Some information/ideas on TMR use, mixing and balancing the mix for dairy cows (part 1)

Most feeds can be used in a TMR, but attention must be given to the balance of the feeds to meet the cows’ needs as well as how the feeds are mixed in the TMR mixer so the feeds are adequately mixed.  Adequate mixing means mixing a sufficient amount of time to get every thing mixed well, but not too much time which will cause the fiber in forages (hay, silage, straw)  to become too small.

Anyone mixing a TMR should have the following goals:

1.       Providing an economical, nutrient balanced ration for the cows to be fed.

2.       Provided a consistent blend of feeds in the feed bunk.

3.       Mix the feeds so that the blend has the correct particle size.

4.       Keep cost in line for everyone.

Let me give some general comments on what to look for in a balanced ration (especially when fed as a TMR) and then add some additional information.   The person and company mixing TMRs for dairy cattle should consider at least the following in balancing the TMR.

1. The type of mixed ration.   We routinely talk about TMR mixes, but they may not be a TMR as such  although they work very well for the farmer.   Examples follow

a.       Total mixed ration (TMR):   This actually means all feeds (forages, grains, supplements, additives) put before the cow are mixed in the mixture and is a TMR in the full sense.

b.       Many diets called TMRs are actually mixed partial rations.    A farmer or company may mix alfalfa hay, silages, grains and supplements in the mixer.   However, he may want to give one group more protein supplement or energy so he top dresses the mixed ration with a kg or so of soybean meal or of a grain mix rather than making several different diets.   Other farmers may buy a partial mix but have some hay at home so they feed 2-3 kg of hay along with the mixed ration.   The best approach is the full TMR, but partial mixed rations may work best for some groups.

2.       The proper nutrients required by the dairy cows being fed.  (The term feedstuffs or feed refers to ingredients such as grains, forages, protein supplements, by-product feeds of various feed processing plants).

a.       Diets for dairy cows need to be balanced for energy, protein, fiber, major (calcium, phosphorous, magnesium, sodium and chloride) and trace minerals (e.g., give attention to sulfur, cobalt, copper, manganese, zinc, iodine and selenium.)

b.       The nutrients needed by the cows will depend upon their milk production and other factors.   Ideally, we would like to feed a different mix to high, medium and low producers.   Under practical conditions this is often not possible especially on farms with a small number of dairy cows, so dairy farmers often feed for high production in early lactation and medium production in late lactation.   It is not wise to feed dry (non lactating) cows a lactating diet.

c.       The feedstuffs normally provide and are balanced to meet energy, protein and fiber.

d.       The amount of energy, fiber and protein that each feed contains will vary according to the type of ingredient (e.g., alfalfa hay is a good source of energy and protein; corn silage is a good to excellent source of energy, but low in protein), the source of the feed, the maturity when the feed was cut and harvested and many other factors.  For example, the nutrient content of corn silage or even grain corn can vary from source to source.   Thus, the variation in nutrient content of feeds used in the mix must be considered.

e.       Feedstuffs contain minerals and can meet many of the mineral needs, but salt (sodium and chloride) is always needed and other additional major minerals (e.g., Ca, P, Mg and S) are often needed.

f.        Feedstuffs also contain trace minerals, but the amount of trace minerals will vary from region to region and according to the feeds used.   Often a “trace mineral package” is used to supplement TM needs, but it is very important to know the content in the feed stuffs if at all possible.

g.       Vitamin A, D and E are often supplemented in the dairy cow feeds, especially if the cows are confined within a barn.  However, these vitamins may also be provided by the feedstuffs.

h.       Although not necessarily fed to supply a nutrient requirement, some supplement products supply   nutrients.  For example, sodium bicarbonate is added as a rumen buffer, but also supplies sodium so the amount of salt maybe less.

3.       Feeds to go into the TMR:   Many different feeds can be used in dairy diets, but many factors need to be considered in determining the amounts to be used.   If we classify the feeds, it may be easier to discuss their place in the diet.

a.       Typical Feed Classification with comments

                                           i.     FORAGES:  Feeds with greater than 18% crude fiber (CF) are classed as FORAGES.  This would include alfalfa hay, grass hay, elephant grass, silages, straw, etc though the quality of these will vary greatly due to variation in fiber (lower fiber indicates better quality) and  some high quality, young forages may contain less than 18% CF.  Dairy cows MUST have at least 30% long type forage in their diets to meet the FIBER needs of the cows.   The fiber content of forages vary, for good production, we desire high quality forages such as alfalfa hay, corn silage or young grass.   More forage can be fed if the hay is low in fiber.   Lower quality forages (e.g., grass hays, some straws) may be sufficient for very low producers and dry cows if supplemented sufficiently.  It is difficult, if not impossible, to supplement high fiber feeds such as rice straw sufficiently to meet  Regardless, cows MUST have some forage in the diet and this forage MUST NOT be chopped or ground too small (< about 7 cm length) or it will lose the value of the fiber.

                                          ii.     Alfalfa hay has a high content of most minerals as well as protein and a good amount of energy, so alfalfa hay requires less supplementation of these nutrients than is required for other forages.    

                                         iii.     ENERGY FEEDS: Cereal grains such as corn grain, barley or wheat and other feeds are considered an ENERGY source.   Variations exist, but feeds with less than 18% crude fiber (CF) and less than 20% crude protein (CP) normally are ENERGY feeds.   Cassava is not a grain, as such, but would be a high energy feed.

                                         iv.     SUPPLEMENTS:   These are feeds that are high in one or more nutrients that are fed to increase the concentration of that nutrient in the diet.  Typical supplements may be classified as:

1.       PROTEIN Supplements:  Feeds with over 20% CP and less than 18% CF.   These could include soybean meal, cottonseed meal, etc.

2.       FAT supplements which are very high in energy such as tallow, dry fat, etc.

3.       MINERAL Supplements:   This would include major mineral sources (e.g., salt calcium carbonate, dicalcium P, magnesium, etc.) and packages with high concentrations of one or more trace mineral.

4.       Vitamin Supplements.  Packages with high concentrations of Vitamin A, D or E.

                                          v.     BY-PRODUCT FEEDS:  Feeds such as the with beer residue, pineapple residue, sugar cane by product, peanut skins that you mention and many others such as whole cotton seed, wheat mill feeds, bakery products, etc are classified or called BY-Product feeds.  Many supply a good source of various nutrients, but one or more characteristics usually limit the amount that can be used in the diet.

                                         vi.     FEED ADDITIVES:    Rumen buffers, enzymes, etc that may or may not provide some nutrients or other advantages normally fall in this category.   Other than rumen buffers, be very careful on spending money on these unless the herd is producing very high amounts of milk.  

b.       Limitations of feeds

                                           i.     Nutrient needs must be met even with high priced feeds/supplements, but supplementing over and above the cows needs will limit the amount of some feeds (e.g., protein and mineral supplements)

                                          ii.     It is physically impossible for cows to take in huge amounts of low quality forages.  

                                         iii.     Excess amounts of high energy feeds will cause founder and other digestive upsets.

                                         iv.     Some feeds such as alfalfa hay, corn silage or good grass hay may be fed ad libitum if other factors do not dictate that less should be fed (e.g., available supply of the feeds, price, nutrient needs such as protein for corn silage, etc.)   

                                          v.     Some feeds may be satisfactory at low amounts, but have one or more factors that give problems if high amounts are fed.

1.       Peanut skins.    High amounts of tannins in peanut skins bind the protein in the gut of the cows so peanut skins are NOT recommended for dairy cattle though they have been fed to beef cattle at low levels (2-5%).

2.       Brewers (beer) grains or by-products, wet or dry.    These can be excellent feeds, but normally should not be included at over 6-8% (Dry matter basis) of the diet.

3.       Cassava meal is a good energy source but very low in protein.   Feeds low in protein require large amounts of protein supplements such as soybean meal to balance the protein. 

4.       Pineapple residue:   Data indicates that this feed is low in CP (~ 4-5% DM) and a relatively good energy source somewhat similar to that of lower quality corn silage.    My experience in Thailand indicted that the cows liked the feed.   Plant herbicide or pesticide residues may be of concern if they transfer into the milk.   I would limit this to 10% of the diet DM unless other data gives a better value. 

5.       High fat feeds/supplements must be fed with caution so as not to decrease digestibility.   For example, whole cottonseed is a very palatable, high energy, digestible fiber feed with a good amount of protein, but the amount is normally limited to 10-12% of the diet DM because the high fat content can reduce digestion.

6.       High water content of the feeds is of concern.   See below.

4.       Water content of the feeds and in the TMR.

a.       TMRs can be fed without wet products or adding water, but some high moisture feeds (e.g., beer residue, silage, green chop) is of benefit.  They help palatability and often decrease separation of particles in the bunk.

b.       Excess water in the TMR (over 50% of the mix) will/may decrease the dry matter intake and therefore decrease production.

c.       TMRs with wet products will spoil in the Vietnam warm weather within one day.    Thus, any TMRs with wet products need to be fed out the day it is mixed.   If possible, it is best to mix wet TMRs for only one feeding per day even though feeding the TMR should be fed in at least two feedings per day.

d.       If all dry ingredients are used in the TMR, some water can be added to the mixer before placing the feed in the cows bunks. 

e.       Some water or high moisture feeds help prevent cows from sorting out grain or other palatable feeds in the TMR. 

5.       Storage requirements of ingredients to be mixed.

a.       It is difficult for most farmers or companies to have an adequate number of storage bins if too many ingredients are included in a TMR.   Thus, major feeds and necessary supplements should be included in the TMR.   Some feeds may be a good and even economical feed, but can not be used if storage area is limited. 

b.       Storage of wet feeds becomes a real concern.    Wet feeds will spoil before mixed in the TMR without special storage facilities.    For example, the pineapple residue and beer product (if wet) will require a storage somewhat similar to that for silage.   Wet beer (brewers) products is normally very wet so should be kept so the water does not drain into other feeds.   The storage should be narrow and fairly deep to limit surface exposure to air damage and covered with a tarp.   In the hot US, we indicate that wet beer products should not be kept longer than about 7 days.   The storage for the wet pineapple residue will require a similar storage to that of wet brewers grains or corn silage (if moisture content is 60-60%).    Keep surface area exposed to air at a minimum.   Pack the residue if it is of a similar moisture content to corn silage.

c.       Have adequate bin space to store dry products for a turn over (replacement of all the feed) ever 2-3 weeks.   Limit rodent damage and any spoilage.  

6.       Some limitations on mixing some ingredients.

a.       Many limitations on the amounts are included above. 

b.       Excess amounts of some dry forages are difficult to mix in a TMR mixer.   The semi chopped alfalfa hay provided by Anderson Hay is relatively easy to include in a good mixer.   Long grass hay may give problems if included to any significant amount in the mix.    Talk with the manufacturer about the feeds you want to use.

c.       If cows sort out the feeds, the diet becomes unbalanced.  

7.       Cost of feeds for optimum economic returns.

a.      The nutrient needs of the cows dictate that some high cost feeds (e.g., protein and mineral supplements) must be included at a sufficient amount in the mix.  A cheap diet often is not the most economical diet because milk production suffers.

b.       A good blend of high quality forage will reduce the amount of more expensive feeds.   High quality alfalfa hay will decrease the amount of protein supplements, calcium supplements and even energy feeds included.    Good quality corn silage will decrease the amount of energy feeds needed, but will require more protein and calcium supplements than is required by alfalfa hay.

(To be continued)