Nutritional recommendations of feedlot consulting nutritionists: The 2007 Texas Tech University survey 1

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1 Published December 8, 2014 Nutritional recommendations of feedlot consulting nutritionists: The 2007 Texas Tech University survey 1 J. T. Vasconcelos 2 and M. L. Galyean Department of Animal and Food Sciences, Texas Tech University, Lubbock ABSTRACT: Forty-two consulting feedlot nutritionists were asked to participate in a survey regarding nutritional recommendations for feedlot cattle. Eleven nutritionists chose not to participate or did not reply to our request. Thirty-one nutritionists agreed to participate, and 29 completed the survey. Their practices were located in the following states: Texas, Kansas, and Oklahoma (46.43%); Iowa, Nebraska, Colorado, and South Dakota (31.25%); Washington and Idaho (8.93%); Arizona and California (6.25%); and other states (7.14%). The survey was conducted using a Web-based system and included 74 questions divided into sections that covered general information about the nutritionist s practice (n = 8 questions); commodity information (n = 13); use of grain coproducts (n = 5); information regarding roughage sources and levels (n = 4); methods used to adapt cattle to finishing diets (n = 3); information about supplements and micronutrients (n = 7); types of feed mixers (n = 2) and feed mills (n = 1) used by clients; feeding (n = 1) and cattle management (n = 5); liquid feeds (n = 7); recommendations for nutrient formulation (n = 15); information resources used as the basis for nutritional recommendations (n = 2); and perceived needs for additional information on items or nutrients not addressed in the survey. With respect to nutrient formulation practices, the results indicated that the recommended concentrations of major nutrients and trace minerals typically fell within a range of 1 to 2 times the NRC (2000) recommendations for beef cattle; however, some important aspects of the NRC models (e.g., formulation for degradable intake protein) were not applied by the majority of respondents. Data from this survey provide a snapshot of practices used by feedlot nutritionists and should aid in development of future National Research Council models and recommendations. Key words: beef cattle, feedlot, nutrient recommendation, nutritionist 2007 American Society of Animal Science. All rights reserved. J. Anim. Sci : doi: /jas INTRODUCTION Nutritional recommendations and practices of consulting nutritionists can provide valuable information on the extent to which nutrient requirement recommendations that have been developed in an academic environment are applied in practical beef cattle feeding operations. Previously published summaries of nutritional recommendations by feedlot consulting nutritionists have been cited frequently to describe nutritional practices used in beef cattle feeding (Galyean, 1 Funds to conduct and summarize this survey were provided by the Jessie W. Thornton Chair in Animal Science Endowment at Texas Tech University. The authors thank the 29 respondents for their timely completion of surveys and for their participation in this project. We also thank N. A. Cole (USDA-ARS, Bushland, TX) for his insightful review of the manuscript. 2 Corresponding author: judson.vasconcelos@ttu.edu Received May 9, Accepted June 14, ; Galyean and Gleghorn, 2001). Galyean (1996) surveyed 6 consulting nutritionists regarding concentrations and sources of CP in feedlot finishing diets. The results indicated that recommended CP concentrations exceeded values calculated using standard values of the NRC (1984) factorial system; however, the concentrations being applied in practice were in close agreement with those suggested by the NRC (1996) MP system. Galyean and Gleghorn (2001) conducted a more detailed survey in which 19 consulting nutritionists representing all the major cattle feeding areas of the United States provided data about industry nutrition and management practices. Their results verified the more limited survey of Galyean (1996) with respect to CP concentrations and expanded the knowledge base with respect to recommendations for other nutrients (e.g., minerals and vitamins) as well as management practices typically applied by practical nutritionists. The objectives of the present survey were to update information contained in the Galyean and Gleghorn (2001) survey and to evaluate new nutritional and man- 2772

2 Feedlot consulting nutritionist survey 2773 agement information not obtained previously. These data should be useful for understanding industry practices and thereby facilitating the design of industryoriented research as well as for development and evaluation of recommendations in future National Research Council (NRC) beef cattle nutritional requirement publications. MATERIALS AND METHODS Animal Care and Use Committee approval was not obtained for this study because no animals were used. Nutritionists Based on consultation with industry technical service professionals and personal knowledge, 42 nutritionists were selected to represent practices in all of the major cattle feeding areas of the United States (e.g., Midwest, High Plains, and Southwest) and were contacted by e- mail regarding their interest in participating in the survey. Four nutritionists chose not to participate, and 7 did not return our request. Thirty-one nutritionists agreed to participate, but only 29 completed the survey. Approval to conduct the survey was granted by the Texas Tech University Institutional Review Board. Data Collection The survey was conducted with the use of a Webbased survey tool ( last accessed 19 July 2007). Each of the 31 nutritionists who agreed to take part in the survey was sent an e- mail message describing how to access the survey and given an identification number to be used when taking the survey. Two nutritionists preferred to receive a paper copy of the survey, which was provided to them as a portable document format (.pdf) file (Adobe Systems Inc., San Jose, CA) via . These 2 nutritionists returned a completed paper copy of the survey to us by surface mail. All participants received a guarantee of anonymity and were requested to complete the survey at their earliest possible convenience. The 29 completed surveys were received within 1 mo. Survey Questions The survey contained 74 questions divided into several categories, including general information (n = 8 questions); general commodity information (n = 13); questions about the use of grain coproducts (n = 5); roughage sources and levels (n = 4); finishing diet adaptation methods (n = 3); supplements and micronutrients (n = 7); feed mixers (n = 2); feed mills (n = 1); feeding management (n = 1); cattle management (n = 5); liquid feeds (n = 7); formulation practices (n = 15); and information resources used for nutritional recommendations (n = 2). The final question in the survey asked for comments about other nutrients supplemented in finishing diets that were not listed in the survey. Data Analyses All data were tabulated in Microsoft Excel spreadsheet (Microsoft, Redmond, WA). The number of responses per question, mean, minimum value, maximum value, and mode were calculated for all questions using spreadsheet formulas. RESULTS AND DISCUSSION General Information Of the 29 nutritionists who completed the survey, 19 (65.52%) reported being associated with an independent practice, 7 (24.14%) worked for a corporate feed manufacturing company, 2 (6.90%) worked for a corporate cattle feeding company, and 1 (3.45%) worked independently and also for a corporate feed manufacturing company. The largest percentage of respondents have been in practice for more than 26 yr (10; 34.48%), with 8 (27.59%) practicing for 16 to 25 yr, 3 (10.34%) for 11 to 15 yr, 7 (24.14%) for 5 to 10 yr, and 1 (3.45%) for 5 yr or less. Approximately three-quarters (22) of the respondents hold a PhD as their terminal degree, whereas the remaining 7 have an MS degree (24.14%). Their practices are located in Texas, Kansas, and Oklahoma (46.43%); Iowa, Nebraska, Colorado, and South Dakota (31.25%); Washington, and Idaho (8.93%); Arizona and California (6.25%); and other states not included in the survey list (7.14%). Most nutritionists in this survey (22; 70.97%) do not practice outside the United States; however, 4 (12.90%) practice in Mexico and South America, 2 (6.45%) practice in Canada, and 3 practice in other countries (Australia, South Africa, and Czech Republic; 9.68%). The self-reported number of animals serviced per year averaged 620,828 (minimum = 75,000; maximum = 3,000,000; mode = 1,000,000) for the 29 respondents, which corresponds to more than 18 million animals on feed per year or slightly more than 69% of the cattle on feed in the United States (approximately 26 million animals on feed per year) based on the USDA estimates (NASS, 2007). General Commodity Information Grain. Corn was the primary grain used by all 29 (100%) nutritionists who participated in this survey (Table 1). Corn also was the top grain choice of nutritionists surveyed by Galyean and Gleghorn (2001). The secondary grain most used was wheat, followed by sorghum and barley. Six nutritionists did not use a secondary grain in the feedlots served by their practices. Grain Processing Method. Steam-flaking was the processing method most commonly used in the feedlots serviced by our respondents (19; 65.52%), which agrees with the earlier observations of Galyean and Gleghorn (2001). Dry-rolling was used as the primary processing method by 4 nutritionists; high-moisture harvesting and storage was used by another 4; and a combination

3 2774 Vasconcelos and Galyean Table 1. General commodity information recommended for finishing diets by the consulting nutritionists surveyed Item No. of responses % of responses Primary grain used Corn Secondary grain used None Barley Sorghum Wheat Primary grain processing method Steam-flaking Dry-rolling High-moisture harvesting and storage Dry-rolling and high-moisture harvesting and storage combined Secondary grain processing method None Steam-flaking Dry-rolling High-moisture harvesting and storage Reconstitution Source of information on energy values NRC NRC with modifications NRC and own data Only own data Internal company model Journals, close-outs, and NRC Starch availability method recommended 2 Enzymatic Gas production Gelatinization Enzymatic and gas production Enzymatic and gelatinization Enzymatic and flake color index Enzymatic, Flake Color Index System, and KSU refractometer None Other Level of inclusion of grain in the finishing diet, % of DM 50 to to to to to or more Corn = Zea mays L responses. 3 Kansas State University; Sindt et al. (2000). of dry-rolling and high-moisture harvesting and storage was used as the primary processing method by 2. Nine nutritionists reported high-moisture harvesting and storage as the second most common processing method, 8 each reported steam-flaking and dry rolling was the secondary method, 1 nutritionist reported reconstitution, and 3 did not indicate use of a secondary processing method (Table 1). Source of Information on Feed Energy Values. The NRC was the main source of information on energy values for 82.76% of the respondents (Table 1), with the remaining 5 nutritionists using the NRC values with modifications or adaptations based on their own data or other sources such as internal company models and personal data (Table 1). Three of these nutritionists indicated that they used NRC recommendations with additional information from their own data set and peer-reviewed journals, and 1 used only a model developed by the feed company for which this person worked. Most of the nutritionists did not specify which edition of the NRC they use. Starch Availability Method. In the US feedlot industry, grains are processed to increase energy (starch) availability. Given that steam-flaking is the most common grain processing method, one might expect considerable effort being devoted to assessment of the effects of processing on starch availability. Thus, we asked participants to identify the method they typically used to assess the success of the steam-flaking process (Table 1). The enzymatic method to determine starch avail-

4 Feedlot consulting nutritionist survey 2775 ability was preferred by 44.83% of the nutritionists, whereas a gas production method was preferred by 13.79% and gelatinization by 6.90%. Five nutritionists (17.24%) used a combination of the enzymatic method with gas production, gelatinization, Flake Color Index System (FCIS; a proprietary color intensity measurement device marketed by Lextron Inc., Greeley, CO), or the Kansas State University refractometer method (Sindt et al., 2000). One nutritionist used another method not listed in the survey (3.45%), and 3 nutritionists did not use any method to assess starch availability. It should be noted that an important use of these methods is for quality control in standardizing the steamflaking process to yield a consistent product from day to day. Level of Inclusion of Grain in Finishing Diets. As stated by Brown et al. (2006), the cost per megacalorie of NE m or NE g of dietary ingredients favors feeding high-concentrate diets based on cereal grains in finishing diets. In addition, handling characteristics of most dry forages also favor minimizing forage inclusion because of improved operational efficiency in feedlot mills (Brown et al., 2006). Thus, it is not surprising that results from the present survey showed that finishing diets formulated by our respondents contain high concentrations of grain. Two-thirds of our nutritionists formulated diets containing from 70 to 85% grain (80 to 85% = 34.48%; 70 to 80% = 31.03%). Six nutritionists formulated diets for 60 to 70% grain, 2 for 50 to 60%, and 2 for 85 to 90% grain. None reported formulation of diets with more than 90% grain. Given the high level of inclusion of grain coproducts (as noted in a subsequent section) in finishing diets, it is likely that some respondents included and some excluded grain coproducts in their response to this question. Energy and Starch Recommendations The average NE g concentration recommended for finishing diets was 1.50 Mcal/kg (29 responses) with a minimum value of 1.37, a maximum of 1.70, and a mode of 1.54 (Table 2). Dietary NE g concentrations of this magnitude reflect low roughage concentrations and extensive use of supplemental fat that will be discussed in subsequent sections. In terms of grain processing, the average bulk density recommended for steamflaked corn was 0.35 kg/l, (27 pounds/bushel), whereas for sorghum, the average recommendation was 0.33 kg/ L (26 pounds/bushel; Table 2). The recommended starch availability (using the enzymatic method) was 60% for corn and 62% for sorghum, with values 4 to 5% less when gas production methods were used to assess starch availability. On average, 11.8% of clients used the FCIS. This system is not intended to provide a direct measure of starch availability but to allow a rapid measure of flake color that is presumably associated with starch availability. More importantly, the FCIS measure is potentially repeatable over time, thereby allowing it to be used for quality control in the steamflaking process; however, because the system is proprietary, there is no published research on its use. Steam flaking is known to increase the feeding value of corn above that of whole or dry-rolled corn; however, the magnitude of this improvement is not often fully recognized (Zinn et al., 2002). Our respondents seemed to recognize the greater energy value of steam-flaked corn and considered steam-flaked corn to increase in NE g concentration by an average of 10.9% compared with dry-rolled corn and 6.8% compared with highmoisture corn (Table 2). In contrast, NRC (1996) suggested an increase of only 4.5% for steam-flaked vs. dry-rolled corn, and no difference in the NE g concentration of high-moisture and steam-flaked corn. Thus, although most (82.76%) of our nutritionists used the NRC as their source of information on energy values, they deviated substantially from NRC estimates of NE g values for processed grains. Grain Coproduct Use in Finishing Diets The increase in fuel ethanol demand has increased the milling of corn and sorghum for ethanol production and other uses of grain starch. As a result, grain coproducts from the dry and wet milling processes are being used extensively as protein and energy sources for ruminants. The average percentage of clients that use grain coproducts in finishing diets was 82.76%, with the primary grain coproducts used being wet distiller s grains, dry distiller s grains with solubles (corn, sorghum, or both), wet corn gluten feed, and dry corn gluten feed. These grain coproducts were included in finishing diets at concentrations (DM basis) ranging from 5 to 50% (average = 16.5%; mode = 20%). Responses to the question regarding the second most commonly used grain coproduct resulted in the same coproducts noted for the primary list, with the addition of wheat middlings. Secondary grain coproducts use, on average, was 14.2% of finishing diets (Table 3). Roughage Sources and Levels and Fiber Analyses Methods A common question raised from previous surveys dealt with whether inclusion levels for roughage in finishing diet varied during summer and winter seasons, so in contrast to the previous survey of Galyean and Gleghorn (2001), the question regarding roughage level was separated by season. During the summer, our respondents used slightly less (average = 8.30%) roughage than during the winter (average = 9.00%), with the primary roughage source being corn silage (41.38%), followed by alfalfa (31.03%; Table 4). Although roughage levels are similar to values noted by Galyean and Gleghorn (2001), our findings with roughage source contrast with theirs, in which alfalfa was considered the primary roughage source used by 68% of the nutritionists they surveyed, with corn silage considered the secondary roughage source by most nutritionists. The

5 2776 Vasconcelos and Galyean Table 2. Energy and starch recommendations provided by the consulting nutritionists surveyed No. of Item Mean respondents Minimum Maximum Mode Energy concentration (NE g ) recommended, Mcal/kg Bulk density for steam-flaked grains, kg/l (pounds/bushel in parentheses) Corn (27) (24) 0.37 (29) 0.36 (28) Sorghum 0.33 (26) (22) 0.36 (28) 0.33 (26) Starch availability recommended, % Enzymatic method - corn Enzymatic method - sorghum Gas production method - corn Gas production method - sorghum Use of the Flake Color Index System by clients, % Assumed increase (%) in NE g concentration of steam-flaked corn compared with: Dry-rolled corn High-moisture corn Corn = Zea mays L. Table 3. Grain coproduct use in finishing diets by the consulting nutritionists surveyed Item % Percentage of client use of grain coproducts in finishing diets Mean 82.8 Minimum 20.0 Maximum Mode Level of inclusion of primary grain coproduct used Mean 16.5 Minimum 5.0 Maximum 50.0 Mode 20.0 Level of inclusion of secondary grain coproduct used 1 Mean 14.2 Minimum 5.0 Maximum 45.0 Mode 10.0 n % of responses Primary grain coproduct used Wet distiller s grains (corn, 2 sorghum, or both) Dry distiller s grains with solubles (corn, sorghum, or both) Wet corn gluten feed Dry corn gluten feed Other Secondary grain coproduct used Wet distiller s grains (corn, sorghum, or both) Dry distiller s grains with solubles (corn, sorghum, or both) Wet corn gluten feed Dry corn gluten feed Wheat middlings None responses. 2 Corn = Zea mays L. greater use of corn silage noted in the present survey likely reflects the broader geographical area covered by the respondents in the present survey compared with the survey of Galyean and Gleghorn (2001), in which fewer nutritionists participated who practiced extensively in Midwestern cattle feeding areas. Other primary roughage sources that were mentioned in the present survey included cottonseed hulls, cotton burrs, and Sudangrass hay, all of which also were included in the secondary roughage source list (Table 4). The fiber analysis most commonly considered in formulation (Table 4) was the crude fiber method (41.38%), followed closely by NDF (34.48%). Fewer of our respondents used ADF method, and 4 did not consider any method of fiber analysis in formulation. The use of crude fiber in formulation might reflect its common use in the feed industry, with many feed formulation programs automatically generating estimates of dietary crude fiber concentration. Galyean and Defoor (2003) suggested that NDF supplied by roughage was a reasonable method of formulating finishing diets with different roughage sources (e.g., effective for determining roughage substitution values). Whether NDF use will increase over time probably depends on the availability of rapid and reliable analytical estimates of NDF for concentrate diets. Cattle Management Sorting Systems. Methods to sort cattle into more uniform outcome groups are becoming increasingly important in the feedlot industry (MacDonald et al., 2006). With our respondents clients (data not shown), those who sorted cattle into outcome groups were the majority (41.4%; 29 responses). The most common time of sorting was at arrival for 37.2% of the clients (26 responses); reimplant for 29.2% of clients (25 responses); and other times for 28.7% (23 responses). The sorting systems

6 Feedlot consulting nutritionist survey 2777 Table 4. Roughage sources and levels and fiber analysis methods used by the consulting nutritionists surveyed Table 5. Cattle adaptation methods used by the consulting nutritionists surveyed Item % of DM Item No. % of responses Typical range of inclusion of roughage in finishing diet summer Mean 8.30 Minimum 4.50 Maximum Mode 9.00 Typical range of inclusion of roughage in finishing diet winter Mean 9.00 Minimum 0.00 Maximum Mode n % of responses Primary roughage source Corn silage Alfalfa Sorghum silage Cottonseed hulls Cotton burrs Sudangrass hay Other Secondary roughage source Corn silage Alfalfa Sorghum silage Cottonseed hulls Cotton burrs Sudangrass hay Other Method of fiber analysis considered in formulation Crude fiber NDF ADF None Method(s) used for adapting cattle to finishing diets Multiple step-up diets Two-ration blending Multiple step-up diets and 2-ration blending Other adaptation method No. or % Multiple step-up diets Number of step-up diets used (n = 24) Mean 3.1 Minimum 2.0 Maximum 5.0 Mode 2.0 Number of days per diet (n = 23) Mean 7.2 Minimum 4.0 Maximum 11.0 Mode 7.0 Initial level of roughage, % (n = 23) Mean 39.9 Minimum 27.5 Maximum 46.0 Mode 45.0 Two-ration blending Average number of days to the final diet (n = 6) Mean 21.0 Minimum 19.0 Maximum 25.0 Mode 21.0 Initial level of roughage, % (n = 4) Mean 40.0 Minimum 37.5 Maximum 42.5 Mode 40.0 used were as follows: (1) BW (61.6%; 26 responses); (2) ultrasound (8.5%; 26 responses); and (3) other methods, which are used by 24.3% of the clients (25 responses). All consulting nutritionists surveyed were responsible for their clients implant strategy (data not shown). The recommended maximum number of days on the terminal estrogen/trenbolone acetate implant was 110 d for almost half (14) the 29 nutritionists surveyed. Others recommended 120 (7), 130 (7), or 140 d (1). Cattle Adaptation Methods. The initial time spent adapting cattle to feedlot finishing diets is a critical period in which nutritional management practices can potentially promote or impair subsequent performance and health (Brown et al., 2006). Twenty-two of the 29 nutritionists surveyed recommend multiple step-up diets to adapt cattle to the finishing diet (diets with stepwise increases in the concentration of grain and corresponding decreases in roughage level). On average, 3.1 diets were fed before the finishing diet. The mode, however, was 2 diets (Table 5), with an average of 7.2 d per diet (mode = 7). The initial level of roughage during the adaptation process with this method varied from 27.5 to 46.0% (average = 39.9%; mode = 45.0%). Two-ration blending (feeding varying proportions of a higher- and a lower-roughage diet) was used by only 4 nutritionists, with an average and mode of 21 d to the final diet, and an average and mode for initial level of roughage of 40.0%. Two nutritionists used both multiple step-up diets and 2-ration blending, and 1 nutritionist used another adaptation method not listed in the survey. Most nutritionists recommended an average of 21 d for adaptation, regardless of the method used. According to Brown et al. (2006), performance studies indicate that when cattle are offered ad libitum access to feed, adapting feedlot cattle with incremental increases in dietary concentrate from approximately 55 to 90% of diet DM, in 14 d or less generally results in decreased performance during adaptation or over the entire feeding period compared with adapting cattle over longer periods of time (e.g., 21 d). Feeding and Feed Mills Supplements, Mixers, Feed Mill Systems, and Feeding Management. Our respondents reported that the percentage of their clients who use liquid supple-

7 2778 Vasconcelos and Galyean Table 6. Feeding and feed mill information provided by the consulting nutritionists surveyed No. of Item Mean respondents Minimum Maximum Mode Supplements and microingredients Clients who use liquid supplements, % Inclusion level of liquid supplements, % Clients who use pelleted dry supplements, % Inclusion level of pelleted supplements, % Clients who use loose dry supplements, % Inclusion level of loose dry supplements, % Clients who use microingredient machines, % Mixers Clients who use stationary mixer/delivery truck, % Clients who use truck-mounted mixers, % Clients who use vertical mixers, % Clients who use horizontal mixers, % Feed mill system Clients who use batch system, % Clients who use continuous-flow system, % Clients who use flat storage and truck mixer, % Feeding management Clients where cattle are fed 1 time daily, % Clients where cattle are fed 2 times daily, % Clients where cattle are fed 3 times daily, % Clients where cattle are fed more than 3 times daily, % ments (Table 6) was 45.4%, and these supplements were included on average as 5.2% of the dietary DM. Similarly, the 38.6% of clients who used pelleted dry supplements had an average inclusion level of 5.0% (DM basis). Loose dry supplements are used by fewer clients (10.4%) at an average 5.0% inclusion rate, but the mode was 3.0%. Our respondents indicated that 49.0% of their clients used microingredient machines. A stationary mixer/delivery truck approach was used by an average of 30.1% of the clients served by our respondents, with 66.8% of the clients using truck-mounted mixers. Vertical mixers are used by only 3.7% of the clients serviced by our nutritionists, with most (96.0%) using horizontal mixers. When describing feed mill systems, nutritionists reported that 33% of their clients used batch systems, whereas only 4.9% used a continuousflow system. Most clients (62.1%) used flat storage and a truck-mounted mixer (Table 6). Cattle in feedlots advised by our respondents were typically fed 2 (46.4%) or 3 (46.0%) times daily (Table 6). In 3.4 and 0.8% of the feedlots, cattle were fed once daily or more than 3 times daily, respectively. Use of Liquid Feeds Non-fat liquids were used by 32.6% of the clients serviced by our nutritionists (Table 7), with an average recommended level of non-fat liquids of 4.4% and a mode of 5.0%. The primary non-fat liquid used in finishing diets was condensed corn distiller s solubles (CCDS), followed by molasses, molasses blends, and CCDS in combination with blends. On average, 71% of clients used added fat, with the primary fat source being tallow, followed by yellow grease, a combination of sources, or choice white grease (Table 7). The average recommended level of added fat was 3.1%, with a very similar mode of 3.0%. The maximum total fat (from basal ingredients plus added fat) recommended was 7.6% (mode = 8.0%). As noted previously, extensive use of added fat is an important factor associated with the high NE g concentration of finishing diets used by most respondents. Recommended Nutrient Composition for Finishing Diets Protein and NPN. Knowledge of CP concentrations has become increasingly important in the feedlot industry because of the environmental impacts associated with the losses of N to the environment. The average CP concentrations recommended for finishing diets was 13.34% (mode = 13.5%), which is very similar to the value reported by Galyean (1996) and Galyean and Gleghorn (2001). The urea concentration in finishing diets recommended by our respondents was 1.01% (mode = 1.2%), with a maximum CP allowed from NPN of 2.83% (mode = 3.0%). Perhaps somewhat surprisingly, most of our nutritionists did not formulate for degradable intake protein (DIP; 20 respondents or 68.97%). Similarly, Galyean and Gleghorn (2001) reported that approximately 74% of their 19 respondents did not formulate for DIP. In the present survey, for the 9 respondents who use DIP, the recommended DIP level was 8.5% of the DM, with a mode of 7.0%. The primary sources of plant-based protein (data not shown) were either generally described as by-products (5) or

8 Feedlot consulting nutritionist survey 2779 Table 7. Use of liquid feeds use by the consulting nutritionists surveyed No. of Item Mean respondents Minimum Maximum Mode Clients who use added non-fat liquids, % Recommended levels of non-fat liquids, % Clients who use added fat, % Primary fat source Tallow, % Yellow grease, % Brown grease, % Choice white grease, % Blend of sources, % Recommended level of added fat, % Maximum total fat recommended, % specified as distiller s grains (3), dried distiller s grains (5), wet distiller s grains (3), gluten feed (2), or wet corn gluten feed (1). Traditional sources of plant-based protein such as soybean meal and cottonseed meal were used by 5 and 4 nutritionists, respectively. The second most commonly used sources of plant-based protein included: none (6), cottonseed meal (4), dried distiller s grains (4), soybean meal (2), canola (2), sunflower meal (2), distiller s grains (1), wet distiller s grains (1), mill run (1), corn gluten feed (1), wheat middlings (1), gluten feed (1), CCDS (1), oilseed meal (1), or by-products (1). Mineral Availability. As done previously by Galyean and Gleghorn (2001), the extent to which concentrations of minerals in basal dietary ingredients were considered in formulation was assessed. Sixteen (55.2%) of our nutritionists give full value in formulation to basal dietary ingredient mineral concentrations, and 11 (37.9%) give only partial value in formulation. Two (6.9%) nutritionists did not consider basal mineral concentrations in formulation (data not shown). Major Minerals. The average Ca concentration recommended for finishing diets was 0.70% (Table 8), and all 29 nutritionists used limestone as the source of Ca (data not shown). Phosphorus concentration recommended for finishing diets was 0.30%, and as expected, 24 of 29 nutritionists did not add P to the finishing diets, likely reflecting an appreciation that the requirement for P by feedlot cattle is less than P supplied by basal ingredients in feedlot diets (Vasconcelos et al., 2007). Thus, our data suggest that feedlot nutritionists have responded to environmental concerns by decreasing P supplementation to cattle. The recommended Mg concentration of finishing diets was 0.22% (mode = 0.25%). The sources of Mg used (data not shown) were MgO (16; 59.3% of 27 respondents), MIN-AD (a commercially available Ca-Mg carbonate; 9; 33.3% of 27 respondents), both MgO and MIN-AD (1; 3.7% of 27 respondents), and MgCl (1; 3.7% of 27 respondents). The average K concentration recommended for finishing diets was 0.70%, and the average S concentration recommended for finishing diets was 0.22%. Salt levels were, on average, 0.30% of the DM. Trace Minerals. Recommended concentrations of trace minerals are presented in Table 8. Except for Fe, which was not typically added (mode = 0), these recommendations are close to those of NRC (1996), especially in terms of the mode. Some nutritionists, however, recommended relatively high concentrations of certain minerals (e.g., Cu and Zn), which increased average values relative to NRC (1996) recommendations. Overall, the average concentrations of trace minerals recommended by the nutritionists in the present survey are greater than the concentration of trace minerals reported by nutritionists in the Galyean and Gleghorn (2001) survey. Vitamins. The average vitamin A concentration recommended by our respondents was 5,215.0 IU/kg, and the average vitamin E concentration was 25.7 IU/kg. The average vitamin D recommendation was IU/ kg, but the mode was 0, indicating that most nutritionists do not commonly supplement vitamin D. As observed by Galyean and Gleghorn (2001), average vitamin A concentration was greater than the NRC (1996) recommendations; likewise, vitamin E levels were somewhat greater than the NRC (1996) recommendations. Sources of Information In terms of sources of information used by our respondents (data not shown), a surprisingly high number (20.7%) used the NRC (1984) as their sole source of information. Seven nutritionists used the NRC (1996) as their only source of information (24.1%), whereas another 7 used both the NRC (1984) and NRC (1996). One nutritionist (3.45%) used both the NRC (1996) and the Cornell Net Carbohydrate and Protein System (CNCPS); 1 used the NRC (1976) and the NRC (1984); 1 used the NRC (1976), NRC (1984), and the NRC (1996); and 1 used NRC (1984), NRC (1996), and the CNCPS. Finally, 1 nutritionist used the NRC (1996) plus other sources, and 1 used the NRC (1984) and NRC (1996) plus other sources, and 3 of the respondents used only other sources. The CNCPS was not mentioned in

9 2780 Vasconcelos and Galyean Table 8. Formulation information for finishing diets used by the consulting nutritionists surveyed (%, DM basis) No. of Item Mean respondents Minimum Maximum Mode Protein CP concentration in finishing diets, % Urea recommended for finishing diets, % Maximum CP allowed from NPN, % Nutritionists who formulate for DIP 1 20 (68.97%) = No 9 (31.03%) = Yes DIP recommended for finishing diets, % Major minerals, % Ca P Is P added? 24 (82.8%) = No 5 (17.2%) = Yes Mg K S Salt Trace minerals, mg/kg Cu Zn Mn Fe Se I Co Vitamins, IU/kg A 5, , , ,409.2 E D , Degradable intake protein. the Galyean and Gleghorn (2001) survey, suggesting that some practicing nutritionists have started to apply nutritional recommendations from published sources other than the NRC. Nonetheless, the importance of the NRC publications is evident in that 17 nutritionists used the NRC (1984) and 19 used the NRC (1996) as a reference source for formulation. With respect to source of scientific or recent information, the Journal of Animal Science was mentioned by 27 of the 29 nutritionists. The Professional Animal Scientist was noted by 19, Feedstuffs by 17, Beef magazine by 6, Animal Feed Science and Technology by 2, Feedlot magazine by 3, and other sources (university reports, private or in-house research, and other peer-reviewed journals) by 7. When asked about nutrients not assessed in the survey, 6 respondents mentioned the use of thiamin in diets with grain coproducts. One nutritionist cited NPN (urea) levels, with reference to how NPN concentrations vary with grain processing method and concentration of grain coproducts in the diet. The results of our survey provide a summary of nutritional recommendations currently being applied in the feedlot industry and also give some insight into management practices recommended by consultants. Generally, most major and trace mineral recommendations fell within a range from 1 to 2 times the NRC (1984, 1996) recommendations; however, a slight trend for oversupplying of nutrients was observed, perhaps reflecting some degree of a desire to err on the side of caution and provide a safety net for both the consultant and the producers they serve. Failure to apply concepts like the use of DIP in assessing protein adequacy is somewhat surprising, but it might reflect the absence of widely accepted laboratory methods for assessing DIP in feed ingredients and diets, as well as the typically low price of urea nitrogen. Overall, the variation noted among responses by these 29 nutritionists was not large, verifying commonality in the sources of information used by these professionals and further suggesting that the values reported herein could be used to describe real-world application of nutritional recommendations. LITERATURE CITED Brown, M. S., C. H. Ponce, and R. Pulikanti Adaptation of beef cattle to high-concentrate diets: Performance and ruminal metabolism. J. Anim. Sci. 84:E25 E33. Galyean, M. L Protein levels in beef cattle finishing diets: Industry application, university research, and systems results. J. Anim. Sci. 74: Galyean, M. L., and P. J. Defoor Effects of roughage source and level on intake by feedlot cattle. J. Anim. Sci. 81(E. Suppl. 2):E8 E16. Galyean, M. L., and J. F. Gleghorn Summary of the 2000 Texas Tech University Consulting Nutritionist Survey. Texas Tech University, Dept. of Anim. and Food Sci., Burnett Center Internet Progress Report No burnett_center/progress_reports/bc12.pdf Accessed March 12, MacDonald, J. C., C. N. Macken, M. P. Blackford, G. E. Erickson, and T. J. Klopfenstein Sorting strategies for long yearling

10 Feedlot consulting nutritionist survey 2781 cattle grown in an extensive forage utilization beef production system. Prof. Anim. Sci. 22: NASS Cattle on Feed. USDA, Washington, DC. mannlib.cornell.edu/usda/current/cattonfe Accessed Mar. 13, NRC Nutrient Requirements of Beef Cattle. 6th ed. Natl. Acad. Press, Washington, DC. NRC Nutrient Requirements of Beef Cattle. 7th ed. Natl. Acad. Press, Washington, DC. Sindt, J. J., J. S. Drouillard, S. P. Montgomery, and T. B. Farran Refractive index: A rapid method for determination of starch availability in grains. Cattlemen s Day, Kansas Agric. Exp. Stn., Manhattan. sections/srp850b_grow.pdf Accessed Apr. 12, Vasconcelos, J. T., L. O. Tedeschi, D. G. Fox, M. L. Galyean, and L. W. Greene Review: Feeding nitrogen and phosphorus in beef cattle feedlot production to mitigate environmental impacts. Prof. Anim. Sci. 23:8 17. Zinn, R. A., F. N. Owens, and R. A. Ware Flaking corn: Processing mechanics, quality standards, and impacts on energy availability and performance of feedlot cattle. J. Anim. Sci. 80: