ means that the nutrient cost may be close to zero.
- * means that the nutrient cost is unlikely to be equal to zero.
- **means that the nutrient cost is most likely not equal to zero.

It is also a time to look closely at the ingredients making up the dairy diets. There are some bargains out there, notably bakery byproduct, gluten feed, distillers dried grains, and wheat middlings. Any producer currently using beet pulp, canola meal, or citrus pulp should talk to their herd nutritionist. It may be time to strategically re-think the feeding program. Unless you are feeding high producing cows (>100 lb/day), the use of blood meal should be minimized. Even if one factors amino acids into balancing dairy diets, fish meal should be considered a grossly overpriced feed ingredient and the same results can be achieved using combinations of other ingredients at a much lower cost.

Table 2. Calibration set.

Table 3. Appraisal set.

These estimates were derived using the software SESAME Version 2.05 written at The Ohio State University. For additional information, please refer to Buckeye Dairy News Vol. 5, Issue 2, March 2003.

Dr. Bill Weiss, Dairy Specialist, Ohio State University 

In many areas of Ohio, corn silage yields were much lower than average last year because of the drought. Forage supplies are tight and hay prices are extremely high, but on the bright side, first cutting of alfalfa is approaching rapidly. Diets with less than typical concentrations of corn silage can be fed safely. The following steps should be followed if forage supply is limited.

1. Determine current corn silage inventory.

Example. 1000 tons of corn silage was harvested last September. The silage is fed to 150 lactating cows at the rate of 40 lbs/day. Since harvest, 660 tons have been fed (150 cows x 40 lbs x 220 days) leaving 340 tons.

2. Determine maximum amount of corn silage that can be fed based on available inventory.

Example (continued). As of May 1, 340 tons of corn silage is available. At the current feeding rate (40 lb X 150 cows = 3 tons/day), the remaining corn silage will last about 113 days (340 tons remaining divided by 3 tons fed/day). New crop corn silage will be available on October 1 (150 days). The maximum amount of corn silage that can be fed is 340 tons divided by 150 days = 2.3 tons/day or about 30 lb/head/day. To ensure adequate supply, reduce that value by 10%. The maximum amount of corn silage that should be fed is 27 lb/day per cow.

3. If inventory is not adequate based on current feeding rate, immediately reduce the amount fed to that value calculated in step 2. Changing now, rather than later, will reduce the magnitude of the change.

4. If the amount of corn silage fed must be reduced, replace it with logical alternatives.

Alternative feeds

In typical diets, forage is the major source of dietary fiber (expressed as neutral detergent fiber, NDF) and effective fiber (fiber that stimulates chewing and rumination). Several byproduct feeds have concentrations of NDF equal to or greater than that found in typical forages (Table 1) and can be used to provide NDF. Byproducts, with the exception of whole cottonseed, however, are not good sources of effective NDF.

Feeding diets with inadequate concentrations of NDF and effective NDF is a substantial risk factor for ruminal acidosis. Diets with low concentrations of NDF typically have high concentrations of nonfiber carbohydrates (NFC). In the rumen, NDF usually ferments slower and less extensively than NFC, resulting in less acid production and a higher rumen pH. Effective NDF is important because it stimulates chewing and salivation. Saliva is an excellent buffer and helps maintain rumen pH. When low forage diets are fed, dietary concentrations of NDF, effective NDF, and NFC must be adjusted properly to maintain rumen health.

Table 1. Average concentrations of NDF and crude protein (CP) in common byproducts.

Options when corn silage is limited

1. Replace corn silage with hay crop forages. New crop grass and legumes will be available in Ohio in mid to late May. If these forages will be available, increase their concentrations in the diet and reduce the amount of corn silage. The diet must be reformulated (especially with respect to protein and minerals) when hay crops replace corn silage. If increased feeding of hay crops during the summer will mean that the inventory of hay crops will not be adequate for winter feeding, more acres of corn silage should be planted and chopped.

2. Replace corn silage with byproducts. When low forage diets are fed, dietary concentrations of NDF must be increased and concentrations of NFC must be reduced. Typical diets in Ohio have NDF concentrations in the 27 to 30% range and NFC concentrations in the 38 to 41% range. Low forage diets should contain at least 32% NDF and no more than 38% NFC. Several experiments have shown that diets with 17 to 18% of the dry matter (DM) as forage NDF can be fed to cows without problems as long as the concentration of total NDF in the diet is increased to dilute out NFC and reduce acid production in the rumen. As forage is removed from the diet, it must be replaced with high fiber byproducts, not by starchy feeds such as corn grain. A general rule is for every 1 percentage unit forage NDF is reduced below typical values (approximately 21% of diet DM), total diet NDF should be increased by 2 percentage units. For example, if the amount of forage in a diet is reduced by 2.5 lb/day of DM, the amount of forage NDF fed will be reduced by 1.1 lb (assuming the forage has 45% NDF). To account for a loss in effective NDF, total NDF intake should be increased by 1.1 x 2 = 2.2 lb/day. Soyhulls have about 60% NDF; therefore, 3.7 lb of soyhull DM would be needed to provide 2.2 lb of NDF (i.e., 2.2/0.6 = 3.7). In this example, 2.5 lb of forage and 1.2 lb of corn grain would be replaced with 3.7 lb of soyhulls (all amounts are on a DM basis). Depending on the protein content of the forage, some changes in soybean meal might also be needed. For moderately low forage diets, replacing a portion of the forage and corn grain with a high fiber byproduct may be all that is necessary. The choice of which byproduct to use should be based on cost of the nutrients provided by the feed (see Cost of Nutrients article by Normand St. Pierre) and the need for supplemental crude protein.

If forage supply is severely limited (< 17% of diet DM as forage NDF), the approach outlined above may not be adequate. Dietary NDF concentrations must be increased to dilute NFC as described above and additional sources of effective NDF might also be needed. The only byproduct commonly available in Ohio that is a good source of effective NDF is whole linted cottonseed. Diets with 10 to 15% (DM basis) whole cottonseed can be fed without problems. The minimum amount of cottonseed that should be fed is based on the amount of forage NDF provided in the diet. A general guideline is that forage NDF plus the NDF from cottonseed should equal or exceed 17% of diet DM. For example, if forage NDF is 14%, at least 3 percentage units of dietary NDF should come from whole cottonseed. The minimum amount of cottonseed in the diet equals 3 divided by 0.47 (NDF concentration of cottonseed) = 6.4% of diet DM. Total dietary NDF should be increased from 27% (minimum concentration for adequate forage diets) to about 35% (i.e., 21% forage NDF (requirement with adequate forage diets) minus 17 (amount of NDF from forage and cottonseed in this example) times 2). For this example, the diet would consist of 35% forage (assuming the forage is 40% NDF), 6.4% whole cottonseed, and 58.6% concentrate mix that contains 30% NDF.

Mr. Tom Noyes, Dairy Extension Agent, Wayne County 

With milk prices at record lows, dairy producers look for ways to cut costs and one possibility would be not applying fertilizer to pastures and other forages. Is this a wise decision? Well, that depends. What are the soil fertility levels, what forage productivity do you want, and are there legumes in the stand?

The OSU Extension fact sheet on "Fertility Management of Meadows" provides excellent recommendations for fertilizing pastures and forage crops. It doesn't matter how the forage is harvested (grazed or mechanical), it will remove from the soil the three major nutrients: nitrogen (N), phosphorous (P), and potassium (K). The amount removed depends on the yields. For each ton of tall grass or legume forage, it will remove 13 lb of phosphate (P2O5) and 50 lb of potash (K2O). These nutrients can come from soil reserves, through commercial fertilizers, manure, or livestock nutrient cycling (grazing livestock).

Let's first address the soil levels of these nutrients. Nitrogen soil reserves are relatively low so N needs to be applied or derived from legumes. For good yields of forage, soil P levels need to be maintained at 15 to 25 ppm (30 to 50 lb/acre). Potassium soil levels should be 125 to 200 ppm (250 to 400 lb/acre). On many livestock farms that have regularly applied manure, the levels of P and K may have increased to levels where a year of no commercial fertilizer application will not affect crop yields. Soil P levels of over 35 ppm and K levels of over 200 ppm can provide normal forage yields from soil nutrient reserves, especially for pastures where considerable nutrients are being recycled by the grazing livestock without additional fertilizer.

For N, it is a different story. Applying N and how much to apply will be determined by the legume content of the forage stand. The OSU fertilizer recommendations omit applications of N when the forage content is made up of 35 to 40% or more legumes. When the stand is less than 20% legumes, consider it a grass stand and apply N. Applying small amounts of N to pastures with 20 to 25% legume will increase forage quality and yields.

When grass is the predominant forage species, N fertilization is extremely important. Economic returns have been demonstrated when a total of 150 to 175 lb/acre/year of N are split applied, three times during the growing season. By the time you read this article, the spring application times will have passed, so there will be an opportunity for two more applications.

An application towards the end of June, timed with a potential ½ inch rain, would pay dividends in reducing mid-summer slump. Apply 35 to 40 lb/acre of actual N with a stable N source like diammonium phosphate (DAP) or ammonium sulfate.

For extended grazing in the fall, an application of 30 to 50 lb/acre of N in late August will give you a flush of grass much like spring, which will provide increased forage quality and yields well into the late fall months.

Ms. Dianne Shoemaker, District Dairy Specialist, Ohio State University 

Not once have I ever heard a dairy farmer complain that they just can't seem to attract birds as well as the neighbors. Doesn't matter whether the culprits are starlings, crows, sparrows, pigeons, seagulls, or brown-headed cow birds, farmers covet the barns without the birds. Actually, there is one bird that is welcome. The hawk. Why will they hang out at one farm and not another when they both have more fresh fowl-on-the-wing just waiting to be eaten than a busy Kentucky Fried Chicken drive-thru? If I only knew!

Unwanted birds have become an extremely frustrating problem for dairy farms. The very barn designs that optimize cow comfort also provide favorable habitat for birds. One of the features that makes rafter barns attractive, besides fewer timbers to impede air flow, is that it also provides almost no places for birds to roost. The few places that are available, however, the birds will find.

Management practices such as having TMR in front of the cows 24 hours a day also means that there is TMR available to birds 24 hours a day. You think a cow can sort? Just watch a bird eat all your high-priced grains and supplements. It may sound humorous at first, but the huge flocks of birds that infest some farms can cost thousands of dollars as they consume dry matter intended for the animals. Additional feed, the barn, and farmstead are also contaminated with bird feces and noise.

Birds have the potential to carry and spread diseases harmful to both livestock and people. According to John Paul Seman, Wildlife Biologist with USDA, APHIS Wildlife Services, Salmonella, E. coli 0157, and Campylobacter are three diseases that can be transmitted to cattle, and possibly then to humans when cattle ingest infected bird feces. While these may or may not cause problems for the cows, if transmitted to humans, they can cause gastrointestinal distress and even death in extreme cases.

"European Starlings," fact sheet E-109 from the "Prevention and Control of Wildlife Damage" series is available from your county Extension office. This extensive fact sheet describes many ways to try to control starlings through exclusion, habitat modification, frightening, repellants, toxicants, trapping, and shooting. In many dairy operations, actions such as exclusion, frightening, and repelling have minimal practicality or impact. Other suggestions, such as shooting, have limited application, especially within barns. If shooting is attempted in barns, it is likely that moisture problems will increase as "spot" ventilation appears in the roof.

To help address the growing problem with starlings on dairy farms, the USDA Wildlife Services has begun the DRC-1339 Program. This program involves conditioning pest birds to eat a bait and then using an avicide applied to the bait to control 70 to 90% of an infestation. The DRC-1339 is a slow acting toxicant that appears to be painless in birds. Wildlife Services times applications during months that songbirds are not present (usually November through February). During the actual time that treated bait is made available to starlings, an employee watches to be sure that no songbirds, animals, people, or other non-target species go near the bait.

The farm is responsible for collecting and disposing of dead birds on their property and on other property that the birds may fly to before they die. It is strongly encouraged that you talk to neighbors ahead of time!

The fee for the baiting program is set to help recover application costs. For anyone who has experienced a bad bird infestation (this program is available to those farms with infestations of 1000 birds or more), a $550 fee to cover the cost of bait, avicid, and technical assistance is a good investment.

Want more details or ready to sign up? Contact USDA Wildlife Services at (330) 726-3386 or (614) 892-2514. Participation in the program is first-come, first-served. Since the winter weather if over, DRC-1339 baiting will not take place until next winter. They can however, give you some suggestions for rolling out the un-welcome mat in the meantime.