Discussion of the Relative Value of Soybean Meal vs. Sunflower Meal for Lactating Dairy Cows and Ideas on How to Prove It in the Field
Sunflower Meal is the main protein source of choice for lactating cows in much of Europe because it is available and cheaper than soybean meal. This limits milk production! My observation from considerable experience in formulating and feeding rations for lactating dairy cows in Russia, Ukraine, Kosovo and Bosnia-Herzegovina is that milk production and profitability would increase with greater wealth creation if soybean meal replaced sunflower meal in dairy rations under most feeding regimes. Therefore, it is of economic importance to dairy producers, milk processors, consumers and producers of soybean meal that this message be told to and adapted by dairymen.
This narrative will (1) look at why soybean will produce more milk than sunflower meal and (2) discuss ways to spread this message and get it applied by dairy producers in targeted countries.
The following table shows selected relative nutrient values of corn, sunflower and soybean products. Our discussion will focus on these comparative values.
Selected Nutrient Values of Corn, Sunflower & Soybean Products
|Ingredient NameNutrients given on Dry Matter basis||Crude Protein %||RDP gm/100 gm (4x)||RUP gm/100 gm (4x)||Digestible RUP (4 x) gm/100||NFC % @ 4x Maint.||NElact. Mcal/kg 4x Maint|
|Sunflower Ml., Solvent||28,4||23,9||4,5||4,1||22,2||1,30|
|44%, SBM, Solvent||49,9||32,6||17,3||16,1||27,0||2,02|
|48% SBM Solvent||53,8||30,9||22,9||21,3||28,9||2,09|
|44% SBM, Expeller||46,3||14,4||31,9||29,7||18,4||2,25|
|High Heat SBM||50,0||10,3||39,7||36,9||11,2||2,09|
SBM = Soybean Meal. SFM = Sunflower Meal, solvent extracted. RDP = Rumen Degradable Protein (ammonia, amino acids and peptides). RUP = Rumen Undegradable Protein with an emphasis on digestible (absorbed as amino acids) rumen RUP (by-pass protein). 4x = dry matter intake at four times maintenance requirement. NFC = Non-Fiber Carbohydrates (sugar, starch & pectin). NElact. = Net Energy for lactation. Nutritive values obtained or calculated from 2001 Dairy Requirements published by U. S. National Research Council, Washington, D.C. Formulas created using their software.
Why is protein added to dairy rations? Under most forage situations (except for mature grass forage or where only corn silage is fed) the requirement by the rumen microbes (the only place RDP can be utilized) for rumen degradable protein, is met. With the rumen microbes producing at their capacity, more rumen undegradable protein that supplies digestible protein directly to the small intestine (where it is absorbed as amino acids into the blood stream) is needed for milk production levels above 15 to 20 liters/cow/day.
When protein sources are added, they all supply RDP along with RUP. Therefore at higher production levels supported by added protein supplements, there is enough RDP. Look at the above table and note the relative values of RDP and RUP for solvent extracted sunflower meal (SFM) and 44 % solvent extracted soybean meal (SBM). 44% solvent extracted SBM supplies 36% more RDP than SFM (32.6% vs. 23.9%. Therefore, if you were buying SFM and SBM only for their RDP content, you could pay 36% more for 44% solvent extracted SBM than for solvent extracted SFM. Under most forage feeding regimes, and particularly for production over 15 to 20 liters/cow/day, protein is added for its digestible RUP contribution. On this bases, note that 44% solvent SBM is almost four times as valuable in RUP as solvent SFM (16.1% vs. 4.1%). (48% solvent SBM supplies 21.3 digestible RUP. High heat treated SBM, 36.7 %) Note that corn supplies nearly as much digestible RUP as solvent extracted SFM (4.0% vs. 4.1%). If you need to add RUP to the ration, solvent extracted SFM is no better than corn, making SFM a very poor choice. In fact, if you want high production, you can't get there with SFM. Note that sunflower seeds supply almost no RUP (1.7%).
In addition, solvent extracted SFM is very low in energy due to its high lignin (wood) content (9.5%) versus solvent extracted 44% SBM (0.7% lignin). Lignin is not digestible. The non-fiber carbohydrate (NFC) value for solvent extracted SFM vs. solvent extracted 44% SBM is 22.2% vs. 27.0%. Solvent extracted SFM supplies only 64% as much Net Energy for Lactation (NEl) as does 44% solvent extracted SBM.
Therefore, even if you want only RDP, you can pay 36% more for solvent extracted SBM than for solvent extracted SFM. If you are looking for RUP, which is likely, you can pay 4 times as much for SBM as for SFM. When you add in the higher energy value of SBM vs. SFM, SBM becomes even more valuable than SFM for high producing dairy cows.
I can not foresee a situation (forage quality or type, price and/or level of milk production) where 44% solvent SBM is not a better feed buy for lactating dairy cows than solvent extracted SFM. We need to get this word out to dairy producers.
You may be wondering why I was so careful to state "solvent extracted" in describing SBM and SFM. Most of the SFM available in the area in which I'm working in the Former Soviet Union (FSU) and the Balkans is mechanically extracted SFM. Mechanical extraction supplies heat and heat converts some of the RDP to RUP. How much is the question. Comparing 44% solvent to 44% expeller SBM shows an 84% improvement in digestible RUP (16.1% vs. 29.7%). On this basis, mechanically extracted SFM would have 7.5% digestible RUP (1.84 x 4.1%). If the comparison is of the improvement in digestible RUP from roasting soybeans, there is a 43% improvement from roasting (10.1% to 14.4%), suggesting roasting would elevate digestible RUP of SFM from 4.1% (solvent) to 5.8%. If these comparisons are predictive, mechanically extracted SFM is still less than half as valuable as solvent extracted SBM for supplying RUP.
We need to determine the actual values for RDP and RUP of mechanically extracted SFM, compare them to solvent SFM and tell or demonstrate this to dairy producers.
Dr. Dan Undersander, forage specialist from the University of Wisconsin has offered to run RDP and RUP evaluations on mechanically extracted SFM (done by placing samples in nylon bags inside the rumen - in situ). I can get the samples collected in various locations including Krasnodar, Russia, Novosibirsk, Russia and the Balkans.
We need a sponsor who will fund this project.
We need this information on RUP to improve our recommendations to dairy producers in areas where SFM (solvent or mechanically extracted) is fed. Also, I think this information would be very interesting to the producers of soybean meal, as I think our research will show that solvent extracted 44% SBM is over twice as valuable as mechanically extracted SFM and four times as valuable as solvent extracted SFM, which makes SBM the protein source of choice in almost all situations. With this information, we can have solid data to back up our anecdotal observations in the field (over a wide area involving multiple feeding trials) that feeding SBM instead of SFM increases milk production and the protein content of milk from lactating cows and sheep. By having this information, it would be easier to convince dairy producers that they should feed SBM.
Our field tests and computer simulations show that adding 1 kg of 44% solvent extracted SBM and 1 kg of ground corn will support 5 liters more milk production in cows that have the genetic potential to increase milk production. (This would allow Holstein cows to compete favorably with Simmentals). This would convert 1 monetary unit into 2.5 monetary units (Bosnia). This will happen fast with the cow responding in less than a week. The timing of a positive cash flow depends upon how fast the milk processor pays for the milk received. Great strides can be made in the field by making small amounts of SBM available to producers to try on their best cows. They would like the results.
Even more convincing would be controlled feeding trials testing SFM (solvent extract and mechanically extracted) versus 44% solvent extracted SBM. It would be valuable to compare 48% solvent extracted SBM also. If expeller SBM is fed, the data (above table) suggest that under roughage programs composed of mature grass hay there may be a need to feed a source of RDP. This could be 44% solvent SBM or even urea. If good grass hay, legume hay or pastures are fed, RDP needs will be met even with expeller SBM.
Another thing concerns me about SFM with hulls. Does the high neutral detergent fiber content (NDF = lignin, cellulose and hemi-cellulose = structural carbohydrates) of SFM act like forage neutral detergent fiber and decrease dry matter intake of lactating dairy cows? (SFM contains 40% NDF; 44% SBM, 14.9% NDF). I'm proposing that it does as sunflower hulls are wood, they are light and they undoubtedly float in the rumen, getting caught up in the rumen mat and the rumen bolus that is aspirated by the cow. Increased chewing is not for free, thus it reduces total dry matter intake. This would be fairly easy to prove. In fact, pure sunflower hulls could be fed and dry matter intake (DMI) noted along with milk production. Both would be expected to decline. It would be interesting to count the average number of times a cow chews a bolus before swallowing it when sunflower hulls are fed (and also SFM), versus when they are not fed. If the hulls reduce DMI, then there is another nail pounded into the coffin of feeding SFM for dairy cows.
Some processing plants partially dehull sunflower seeds before oil extraction. One plant I visited in Krasnodar partially dehulled the seeds (and burned the hulls in their furnace for heat) then mechanically extracted the oil from the remaining seed. They pointed out that they didn't let the temperature get too high in order to maintain good digestibility. My comment was that letting the temperature rise would improve RUP and make the SFM more valuable for ruminants. (I still don't think it would competitive to SBM.)
(Partially dehulled SFM may be competitive to SBM in rations fed to pigs if lysine is added to the diet. My Pig Profit Planner can be used to determine relative costs of gain.)
A 1200 cow dairy I work with in Krasndar Oblast, Russia added SBM to their diet and reported an increase in milk production of several liters and an increase in the protein in the milk from 2.7% to 3.2%, which made the dairy processor very happy. Since USAID and UNDP projects are focused on helping dairy producers and milk processors improve their profitability, lending programs that would help make SBM available to producers through their milk processors should be encouraged. Loans could be made to processors to buy SBM that would be supplied to milk producers on credit, with its cost subtracted from their next milk check. This would produce a positive cash flow and improved profitability for the milk producers while giving the processors more milk with a higher protein content, which would of course increase cheese yield and their profitability.
It would be informative if the sunflower oil extraction plant in Krasnodar ran at different temperatures, collect SFM samples and have Dr. Undersander run RDP and RUP tests to get an idea of the extent heat at various temperatures converts RDP to RUP in SFM.
My thesis is that soybean meal rather than sunflower meal should be fed to lactating dairy cows in order to increase milk production and profitability. Field results support this thesis. If we had good experimental data on relative rumen degradable protein and rumen undegradable protein values and actual controlled feeding tests, we would be on stronger footing to recommend feeding SBM rather than SFM to producing milk cows. These data would be useful to those advising dairy producers on how to feed lactating cows, to dairy producers and to the producers of SBM.
Who would like to step forward and fund these studies and/or supply SBM for field testing? Even 100 kg of SBM provided to selected dairymen would spread the word.
Roy Chapin, Ph.D. Animal Nutritionist
11145 Chapin Lane, Amity, Oregon 97101
Written on 19 May 2004 in Sarajevo, Bosnia-Herzegovina while on assignment for USAID LAMP (Sarajevo, Tuzla, Banja Luka & Mostar) and UNDP (Srebrenica).