Survey of the nutritional recommendations and management practices adopted by feedlot cattle nutritionists in Brazil

Animal Feed Science and Technology 197 (2014) 64–75

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Survey of the nutritional recommendations and management practices adopted by feedlot cattle nutritionists in Brazil C.A. Oliveira, D.D. Millen ∗ Animal Science College, São Paulo State University (UNESP), Dracena campus, Dracena, São Paulo 17900-000, Brazil

a r t i c l e

i n f o

Article history: Received 19 November 2013 Received in revised form 25 June 2014 Accepted 26 August 2014 Keywords: Adaptation Distribution Forages Grains Ionophores

a b s t r a c t Thirty-three feedlot cattle nutritionists were surveyed to evaluate the management practices and nutritional recommendations adopted by feedlots in Brazil. The web-based survey consisted of 81 questions that included: general information (n = 10); general commodity information (n = 15); use of coproducts (n = 5), roughage source and level (n = 5); adaptation methods (n = 7); feed mixers (n = 6); feeding management (n = 6); cattle management and type of cattle fed (n = 13); formulation practices (n = 9); information resources used for nutritional recommendations (n = 2); and additional questions (n = 3). In total, the 33 nutritionists were responsible for approximately 2,658,000 animals, and moreover, 65.5% of those participants had clients that feed less than 5000 animals yearly. Corn was the primary source of grain used in feedlot diets (87.9%) and cracking was the primary processing method recommended by nutritionists (57.6%). The average concentrate and roughage inclusion in finishing diets was 79.0% and 21.0%, respectively. The main challenges faced by nutritionists are the lack of available and precise equipment and lack of trained employees with respiratory diseases as the main health problem. This survey of nutrition and management practices should aid in the development of research for the feedlot industry in Brazil and similar tropical climates, as well as provide data to facilitate the broader application of future NRC models. © 2014 Elsevier B.V. All rights reserved.

1. Introduction Brazil has the largest commercial cattle herd in the world with more than 205.3 million cattle in its territory (IBGE, 2012) and is the second largest exporter of beef, which exported 1,097,310 tons in 2011 and 1,243,610 tons in 2012 (ABIEC, 2012). The relatively new Brazilian beef feedlot industry has grown substantially in the last 10 years, as the external market demand for fed-cattle has increased. The beef cattle industry in Brazil is characterized by animals finished predominantly on pasture, and in 2011 there were 28,805,333 head slaughtered (IBGE, 2012), from which only 3,377,311 animals slaughtered (ANUALPEC, 2012) were from feedlots (11.72% of total). The Nellore breed represented the majority of feedlot cattle in Brazil, in which 75.3% of nutritionists’ clients used this breed in 2008 (Millen et al., 2009). However, nutritional information on zebu cattle, when they are fed diets containing high amounts of concentrate, is restricted (Chizzotti et al., 2008).

Abbreviations: TDN, total digestible nutrients; NDF, neutral detergent fiber; DM, dry matter; DIP, degradable intake protein. ∗ Corresponding author. Tel.: +55 18 3821 8154; fax: +55 18 3821 8208. E-mail address: [email protected] (D.D. Millen). http://dx.doi.org/10.1016/j.anifeedsci.2014.08.010 0377-8401/© 2014 Elsevier B.V. All rights reserved.

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Surveys involving feedlot nutritionists are used to describe the nutritional and management practices in the United States feedlots (Galyean, 1996; Galyean and Gleghorn, 2001; Vasconcelos and Galyean, 2007), and more recently in Brazil (Millen et al., 2009). Surveys aim to provide a current snapshot of the feedlot system in the country, describing the nutritional management, identifying possible critical issues in the operations in order to adequate diets and management, and facilitate the industry-oriented research in areas that need further pursuit. Millen et al. (2009) have reported in a survey, problems related to feed delivery, respiratory diseases, grain processing, diet formulation, equipment precision and availability. Therefore, the objectives of this study were: (1) to provide an overview of current nutritional management practices adopted in the Brazilian feedlots, (2) to identify the most critical points for improvement and feedlots that have shown evolution compared to the previous survey conducted by Millen et al. (2009), and (3) to collaborate and guide the development of new research for the feedlot industry. 2. Materials and methods Animal care and use committee approval was not obtained for this study because no animals were used. Fifty consulting feedlot nutritionists were invited to participate in the survey. These professionals were identified to represent typical cattle feeding practices in different areas of Brazil and were contacted either by e-mail or telephone regarding their interest in participating in the survey. Eleven nutritionists did not agree to participate, leaving 39 who agreed to participate, and 33 who ultimately completed the survey. This survey was conducted using similar methods to those of Vasconcelos and Galyean (2007) and Millen et al. (2009), which included a web-based survey tool (http://www.surveymonkey.com). The 39 nutritionists who agreed to participate received preliminary instructions about completing the survey, and each participant was assigned an identification number. The participants were guaranteed anonymity and asked to complete the survey as quickly as possible. All 33 consultants completed the survey within 1 month (from 01/15/2013 to 02/15/2013). The 81 questions in the survey were divided into several categories, including: general information (n = 10 questions); general commodity information (n = 15); use of coproducts (n = 5); roughage source and level (n = 5); finishing diet adaptation methods (n = 7); feed mixers (n = 6); feeding management (n = 6); cattle management and type of cattle fed (n = 13); formulation practices (n = 9); information resources used for nutritional recommendations (n = 2); additional questions (n = 2); and a final question regarding challenges faced in the field associated with applying nutritional recommendations in practice. The terms “primary” and “secondary” were used to describe the most often and second most often used feedstuffs and grain processing methods. As in Vasconcelos and Galyean (2007) and Millen et al. (2009), all data were tabulated in an Excel spreadsheet (Microsoft, Redmond, WA). The number of responses, mean, minimum value, maximum value, and mode were calculated for all questions. 3. Results 3.1. General information When asked about the nature of their professional practice, 15 (45.4%) nutritionists worked for a corporate feed manufacturing company, 11 (33.3%) reported that they are associated with nutritional consulting company, 4 (12.1%) reported to work as independent consultants, 2 (6.1%) worked in a university, and only 1 (3.0%) worked in a research center. Most nutritionists surveyed (n = 14, 42.4%) had been in the nutrition business for 10 years or more, 6 (18.2%) had been practicing from 8 to 10 years, 6 (18.2%) from 5 to 8 years, and 7 (21.2%) from 2 to 5 years. Among nutritionists surveyed, 15 (45.4%) had a Bachelor of Science degree (agronomy, animal science, or veterinary medicine) with specialization courses in cattle nutrition, 8 (24.2%) reported having a Ph.D. degree, 6 (18.2%) had a Master of Science degree, and 4 (12.1%) had only a Bachelor of Science degree with a major in agronomy, animal science, or veterinary medicine. Moreover, 25 nutritionists (62.5%) obtained their degree in universities of the state of São Paulo. The main states of the country where nutritionists work, 10 (30.3%) responded São Paulo, 9 (27.3%) worked in Mato Grosso do Sul, 4 (12.1%) reported worked in Mato Grosso, 4 (12.1%) in Goiás, 2 (6.1%) responded Paraná, 2 (6.1%) worked in Tocantins, 1 (3.0%) in Minas Gerais, and 1 (3.0%) in Rondônia. In addition, some of the nutritionists interviewed assisted clients in more than 1 state. On the other hand, 75.8% (n = 25) of the respondents did not assist clients in other countries, and 24.2% (n = 8) cited clients in Paraguay, Argentina, Chile, Uruguay, Mexico, Angola, Sudan and Costa Rica, where 1 professional represented each country listed above. On average, nutritionists visited their clients every 26.3 days. Regarding the average number of cattle in feedlots the nutritionists serviced (n = 32), 21 (65.6%) participants had clients that feed less than 5000 animals, 4 (12.5%) had clients ranging from 5001 to 10,000 animals, whereas 7 (21.9%) nutritionists assisted only feedlots with a capacity of more than 10,000 animals on feed. 3.2. General commodity information 3.2.1. Grains The corn the primary source of grain used in feedlot diets (n = 29, 87.9%), followed by sorghum (n = 4, 12.1%; Table 1). Likewise, most of the corn fed in Brazil was flint type (n = 28, 96.5%; Table 1).

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Table 1 General commodity information recommended for finishing diets by the Brazilian consulting nutritionists surveyed. Item

No. of responses

% of responses

Primary grain used Corn Sorghum

29 4

87.9 12.1

Secondary grain used (n = 32) Corn Sorghum

28 4

87.5 12.5

Type of corn used (n = 29) Flint Dent

28 1

96.5 3.4

Primary grain processing method Only cracked Finely ground Steam-flaking High-moisture harvesting and storage

19 12 1 1

57.6 36.4 3.0 3.0

Secondary grain processing method (n = 32) Finely ground Only cracked High-moisture harvesting and storage Whole shelled grain None

13 9 6 3 1

40.6 28.1 18.8 9.4 3.1

Level of inclusion of grain in finishing diet, % of DM 20–35 36–50 51–65 66–80 81% or more

2 6 17 6 2

6.1 18.2 51.5 18.2 6.1

Level of inclusion of concentrate in finishing diet, % of DM Less than 55 56–70 71–80 81–90

2 4 13 14

6.1 12.1 39.4 42.4

Type of energy unit used to formulate finishing diets Total digestible nutrients (TDN) Metabolizable energy (ME) Net energy for gain (NEg) Non-fibrous carbohydrates (NFC)

26 4 2 1

78.8 12.1 6.1 3.0

3.2.2. Grain processing Nineteen (57.6%) nutritionists reported that primary grain processing method adopted was only cracked, whereas 12 (36.4%) participants responded fine grinding (Table 1). Also, nutritionists (n = 30) reported that the average particle size of corn used in finishing diets was 3.6 mm (minimum = 1.0 mm; maximum = 8.0 mm; mode = 3.0 mm). Likewise, processing methods, such as steam-flaking and high-moisture harvesting and storage, were mentioned by one nutritionist (3.0%) each as the primary processing method (Table 1). 3.2.3. Level of inclusion of grain and concentrate in finishing diets When asked about the level of inclusion of grains in finishing diets, 17 (51.5%) consultants included from 51 to 65% (Table 1). Moreover, 8 (24.3%) nutritionists recommended more than 66% of grains in the finishing diets in Brazil (Table 1). With respect to the inclusion level of concentrate (grain plus other concentrate ingredients) in finishing diets, 27 (81.8%) nutritionists recommended levels from 71 to 90% (Table 1). Moreover, the average inclusion level of concentrate in this study was 79.0%. 3.2.4. Sources of information on feed energy values The unit of energy used by the majority of Brazilians nutritionists to formulate finishing diets was the total digestible nutrients (TDN; n = 26, 78.8%), followed by metabolizable energy (12.1%), net energy for gain (6.1%) and non-fibrous carbohydrates (3.0%; Table 1). Of the 26 nutritionists who reported the use of TDN to formulate finishing diets for feedlot cattle, 23 responded that the average level of energy used in their finishing diets was 73.9% (minimum = 67.7%, maximum = 80.0%, mode = 70.0%). The main source of information for feed energy values was the RLM, which was cited by 17 nutritionists

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Table 2 Concentrate coproduct and roughage sources and levels and fiber analysis methods used in finishing diets by the Brazilian consulting nutritionists surveyed. Item

No. of responses

% of responses

Primary concentrate coproduct used Whole cottonseed Soybean hulls Citrus pulp, pellets Soybean and corn residues

17 8 7 1

51.5 24.2 21.2 3.0

Secondary concentrate coproduct used (n = 32) Soybean hulls Whole cottonseed Citrus pulp, pellets Cottonseed hulls, high oil Cottonseed hulls, low oil Beans residues Soybean residues

11 9 5 3 2 1 1

34.3 28.1 15.6 9.3 6.2 3.1 3.1

Primary roughage source Corn silage Sorghum silage Sugarcane bagasse Sugarcane Grass silage

9 8 7 5 4

27.3 24.2 21.2 15.2 12.1

Secondary roughage source Sugarcane bagasse Corn silage Sugarcane Sorghum silage Grass silage Sugarcane silage

9 8 7 5 3 1

27.3 24.2 21.2 15.2 9.1 3.0

24 5 2 1 1

72.7 15.2 6.1 3.0 3.0

Preferred method of fiber analysis NDF Physically effective NDF ADF Fiber indexa None Typical range of inclusion of roughage in finishing diets

% of DM

Mean Minimum Maximum Mode

21.0 10.0 45.0 20.0

a

Index used in the RLM (Rac¸ão de Lucro Máximo) Brazilian software.

interviewed (51.5%). The second most used source of information for feed energy values was the NRC (1996), which was chosen by 16 nutritionists (48.5%), 9 (27.3%) participants responded that used the Cornell Net Carbohydrate and Protein System (CNCPS), 4 (12.1%) the Agricultural and Food Research Council (AFRC), 2 (6.1%) the BR-Corte, and 1 (3.0%) nutritionist reported the use of their own data and experience. 3.3. Use of coproducts In general, most of the clients serviced by the nutritionists fed some sort of coproduct in finishing diets (mean = 82.4%; minimum = 30.0%; maximum = 100.0%; and mode = 100.0%). Whole cottonseed was the primary coproduct included in finishing diets, being used by 17 (51.5%) of the nutritionists (Table 2). Use of soybean hulls was reported by 8 (24.2%) nutritionists, whereas citrus pulp pellets was reported by 7 (21.2%; Table 2). The level of inclusion of whole cottonseed was 14.9% (minimum = 10.0%; maximum = 20.0%; and mode = 15.0%), and also present data indicate that soybean hulls and citrus pulp pellets are widely used in Brazilian feedlots with inclusion means of 30.4% and 40.0%, respectively. 3.4. Roughage sources and levels and fiber analysis methods The typical roughage inclusion in finishing diets by the nutritionists surveyed was 21.0% (minimum = 10.0%; maximum = 45.0%; mode = 20.0%; Table 2). In addition, average recommended concentrations of NDF were 21.1% (minimum = 9.0%; maximum = 30.0%; and mode = 25.0%). Nine (27.3%) nutritionists reported that corn silage was the primary

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Table 3 Cattle adaptation methods used by the Brazilian Consulting nutritionist surveyed. Item

No. of response

% of response

Methods used for adapting cattle to finishing diets Multiple step-up diets Only one diet containing less energy than final diet Final diet limited by quantity Blending of two diets Blending of two diets + Multiple step-up diets None + Multiple step-up None

20 5 4 1 1 1 1

60.6 15.1 12.1 3.0 3.0 3.0 3.0

Receiving program None Some days on pasture Pasture plus bunk containing concentrate Pasture plus bunk containing roughage and concentrate

14 9 6 4

42.4 27.3 18.2 12.1

Average number of days in the receiving program (n = 24)

N◦

Mean Minimum Maximum Mode

8.9 0.0 30.0 9.0

Table 4 Recommendations for each adaptation method used by the Brazilian consulting nutritionists surveyed. Item

Mean

Multiple step-up diets Average number of days to the final diet Initial level of roughage, % of DM Number of step-up diets used Number of days per diet

18.6 50.5 3.1 6.6

Final diet limited by quantity Average number of days to the final diet Initial level of roughage, % of DM No. of steps used Average number of days per step used

No. of responses

Minimum

Maximum

Mode

18 18 18 15

7.0 22.0 2.0 2.0

35.0 75.0 10.0 15.0

22.0 60.0 3.0 7.0

10.0 21.8 3.0 3.1

3 4 3 4

8.0 10.0 2.0 2.0

12.0 40.0 4.0 5.0

– – – –

Only one diet containing less energy than final diet Average number of days to the final diet Initial level of roughage, % of DM

36.7 36.2

4 4

7.0 20.0

65.0 60.0

– –

Blending of two diets Average number of days to the final diet Initial level of roughage, %DM

37.5 47.5

2 2

30.0 35.0

45.0 60.0

– –

source of roughage utilized in finishing diets, followed by sorghum silage (n = 8, 24.2%), sugarcane bagasse (n = 7, 21.2%), fresh chopped sugarcane (n = 5, 15.2%), and grass silage (n = 4, 12.1%; Table 2). With respect to the preferred method of fiber analysis, 24 (72.7%) nutritionists preferred the NDF, whereas the physically effective NDF was cited by 5 (15.2%) participants (Table 2).

3.5. Cattle adaptation methods Twenty (60.6%) respondents used multiple step-up diets to adapt feedlot cattle to the finishing diets (Table 3). Five (15.1%) nutritionists responded that they use only one diet containing less energy than the finishing diet, 4 (12.1%) used the final diet restricted by quantity, 1 (3.0%) participant adopted the use of 2-ration blending system, and 1 (3.0%) used one of the following combined options: multiple step-up diets and 2-ration blending; none and multiple step-up diets; or none (Table 3). When the multiple step-up diets were adopted, 3.1 diets on average were fed within the adaptation period, with an average of 6.6 days per diet (Table 4). The average number of days of the adaptation period was 18.6 for multiple step-up diets and 10 days when the final diet limited by quantity was used (Table 4). Present data show that the diets fed during the step-up period are typically switched in less than 7 days (average = 6.6; minimum = 2.0; maximum = 15.0; and mode = 7.0). Information about receiving management programs is provided in Table 3. Most part of the nutritionists (n = 14, 42.2%) did not recommend any receiving program for their clients. However, when animals go through some kind of receiving

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Table 5 Mixers and feeding management information provided by the Brazilian consulting nutritionists surveyed. Item

Mean

No. of respondents

Mixers Clients who use only delivery truck, % Clients who use stationary mixer/delivery truck, % Clients who use truck-mounted mixers, % Clients who do not use any mixer, %

Minimum

Maximum

Mode

33.8 10.7 52.3 3.0

33 33 33 33

– – – –

– – – –

– – – –

Feed delivery Clients who use programmed delivery per pen, % Clients who use continuous delivery, %

46.7 53.3

29 29

– –

– –

– –

Feeding management Clients where cattle are fed 1 time daily, % Clients where cattle are fed 2 time daily, % Clients where cattle are fed 3 time daily, % Clients where cattle are fed 4 time daily, % Clients where cattle are fed more than 4 times daily, % Daily feeding interval, h Feed sampling frequency, days Bunk space per animal, cm Area per animal in a pen, m2

0.0 6.1 33.3 30.4 30.3 2.9 36.5 40.9 16.5

33 33 33 33 33 32 27 33 33

1.0 7.0 30.0 10.0

15.0 180.0 70.0 35.0

4.0 30.0 35.0 15.0

Feed mixing Average mixing time finishing diets, min Clients who add water to finishing diets, % Water added to finishing diets, % DM in finishing diets, %

8.4 22.3 11.0 60.4

32 32 16 32

2.0 – 3.0 25.0

20.0 – 25.0 73.5

5.0 – 11.6 65.0

program, they spend on average 8.9 days (Table 3), and “only some days on pasture” was the most cited receiving program (n = 9, 27.3%; Table 3) by the nutritionists interviewed. 3.6. Feeding and bunk management 3.6.1. Mixers Nutritionists indicated that 52.3% of their clients use truck-mounted mixers, 33.8% of nutritionists’ clients used only delivery trucks, 10.7% used a stationary mixer/delivery truck approach, and 3.0% of the clients did not use any type of mixer (Table 5). Similarly, our participants reported that 52.9% of their clients use horizontal mixers, 30.9% use vertical mixers, and 16.2% of the clients used neither vertical nor horizontal mixers (the mixing is done by hand in the feed bunk, or diet components are stratified by alternating layers of concentrate and roughage inside of the delivery truck). 3.6.2. Feed delivery and mixing With respect to methods of feed delivery, 53.3% of our respondents reported that their clients use continuous delivery (kilograms offered per pen is not controlled) and 46.7% use programmed delivery per pen based on feed bunk scores (Table 5). The average mixing time for the finishing diets recommended by our nutritionists was 8.4 min (mode = 5.0 min), with an average of 22.3% of nutritionists’ clients who added water in the mixed diet, with the average level of water inclusion at 11.0% (Table 5). The average dry matter content of finishing diets reported by the nutritionists was 60.4% (Table 5). 3.6.3. Feeding and bunk management Most of the clients served by the nutritionists surveyed typically feed 3 (33.3%) times per day. In 30.4% and 30.3% of the feedlots, cattle were fed 4 times or more than 4 times daily, respectively (Table 5). In addition, the daily feeding interval averaged 2.9 h (mode = 4.0 h). With respect to bunk management, most of the nutritionists (n = 21, 63.6%) reported that their clients leave bunks within a range from 1.0 to 3.0% of orts, 18.2% (n = 6) reported that their clients used clean-bunk management, whereas 15.2% (n = 5) indicated that their clients leave bunks within a range from 3.0 to 5.0% of orts, and only 3.0% (n = 1) of nutritionists reported that their clients leave a range from 5% to 10% of orts. Furthermore, the average bunk space per animal adopted by clients of the nutritionists interviewed was 40.9 cm (mode = 35.0 cm; Table 5), and the average area per animal in a pen of the clients of our respondents was 16.5 m2 (mode = 15 m2 ; Table 5). 3.7. Management of newly received cattle For the criteria used to sort cattle at arrival in the feedlot, 12 of 32 (37.5%) participants indicated that their clients use only body weight for sorting, 11 (34.3%) reported that their clients sort cattle using both body weight and body condition score, 4 (12.5%) indicated the use of only body condition score, 2 (6.2%) consultants reported that their clients use body weight and

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Table 6 Cattle performance information provided by the Brazilian consulting nutritionists surveyed. Item Avg. initial age, months Calves Bullocks Steers Heifers Cull cows Avg. initial body weight, kg Calves Bullocks Steers Heifers Cull cows Avg. final body weight, kg Calves Bullocks Steers Heifers Cull cows Days on feed Calves Bullocks Steers Heifers Cull cows Average daily gain, kg Calves Bullocks Steers Heifers Cull cows

Mean

No. of responses

9.7 24.4 21.3 19.2 61.4

21 32 26 28 22

239.0 369.0 388.5 271.8 340.4

21 31 31 27 24

432.7 507.5 495.8 372.6 430.0

20 31 26 28 25

129.8 87.7 85.6 75.0 60.8

20 31 26 28 25

1.40 1.50 1.40 1.23 1.25

21 31 25 27 24

Item

Mean

Feed-to-gain-ratio Calves 5.9 Bullocks 6.8 Steers 7.8 Heifers 7.1 Cull cows 8.4 Dry matter intake, kg/d Calves 8.2 Bullocks 10.8 Steers 10.4 Heifers 7.8 Cull cows 10.1 Nellore 10.2 Crossbred 10.7 Dry matter intake, % of body weight Calves 2.5 Bullocks 2.3 Steers 2.3 Heifers 2.3 Cull cows 2.5 Nellore 2.0 Crossbred 2.8 Clients who feed, % Calves 15.3 Bullocks 84.5 Steers 23.3 Heifers 30.9 Cull cows 27.4 Nellore 77.4 Crossbred 55.2

No. of responses 15 24 28 18 16 16 22 21 21 21 24 22 20 30 24 24 22 26 24 21 29 25 24 24 21 29

real-time ultrasound, 2 (6.2%) reported the use of body weight and breed, whereas only 1 (3.1%) participant reported that their clients used only real-time ultrasound for sorting cattle. 3.8. Cattle performance information Most cattle fed in Brazilian feedlots are bullocks (fed by 84.5% of the clients), with a short finishing period (87.7 days; Table 6). Moreover, 77.4% of the clients serviced by our respondents fed Nellore cattle, and 55.2% fed crossbred. The typical average daily gain in the feedlots serviced by our nutritionists was 1.40, 1.50, 1.40, 1.23, and 1.25 kg for calves, bullocks, steers, heifers, and cull cows, respectively. 3.9. Recommended nutrient composition for finishing diets 3.9.1. Fat The average dietary fat concentration in finishing diets (DM basis) recommended by the nutritionists surveyed was 4.6% (mode = 5.0%; Table 7). The maximum dietary fat concentration recommended (DM basis) by the nutritionists was 6.1% (mode = 6.0%; Table 7). The main source of fat was whole cottonseed, recommended by 20 (62.5%) respondents. 3.9.2. Protein The average crude protein concentration (dry matter basis; Table 7) recommended for finishing diets was 13.4% (mode = 13.5%). The urea concentration in finishing diets recommended was 1.4% (mode = 1.0%; Table 7). The recommended concentration of true protein (dry matter basis) by our nutritionists was 8.1% (mode = 9.75%; Table 7). The recommended DIP level by Brazilian consultants was 9.2% of DM, with a mode of 9.0% (Table 7). The primary source of plant-based protein used by the nutritionists surveyed (n = 32) was cottonseed meal (n = 19; 59.4%), followed by peanut meal (n = 7; 21.9%) and cotton cake (produced by pressing whole cottonseed for oil extraction; n = 2; 6.2%). Others plant-based protein feedstuffs, such as soybean meal, soybean residues, whole cottonseed, and sunflower meal were mentioned by 1 nutritionist each (Table 7). 3.9.3. Feed additives The participants reported that 99.2% of their clients use some kind of feed additive in finishing diets (data not shown). Thirty-one nutritionists (93.9%) reported that the primary feed additive used were ionophores, followed by yeast (n = 1, 3.0%) and probiotics (n = 1; 3.0%). The recommended level of ionophores in finishing diets was 22.7 mg/kg of dry matter on average; however, the question related to ionophores did not address which specific ionophores were used. The secondary

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Table 7 Fat and protein recommendations for finishing diets used by the Brazilian Consulting nutritionist surveyed. Item

Mean

No. of respondents

Minimum

Maximum

Mode

Recommended dietary fat, % of DM Maximum dietary fat recommended, % of DM Recommended level of crude protein, % of DM Recommended level of true protein, % of DM Recommended level of urea, % of DM Nutritionists who formulate for DIPa (n = 33) DIP recommended for finishing diets, %

4.6 6.1 13.4 8.1 1.4 29 (87.9%) = Yes 9.2

31 30 31 31 30 4 (12.1%) = No 21

3.0 5.0 9.3 3.6 0.7

6.0 10.0 16.6 11.5 3.0

5.0 6.0 13.5 9.75 1.0

5.0

12.0

9.0

No. of responses

% of responses

Main source of fat (n = 32) Whole cottonseed Cotton cake From non-fat feedstuffs used (corn, etc.)

20 07 05

62.5 21.9 15.6

Primary protein source (n = 32) Cottonseed meal Peanut meal Cotton cake Soybean meal Soybean residues Whole cottonseed Sunflower meal

19 07 02 01 01 01 01

59.4 21.9 6.2 3.1 3.1 3.1 3.1

a

Degradable intake protein.

feed additives used by clients serviced by our nutritionists included yeast (35.3%; 6 of 17 respondents), antibiotics (35.3%; 6 of 17 respondents), buffers (23.5%; 4 of 17 respondents), and ionophores (5.8%; 1 of 17 respondents). 3.10. Sources of information With respect to sources of information used by Brazilian nutritionists (n = 32; data not shown), 65.5% (n = 20) of respondents used the NRC (1996), 56.2% (n = 18) the RLM, 31.2% (n = 10) the CNCPS-Cornell, 18.7% (n = 6) used personal information, 9.3% (n = 3) used the BR-Corte, 9.3% (n = 3) the AFRC, 3.1% (n = 1) NRC published in 1984 and 3.1% (n = 1) used the NRC published in 1976. In this question, participants were able to choose more than one alternative. In terms of the main source of scientific and recent information, 80.6% (25 of 31 responses) of nutritionists cited the Journal of Animal Science, 51.6% (n = 16) identified the Brazilian Journal of Animal Science, 12.9% (n = 4) noted the Feedstuffs, 6.4% (n = 2) DBO and 3.2% (n = 1) cited the Gestão Agropecuária. Likewise, nutritionists also were able to choose more than one alternative in this question. 3.11. Major problems reported by the nutritionists 3.11.1. Health problems When asked (n = 32) about the main health problem faced by their clients, 13 (40.6%) nutritionists identified respiratory diseases, 11 (34.4%) responded acidosis, 3 (9.4%) indicated cysticercosis, 2 (6.2%) reported that their clients do not have many incidences of health problems, 1 (3.1%) reported problems involving laminitis, and 1 (3.1%) responded that clostridiosis was the main health problem faced by his clients. 3.11.2. Major challenges In an open question, in which nutritionists (n = 31) were able to choose more than one alternative, 18 (58.1%) participants responded that availability and precision of equipment was the most challenging issue to apply their nutritional recommendations, 16 (51.6%) reported that lack of trained employees, 12 (38.7%) indicated the use of same diet for different types of cattle, 8 (25.8%) cited the logistics, and 1 (3.2%) reported that the most difficult issue to apply their recommendations was to convince the feedlot owner to “do the right thing.” 4. Discussion 4.1. General information It was observed an increase in the percentage of nutritionists serving feedlots that feed more than 10,000 animals (21.9% vs. 3.2%), when compared to the previous survey conducted by Millen et al. (2009), which may imply that feedlot operations have been growing in Brazil in the last 3 years. In total, the 33 nutritionists surveyed were responsible for approximately

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2,658,000 animals, which is lower than the 3,377,311 animals finished in feedlots reported by ANUALPEC (2012) and the 3,163,750 animals reported by Millen et al. (2009). Thus, the nutritionists who participated in this survey accounted for 78.7% of feedlot cattle in Brazil. 4.1.1. Grain Corn is still the primary source of grain used in finishing diets in Brazil (n = 29, 87.9%), as reported in previous surveys conducted in Brazil (Millen et al., 2009) and the USA (Vasconcelos and Galyean, 2007). However, with respect to the primary grain processing method, cracking was the preferred method recommended by the nutritionists surveyed (n = 19, 57.6%), which is different if compared to the survey conducted by Millen et al. (2009), where 54.8% of the nutritionists responded that the primary grain processing method used was fine grinding, followed by coarse grinding method (45.2%). Likewise, processing methods, such as steam-flaking and high-moisture harvesting and storage, were not among the preferred methods in the study conducted previously by Millen et al. (2009). Based on this fact, Brazilian feedlots started to be interested in improving the digestibility of the flint-type grains fed to the animals for better feedlot performance as indicated by Owens et al. In terms of level of inclusion of grains, the result of 51.5% of nutritionists recommending from 51% to 65% is similar to the 51.6% reported by Millen et al. (2009); however, when compared to a survey of the U.S. (Vasconcelos and Galyean, 2007), 65.5% of nutritionists recommended from 70 to 85% grain in finishing diets, with the majority of these grains processed as steam-flaked, which shows that Brazilian feedlots can greatly improve the efficiency of grain utilization, as well as its inclusion levels. Moreover, 8 (24.3%) nutritionists recommended more than 66% of grains in the finishing diets in Brazil (Table 1), suggesting an increase in the level of grain inclusion, as Millen et al. (2009) had previously reported that only 6.5% of nutritionists recommended more than 66% of grains in these diets. With respect to the inclusion level of concentrate (grain plus other concentrate ingredients) in finishing diets, 27 (81.8%) nutritionists recommended levels from 71 to 90% (Table 1), suggesting a large increase compared to the previous survey conducted by Millen et al. (2009), in which 58.1% of nutritionists recommended these same levels of inclusion. Moreover, the average inclusion level of concentrate in this study was 79.0%, which was 7.8% greater than the survey (71.2%) reported by Millen et al. (2009). The greater inclusion of grains, as well as concentrate feedstuffs, in the finishing diets in Brazil in the last 3 years led to the feeding of more energetic diets. This fact may explain the largest use of corn processed as cracked rather than finely ground, as previously reported (Millen et al., 2009), because the increased inclusion of concentrate ingredients in finishing diets concomitantly leads to reduced inclusion of forage, which increase rumen degradation rate, suggesting that the lesser processed grains, the slower acid rate production, which may help to contain excessive acidification (Vasconcelos and Galyean, 2008). The increasing in the average level of concentrate ingredients in the finishing diets in Brazil was, in part, due to the larger feedlot operations, as reported earlier in this study, because as feedlot operations get larger, costs are extremely high if inclusion levels of forages are not reduced. With respect to the main source of information for energy values, the RLM become more popular among Brazilian nutritionists, which was cited by 51.5% of nutritionists interviewed. Previously, Millen et al. (2009) had reported that NRC (1996) was the main source of information for feed energy values used by the majority of Brazilian nutritionists (61.3%) and RLM was adopted by only 9.7% of respondents. One of the reasons by which RLM has become more popular is because it is in Portuguese and nutritionists can also formulate their diets, and not only evaluate them, which is the case of CNCPS and NRC. Furthermore, TDN is still the unit of energy used by the majority of Brazilians nutritionists (78.8%) to formulate finishing diets as reported previously by Millen et al. (2009). 4.2. Use of coproducts Whole cottonseed is still most used coproduct in Brazilian feedlot. In a previous survey (Millen et al., 2009), whole cottonseed was also the primary coproduct included in finishing diets in Brazil. The level of inclusion of whole cottonseed found in this survey (14.9%) was similar to the 15.0% reported by Millen et al. (2009). Cranston et al. (2006) observed no adverse effect on the performance of feedlot cattle using up to 15.0% whole cottonseed in the finishing diets. 4.3. Roughage sources and levels and fiber analysis methods The typical roughage inclusion in finishing diets by the nutritionists surveyed was 21.0%, which is less than the 28.8% reported by Millen et al. (2009). This shows that the inclusion of roughage in finishing diets in Brazil have been reduced over the years, as inclusion of grains and concentrates has increased, as reported previously. Again, as feedlot operations become larger lower should be the level of inclusion of roughages in the finishing diets, because it decreases operational costs, as well as facilitates the logistics of the entire operation. In addition, this average value of inclusion of roughages reported in this study is nearly 2.3-fold greater than the concentration of roughage used by the United States feedlot consulting nutritionists (Vasconcelos and Galyean, 2007). In addition, average recommended concentrations of NDF were 21.1%, which shows a reduction of 5.3% when compared to the study of Millen et al. (2009). In contrast, Strasia and Gill (1990) recommended a minimum of 15% of NDF for formulating finishing diets for beef cattle to avoid further risks of digestive disorders. Furthermore, NDF is still the preferred method of fiber analysis cited by the nutritionists (Millen et al., 2009).

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The fresh chopped sugarcane used to be the primary roughage source used by Brazilian feedlot nutritionists (Millen et al., 2009), and the main reason for this reduction is explained by the fact that feedlot operations have become larger, which complicates the daily logistics, either by: cutting huge amounts of sugarcane, or transporting the low dry matter sugarcane to the bunks. Based on this fact, the use of conserved materials, such as corn and sorghum silages, has become more common in Brazilian feedlots, as reported previously in this survey. 4.4. Cattle adaptation methods In the present survey, and in Vasconcelos and Galyean (2007) and Millen et al. (2009), the multiple step-up diets were the adaptation protocol of choice of most nutritionists surveyed. Also, the average number of days of the adaptation period was 18.6 for multiple step-up diets and 10 days when the final diet limited by quantity was used (Table 4). The main advantage of using multiple step-up diets to adapt feedlot cattle to high concentrate diets is because it leads to a more gradual change in rumen epithelium and population. In addition, as the measurement of dry matter intake is a problem in most Brazilian feedlots, the use of the final diet limited by quantity is not recommended. Likewise, Brown et al. (2006) reported that cattle performance might be decreased if cattle are adapted from 55% concentrate to a final diet of approximately 90% concentrate in 14 days or less. The final diet recommended by the Brazilian nutritionists contained less energy (average 79.0% concentrate) than the typical 91.0% concentrate used in finishing diets in the United States (Vasconcelos and Galyean, 2007), which may allow the use of adaptation protocols in less than 14 days, however further studies are needed to confirm this hypothesis. In addition, because of the greater use of roughage in Brazilian feedlot diets than in the United States, little emphasis seems to be placed on receiving programs, with approximately half of the respondents not using a receiving program during the adaptation period. 4.4.1. Feeding and bunk management When compared to the survey conducted by Millen et al. (2009), a considerable change in terms of mixers was noted, because the percentage of clients who use truck-mounted mixers increased (52.3% vs. 40.5%), as well as the proportion of clients who use horizontal mixers (52.9% vs. 33.9%). Likewise, the percentage of clients of the nutritionists who dot use any type of mixer decreased (16.2% vs. 33.4%). As the capacity of Brazilian feedlots are increasing, as well as the inclusion level of concentrates in finishing diets, it requires more accurate management in terms of feed mixing and delivery to avoid possible digestive disorders. Thus, with respect to the mixers, an evolution was observed in the Brazilian feedlots, as a result of the intensification of the system. With respect to methods of feed delivery, the most part of the clients of nutritionists still use continuous delivery (kilograms offered per pen is not controlled) rather than programmed delivery per pen based on feed bunk scores (Millen et al., 2009). The main reason for delivering feed continuously is either because most delivery trucks do not have a scale system or due a limited number of delivery trucks available. This fact shows that in the recent years the clients of our participants were more concerned to modernize and equip the feedlot operations, as just shown in the discussion about mixers, than establish protocols for rations delivery and for collecting data on dry matter intake per pen. Regarding inclusion of water in finishing diets, the percentage of clients who added water in the mixed diet increased 10.2% (to 22.3%) when compared to the study conducted by Millen et al. (2009), which may be explained by the greater inclusion level of concentrates that is currently being used by the Brazilian feedlots. Therefore, the average dry matter content of finishing diets reported by the nutritionists of 60.4% is very similar to the 59.9% reported by Millen et al. (2009). With respect to the feeding frequency, most of the clients served by the nutritionists surveyed typically feed 3 (33.3%) times per day. Millen et al. (2009) reported that the majority of the nutritionists’ clients (36.6%) fed cattle more than 4 times daily. Therefore, in this study was observed a decreasing in feeding frequency, which also may be explained by the increased capacity of Brazilian feedlots or the delivering of diets containing lower levels of roughage, which allows the loading of greater amounts of feed into the same delivery trucks. In the United States, where higher levels of concentrate are fed to feedlot cattle (about 91.0%), clients of nutritionists feed cattle between 2 and 3 times daily (Vasconcelos and Galyean, 2007). Furthermore, the average bunk space per animal adopted by clients of the nutritionists interviewed was 40.9 cm, which is a short space, and may be one of the reasons to explain the higher feeding frequencies in the Brazilian feedlots. Moreover, shorter bunk spaces commonly lead to the adoption of leaving bunks with a greater amount of orts, as observed in this study. 4.5. Management of newly received cattle Twelve of 32 (37.5%) participants indicated that their clients use only body weight for sorting, and 11 (34.3%) reported that their clients sort cattle using both body weight and body condition score. Millen et al. (2009) had observed previously, that 76.1% of nutritionists indicated that their clients sort cattle only by body weight. An evolution of the sorting criteria has been adopted by Brazilian feedlots, as the use of body condition score combined with body weight leads to greater consistency and uniformity of the pens, and consequently uniformity of ultimate products. Sorting minimizes excess of fat or the lack of and avoids possible discounts on the price paid by the packing plant to the clients of our respondents.

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4.6. Cattle performance information Most cattle fed in Brazilian feedlots are bullocks (fed by 84.5% of the clients), with a shorter finishing period in Brazil (87.7 days; Table 6) than in the United States (about 170 days; Elam et al., 2009). When compared to the previous survey (Millen et al., 2009), it was observed a greater use of bullocks (84.5% vs. 69.5%) and crossbred (55.2% vs. 46.4%). The use of higher levels of concentrates in the finishing diets in Brazil makes fat deposition easier and faster, which is more feasible with the use of bullocks rather than steers, as bullocks normally present better feed to gain ratio, as shown in Table 7 and reported previously by many authors (Owens et al., 1995; Restle et al., 2000). It is noteworthy that the average daily gain increased for all types of cattle studied (Table 6) when compared to the previous survey conducted by Millen et al. (2009), which may be related to the higher levels of concentrate ingredients (79.0% vs. 71.2%) reported in this study by the nutritionists surveyed. Nutritionists reported greater dry matter intake for crossbreds than for Nellore cattle (Table 6); what is in agreement with the information provided by Millen et al. (2009) in the previous survey and by Pacheco et al. (2012) that reported greater dry matter intake for crossbred bullocks (1/2 Angus × 1/2 Nellore and Canchim) when compared to Nellore animals. 4.7. Recommended nutrient composition for finishing diets The average dietary fat concentration in finishing diets of 4.6% (DM basis) found in this study is very close to the 4.7% reported by Millen et al. (2009). The maximum dietary fat concentration recommended (DM basis) by the nutritionists was 6.1%, which is less than the 7.6% value reported by Vasconcelos and Galyean (2007) and very similar to the concentrations reported in a previous Brazilian survey conducted by Millen et al. (2009). This may be due to greater inclusion of forage in the finishing diets in Brazil (21.0%) when compared to the United States (9.0%; Vasconcelos and Galyean, 2007), because high concentrations of dietary fat may impair fiber digestion (Plascencia et al., 2003). Just like in this survey, whole cottonseed was reported previously by Millen et al. (2009) as the main source of fat in Brazilian feedlots. The average crude protein concentration (DM basis) recommended for finishing diets of 13.4%, observed in this survey, agrees with values reported previously by Galyean (1996), Galyean and Gleghorn (2001), Vasconcelos and Galyean (2007), and Millen et al. (2009). Moreover, this value is greater than the 12.2% of crude protein concentration recommended by NRC (1996) for finishing diets. The greater inclusion of crude protein in finishing diets both in Brazil and the United States is an attempt to meet the requirements of rumen microorganisms; as the greater inclusion of concentrate feedstuffs, the requirement for nitrogen in the rumen is greater. Most Brazilian consultants (87.9%) formulated for degradable intake protein (DIP), which differs from data reported by other surveys (Galyean and Gleghorn, 2001; Vasconcelos and Galyean, 2007), in which most U.S. feedlot nutritionists responded that they did not formulate for DIP. The recommended DIP level of 9.2% greater than the level of 9.0% reported by Millen et al. (2009) in a previous survey. The primary source of plant-based protein used by the nutritionists surveyed was cottonseed meal, however, according to the survey conducted by Millen et al. (2009), soybean meal was the primary plant-based protein used by Brazilian feedlots, but due to its higher price, nutritionists started recommending more feasible products, in terms of cost, such as cottonseed meal and peanut meal. Based on this fact, the level of true protein decreased in finishing diets in Brazil (8.1% vs. 9.4%; Millen et al., 2009), and recommended level of urea increased (1.4% vs. 1.2%; Millen et al., 2009) to offset DIP level. Regarding feed additives, ionophores are still the primary feed additive used in finishing diets in Brazil, as reported previously by Millen et al. (2009). However, the question related to ionophores did not address which specific ionophores were used. 4.8. Sources of information As reported by Millen et al. (2009) previously, the NRC (1996) and RLM are still the most important sources of information used by Brazilian nutritionists. The NRC publications are the most common source of information used by feedlot consulting nutritionists in the U.S. (Galyean and Gleghorn, 2001; Vasconcelos and Galyean, 2007). As observed in this survey, the Journal of Animal Science had been cited before by Vasconcelos and Galyean (2007) and Millen et al. (2009) as the main source of scientific information used by feedlot cattle nutritionists. 4.9. Major problems reported by the nutritionists Respiratory diseases in general and acidosis are still, in this same order, the main health problems, as reported previously by Millen et al. (2009), which implies that studies to control or avoid these two problems in Brazilian conditions, should be conducted to improve the efficiency and productivity of feedlots in Brazil. Likewise, availability and precision of equipment and lack of trained employees are still the major challenges for Brazilian nutritionists put into practice its nutritional recommendations (Millen et al., 2009). 5. Conclusions It was observed in this study that the variations for some responses was not large when compared to the previous Brazilian survey conducted by Millen et al. (2009), in which corn is still the primary grain used in finishing diets, as well as ionophores

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are still the most used feed additive. On the other hand, it was detected in this survey that feedlot operations are getting larger in Brazil, and this fact led to some changes in terms of nutritional recommendations and management practices. The average level of inclusion of concentrate increased as well as the inclusion of grains in finishing diets. Grains became less processed and the feeding frequency was reduced from more than 4 times daily to between 3 and 4 times daily. Although some advances were noted in the Brazilian feedlots with this survey, some points still need to be improved, such as: (1) starch utilization by adopting more intensive processing methods, such as steam-flaking corn or high-moisture corn grain ensilage, as the most of the corn fed to feedlot cattle in Brazil are flint-types; (2) measure dry matter intake, because more than half the clients of the nutritionists did not control the quantity of feed offered per pen, which might be explained by limitations in availability of equipment and trained employees; (3) use of energy units other than TDN to formulate diets for feedlot cattle, but studies to determine the energy of feedstuffs based on net energy for gain or metabolizable energy are still needed. This survey of nutritional and management practices should aid in the development of research for the feedlot industry in Brazil and similar tropical climates, as well as provide data to facilitate the broader application of future NRC models. Conflict of interest The authors declare that they do not have any conflict of interest related to the manuscript. References ABIEC – Associac¸ão Brasileira das Indústrias Exportadoras de Carne, 2012. Exportac¸ões Brasileiras de Carne Bovina, Available at: http://www.abiec. com.br/download/relatorioexportacao2012 jan dez.pdf (accessed 19.01.13.). ANUALPEC, 2012. Anuário da Pecuária Brasileira, first ed. Instituto FNP and Agra FNP Pesquisas Ltda, São Paulo, Brazil. Brown, M.S., Ponce, C.H., Pulikanti, R., 2006. Adaptation of beef cattle to high-concentrate diets: performance and ruminal metabolism. J. Anim. Sci. 84, E25–E33. Chizzotti, M.L., Valadares Filho, S.C., Valadares, R.F.D., Chizzotti, F.H.M., Tedeschi, L.O., 2008. 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Summary of the 2000 Texas tech university consulting nutritionist survey. In: Texas Tech University, Dept. of Anim. And Food Sci. Burnett Center Internet Progress Report 12, Available at: http://www.asft.ttu.edu/burnett center/progress reports/bc12.pdf (accessed 20.11.12.). IBGE – Instituto Brasileiro de Geografia e Estatística, 2012. Indicadores IBGE – Estatística da produc¸ão pecuária, Available at: http://www.ibge.gov. br/home/presidencia/noticias/noticia visualiza.php?id noticia=2107&id pagina=1 (accessed Jan 19.01.13.) (in Portuguese). Millen, D.D., Pacheco, R.D., Arrigoni, M.D.B., Galyean, M.L., Vasconcelos, J.T., 2009. A snapshot of management practices and nutritional recommendations used by feedlot nutritionists in Brazil. J. Anim. Sci. 87, 3427–3439. NRC, 1996. Nutrient Requirements of Beef Cattle [NRC], second ed. National Academy Press, Washington, DC, USA. Owens, F.N., Gill, D.R., Secrist, D.S., Coleman, S.W., 1995. 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