Crop Profile for Cotton Gin By-Product Use in Beef Cattle and Dairy Cow Diets in Texas

Prepared: November, 2001

General Production Information

A survey was conducted by interviewing over 30 experts in the cotton and livestock industry to ascertain the disposition of cotton gin by-product (CGB). Emphasis was placed in the geographic region where the majority of this by-product is produced in the U.S. Cotton gin by-product consists of extraneous plant parts which accumulate as cotton fiber is separated from the seed at the gin. CGB consists of residual plant parts from mechanical harvesting and remnant seed (motes) and lint from ginning; in times past referred to as "gin trash." CGB is considered as a raw agricultural commodity (RAC) which includes many other crops grown for livestock feed and parts or by-products of other crops with useful nutritional or feeding value.

CGB contains 4 to 8% protein and has some nutritional value as a roughage for ruminant livestock. More than 2.3 million tons of cotton gin by-product are produced in 17 states, but nearly 60% occurs within 150 miles of Lubbock, Texas, in close proximity to major beef feed lots of the U.S. Over 50% of the product is applied to farmland as a soil amendment. Less than 45% is fed to ruminant livestock, including cows and stocker cattle on pasture.

Less than one-fourth of the U.S. beef feedlots use CGB. Most estimates of CGB use were about 5% of the diet since hay and other roughages are more available and desirable. Actual use of CGB in feed lots is dramatically lower than the 20% levels used in EPA human health risk calculations in pesticide reside safety assessments.

Lactating dairy cows are highly sensitive to feed ingredients. Dairy producers will not take risks in using questionable feed ingredients. None of the dairy nutritionists consulting in this assessment knew of any CGB being fed to lactating dairy cows. They strongly advised their clients against doing so because the risks are too great and there were no savings. None of the nutritionists had formulated any lactation rations containing CGB or seen it being fed. The 20% dietary assumption used in EPA pesticide assessments incorrectly reflects feeding practices and ration formulations in the dairy industry.

For the future, it will be important for all pesticide registrations or re-registrations for cotton to include a tolerance for feeding cotton gin by-product since this material has both nutritional value in feeding beef livestock and economic implications for the cotton industry.

1 This document may be cited as Dudley T. Smith. 2001. Cotton gin by-product use in beef cattle and dairy cow diets. Soil & Crop Sci. Dept. Technical Report 01-08, Texas A&M University, College Station, TX.

 



Cultural Practices

Pesticide considerations in feedstuffs

Potential pesticide residues in livestock feed ingredients are considered in human health and dietary assessments by the U.S. Environmental Protection Agency (EPA).

The use of a feedstuff or by-product is considered to be significant when annual production exceeds 250,000 tons or it makes up more than 10% of a feed ration. In safe guarding human health, EPA must consider pesticide levels in 99% of all feedstuffs used in the domestic production of 95% of the meat, milk, and eggs consumed by the public.

Livestock dietary percentages of feedstuffs in pesticide assessments were summarized by Markle et al. (1998) and include more than 150 agricultural crops grown for feed, crop products, or by-products of agronomic and horticultural crops. However, many of these percentages are based on historical on-farm and small-scale agriculture, well before todayís commercial production systems. Consequently, many of the feedstuff percentages used by EPA in risk calculations on livestock diets are substantially higher than those actually being fed in commercial meat and milk production. These dietary factors should be revised to more correctly reflect the scientific nutrition and food safety practices in the beef and dairy industries.

Cotton gin by-product (CGB) is one of many raw agricultural commodities (RAC) with economic and nutritional value to commercial livestock industries in the U.S. This report summarizes the use of cotton gin by-product in beef feedlots and dairies, based on personal and phone interviews with over 30 experts.


Generation of Cotton Gin By-product

The ginning of cotton (the separation of lint from the seed) results in "cotton gin by- product" (CGB), a mixture of extraneous plant parts which includes leaves, petioles, carpels, small seed (motes), and lint. CGB provides useful roughage and nutritional value for ruminant livestock. Previously referred to as gin trash, this by-product is a bulky, low-nutrient product that accumulates at harvest time and must be removed from the gin yard.

All cotton is mechanically harvested in the U.S. The method of harvest determines the amount of CGB that is produced in a region. Cotton pickers are the most common method of harvesting and are predominately used in the southern regions of the cotton belt. Pickers consist of a complex of rotating fingers that pull cotton fiber from an open boll, with minimal removal of other plant parts. Pickers result in the least amount of cotton gin by-product (150 to 200 pounds per bale of lint) at the gin (Table 1).

In contrast, stripper cotton is grown predominately in the southern great plains in the southwestern US (TX, OK, and KS). Stripper-harvested cotton is produced with fewer inputs and lower cost due to the shorter growing season, weather uncertainties, and other factors. Stripper harvesters consist of fewer moving parts and are less expensive than pickers. Plant bracts, leaves, petioles, and extraneous plant parts are literally stripped from the stalk in the harvesting process. Stripper harvesters result in 700-800 pounds of CGB per 500 lb bale of ginned lint. However, 54% of todayís strippers are equipped with bur extractors and field cleaners. These on-harvester field cleaners leave at least half of the plant trash in the field which has reduced the amount of CGB in the industry by 26% over the past 10 years. The concentration of CGB at the gin will continue to decrease as older stripper harvesters are replaced with newer machines equipped with field cleaners.

Table1. Quantities of Cotton gin by-product as related to harvesting methods.

Field harvesting method CGB produced at the gin

 

(lb CGB per bale of lint)
Picker

150-200

Stripper - with field cleaner

300-400

Stripper - no cleaner

700-800


Pesticide use in stripper cotton was itemized by regions within Texas (Smith et al. 1996, 1997). Desiccants and defoliants are commonly applied as a harvest aid to enhance mechanical harvesting of cotton. In northern areas, such as the High Plains region of Texas, desiccants are used to enhance mechanical harvest prior to freezing weather. Pesticide tolerances have been established for these products with regard to livestock feed use. It should be noted that no arsenic acid has been used in the industry since 1994 (Smith et al. 1996).


CGB production, location, and value.

Nearly 60% of the nationís CGB is produced in west Texas in a 150 mile radius of Lubbock, Texas, where stripper cotton predominates. The remaining 40% of the CGB in the U.S. is distributed across 16 other states, mostly in northern areas in the cotton belt where the growing season is short.

The ginning season for seed cotton varies from 2 to 5 months. From 10,000 to 50,000 bales are processed at a gin, which generates a considerable amount of cotton gin by-product for disposal. Decades ago CGB was burned but incineration is no longer practiced. However, it is essential for CGB to be moved from the gin yard for fire, safety, and environmental reasons.

The total volume of CGB in Texas is estimated at 1.1 to 1.3 million tons. The product is difficult to handle due to the low bulk density and expense, relative to its economic value as a feed. Grinding and further processing for feed requires substantial energy input particularly when nutrient values are considered.

Geographic location is a key issue in considering CGB use in livestock diets; 38% of the nationís beef feedlots are located north of Lubbock within 150 miles of Amarillo, Texas. Consequently, the principle supply of CGB and the major beef feedlots in the U.S. are located close together. Any significant use of CGB in livestock diets in feeding beef cattle the U.S. would occur in beef cattle in this region.

Gins offer CGB as a free commodity to local farmers and others in exchange for removal. While the CGB product has some economic value, the costs of loading, hauling, and any processing are about equal to the value as a soil amendment or unprocessed livestock feed. Farmers, private contractors, and commodity brokers usually use the product within 10 to 40 miles of the gin and seldom over 150 miles from its origin, due to transportation costs. The economics of removal vary from $10 to $35 per ton, depending on any processing (grinding), transportation, and the cost and availability of other roughages.


Uses: land disposal, pelleting, and feeding.

Over 50% of all CGB in the U.S. is applied to soil as a raw or composted product. The product is commonly spread on farm land close to a gin as a soil amendment at the rate of 3 tons or more per acre. An additional 4 to 6% is used as an absorbent material and a very nominal amount may be processed, composed, and bagged for sale to consumers. As a result, 45% is the maximum quality available for feeding to some form of livestock.

Over a decade ago a few gins in the High Plains region installed pellet mills. Dirt was removed and CGB was ground and extruded into pellets. However, gins stopped manufacturing pellets since energy costs for grinding and extrusion exceeded the economic value of the processed product. Market prices for CGB pellets were closely tied to the supply and prices of other roughages, which result in variable economic returns. Pellets where easier to handle and other ingredients could be blended but the nutritional limitations of CGB are still prevalent in the finished product. Economic and engineering research is continuing in the High Plains region but the use of pelleted CGB on a commercial basis is not foreseeable in the near future.

General estimates of feed uses of CGB vary but two reliable surveys were conducted by the National Cotton Council and Texas Tech University (Castleberry and Elam 1998, 1999). Survey results show that 30 to 48% of the total available CGB is fed to livestock. These figures are considered to be maximum amounts, due to the economics of handling and hauling the product and the limited nutritional and seasonal value to livestock producers. Actual use varies in relation to the cost and availability of other roughage. For example, high availability of alfalfa hay in the inter-mountain and irrigated west decreases the demand for CGB while adverse weather or seasonal conditions has a converse effect.


Use in CGB in feeding beef cattle

Unquestionably, CGB is nutritionally useful to livestock producers and itís removal from the gin has economic implications for the cotton industry. But it should be recognized that CGB is a course, highly heterogenous, low-quality, low-nutrient roughage with highly variable nutrient content. Crude protein ranges from 4 to 8%, depending on the amount of cottonseed and motes (immature seed) that are present. The product is high in crude fiber due to cellulose and hemi-cellulose components. A portion of the total CGB in the U.S. is used for feeding beef cattle, since these ruminants need roughage at key times of the year. CGB is fed beef cows, stocker cattle on winter pasture, and steers and heifers in beef finishing lots.

Cow-calf systems: Each year a significant portion of CGB is hauled from the gin and simply dumped in pastures for beef cows. These mature cows will selectively feed on the discarded material and consume perhaps 30% of the portion offered while grazing on permanent pastures in the winter months. The protein content from remnant cottonseed is of particular value to ranchers.

Winter stocker cattle: Stocker cattle are grazed during the winter on hard red winter wheat in the high plains region. These cattle sometimes need roughage and dry matter to go along with the succulent wheat forage. Unprocessed CGB may be spread or dumped as a feedstuff in these large pastures. In both cases, of overwintered cows or stocker cattle on winter wheat, it should be noted that the unprotected CGB deteriorates rapidly due to weather and is not a prolonged source of feed.

Feed lot cattle: Most of the CGB used in feedlots is handled by commodity brokers who contract to collect, grind, and deliver the product to feedlots. Bulk material may be stock piled for short periods before blending and formulating rations. While CGB is an important roughage with economic value for feeding livestock, the use of CGB in feedlot rations is limited and depends on many factors which are itemized below:

  1. Commercial feedlots rely on consulting nutritionists (many with a Ph.D.) to formulate safe, least-cost rations to meet the growth and finishing requirements of feeder cattle. Nutritionists and feedlot managers place emphasis on maintaining animal growth to produce wholesome meat. Consumer acceptance and safety is of paramount importance to the feeders.

  2. Animal nutritionists select and blend ingredients for feedlot rations based on:

  3. Nearly 200 commercial feedlots in the multi-state High Plains region (TX, OK, NM, KS) are members of the Texas Cattle Feeders Association (the TCFA is located in Amarillo). These feedlots produce 38% of the nationís beef and conform to a Beef Safety and Quality Assurance Plan which is based on HACCP principles. The TCFA staff includes a Quality Assurance Specialist who assists feed yards in their HACCP programs. The use of feedstuffs from undocumented or questionable origins is highly discouraged and seldom practiced since consumer confidence is of greater importance.

  4. Any discussion of CGB must consider other roughages. Alfalfa hay, corn or sorghum silage, cottonseed hulls, and many other roughages are commonly formulated into beef rations. These commodities provide bulk in the ration, along with high energy and protein-rich ingredients. Nutritionists prefer these roughages over CGB due to the higher quality, consistency of supply, and quality assurance associated with these products.

  5. CGB is blended with other feedstuffs as part of a complete ration to provide adequate energy and protein for growth. The CGB ingredient is ground for blending and is never fed as a sole ingredient. A feedlot animal typically consumes 1.5 tons of all feeds prior to slaughter. The percentage of CGB used in the diet is variable within a year and between years - depending on weather (supply of other roughages), energy costs (grinding and transportation expenses), and other factors that affect the price and availability of other roughages.

    CGB feeding practices in U.S. feedlots: Animal scientists and consulting nutritionists indicated that the present 20% dietary level for CGB used by EPA in calculating beef rations (Markel et al. 1998) over-states practices in the industry. Two common scenarios were identified in U.S. feedlots:

    1. 77 to 85% of the feedlots do not use CGB in their rations. Most feedlots in the U.S. do not use any CGB in beef finishing rations. Reasons commonly cited by industry leaders and nutritionists included:

      • More desirable local roughages are available (local or shipped-in alfalfa, corn and sorghum silage, other hays, etc).
      • Other roughages are more consistent in nutritional content and are easier to formulate and feed.
      • Some feedlots still have concerns about pesticide residues.
      • Most feedlots are far away from cotton gins where CGB is generated. Hauling costs are high and the CGB supply is extremely small relative to the massive amounts of feed required by feedlots.

    2. 15 to 23% of the feedlots use CGB. Less than one-fourth of the nationís feedlots use CGB. Those that do use CGB are located in the southern great plains and tend to follow these trends:

      • CGB is blended as a roughage with other feedstuffs. Use is seasonal.
      • Percentages in rations are based on growth needs and stage of development.
      • Little incentive to use high amounts of CGB in a ration, considering the high energy and protein requirements for rapidly growing steers or heifers.
      • When used, 5% CGB is a common level in the total diet.

      Previous estimates of CGB use in beef diets were developed and provided to EPA by J. Barron (1997 MRID 44386602). We reviewed the calculations and assumptions in MRID 44386602 and considered them to be reasonable and relevant to feedlot practices today. For example, if 30% of all available CGB were fed in feedlots, the average diet would contain 1.5% CGB, not 20% as presently included in pesticide assessment calculations.


      Use in CGB in feeding lactating dairy cows

      Several dairy nutritionists were surveyed about CGB use in milking operations. All emphatically stated that CGB was not fed to lactating dairy cows. Nutritionists pointed out that CGB is not included in lactating rations at any percentage for several reasons:

      1. Commercial dairies are closely managed production units consisting of several hundred cows being milked at least twice a day. Profitability depends on sustained milk production which is directly related to the nutritional quality and intake of feed. Energy content of CGB is too low to sustain high milk production.
      2. Feed ingredients" are one factor that can be controlled in a dairy operation. Nutrient intake, digestibility, and palatability of feedstuffs are primary concerns. Only feed ingredients of known origin and consistent nutritional quality are used. The use of feeds of unknown origin or quality are not worth risking performance.
      3. Milk producers are concerned about maintaining product quality and consumer confidence, especially for infant and fresh milk markets. Use of CGB introduces too many uncertainties.
      4. Pesticide risk assessments using CGB as 20% of the lactating cow diet are not realistic, since no (0%) CGB is fed to any lactating dairy cows.

       

       

      Contacts

      Interview participants included research and Extension personnel in crop and livestock production, private consultants who advise beef and dairy producers on ration formulation and management practices, commodity brokers and representatives involved with RACs, and commodity leaders. Participant experience varied from 5 to 40 years: 56% had over 20 years of experience, 23% had 10 to 20 years of experience, and 18% had 5 to 10 years experience. A partial list of participants follows.

      Mr. Roy Baker
      Agricultural Engineer
      Location Leader, USDA ARS
      Cotton Ginning Lab
      Lubbock, Texas
      806-746-5353

      Dr. Emmett Elam
      Agricultural Economist
      Dept. of Agricultural Economics
      Texas Tech Univ.
      Lubbock, Texas
      806-742-2821

      Mr. Gary Goodall
      Consulting Nutritionist
      Consultant - dairy production rations
      College Station, Texas
      979-458-2710

      Mr. Ben Jones
      Feed Registrant
      Texas Feed & Fertilizer Control Service
      College Station, Texas
      979-857-4111

      Dr. Bill Mies
      Beef Cattle Management & Nutritionist
      Dept. of Animal Science
      Texas A&M University
      College Station, Texas
      979-845-9284

      Dr. Ted McCullom
      Beef Specialist - Feedlot Nutrition
      Dept. of Animal Science
      Texas Ag. Extension Service
      Amarillo, Texas
      806-359-5401

      Dr. David Hutchinson
      Consulting Nutritionist Animal-Agricultural Inc.
      Consulting - Beef & Dairy
      Amarillo, Texas
      806-359-1091

      Dr. Reed Richardson
      Animal Nutritionist
      Dept. of Animal Science
      Texas Tech University
      Lubbock, Texas
      742-2516

      Dr. Calvin Parnell, Ag Eng.
      Ginning and Processing
      Dept. of Ag. Engineering
      Texas A&M University
      College Station, Texas
      979-845-3985

      Dr. Bryan Shaw
      Ag. Engineer- Env. Quality
      Dept. of Ag. Engineering
      Texas A&M University
      College Station, Texas
      979-845- 9793

      Dr. Sandra Stokes
      Dairy Specialist & Nutrition
      Dept. of Animal Science
      Texas Ag. Extension Service
      Stephenville, Texas
      817-968-4144

      Dr. Chris Woelfel
      Dairy Consultant
      Private Consultant
      Dairy Nutrition
      College Station, Texas
      979-690-1150

      Mr. Tony Williams
      Executive Director
      Texas Cotton
      Ginners Association
      Austin, Texas
      512-476-8388

      Mr. Ben Weinheimer
      Regulatory Manager
      Texas Cattle
      Feeders Association
      Amarillo, Texas
      806-358-3681, 670-8232

      Mr. Donnie Wheeless
      Gin Manager
      Associated Cotton Growers
      Cooperative Gin
      Crosbyton, Texas
      806-675-2373

      Ms. Nixie Guin
      Feedstuffs Broker
      Lone Star Commodities
      Lubbock, Texas
      806-798-8900

      Mr. Jerry Warren
      County Agricultural Agent
      Terry Country Office
      Texas Ag. Extension Service
      Brownfield, Texas
      806-637-4060

      Dr. Monty Dozier
      Specialist
      Environmental Quality
      Dept. Soil & Crop Sciences
      Texas Ag. Extension Service
      College Station, Texas
      979-845-2761

      Dr. Al Wagner
      Vegetable Processing Specialist
      Dept. of Horticulture
      Texas Ag. Extension Service
      College Station, Texas
      979-845-7341

       

       

      References

      1. Barron, J. 1997. Cotton gin trash as an animal feed item and the bromoxynil cotton registration: A discussion paper to support Petition 3F4233, renewing bromoxynil cotton tolerances and registration. Sept. 17, 1997. EPA MRID 44386602 34p.

      2. Castleberry, M. and E. Elam. 1998. Production and disposal of cotton gin waste from the Texas High and Low Plains. Proc. 1998 Beltwide Cotton Conf. p 1669-1674.

      3. Castleberry, M. and E. Elam. 1999. Economics of cotton gin waste as a roughage ingredient in cattle feedlot rations on the Texas High Plains. Proc. 1999 Beltwide Cotton Conf. p 1472-1478.

      4. Markle, G. M., J. J. Baron, and B. A. Schneider. 1998. Food and feed crops of the United States. Table 1: Raw agricultural and processed commodities and feedstuffs derived from crops. p 392-400. Meister Pub. Co. Willoughby, OH.

      5. Smith, D., T. Fuchs, and R. Holloway. 1996. Cotton pests, pesticide use, and related management practices by Texas growers. Departmental Tech. Report 96-06. 33p.

      6. Smith, D. T., T. Fuchs, and R. Holloway. 1997. Agricultural chemicals in Texas: assessment of grower preferences and practices. Proc. Beltwide Cotton Conf. p 789-791.