Feeding total mixed rations

• With every bite or mouthful cows will eat a nutrient-balanced ration.

• Cows will eat a fixed amount of forages and concentrates needed for good production and health. It’s harder for cows to be picky while eating.

• A TMR lowers the risk of digestive upset, stabilizes rumen pH and optimizes rumen feed digestion.

  • The rumen microorganisms have a uniform supply of protein and carbohydrates throughout the day. This maximizes rumen fermentation and the production of rumen microbial protein.

• TMR mixers can reduce the work of feeding cows and save labor costs.

• A TMR provides more control and accuracy over the amount of feed given than separate ingredients.

• Feeding a TMR that’s correctly balanced for your cows can increase milk production 1 to 2.5 kilograms per cow daily.

• Milk fat and other components can increase.

• You can successfully feed small amounts of low quality forages or unpalatable feed in a TMR. This feed practice also allows cows to better use these feeds than when fed separately.

• It’s easier to measure daily feed intake.

  • By knowing daily intakes, you can correctly balance your cows’ ration, which reduces feed waste and costs.

• All cows in the group get the same ration. Individual feeding isn’t possible.

• You need a mixer to correctly feed a TMR.

  • Feed mixers with weighing equipment are expensive.

• Dry forages such as hay or straw may not mix well in some TMR mixers.

  • You may need more equipment to chop the hay or straw before adding it to the mixer, depending on the type of mixer you use.

• You need to group cows to effectively use TMR feeding.

  • Cows in a group should be as uniform in milk production and body weight as possible. Differences in milk productions (over 10 kilograms per day) or body weights (over 100 kilograms) within a group can result in some cows being over or under fed. This can increase feed costs or milk production loss.

  • Have at least three lactating cow groups for cost effective TMR feeding.

Pre-fresh cows have a low dry matter intake (about 10 kilogram per day). They need a high-fiber ration that contains the nutrients they need for the following.

• Preparing for the calf’s birth

• Starting lactation

• Helping prevent metabolic problems

The ration should contain the following:

• About 3 kilograms of grain

• 2 to 3 kilograms of good quality hay plus forage like corn silage

• Proteins

• Minerals

• Feed additives needed to make the ration palatable and help prevent metabolic disorders

Fresh cows have low dry matter intakes, but high nutrient needs as they start lactation. Their ration should contain enough fiber (2 to 3 kilograms of good quality hay) to help promote good rumen function. It should also contain other forages and concentrates for a good start towards high milk production and entering the high production group.

High-producing older cows reach peak milk production and peak dry matter intake. The goal for feeding this group is to keep high milk production to get cows bred back for next lactation. You can consider this group a reproduction group because heat detection and breeding occurs

First lactation cows tend to do better if they have their own group for social and nutrition reasons. These cows reach peak dry matter intake and milk production slower than older cows. Yet they’re more constant in keeping milk production than older cows. This group can stay together for 250 days in milk or more before moving to a late lactation group.

Mid-lactation cows should be pregnant with milk production averaging 75 to 85 percent of the high group. Feed this group a ration higher in forages and slightly less nutrient dense than the high group ration.

In this group, you can mix first lactation cows (over 250 days in milk) with older cows if barn space doesn’t allow you to keep first lactation cows separate for the whole lactation. These cows need a high forage ration to maintain milk production and avoid fattening cows.

The goal of the dry period is to prepare the cow for the next lactation. The TMR should contain mostly good to medium quality forages to promote maximum rumen fill and rumination. Cows will need enough protein and proper mineral balance in their ration.

Dairy cow rations are formulated on a dry matter basis. The amounts of each feed fed are on an as is or as fed basis. Knowing the correct dry matter (100 - percent moisture) of ensiled forages and wet grains and feeds fed in the TMR is key to mixing and feeding a balanced ration.

Use a moisture tester to test all ensiled forages and wet feeds once or twice a week for moisture or dry matter content. You may feed too much if you underestimate the feed’s dry matter content, thinking it has more moisture than it does. You may not feed enough if you overestimate the dry matter of a feed, thinking it has less moisture than it does.

You can notice changes in dry matter content through:

• Changes in the size or volume of the TMR mixed.

• Larger than normal amount of feed remaining the next day (usually means feeds have increased in dry matter).

• No feed remaining the next day (usually means feeds have decreased in dry matter content or increased in moisture).

Count the number of cows in a group daily before feeding. This will allow you to feed the correct amount per cow.

Increase or decrease the amount of TMR you mix based on daily changes in feed intake. Cows don’t eat the same amount of feed every day. Weather and environmental temperatures greatly affect daily feed intakes. When making changes to a TMR, make sure to keep the amount of feeds in proportion.

If feed intakes consistently differ 5 percent (about 2 kilograms) as fed from the amount you balanced for, reformulate the ration using the new feed intake.

Auger mixers

Add feeds in this order when using auger mixers.

1. Grains and other concentrates

2. Ensiled forages

3. Dry forages

   • For the best results, chop or grind dry forages coarsely before adding them to the mixer.

Vertical mixers

Add feeds in this order when using vertical mixers with one or two center augers.

1. Dry or long forages

2. Grains

3. Concentrates

4. Ensiled forages

Mixing times will vary with:

• Mixer-type (auger or vertical)

• Amount of feed in the mixer

• Size of the tractor running the mixer

• Mixer condition (new or old)

After adding the last feed ingredient, five minutes of mixing should be enough time to thoroughly mix the feed. With vertical mixers, final mixing time after you add all ingredients is often only three to five minutes.

Make sure to not over mix the TMR. If you overmix the TMR, the feed particles will be small, and no long physical fiber will remain. This will lead to rumen upsets, low cud chewing and acidosis (low pH).

You can feed a TMR once daily, but twice daily is better, especially during hot, humid summer months. Feeding once in the early morning and once in the evening keeps the feed fresher and promotes feed intake.

Many producers set out the TMR while the cows are in the parlor for milking. After milking, the cows return to the pen and to fresh feed. Cows are most hungry at this time and eating encourages cows to stand. Standing allows the udders to dry off and the teats to seal before lying down.

Push the TMR in towards the pen six or more times daily. Cows eat the feed closest to them first. They can only reach out about 72 centimeters from the pen for feed. Thus, if feed isn’t regularly within the cows’ reach, less aggressive eaters may not be able to maximize their feed intake.  

Pushing feed regularly is also important in overcrowded pens with feed bunk space less than 46 centimeters per cow.

Cows are good at using their noses to sort and separate grain from forage in a TMR. Cows usually eat the grain first and leave long forages for later. In doing this, cows unbalance the TMR by eating only grain at one meal. This can lead to acidosis and off-feed problems.

The drier the TMR, the more the cows sort. A TMR should be between 50 and 55 percent dry matter. Feeding the TMR more than once daily or pushing feed in often helps reduce sorting problems.

Watch for feed refusals daily. Leftover feed in the bunk should look the same as the TMR you’re about to feed. You can tell if cows are sorting and not eating a balanced ration if they leave long forage particles, corn cobs or other single feed ingredients. Chop the long forages or particle feeds finer or replace them with feeds that are harder to sort to avoid this problem.  

Check TMR particles size every two to four weeks. You can use a Penn State Particle Size Separator box to check your TMR.

Aim for your TMR particle sizes to separate as follow:

• 3 to 8 percent of feed on the top screen

• 30 to 50 percent of feed on the middle screen

• 30 to 50 percent of feed on the lower screen

• Less than 20 percent of feed on the bottom pan

Long particles in the TMR or more than 10 percent of TMR on the top screen can allow cows to sort the TMR easier.

Calibrate mixer scales once every three months. Check mixer scales when the mixer is at one-third, two-thirds and full weight capacity. Placing a known amount of weight (25 to 45 kilogram) on each corner of the mixer, at the three weight loads, is a simple way to test the scales.