Source: PennState Extension
Introduction
Feeding a total mixed ration (TMR) helps a dairy cow achieve maximum performance. Since its inception in the 1950s, it has now been the most adopted method for feeding high-producing, indoor-housed dairy cows in the world. This is accomplished by feeding a nutritionally balanced ration, allowing cows to consume as close to their actual energy requirement as possible and maintaining the physical or roughage characteristics, which we now refer to as ration particle size, required for proper rumen function. Advantages and disadvantages of any feeding system, however, must be weighed before choosing a TMR.
Good feeding management practices must be followed to achieve maximum performance from cows. First, monitor forage and feed inventory regularly and allocate to the appropriate animal group. Second, test forages and feeds several times throughout the year or when any noticeable change occurs. When using feeds that provide multiple cuttings, like grasses or alfalfa, the best practice would be to test feeds at least once per cutting. For ensiled feeds, keep in mind that physical structures (i.e., bunker walls, plastic bunker covers, vertical silos, etc.) can impact feed fermentation and the resulting quality. Retesting forages more frequently might prove beneficial if physical structures are impacting quality. Lastly, update ration formulations based on milk production, milk fat and milk protein percent, current body weight and body condition score, moisture changes in forages or high moisture feed ingredients, and prices of current feeds. Checking forage moisture frequently, ideally weekly, is critical to implementing a successful TMR system.
There are several strategies that can be used in TMR systems. Separate TMR can be developed for different animal groups. These can be formulated for fresh cows, early lactation cows, and mid- and late-lactation animals, and for far-off and close-up dry cows. Such multi-group strategies are particularly helpful for meeting the needs of dry cows. Dry cows approximately 3 weeks prior to calving have specific nutrient requirements to minimize metabolic diseases after calving. A one group TMR can be used for lactating cows with or without top-dress feeding. Cows can be grouped based on actual or energy-corrected milk, days in milk, reproductive status, age, nutrient requirements, and health. Different farms have reasons for adopting different strategies for using TMR and these must be a decision of the farm manager based on many aspects of the operation as well as research and personal preference.
Advantages of a TMR Feeding System
Improved feeding efficiency often occurs with herds using a TMR. In a true TMR, each mouthful of feed that the cow consumes contains the proper amount of ingredients for a balanced ration, resulting in a more stable and ideal environment for the rumen microbes and providing adequate carbohydrates and nitrogen sources that vary in their ability and rate of rumen breakdown. This can lead to higher levels of microbial protein supply by the rumen microbes throughout the 24-hour day. A 4% increase in feed utilization can be expected when using a TMR compared to a conventional ration of forage and grain fed separately, twice daily. In addition, the ability to use feeds with various rates of breakdown is enhanced, often enabling even better nutrient utilization. Farmers can also utilize a greater variety of byproduct feeds with a TMR, thereby allowing for ration cost savings. The incidence of digestive and metabolic problems often decreases when a TMR is fed, and milk production has been shown to be as much as 5% higher with a TMR compared to conventional rations because of these benefits.
A TMR provides greater accuracy in formulation and feeding if managed properly. Using feed scales on mixing equipment in a feed area allows the quantity of each ingredient fed to be tightly controlled. When a TMR is mixed properly, a cow cannot consume significantly more or less of forage or concentrate than planned in the ration formulation. Parlor and selective feeding can be discontinued or limited to token amounts to facilitate cow movement, unless specific milking systems such as robotic milking systems are being used. The TMR system is adapted to mechanization with a mixer wagon or a stationary mixer with conveyors or mobile feeders. Mixing equipment must be properly maintained and load cells and scales must be kept in accurate working order. Mixers can be purchased that handle the addition of long hay; however, these are seldom recommended. Many of the TMR mixers that chop long forage also break down other feed and silage particles while they are reducing the long hay particle size. The result is often that the entire TMR has reduced particle size because of attempting to add a few pounds of long dry hay to the mix. It is almost always recommended to chop long forage as a separate commodity before adding it to the TMR mixer and mixing for a limited amount of time as recommended by the manufacturer. This is no more than 4 to 5 minutes–just long enough to achieve a good mixture.
Commodity ingredients can be fed quite effectively in a TMR diet. Both unique and common types of commodities are often less expensive due to bulk handling and direct purchasing. However, quality control must be maintained when purchasing commodity feeds. This often entails additional feed analysis, but additional costs of transportation and handling required by a commercial feed manufacturer are avoided. The quantity of commodity feeds purchased depends on the rate of spoilage, level of use, and available storage space. Purchasing enormous quantities may not be economical due to increased inventory costs. Total feed losses for commodity feeds, including what occurs during storage and handling, can range from 3% for a dry grain product to 15% for a high-moisture product such as wet brewer’s grain. Purchasing should be based on quality and nutrients needed for the ration, not solely on price. Additionally, a greater variety of ingredients allows more flexibility in formulating the ration for various production groups.
One of the major advantages of blending all the feeds together in a TMR is that it can mask the flavor of less palatable feeds. Feeds such as urea, limestone, fats, and some bypass protein sources may be less palatable. However, through blending, they can be added to TMR in reasonable amounts with little to no reduction in feed consumption.
Disadvantages of a TMR Feeding System
Mixing or blending devices needed for the ration require small to moderate expenditures for equipment and maintenance. Further, it is important to follow the manufacturer’s recommendations for mixing. Over-mixing can cause serious problems due to grinding and pulverizing the feed. Inadequate mixing can result in less effective feed utilization by the cows.
Accurate weighing with calibrated scales, which also may involve additional cost and maintenance, is essential. Care must be taken in formulating and mixing the ration. If the diet is not balanced correctly or mixed properly, the cow will suffer reduced performance. While this is true of any feeding system, it is under the control of the person feeding the herd. Remember with a true TMR, cows have no other option for a diet and depend solely on the ration for a balanced diet to achieve production and health.
In some cases, existing buildings, feed alleys, and mangers may make a TMR system impossible to use. Some housing and feeding facilities may not be well suited for a TMR system. Further, it may not be economical for all herds, particularly small herds or those using pasture feeding over an extended period, to implement a TMR system due to the increased cost of the feeding system.
Feeding Management on TMR Systems
The forage should be chopped properly before ensiling. Most forage particles in silage and haylage should range from 3/8 to 3/4 inches in length. Forage particles that are very fine, or grain that is too coarse or whole, should be avoided in the ration. Cows sort against long particles due to their less palatable nature and sort for finer particles in the ration. This behavior can lead to metabolic problems such as subacute ruminal acidosis (SARA). Cows consuming the finer particles of the ration are reducing their particle size consumption and, in effect, their NDF intake. These sorted diets contain more fermentable carbohydrates and less effective fiber than the formulated ration.
Effectively a sorted TMR is not a balanced TMR, and much of the time, effort, and expense involved in making the TMR is lost when it is sorted by the cow.
Develop rations based on current forage analysis reports. Current recommendations are to take the average of at least two separate and independent forage analyses from the same lab before building a TMR. Make ration adjustments when a change in forage is observed. The dry matter of ensiled material should also be checked frequently. Table 1 illustrates how corn silage dry matter percentage can vary within a farm and between farms. Dry matter percentage was tracked across 5 farms for 3 months, shortly after ensiling. While consistency is maintained across some months, others showed high variation between months. Changes in dry matter can cause shifts in feed weight resulting in more or less feed being added to mixer wagons to meet batch weights necessitated by the formulated ration. The more corn silage incorporated into the ration, the more drastic impact on the TMR percent. Changes in dry matter usually are more long-term and progressive. Accuracy of the scales and mixing system is critical to a TMR system, and a regular maintenance schedule should be planned and executed.
Table 1 Corn Silage Dry Matter Percentage Tracked Across 5 Farms for 3 Months
| Farm | Month 1 | Month 2 | Month 3 |
|---|---|---|---|
| 1 | 37.6 | 33.6 | 33.7 |
| 2 | 32.2 | 34.4 | 34.5 |
| 3 | 33.3 | 34.5 | |
| 4 | 32.3 | 28.1 | 33 |
| 5 | 30.5 | 30 |
Determining the actual dry matter intake of cows often helps to indicate problems with forage quality and dry matter content. Cows should be within 5% of the expected dry matter intake. If dry matter intake is significantly higher or lower than predicted, nutrient supply to the animal can be excessive or insufficient, potentially negatively impacting animal health or performance. If actual dry matter intake exceeds 5% of the expected, that ration should be reformulated. Extremely low intakes may indicate that forage quality and/or dry matter contents have changed and may be a limiting factor to intake. Dry matter intake can be calculated using the formula below.
Formula: DMI (lbs./head/day) = ( (lbs. Feed Delivered – lbs. of Feed Refused) / # of Animals Fed ) * Dry Matter Percent
Example of Low Dry Matter Intake for cows averaging 75 lbs. of milk and ration formulated for 49 lbs. DMI:
46 Holstein dairy cows are fed 2,250 lbs. of feed once in the morning and in the afternoon and have, on average, 1% refusals. TMR dry matter is 43.1%.
2,250 lbs. * 2 = 4,500 as fed lbs. feed delivered/day * .01 = 45 lbs. of refusals or 4455 lbs. consumed.
( (4500 – 45 or 4455) / 46 ) * .431 = 41.7 lbs. DMI
Example of Good Dry Matter Intake for cows averaging 75 lbs. of milk and ration formulated for 49 lbs. DMI:
48 Holstein dairy cows are fed 2,925 lbs. of feed once in the morning and afternoon with an average 2.5% refusals. The TMR dry matter is 43.24%.
2925 * 2 = 5,850 as fed lbs. feed delivered/day * .025 = 146 lbs. of refusals or 5704 lbs. consumed.
( (5850 – 146 or 5704) / 48) * .4324 = 51.4 lbs. DMI
While ration formulation programs have methods to predict dry matter intake, they are not always reflective of what is occurring on farms and can be driven by a multitude of external factors. To highlight the importance of TMR moisture, the following example shows how a very wet TMR leads to, comparatively, more feed needing to be delivered.
Example of a High Moisture TMR:
85 Holstein cows are fed 9,361 lbs. per day, split between a morning and evening feeding. Daily refusals average a total of 140 lbs. Cows are consuming 9221 lbs. of feed assuming 48% dry matter for a DMI of 52 lbs.
( (9361 – 140 or 9221)/85) * 0.48 = 52 lbs. DMI
If the TMR dry matter percent is 42, then to achieve the same DMI of 52 lbs., take (9221/85) * 0.42 = 10,524 lbs. consumed. Include the 1.5% refusals for the amount to feed (10,524 lbs. + 158 lbs.) = 10,682 lbs.
The number of animal groups to have in a TMR system is determined by the existing herd size and layout of the barns and loafing areas. An ideal TMR system for an entire farm could have seven main groups: high, medium, and low production lactating cows, far-off and close-up dry cows, and pre-breeding and post-breeding heifers. In addition, many herds separate a first-lactation cow group from older cows for all or part of the first lactation. On many farms, this group is critical, especially if other cow groups are overcrowded. First lactation cows most often respond well if they are undercrowded in terms of feed bunk and resting space per animal. It is also beneficial to separate heifers and mature cows during the transition period. Heifers are new to the calving process and could have additional stress and take longer calving. Housing these animals with mature cows during the transition period is additionally compounded through cow-to-cow competition. Depending on farm size, having this many separate groups may be unrealistic, yet larger farms may have multiple groups of each.
When working with a one- or two-group TMR system, there is less flexibility to formulate rations to meet specific needs. For instance, the lower-producing cows receive the same forage as the higher-producing cows, which may not allow for the optimal use of various forages. In a three-group system, low-group cows can usually be fed cheaper forage to reduce costs. Using a one-group TMR system usually results in higher feed costs because more expensive ingredients such as undegradable protein sources, fats, and certain feed additives are fed to cows in the later stages of lactation. These cows should be fed a ration with higher levels of forage than a one-group TMR would provide.
Lower-producing cows may become over-conditioned in a one-group TMR system. Many of the problems of the one-group system can be avoided by using two groups, especially if one of them is fed according to the above-average group production. Obviously, cow movement and changing social orders within pens is another factor to be considered when deciding the best number of groups for a farm operation. There is no one perfect answer for all systems and some farms will vary the number of TMR groups from year to year to best match other situations and priorities on the farm. The larger the farm, the easier it is to have the larger number of groupings or ration changes throughout the lactation cycle.
Dry cows are often recommended to be divided into two groups, far-off and close-up. Using a two-group TMR system for dry cows can minimize the level of metabolic and nutritional disorders observed at calving and in the postpartum period. The close-up group should be cows two or three weeks from calving, or if it is being balanced for anions and cations, three to four weeks.
To ensure proper ration formulation for growth and development, a two-group TMR system is necessary for heifers with the inclusion of one pre-breeding and one post-breeding heifer group. Young heifers lack the capacity to consume extremely high forage diets while maintaining proper growth. It is necessary for pre-breeding heifers to have an energy- and protein-dense diet.
There are other points to consider when feeding a TMR. First, the ration should be available to the cows 22 to 24 hours a day. To promote maximum feed intake, it is often recommended that refusals for the fresh group remain around 2 to 4%, 1 to 3% for high groups, and 0.5 to 3% for late-lactation groups. In general, feed refusal should not exceed 3 to 4%. Feed refusals can be fed to older heifers, steers, or other beef cattle. Refusals should never be fed to pre-fresh or fresh cows. First-calf heifers should be placed into a higher group than their production level to compensate for the growth they will have in the first lactation. Placing first-lactation heifers in a group separate from older cows reduces competition and gives younger cows improved access to bunk, water, and stall space. Second, if hay or grain is fed separately from the TMR, it should be limited to two to five pounds per head per day. Supplemental grain feeding to high producers may be necessary for one-group TMR systems. However, the amounts to feed will depend on the level of concentrate that is being fed in the TMR. When copious quantities of feedstuffs are fed separately from the TMR, the TMR loses many of the advantages it has over conventionally fed rations. Therefore, if possible, keep all the ingredients in the TMR to maximize performance and profit.
General Approach to Formulating TMR
The key to formulating a TMR is optimizing dry matter intake (DMI). Intakes should be consistent with production and breed and may be depressed when ensiled materials undergo abnormal fermentation. Forage dry matter should consist of good- to excellent-quality forages, especially for high-producing animals. The palatability of forages, the presence of certain weeds, and water quality can affect intake. Intakes may be elevated when forage is chopped too finely, or excessive concentrate dry matter is present. Dry matter intake during the first two weeks post-calving may average 2% of body weight.
The release of the 2021 Nutrient Requirements of Dairy Cattle – Eighth Revised Edition offers two approaches to estimating DMI. One focuses on animal factors and the other on ration dynamics. Both equations have their pros and cons, however, monitoring actual DMI is still recommended. DMI will likely be monitored at a group or herd level, depending on the number of diets fed. Therefore, DMI will be an average of a group, rather than an individual’s actual intake.
The equation using animal factors includes parity, milk energy (Mcal/day), body condition score (5-point scale), and days in milk. Figure 1 shows the comparison between the new equation to the 2001 NRC and the evaluation data set (observed). In the development data set the means were as follows: body weight of 1373 pounds, body condition score of 3.04, days in milk of 108 and milk energy of 29.8 Mcal/day. The inclusion of body condition score is new compared to the 2001 NRC equation.
The animal factor equation requires knowing body weights and body condition scores, which can be difficult and subjective information to obtain on farms. Also, since energy is a calculated value, there can be discrepancies between energy values from the formulated ration compared to a TMR analysis. Body weight and body condition score are very influential in the new DMI equation. The limitation is not having good farm data to incorporate into this equation.
Animal Factor Equation:
DMI (kg/d) = [(3.7 + Parity × 5.7) + 0.305 × MilkE (Mcal/d) + 0.022 × BW (kg) + (−0.689 + Parity × −1.87) × BCS] × [1 − (0.212 + Parity × 0.136) × e(−0.053 × DIM)]
Source: R.A. de Souza, R.J. Tempelman, M.S. Allen, M.J. VandeHaar, 2019. Updating predictions of dry matter intake of lactating dairy cows. J Dairy Sci. 102(9):7948-7960
Figure 1. Lactation curve for the average Holstein dairy cow in the data set. The solid lines represent the observed milk energy (MilkE; blue with circles), observed DMI (red with diamonds), and observed BW (green with ×), and the dashed lines represent the DMI predicted by the NRC, 2001 (Dotted line) and proposed (Dashed line) models.
The second equation estimates intakes based on gut fill and utilizes forage neutral detergent fiber (NDF) percent, acid detergent fiber percent, NDF percent, forage NDF digestibility percent and milk yield. This equation is more appropriate for lactating animals greater than 60 days in milk.
Ration Effects Equation:
DMI (kg/d) = 12.0 − 0.107 × FNDF + 8.17 × ADF/NDF + 0.0253 × FNDFD – 0.328 × (ADF/NDF – 0.602) × (FNDFD − 48.3) + 0.225 × MY + 0.00390 × (FNDFD − 48.3) × (MY – 33.1)
Source: M. S. Allen, D. O. Sousa, and M. J. VandeHaar. 2019. Equation to predict feed intake response by lactating cows to factors related to the filling effect of rations. J Dairy Sci. 102(9):7961-7969.
Table 2 shows the comparison between using the new equation and using the percent of body weight (Table 3) on five herds from the Extension dairy team’s on-farm research projects. Since body weights were not measured on the farms, the average weights from the development and evaluation data set were used (Allen et al, 2019). It was noted that much of the data represented the eastern part of the country and is within line for Pennsylvania dairy operations. There is remarkably close agreement between using both approaches for estimating intakes. The research data typically consists of high-producing cows, and intakes are more aligned for the two herds milking over 85 pounds.
Table 2. Comparison of predicted dry matter intakes using both ration focused equation and percent of body weight.
| Energy Corrected Milk (lbs.) | Percent of Body Weight1(%) | Body Weight – 1373 lbs.2 (DMI lbs.) | Body Weight – 1406 lbs.2 (DMI lbs.) | Ration Focus Equation2,3(DMI lbs.) | |
|---|---|---|---|---|---|
| Farm 1 | 78.7 | 3.8 | 52.2 | 53.4 | 53.8 |
| Farm 2 | 77 | 3.7 | 51.1 | 52.4 | 53.2 |
| Farm 3 | 80.6 | 3.8 | 52.2 | 53.4 | 54.1 |
| Farm 4 | 96.6 | 4.3 | 59 | 60.5 | 58.9 |
| Farm 5 | 89.1 | 4.1 | 56.3 | 57.6 | 56.6 |
Note: Farms 1-5 were on extension projects and had the necessary data to incorporate into the new ration focused equation.
1Dairy Reference Manual, 3rd edition, NRAES-63, 1995.
2Body weights from the development and evaluation data set used in establishing equations for dry matter intakes.
M. S. Allen, D. O. Sousa, and M. J. VandeHaar. 2019. Equation to predict feed intake response by lactating cows to factors related to the filling effect of rations. J Dairy Sci. 102(9):7961-7969.
3Minor change was using energy-corrected milk in place of milk yield to better match the 4% fat-corrected milk with the percentage of body weight recommendations.
Table 3. Using percent of body weight to estimate dry matter intake for large and small breed cattle.
| Milk production, 4% FCM (lbs/day) |
Dry matter intake (% of body weight) Large breeds |
Dry matter intake (% of body weight) Small breeds |
|---|---|---|
| 100 | 4.30 | 5.80 |
| 90 | 4.10 | 5.40 |
| 80 | 3.80 | 5.00 |
| 75 | 3.65 | 4.80 |
| 70 | 3.50 | 4.50 |
| 65 | 3.40 | 4.25 |
| 60 | 3.25 | 4.00 |
| 55 | 3.13 | 3.85 |
| 50 | 3.00 | 3.70 |
| 45 | 2.85 | 3.50 |
| 40 | 2.70 | 3.30 |
| 35 | 2.60 | 3.10 |
| 30 | 2.50 | 2.90 |
| 20 | 2.10 | 2.50 |
The second objective was to compare the new equation to the actual intakes of a dairy herd. Table 4 illustrates the ration information for a well-managed operation, especially for feeding management. The forage ration consisted primarily of corn silage with some triticale. Daily intakes were monitored, and adjustments were made to account for changes in dry matter percent and cow numbers. There was excellent agreement between the predicted dry matter intake and what was consumed. Note that the average for the month was used to compare the predicted intake. As would be expected, there were daily variations so that if one point in time was used, intakes could be off plus or minus by a few pounds. Because the herd was monitoring intakes daily and adjusted, accordingly, feeding management issues were addressed in a timely manner. Making intake comparisons from one day can be misleading.
The ration-focused equation for estimating intakes utilizes common analyses and appears to accurately predict intakes. Since this equation accounts for gut fill, it would not be appropriate to use it for cows less than 60 days in milk. There are other issues occurring during that time, which do not necessarily reflect gut fill. The old standard of using percent of body weight to estimate intakes also appears to be a quick and easy approach to ballpark dry matter intakes. Regardless of the approach, if good feeding management practices are not in place, actual intakes may not be in close alignment with the prediction equation, but that is on management, not the equation.
Table 4. Comparing actual intakes with the ration-focused prediction equation for a 3x milking herd.
| ADF, % | 18.3 |
| NDF, % | 31.7 |
| FNDF, % | 24 |
| FNDFD, % | 60.1 |
| ADF/NDF | 0.58 |
| Milk yield, lbs. | 85.9 |
| Predicted DMI, lbs. | 54.6 |
| Actual DMI, lbs.1 | 54.8 |
Note: ADF-acid detergent fiber; NDF-neutral detergent fiber; FNDF-forage NDF; FNDFD-FNDF digestibility. The ADF and NDF came from the TMR analysis; FNDF came from the formulated diet; FNDFD came from the forage analyses.
1Actual dry matter intake is the average for September.
The ration differences between groups should be minimal, otherwise, cows will decrease milk yield significantly when they are moved to a different group. Limit differences in concentrate dry matter proportions to not over 10 to 15% between groups. The level of concentrate dry matter and protein depends to a certain extent on the production level and the type of forage used (Table 5).
Moving cows through groups in multi-group systems may control body condition in herds fed a TMR. In single-group TMR systems, the percentage of concentrate dry matter may be altered; thin cows could receive supplemental feed and over-conditioned cows could be limited in amounts of the ration fed. In general, it is important to follow sound nutrition practices with respect to crude protein, energy, neutral detergent fiber, non-fiber carbohydrates, fat, macro and micro minerals, and vitamins for the respective levels of production. Monitoring intakes of the TMR is beneficial so that animals do not over- or under-consume.
Dry cows may need at least five pounds of long-stem hay along with a TMR to provide sufficient “effective fiber.” Dry cows placed on a close-up TMR should be kept on the ration until the day they freshen. This applies to both regular and anionic close-up rations (Table 6). Dry cows that are not grouped and offered one TMR may be fed limited amounts of the milk cow TMR for two or three weeks prior to freshening. However, restrictions must be set to ensure that there is adequate forage dry matter intake and that the nutrient densities of protein, minerals, and vitamins do not exceed recommendations for close-up dry cows.
Nutrient specifications for heifer TMRs are in Table 7. Total dry matter intakes are regulated by the bulk of the ration and its energy density. If corn silage is fed heavily in a heifer TMR, intake may have to be controlled and more closely monitored to avoid over-conditioning.
The benefits of using a TMR far outweigh the disadvantages, but each farm has different goals and facilities that may or may not adapt well. Each case should be analyzed to find the most profitable alternative. A carefully designed and well-thought-out system will pay off eventually.
Table 5. Guidelines for nutrient levels in lactating dairy cow TMRsa.
| Stage of Lactation Earlyb | Stage of Lactation Midc | Stage of Lactation Late | |
|---|---|---|---|
| Crude protein, %DM | 17 to 17.5 | 16 to 17 | 15 to 16 |
| Soluble protein, %CP | 30 to 34 | 32 to 36 | 32 to 38 |
| Degradable protein, %CP | 62 to 66 | 62 to 66 | 62 to 66 |
| Undegradable protein, %CPd | 34 to 38 | 34 to 38 | 34 to 38 |
| NEL, Mcal/lb DMe | 0.72 to 0.82 | 0.78 to 0.82 | 0.72 to 0.78 |
| Forage NDF, %DM | 19 to 25 | 25 to 26 | 27 to 28 |
| Total NDF, %DM | 25 to 33 | 25 to 35 | 35 to 38 |
| Fat, maximum, %DMf | 5 to 7 | 4 to 6 | 4 to 5 |
| Calcium, %DMg | 0.81 to 0.91 | 0.77 to 0.87 | 0.70 to 0.80 |
| Phosphorus, %DMg | 0.35 to 0.39 | 0.35 to 0.37 | 0.35 to 0.40 |
| Magnesium, %DMg | 0.28 to 0.37 | 0.25 to 0.34 | 0.22 to 0.28 |
| Potassium, %DMh | 1.00 to 1.50 | 1.00 to 1.50 | 1.00 to 1.50 |
| Sulfur, %DM | 0.23 to 0.24 | 0.21 to 0.23 | 0.20 to 0.21 |
| Salt, %DM or | 0.45 to 0.50 | 0.45 to 0.50 | 0.45 to 0.50 |
| Sodium, %DM | 0.20 to 0.25 | 0.20 to 0.25 | 0.20 to 0.25 |
| Chlorine, %DM | 0.25 to 0.30 | 0.25 to 0.30 | 0.25 to 0.30 |
| Manganese, ppm | 44 | 44 | 44 |
| Copper, ppmi | 11 to 25 | 11 to 25 | 11 to 25 |
| Zinc, ppm | 70 to 80 | 70 to 80 | 70 to 80 |
| Iron, ppm | 100 | 100 | 100 |
| Added selenium, ppm | 0.3 | 0.3 | 0.3 |
| Added cobalt, ppm | 0.2 | 0.2 | 0.2 |
| Added iodine, ppm | 0.5 | 0.5 | 0.5 |
| Total vitamin A, IU/lb DM | 4,500 | 4,500 | 4,500 |
| Added vitamin D, IU/lb DM
– Minimum – Maximum |
750 1,100 |
750 1,100 |
750 1,100 |
| Total vitamin E, IU/lb DM | 30 | 30 | 30 |
| Approximate concentrate, %DMj | 50 to 60 | 40 to 50 | 35 to 45 |
| Approximate DMI, %BW | 4.0+ | 3.5+ | 3.0+ |
aRefers to milk production equivalent to a DHI rolling herd average of 24,000 lb of 4% fat-corrected milk or higher.
bRefers to cows in approximately the first 15 weeks of lactation. DMI during the first month may range from 2.2% BW at calving to 2.8% BW at 14 days and 3.3% at 30 days.
cFollow guidelines for mid lactation animals if a one-group TMR is being fed.
dUse more than one high protein supplement to meet undegradable protein needs (UIP). Often lysine and sometimes methionine are the most limiting essential amino acids. On a largely corn-based ration of silage, grain, or corn by-products; part of the UIP should be furnished by animal or fish protein, soybean protein, or cottonseed protein to provide more lysine. Limit use of brewers, distillers, corn gluten meal, and feather meal in high corn diets.
eNEL needs are dependent upon production level, body condition scores, and deviations in dry matter intake.
fFat at over 5% should be furnished by rumen-inert or by-pass fats.
gUse these minerals at the higher level indicated when fat content exceeds 4.0%.
hUse the higher potassium level during periods of hot, humid weather.
iUse the higher copper levels when low serum copper occurs on rations containing usual levels of 10 to 12 ppm. Induced copper deficiency may result from excessive intake of iron, manganese, molybdenum, and sulfur.
jWhen feeding total mixed rations avoid differences between rations that exceed 10 to 15% for milking groups to avoid excessive drops in production when moving to a lower group. Concentrate level is dependent on forage quality, forage quantity, amounts and types of byproduct feeds, and energy corrected milk.
Table 6. Guidelines for nutrient levels in dry cow TMRs.
| Far-off | Close-up, regulara,b | Close-up, anionica,c | |
|---|---|---|---|
| Crude protein, %DM | 12 to 13 | 13.5 to 14.5 | 13.5 to 14.5 |
| Soluble protein, %CP | 30 to 38 | 30 to 38 | 30 to 38 |
| NEL, Mcal/lb DM | 0.58 to 0.64 | 0.62 to 0.68 | 0.62 to 0.68 |
| Forage NDF, %DM | 19-25, min | 19-25, min | 19-25, min |
| Total NDF, %DM | 25-33, min | 25-33, min | 25-33, min |
| Calcium, %DM | 0.45 to 0.55 | 0.45 to 0.55 | 1.40 to 1.60 |
| Phosphorus, %DM | 0.30 to 0.32 | 0.30 to 0.32 | 0.32 to 0.35 |
| Magnesium, %DM | 0.24 to 0.28 | 0.28 to 0.32 | 0.28 to 0.32 |
| Potassium, %DM | 0.80 to 1.00 | 0.80 to 1.00 | 0.80 to 1.10 |
| Sulfur, %DMd | 0.2 | 0.2 | 0.35 to 0.40 |
| Salt, %DM or | 0.25 to 0.30 | 0.25 to 0.30 | 0.25 to 0.30 |
| Sodium, %DM | 0.10 to 0.12 | 0.10 to 0.12 | 0.10 to 0.12 |
| Chlorine, %DM | 0.20 to 0.24 | 0.20 to 0.24 | 0.70 to 0.80 |
| Manganese, ppm | 38-43 | 38-43 | 38-43 |
| Copper, ppme | 18 to 25 | 18 to 25 | 18 to 25 |
| Zinc, ppm | 70 to 80 | 70 to 80 | 70 to 80 |
| Iron, ppm | 100 | 100 | 100 |
| Added selenium, ppm | 0.3 | 0.3 | 0.3 |
| Added cobalt, ppm | 0.2 | 0.2 | 0.2 |
| Added iodine, ppm | 0.5 | 0.5 | 0.5 |
| Total vitamin A, IU/lb DM | 3,500 | 3,500 | 3,500 |
| Added vitamin D, IU/lb DM
– Minimum – Maximum |
750 1,100 |
825 1,100 |
825 1,100 |
| Total vitamin E, IU/lb DM | 39 | 82 | 82 |
| Approximate concentrate, %DM | 12 to 15 | 22 to 25 | 22 to 25 |
| Approximate DMI, %BW | 2 | 1.8 | 1.8 |
aThe last three to four weeks prior to expected calving.
bRegular or cationic (alkaline) diet.
cAnionic or acidic diet with a cation-anion balance of -100 to -150 milliequivalents per kilogram (mEq/kg). This is based on the simple equation of: mEq/kg = mEq (Na+K) – mEq (Cl+S). Factors to convert from nutrient % to mEq/kg of diet are Na: 435, K: 256, Cl: 282, and S: 624. Example: Calculate the cation-anion balance of a ration with Na at 0.15%, K at 1.10%, Cl at 0.80%, and S at 0.40% (all values are on a dry matter basis). mEq/kg = [(0.15 x 435) + (1.10 x 256)] – [(0.80 x 282) + (0.40 x 624)] = (65.3 + 281.6) – (225.6 + 249.6) = 346.9 – 475.2 = -128.3
dSulfur level of 0.45% in the close-up anionic diet may be tolerated for short periods of time (three to four weeks).
eUse the higher or intermediate levels when an induced copper problem exists due to high iron, manganese, molybdenum, or sulfur intakes.
Table 7. Guidelines for nutrient levels in heifer TMRs.
| 1 to 6 months | 7 to 11 months | 12 to 24 months | |
|---|---|---|---|
| Crude protein, %DM | 16-21 | 13-14 | 13-Dec |
| Soluble protein, %CP | 25 to 30 | 30 to 35 | 30 to 38 |
| Degradable protein, %CP | 45 to 55 | 33 to 37 | 25 to 30 |
| Undegradable protein, %CP | 45 to 55 | 63 to 67 | 66 to 72 |
| NEM, Mcal/lb DM | 0.77 | 0.72 | 0.65 |
| NEG, Mcal/lb | 0.49 | 0.44 | 0.38 |
| Total NDF, min., % | 25-33 | 25-33 | 25-33 |
| Calcium, %DM | 0.59-0.78 | 0.44-0.58 | 0.37-.039 |
| Phosphorus, %DM | 0.32-0.45 | 0.21-0.26 | 0.18-0.19 |
| Magnesium, %DM | 0.22 | 0.22 | 0.22 |
| Potassium, %DM | 0.8 | 0.8 | 0.8 |
| Sulfur, %DM | 0.2 | 0.2 | 0.2 |
| Salt, %DM or | 0.25 to 0.30 | 0.25 to 0.30 | 0.25 to 0.30 |
| Sodium, %DM | 0.10 to 0.12 | 0.10 to 0.12 | 0.10 to 0.12 |
| Chlorine, %DM | 0.20 to 0.24 | 0.20 to 0.24 | 0.20 to 0.24 |
| Manganese, ppm | 50 | 40-44 | 38-43 |
| Copper, ppma | 15 to 25 | 15 to 25 | 15 to 25 |
| Zinc, ppm | 70 to 80 | 70 to 80 | 70 to 80 |
| Iron, ppm | 100 | 100 | 100 |
| Added selenium, ppm | 0.3 | 0.3 | 0.3 |
| Added cobalt, ppm | 0.2 | 0.2 | 0.2 |
| Added iodine, ppm | 0.5 | 0.5 | 0.5 |
| Total vitamin A, μ/lb DM | 1,540-2,500 | 1,540-2,500 | 1,540-2,500 |
| Added vitamin D, μ/lb DM | 420-690 | 475-530 | 580-660 |
| Total vitamin E, μ/lb DM | 22-39 | 25-28 | 31-35 |
| Approximate concentrate, %DM | 60 to 65 | 20 to 25 | 10 to 15 |
| Approximate DMI, %BW | 2.6 | 2.2 | 1.7 |
aUse higher or intermediate copper levels when an induced copper problem exists due to high iron, manganese, molybdenum, or sulfur intake.
Author: Virginia A. Ishler, Extension Dairy Specialist
