FEEDING BY-PRODUCTS OFFERS OPPORTUNITIES

by: Stephen B. Blezinger
Ph.D., PAS


Part 1

As the grain industry has advanced we find ever widening ways to use grain products in other than feeding applications (i.e. corn for the production of ethanol, soybeans for the production of biodiesel, etc.). As the original grain product is converted from its original form to the desired form, in many if not most cases one or more by-products or co-products is produced which has to be disposed of or utilized. Fortunately, as research and practice has proven, in many cases, these by/co-products have nutritional value and can be fed to cattle and other livestock species. Some industry experts believe that we will reach a point in time where cattle will only be fed these associated materials as they believe the base grain (i.e. corn) may become too valuable to be fed in its initial form. We are seeing some of this already in the dairy industry as overall corn use in many rations has decreased as we learn to use by-products more effectively and as we incorporate more digestible forage hybrids (silage, hays) which can effectively provide nutrients that were previously provided by grain sources.

My position for quite some time is that you can feed cattle almost anything if you go about it correctly. This is a bit of an exaggeration but heaven knows researchers and producers have tried! In this series we will discuss feeding by-products to cattle and examine opportunities, challenges and considerations in such an endeavor. The goal is to provide for the nutritional needs of the animal in a cost effective manner. Again, as we move forward, the use of by-products may be the cattle industry's best advantage.

One of the most common and possibly the oldest type of by-products fed are those from the cotton industry. Seldom does a month go by that I do not get at least one call regarding the feeding of various cotton co-products to beef cattle. As with many areas in the cattle industry, much of this results from the vast body of misinformation which exists concerning the use of these products. Other interest is due to the low cost of these products at this time. The markets are lower than they have been in years making cotton co-products extremely cost effective. Feeding products resulting from the growing and ginning of cotton for lint have been used in the cattle feeding industry for years. Products such as whole cottonseed, cottonseed meal, cottonseed hulls, cotton burrs (gin trash), linter's tailings and so on have found a host of uses in the manufacture of cattle feeds. These products are used extensively as protein, energy and fiber sources throughout the south as well as other areas of the United States (I was in a feedmill just this past week in western New York that was using whole cottonseed in their feed formulas). While they provide an excellent and economical source of these nutrients there are a number of factors that need to be taken into consideration in their use. These include the potential contamination by aflatoxin and the gossypol level. We'll examine the use of these products as well as the aforementioned areas of concern.

Cottonseed Meal

Cottonseed meal (CSM) contains less protein and energy than either peanut meal or soybean meal. This is especially true for the available protein component and for this reason rations containing cottonseed meal need to contain a little more protein (1 to 2%) to be equal to rations containing soybean or peanut meal. In general, however, CSM is typically a very useful, normally cost effective feed ingredient. One source of irritation for many cattlemen has been the reduced ability to get “old-process” cottonseed meal. Why the irritation and what's the difference between “old-process” and “new-process?” Old-process CSM was, for years, the protein supplement of choice for many cattlemen. At one time, in order to extract the oil from whole cottonseeds, a mechanical crushing process was used in the mill to basically squeeze out the oil. It simply crushed the seeds and pressed out the oil. This left a cottonseed meal with a good bit of the oil (fat) still intact and therefore was a good source of energy. Fat content from CSM (old-process meal) produced in this manner could run as high as five to seven percent depending on the good (actually how bad) the process was. As time passed, as with so many things, the oil mills continued to search for ways to extract more of the oil. Obviously the oil was of more value in terms of sales than the high fat meal was. As their technology improved a means of extracting the oil by subjecting the meal to a solvent resulted in the removal of more oil from the meal, resulting in cottonseed meal with a much lower (one to two percent) fat content (new-process meal). Subsequently most oil mills have gone to this process, therefore resulting in a much lower availability of the old-process, higher fat/energy CSM. The oil has become even more valuable now as it can be used as a base-product in the production of biodiesel. This is the source of irritation many cattlemen suffer from. While some old-process meal is still produced, it is hard to come by and typically significantly more expensive to purchase because of the demand.

Cottonseed meal can be purchased in bulk, in bags, in loose or meal form or in cubes (often referred to as cottonseed cake).

Whole Cottonseed

If someone were to ask me what the perfect supplement for beef cattle is I'd have to tell them that there is no PERFECT supplement but whole cottonseed comes awfully close. The seed is made up of the internal endosperm or “meat” of the seed which is where the fat and protein is found. The seed coat provides a fiber fraction and the lint, more fiber but a fiber that is more digestible. The physical form of whole cottonseed (WCS) is a suitable feed without further processing. Whole cottonseed contains about 26 to 31 percent ADF, 85 to 90 percent TDN, 15 to 21 percent crude protein and 15 to 17 percent fat (as fed). Since cottonseed may contain less protein (12 to 15 percent) and more fiber than listed in standard feed composition tables when grown or harvested under adverse conditions, a laboratory analysis is suggested.

WCS is fed extensively in the dairy industry and in general is very useful improving protein, energy and fiber intake. Expected responses in milk yield and milk fat percentage are not always attained when feeding WCS, apparently due partially to possible roughage interactions. Dry matter intake is usually increased when WCS is included with fair quality roughages and more acid silages. Whole cottonseed may depress intake if fed at greater than 15 percent of the ration dry matter or greater than seven to nine pounds per dairy cow per day. Success has been obtained with higher levels. Even so, recommended amounts for maximum response are four to seven pounds daily per cow. What all this means is that when feeding WCS at a level greater than those indicated, overall fat in the rumen can become too high. When the fat level in the diet is above about six to seven percent the fat can coat the fiber particles which reduces bacterial action and subsequent digestion. This same situation can be seen in beef cattle when feeding rates are too high.

Feeding of WCS has been found to be quite beneficial as a protein and energy supplement to beef cattle. Some studies have shown that cattle with lower than desirable body conditions (approximately 4) can exhibit higher than expected conception rates and shorter times to rebreeding when they are supplemented with WCS. It has been theorized that the fat from the whole seed, once digested and absorbed, acts as precursors to reproductive hormones thus improving the levels of necessary circulating hormone needed for rebreeding.

In most situations, WCS is available only in bulk forms and has to be handled with a shovel or front end loader which is a definite disadvantage. In some limited situations we are seeing some extruded WCS which is in a pelleted form. This is more expensive but is easier to handle.

Cottonseed Hulls

Cottonseed hulls are used extensively as a roughage source in the southern United States. They are low in protein and energy but high in effective fiber (43 percent). They may be used as the only source of roughage but are more commonly used in combination with limited amounts of silage and/or hay. Cottonseed hulls are very palatable and cows receiving such rations consume about 15 to 25 percent more dry matter than cows receiving silage-based rations (Table 1). They are sometimes included in finely textured concentrate mixes to provide bulk and texture as well as supporting the fat percent. Fuzzy cottonseed hulls are preferred over delinted cottonseed hulls. Also, pelleted cottonseeds have been used in dairy cattle rations (Table 2).



Cottonseed hulls work very well in starting ration for newly weaned calves or fresh cattle just starting in the feedlot. The hulls appear to improve ration texture and subsequently improve palatability.

Areas of Caution and Concern

Some caution is suggested when using both cottonseed meal and whole cottonseed in beef rations and in dairy rations for high-producing cows due to the presence of the yellow polyphenolic pigment gossypol. Auburn University researchers increased the level of cottonseed products in diets to study evidence of gossypol toxicity. Cows consuming the highest level of gossypol showed more panting (heat discomfort) during hot weather, but no significant difference in feed intake or milk production. Physiological changes and gossypol in tissues of cows suggested that intoxication is possible in mature ruminants consuming large amounts of cottonseed products high in free gossypol.

Gossypol is a normally existing pigment compound in cottonseed which can at high levels have a negative effect on livestock performance, especially that of monogastrics. High levels of gossypol can reduce feed consumption as well as reduce liver, cardiac and reproductive function when fed at excessive levels for extended periods of time. Mature cattle can detoxify higher levels of gossypol but care should be taken that daily intake does not exceed 1000 parts per million (.1 percent) in diet dry matter. If any exceptional amounts of cotton products are being fed the gossypol levels should be tested to insure that intakes are not excessive. For example, if you were to feed two pounds of whole cottonseed or even cottonseed cubes to a 1,200 pound cow (her required dry matter intake is about 25 pounds per day) the seed or cubes would need to contain less than one percent gossypol on a dry matter basis.

Much work in both livestock and man has been performed in the ongoing investigation into the effects of gossypol intakes and the subsequent effect on reproductive ability - primarily the production of sperm cells. Current research is focused on the pharmacology of gossypol, a compound with potential as an anticancer drug and also as a contraceptive pill for men. The action of this compound in men to suppress sperm was accidentally discovered in China. The Chinese then tried to develop it as contraceptive pill for men. It was found in these studies as well as similar work in other species that intake of gossypol over a period of time will decrease production of sperm cells and therefore decrease reproductive capability. However, when the source of gossypol was removed, sperm production levels returned to normal within a few weeks.

For the purposes of this article, this simply means that even if bulls consume high levels of cotton products containing high levels of gossypol, they will not be affected permanently. Fed at a couple of pounds of cotton products per day, it is unlikely that bulls will exhibit any reduction in fertility.

Conclusions

Like so many other feed products, cotton co-products are very useful when used judiciously. A little testing ands a little homework can go a long way to help you use products such as these in a safe, cost-effective manner. In Part 2 of this series we will continue this examination of by-product feeding and discuss the opportunities and challenges these products can provide.

Dr. Steve Blezinger is and nutritional and management consultant with an office in Sulphur Springs Texas. He can be reached at 667 CR 4711 Sulphur Springs, TX 75482, by phone at (903) 352-3475 or by e-mail at sblez@verizon.net.







Google
  Web CattleToday.com

Don't forget to BOOKMARK  
Cattle Today Online!