Total Mixed Ration for Dairy Cows – N.Muthusamy

New Delhi, September 23, 2014 – The dairy farmers struggling to tackle the rapidly increasing feed cost, the recent introduction of Total Mixed Ration (TMR) can effectively reduce the feed cost by inclusion of wet by products like brewers grain, tapioca starch waste, fruit industry by products etc., and low quality roughage like maize stover, gram husk etc. The TMR, which consists of mixing of roughage and concentrates in correct quantity and proportion along with the supplements. Milk production and milk components give profit to dairy farmers, improving DMI especially in early and high-producing cows is required to get that done. Wachirapakorn et al. (1997) compared two feeding regimes (Conventional and TMR feeding) found that TMR feeding increase the dry matter intake (DMI) and milk production compared to conventional feeding.

Dry Matter Content of TMR

The balanced rations for dairy cattle, that the cow will receive a certain amount of dry matter from a particular feed. The dry matter content of silages and wet byproducts is vary. As the feed becomes wetter, more feed to be included and as feeds become drier, less of the forage or feed needs to be included in the TMR. The optimum dry matter content of TMR is about 50-60%. The dry matter content of TMR is more than 60% dairy cattle selectively consume (sort) smaller concentrate particles than long forage in the ration. Water addition to a dry TMR as a technique to reduce the degree of feed sorting (Shaver, 2002). Sorting will be increased when adding water to a higher-moisture TMR (58-48%) due to filling effect of the ration (Miller-Cushon and DeVries, 2009)

Estimation dry matter intake

General

DMI (kg/day) = [1.8% x body mass (kg)] + [4% FCM (kg) / 3]

where: 4% FCM = (0.4 x kg milk) + (15 x kg fat) (source: University of Minnesota)

Early lactation
DMI (kg/day) = [0.01641 x bodymass (kg)] + [0.1713 x kg daily milk yield] + [4.534 x daily fat yield]

Mid lactation
DMI (kg/day) = Early lactation DMI x 1.07 (source: University of Wisconsin)

late lactation

DMI (kg/day) = [0.0185 x bodymass (kg)] + [0.305 x 4% FCM (KG)] (source: University of Georgia)

If the expected and actual intake differ by more than 5 to 10% ration should be reformulated.

Table.1 Nutrient concentrations in total mixed rations for Lactating and Dry cows

* Early dry period is from drying off to two weeks pre-partum

** Close to calving refers to last 2 weeks pre-partum to 2 days post-partum Close to calving refers to last 2 weeks pre-partum to 2 days post-partum Close to calving refers to last 2 weeks pre-partum to 2 days post-partum

NSC : RDP ratio

The Non Structural Carbohydrate (starch, sugar) in the diet provides the energy required for microbial protein synthesis. When high levels of NSC are fed with Ruminally Degradable Protein (RDP) can limit microbial growth. The diets should be formulated to provide 35 to 40% NSC and 60 to 65% of the protein as RDP.

Particle Size of TMR

Cows need to consume adequate amounts long forage fiber for cud chewing and more saliva, which helps buffer the rumen environment so that the bacteria can efficiently digest forages. When a TMR mix is over mixed, the particle size of the forages decreases, result in, decreases cud chewing time and saliva production, which lead to an increased incidence of ruminal acidosis, laminitis. Generally, TMR mixing time is about three to six minutes.

The particle size of the TMR will be evaluated using a Penn State particle separator box (see Figure 1). This separator box consists of three separate boxes that allow the TMR mixture to be separated into three particle sizes. The top box retains particles of feed or forage that are greater than 0.75 inch. The middle box retains particles between 0.31 and 0.75 inch. The bottom box has a solid bottom and retains particles less than 0.31 inch. Expected percentages retained on each of the three boxes are shown in Table 2.

TMR Feeding:

Milking cows need quality feed available 20 hours of a day. The TMR can be fed twice in a day, once in the early morning and once in the evening keeps the feed fresher and increase feed intake. TMR machine pushed up feed in front of the cows to stimulate feed intake. When increasing or decreasing the amount of TMR fed. the amounts of each forage, grain, and other ingredients need to be increased in proportion to the originally formulated TMR. Samples should be collected at the beginning, middle, end of the feed delivery, and residual feed in the feeder should be evaluated. These results need to be compared to detect any potential problems. When increasing or decreasing the amount of TMR fed, the amounts of each forage, grain, and each of the other ingredients need to be increased in proportion to the originally formulated TMR

Grouping of dairy animals for TMR Feeding

Dairy herds feeding a TMR should have a minimum of 3 milk production groups and 2 dry cow groups. The groups are following:

1. Pre-Fresh or close-up dry cows (2 to 3 weeks before calving).

The dry matter intake of this group is about 10 kg/day. This group of animal require more fiber in the ration and contains all the nutrients required to prepare for the birth calf, initiation of lactation and help to prevent metabolic problems. This ration should contain about 3 kg of grain, 2 to 3 kg of good quality hay plus forage like corn silage and the proteins, minerals and feed additives needed to make the ration.

2. Fresh cow group (1 to 21 days after calving). These cows have a low dry matter intake, but a high nutrient requirement as they begin the lactation. The ration should contain adequate fiber (2 to 3 kg of good quality hay) to help promote good rumen function plus other forages and concentrates to start high milk production.

3. High producing older cow (2nd lactation and above) group (21 to 180 days in milk).

This group require more dry matter for peak milk production and breeding.

4. First lactation or first calf heifer group.

They are slower to reach peak dry matter intake and milk production, but more persistent than older cows. This group can stay for 250 days in milk or more before moving to a late lactation group.

5. Mid-lactation cows (180 to 250 days in milk).

Cows in this group should be pregnant and milk production should average 75 to 85% of the high group. The ration fed to this group should be higher in forages and slightly less nutrient dense than the high group ration.

6. Late lactation pregnant cow group (250 days in milk to dry off).

The first lactation cows, over 250 days in milk, can be mixed with older cows for the entire lactation. The ration will be high in forage towards maintaining milk production and avoiding over conditioning or fattening cows.

7. Far-Off dry cows (220 to 260 days pregnant).

The goal of the dry period should be to prepare the cow for the next lactation. The TMR should contain good to medium quality forages to promote maximum rumen fill, Adequate protein and mineral balance in the ration is required.

Advantages of a total mixed ration

· Increased dry matter intakes (DMI). Peak DMI is achieved 4 to 8 weeks earlier than conventional systems.

· All forages, grains, protein supplements, minerals and vitamins are thoroughly mixed.
· Selective feeding can be reduced.

· Totel mixed ration formulated according to stage of lactation and milk yield.

· Each mouthful of feed consume by the cow contains balanced ration.

· TMR increase feed efficiency, compared to a conventional ration.

· The incidence of digestive and metabolic problems decrease.

· The milk production can be increased with TMR compared to conventional methods.

· The TMR system is well adapted to mechanization with either a mixer wagon, cart or a stationary mixer with conveyors or mobile feeders.
· Variety of ingredients is used to make total mixed ration.

Disadvantages of the total mixed ration

· Grouping of cows is not feasible in small herds (less than 50 cows). If not grouped according to production, cows in late lactation are likely to get fat.

Additional equipment is needed to chop the hay or straw before being added to the TMR mixer.

References:

Kononoff, P. J., A. J. Heinrichs, and D. R. Buckmaster. 2003. Modification of the Penn State Forage and Total Mixed Ration Particle Separator and the Effects of Moisture Content on its Measurements. J. Dairy Science. 86: 1858-1863

Miller-Cushon, E. K., and T. J. DeVries. 2009. Effect of dietary dry matter concentration on the sorting behavior of lactating dairy cows fed a total mixed ration. J. Dairy Sci. 92:3292–3298.

Shaver, R. D. 2002. Rumen acidosis in dairy cattle: Bunk management considerations. Adv. Dairy Technol. 14:241–249.

Wachirapakorn, C., T. Puramongkol and V. Seepuang. 1997. Total mixed ration (TMR) or complete ration (CR) for dairy cows. J.Dairy Cows. 5:53
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