Go to Top Go to Bottom
Asian-Australas J Anim Sci > Volume 30(11); 2017 > Article
González-Vizcarra, Plascencia, Ramos-Aviña, and Zinn: Influence of substituting steam-flaked corn for dry rolled corn on feedlot cattle growth performance when cattle are allowed either ad libitum or restricted access to the finishing diet

Abstract

Objective

The influence of substituting steam-flaked corn (SFC) for dry rolled corn (DRC) on feedlot cattle growth performance and dietary net energy when cattle are allowed either ad libitum or 2-h restricted access to the finishing diet was evaluated.

Methods

Treatment effects were tested using 96 crossbred steers (251±2 kg) during the initial 56 d of the finishing phase. Cattle were blocked by weight and randomly assigned within blocks to 16 pens (4 pens/treatment). Bunk space was sufficient (41 cm/head) to allow all steers access to the feed bunk at the same time. Treatments consisted of two finishing diets containing (dry matter basis) 77.1% corn grain processed by dry rolling (density = 0.50 kg/L) or steam flaking (density = 0.36 kg/L). Cattle were fed twice daily at 06:00 and 14:00 h, allowing for approximately 5% residual. In the case of restricted feeding, steers were allowed access to feeders for 1 h following each feeding, after which residual feed was withdrawn.

Results

There were no treatment interactions on dry matter intake (DMI), average daily gain (ADG), gain efficiency (G:F), or dietary net energy (NE). Restricting feed access time reduced (p <0.01) feed intake, and hence, ADG. Substitution of SFC for DRC increased (p<0.01) ADG, feed efficiency (G:F), and estimated dietary NE, without affecting DMI. Based on tabular net energy of maintenance (NEm) value (2.18 Mcal/kg) for DRC, the estimated NEm value for SFC using the replacement technique, averaged 2.44 Mcal/kg; an improvement of 10.7%. The ratio of observed-to-expected dietary NE was not affected by feed access time.

Conclusion

Substitution of SFC for DRC in finishing diets for feedlot cattle enhanced ADG, gain efficiency, and the NE value of the diet. Although restriction of feed access time depressed DMI and ADG, it did not affect the comparative benefit of steam flaking toward enhancement of ADG, G:F, and dietary NE.

INTRODUCTION

The enhancement in corn digestion due to steam-flaking has been clearly demonstrated. Compared with dry rolled corn (DRC), steam flaked corn (SFC) increases ruminal and total tract starch digestion by an average of 25% and 10%, respectively [1,2], and the net energy (NE) value of corn for maintenance and gain by 13% and 16%, respectively [3]. The increase in NE is consistent with a 10% increase in total digestible nutrients, reflecting the fact that steam flaking increases the digestion of non-starch organic matter to the same extent that it increases starch digestion [2,4]. In a 12-trial summary, Zinn et al [3] observed that substitution of SFC for DRC in growing-finishing diets for feedlot cattle also increased (6.3%) average daily gain (ADG). The basis for this effect is uncertain. In as much as the substitution of SFC for DRC increases the energy density of the diet, it follows that to the extent that time allowed at the feed bunk is restricted, the substitution could result in greater energy intake and hence, growth-performance. Although feedlot cattle frequent the feed bunk on multiple occasions throughout the day, the actual time speJnt consuming feed is less than 2 hours [57].
The objective of this experiment was to evaluate how feed access (either ad libitum or restricted) affects the feeding value of steam-flaked and dry rolled corn as assessed based on growth-performance measures in feedlot steers.

MATERIAL AND METHODS

Diets, animals, and experimental design

All procedures involving animal care and management were in accordance with and approved by the University of California, Davis, Animal Use and Care Committee.
Ninety-six crossbreed steers (251±2 kg) were utilized to evaluate the influence of substituting SFC for DRC on feedlot cattle growth performance when cattle are allowed either ad libitum or 2-h restricted access to the finishing diet during to the initial 56 d of the finishing phase. Upon arrival, steers were vaccinated against infectious bovine rhinotracheitis, bovine viral diarrhea (type 1 and 2), parainfluenza 3 virus, and bovine respiratory syncytial virus (Cattle Master Gold FP 5 L5, Zoetis, New York, NY, USA), clostridia (Ultrabac 8, Zoetis, USA), treated against internal and external parasites (Dectomax, Zoetis, USA), injected with 1,500 IU vitamin E (as d-alpha-tocopherol) 500,000 IU vitamin A (as retinyl-palmitate) and 50,000 IU vitamin D3 (Vital E-AD, Stuart Products, Bedford, TX, USA), and 300 mg tulathromycin (Draxxin, Zoetis, USA). Following a 45-d receiving period, steers were implanted with Synovex C (Zoetis, USA), blocked by weight into four groups and randomly assigned within weight groupings to 16 pens (six steers per pen). Pen areas were 62 m2 with 25 m2 overhead shade, automatic waterers, and 2.44 m fence-line feed bunks (41 cm/steer linear bunk space). Treatments consisted in two finishing diets (Table 1) containing 77.1% corn grain (dry matter [DM] basis) processed by either dry rolling or steam flaking. Dry rolled corn was prepared by passing corn through rollers that had been adjusted so that kernels were broken to a density of 0.50 kg/L. Steam-flaked corn was prepared as follows: A chest situated directly above the rolls (46×61 cm, corrugated) was filled to capacity (440 kg) with corn and brought to a constant temperature (102°C) at atmospheric pressure using steam (boiler pressure 6.89 kPa). The corn was steamed for 25 min before starting the rolls. Tension on the rolls was adjusted to provide a flake density of 0.36 kg/L. Retention time of grain in steam chamber was set at approximately 25 min. The SFC was allowed to air-dry before incorporation into the complete mixed diet. Feeding management treatments were: i) ad libitum (24 hours feed access), or ii) restricted (2 hours feed access). Steers were provided fresh feed twice daily at 06:00 and 14:00 h, allowing for approximately 5% residual. In the case of steers provided ad libitum access to feed, refusals were collected and weighed prior to the morning for determination of daily feed intake. In the case of restricted steers, access to feed was limited 1 h following each feeding, after which residual feed was withdrawn. The DM content (method 930.15 [8]) of feed and feed refusal was determined daily. All steers were provided ad libitum access to water. The experiment lasted 56 days.

Calculations

Energy gain (EG, Mcal/d) was calculated by the equation: EG = 0.0557SBW0.75×ADG1.097; where EG is the daily deposited energy and shrunk body weight (SBW) is the average body weight×0.96 [9]. Maintenance energy (ME), Mcal/d) was calculated by the equation: ME = 0.077SBW0.75 [10]. From the derived estimates of net energy required for maintenance and gain, the NEm and NEg values of the diet were obtained using the quadratic formula:
x=(-b-b2-4ac)/2c
Where x = diet NEm, Mcal/kg, a = −0.41ME, b = 0.877ME+ 0.41DMI+EG, and c = −0.877DMI, and NEg = 0.877NEm − 0.41 [11].

Statistical analysis

The trial was analyzed as a randomized complete block design with a 2×2 factorial arrangement of treatments, using pens as experimental units according to the following statistical model: Yij = μ+Bi+Tjij, where μ is the common experimental effect, Bi represents initial weight block effect, Tj represent dietary treatment effect, and ɛij represents the residual error. Performance data were determined considering initial and final shrunk (live weight reduced 4% to account for digestive tract fill) weight. Treatments effects were separated by means of the following orthogonal polynomials: i) Corn processing (steam flaked vs dry rolled), ii) feeding system (ad libitum vs restricted), and iii) the corn processing× feeding system interaction. Significant difference was considered when the p-value was ≤0.05 and tendencies when p>0.05≤0.10. Data were analyzed using the MIXED procedure of SAS [12].

RESULTS AND DISCUSSION

Treatment effects on growth performance and estimated dietary NE of steers are shown in Table 2. There were no treatment interactions on dry matter intake (DMI), ADG, feed efficiency (G:F), or dietary NE. There was a feeding management by corn processing interaction (p = 0.05) on the within-pen standard deviation (SD) in steers ADG. Under condition of ad libitum feed access, the SD for within-pen ADG was greater in steers fed DRC- vs SFC-based diets. In contrast, under conditions of restricted feed access the SD for within-pen ADG was greater for SFC- vs DRC-based diets. The basis for these differences in within-pen ADG is not certain. Daily weight gain is closely associated with energy intake [13]. Accordingly, variation in ADG can be interpreted as a reflection of variation in DMI. Limit feeding programs where the daily amount of feed provided was restricted by 5% to 10% has in some instances [14,15] decreased within-pen variation in ADG. Whereas, in other cases [16,17] limiting the amount of feed provided did not affect within-pen variation in ADG. As dietary treatments allow for growth rates that more closely approximate genetic potential, it is expected that variation in ADG will diminish. This effect is apparent for steers with ad libitum access to feed. Conversely, when feeding management restricts the animal’s ability to achieve its genetic potential greater variation in individual ADG is expected due to differences in individual feeding activity (aggression at the feed bunk). Management restrictions resulting in marked reductions in both ADG and within pen SD for ADG (as was the case with restricted access time to the DRC-based diet), may reflect generalized subclinical acidosis [5].
In the present study, the amount of feed provided was not restricted. Instead, we evaluated how the amount of time allotted to consume feed affects growth-performance responses to DRC- vs SFC-based diets. The amount of time feedlot cattle spend actually consuming feed has been a recurring research topic, with estimates of average consumption rates ranging from 0.075 to 0.400 kg/min [5,6,1820]. Differences in feeding rates seem to be largely a function of how the assessment is done (for example, time spent at, or in close proximity to the feed bunk vs time spent with the head in the feed bunk). Based on radio telemetry (measuring time spent when the cattle head comes with 50 cm of the outside edge of the feed bunk), cattle spent a total of 32±5 min/d consuming 12.2 kg of a barley-based finishing diet [5]. Rate of feed consumption averaged 0.38 kg/min, with an average feeding frequency of 7.1±0.6 visits/d to the feed bunk. Applying a similar approach, Schwartzkopf-Genswein et al [6] observed that over a 153-day finishing period, steers spent a total of 106±5 min/d consuming 8.2 kg of a steam-rolled barley-based diet. The rate of feed consumption averaged 0.077 kg/min, with an average feeding frequency of 9±0.2 visits/d to the feed bunk. In contrast, Golden et al [7], using the same technique, observed that steers spent an average of 51 min/d consuming 7.1 kg of a whole corn-based finishing cattle diet. The rate of feed consumption averaged 0.14±0.03 kg/min, with an average feeding frequency of 16±3 visits/d to the feed bunk. From the above, it is apparent that for feedlot cattle fed high-grain finishing diets, frequency of visits to the feed bunk can be quite variable. Nevertheless, in these studies the total time spent consuming feed will be less than two hours, with rate of feed consumption being partly dependent on differences in total feed consumed. In the present experiment, bunk space was sufficient (41 cm/head) to allow all steers access to the feed bunk at the same time. Notwithstanding, restricting access to feed to two periods of one hour each resulted in a marked reduction (p<0.01) in DMI, and hence, ADG.
Consistent with previous work [3], the substitution of SFC for DRC increased (p<0.01) ADG, G:F, and estimated dietary NE, without affecting (p = 0.50) DMI. Given that the NEm value for DRC is 2.18 Mcal/kg [21], the estimated NEm value for SFC using the replacement technique, averaged 2.44 Mcal/kg; an improvement of 10.7%. This result is in agreement with the 11.3% average increase in the NEm value of SFC vs DRC reported in a 12-trial summary [3].
Compared with ad libitum feed access, restricting feed access to 2 h/d markedly decreased (18%, p<0.01) DMI, and hence, ADG (27%, p<0.01), and G:F (12%, p = 0.02). However, the ratio of observed-to-expected dietary NE was not affected (p = 0.50). Hence, daily gain and feed efficiency were predictable functions of differences in dietary NE and observed DMI. As indicated previously, provided all steers simultaneously feed at the bunk (as was the case in this study), the restriction of feed access time, per se, to 2 h/d should not have limited steer’s ability to consume sufficient feed to achieve its growth potential. Hence, changes in growth-performance between ad libitum vs restricted feed access time may reflect the importance of meal size and frequency of feeding (not measured in this study).
Why the substitution of SFC for DRC results in greater energy intake is not certain. Using diet formulations comparable to those fed in the present study, Plascencia et al [20] observed that rate of consumption of DRC-based diets was actually slightly greater (14%, p = 0.02) than that of SFC-based diets, averaging 0.107 and 0.097 kg/min. It follows then that independently of corn processing, 6 kg of DM (average of DM intake observed with ad libitum feeding; Table 2) could have been consumed in a total of 60 min (6 kg×0.10 kg/min). Hence, the lack of increased intake of the DRC-based diet sufficient to compensate for its lower energy density was not a simple function of feed access time. Furthermore, there was no interaction (p = 0.89) between grain processing and feed access time on comparative intake of the DRC- and SFC-based diets.

CONCLUSION

In conclusion, the substitution of steam-flaked corn for dry rolled corn in finishing diets for feedlot cattle will enhance ADG, G:F, and the NE value of the diet. Although restriction of feed access time depressed DMI and ADG, it did not influence the comparative benefit of steam flaking toward enhancement of dietary NE and ADG.

Notes

CONFLICT OF INTEREST

We certify that there is no conflict of interest with any financial organization regarding the material discussed in the manuscript.

Table 1
Composition of experimental diets (DM basis)1)
Items Corn processing

Dry rolled Steam-flaked
Ingredient composition (% DM)
 Dry rolled corn 77.10 0.00
 Steam-flaked corn 0.00 77.10
 Rice straw 5.00 5.00
 Alfalfa hay 5.00 5.00
 Yellow grease 3.50 3.50
 Cane molasses 5.00 5.00
 Fishmeal 1.50 0.00
 Urea 0.60 1.00
 Laidlomycin (mg/kg) 12.20 12.20
 Limestone 1.34 1.50
 Dicalcium phosphate 0.36 0.50
 Magnesium oxide 0.20 0.20
 Tracemineralized salt2) 0.40 0.40
Nutrient composition (%)3)
 NEm (Mcal/kg) 2.10 2.24
 NEg (Mcal/kg) 1.44 1.57
 Crude protein (%) 11.5 11.5
 NDF (%) 13.4 13.45
 Calcium (%) 0.80 0.80
 Phosphorus (%) 0.38 0.36

DM, dry matter; NEm, net energy of maintenance; NEg, net energy for gain; NDF, neutral detergent fiber.

1) Diets formulations were balanced for crude protein, estimated metabolizable protein, Ca and P per kg dry matter intake [21].

2) Trace mineral salt contained: 0.052% KI; 0.68% CoSO4; 1.04% CuSO4; 1.07% MnSO4; 1.24% ZnO4; 3.57% FeSO4; 92.96% NaCl.

3) Calculated based on tabular NE values for individual feed ingredients [21].

Table 2
Influence of corn processing and time period of feed access on growth performance and dietary energy of feedlot steers
Items Treatments1) SEM p value


SFC-24h DRC-24h SFC-2h DRC-2h SFC vs DRC 24 h vs 2 h Processing× feed access
Days on fed 56 56 56 56 - - - -
Pens 4 4 4 4 - - - -
Weight (kg)2)
 Initial 251.9 252.1 249.0 252.8 0.91 - - -
 Final 327.1 319.0 308.1 296.7 3.10 0.02 <0.01 0.61
Weight gain (kg/d) 1.34 1.19 1.06 0.78 0.06 <0.01 <0.01 0.33
DM intake (kg/d) 6.10 5.99 5.01 4.85 0.19 0.50 <0.01 0.89
Gain to feed 0.221 0.200 0.212 0.160 0.008 <0.01 0.02 0.08
Observed NE (Mcal/kg)
 Maintenance 2.18 2.05 2.22 1.96 0.04 <0.01 0.55 0.12
 Gain 1.50 1.39 1.54 1.31 0.04 <0.01 0.55 0.12
NE, observed-to-expected3)
 Maintenance 0.97 0.98 0.99 0.93 0.02 0.20 0.50 0.11
 Gain 0.96 0.97 0.99 0.91 0.02 0.20 0.49 0.11
Means for SD for ADG 0.238 0.366 0.301 0.224 0.044 0.59 0.40 0.05

SFC, steam-flaked corn; DRC, dry rolled corn; SEM, standard error of the mean; DM, dry matter; NE, net energy; SD, standard deviation; ADG, average daily gain.

1) SFC-24h, diet with steam flaked corn accessed all day; DRC-24h, diet with dry-rolled corn allowed during all day; SFC-2h, diet with steam flaked corn accessed 2 hours only per day; DRC-2h, diet with dry-rolled corn allowed during 2 hours day.

2) Initial and final weights were reduced by 4% to account for digestive tract fill.

3) Expected diet NE based on tabular values for individual dietary ingredients [21].

REFERENCES

1. Huntington GB. Starch utilization by ruminants: from basics to the bunk. J Anim Sci 1997; 75:852–67.
crossref pmid
2. Zinn RA, Owens FN, Ware RA. Flaking corn: processing mechanics, quality standards, and impacts on energy availability and performance of feedlot cattle. J Anim Sci 2002; 80:1145–56.
crossref pmid
3. Zinn RA, Barreras A, Corona L, Owens FN, Plascencia A. Comparative effects of processing methods on the feeding value of corn in feedlot cattle. Nutr Res Rev 2011; 24:183–90.
crossref pmid
4. Barajas R, Zinn RA. The feeding value of dry rolled steam-flaked corn in finishing diets for feedlot cattle: influence of protein supplementation. J Anim Sci 1998; 76:1744–52.
crossref pmid
5. Gibb DJ, McAllister TA, Huisma C, Wiedmeier RD. Bunk attendance of feedlot cattle monitored with radio frequency technology. Can J Anim Sci 1998; 78:707–10.
crossref
6. Schwartzkopf-Genswein KS, Beauchemin KA, Gibb DJ, et al. Effect of bunk management on feeding behavior, ruminal acidosis and performance of feedlot cattle: a review. J Anim Sci 2003; 81:Suppl 2E149–E58.

7. Golden JW, Kerley MS, Kolath WH. The relationship of feeding behavior to feed efficiency in crossbred Angus steers traditional and no roughage diets. J Anim Sci 2008; 86:180–6.
crossref pmid
8. AOAC. Official Methods of Analysis. 17th edAssociation of Official Analytical Chemists. Gaithersburg, MD: AOAC International; 2000. p. 69

9. Committee on Nutrient Requirement of Beef Cattle, National Research Council. Nutrient requirements of beef cattle. 6th edWashington, DC: National Academy Press; 1984.

10. Garrett WN. Energetic efficiency of beef and dairy steers. J Anim Sci 1971; 32:451–6.
crossref
11. Zinn RA, Shen Y. An evaluation of ruminally degradable intake protein and metabolizable amino acid requirements of feedlot calves. J Anim Sci 1998; 76:1280–9.
crossref pmid
12. SAS. User’s guide: statistics version SAS/STAT 9. 6th edCary, NC: SAS Inst., Inc; 2000.

13. Lofgreen GP, Garrett WN. A system for expressing net energy requirements and feed values for growing and finishing beef cattle. J Anim Sci 1968; 27:793–806.
crossref
14. Hicks RB, Owens FN, Gill DR, Martin JJ, Strasia CA. Effects of controlled feed intake on performance and carcass characteristics of feedlot steers and heifers. J Anim Sci 1990; 68:233–44.

15. Pritchard RH, Bruns KW. Controlling variation in feed intake. J Anim Sci 2003; 81:Suppl 2E133–E8.

16. Zinn RA. Influence of fluctuating feed intake on feedlot cattle growth-performance and digestive function. In : 9th Proceedings Southwest Nutrition Management Conference; 1994 February 26–27; Tucson, AZ. p. 77–83.

17. Soto-Navarro SA, Krehbiel CR, Duff GC, et al. Influence of feed intake fluctuation and frequency of feeding on nutrient digestion, digesta kinetics, and ruminal fermentation profiles in limit-fed steers. J Anim Sci 2000; 78:2215–22.
crossref pmid
18. Welch JG, Hooper AP. Ingestion of feed and water. Church DC, editorThe ruminant animal: digestive physiology and nutrition. Upper Saddle River, NJ: Prentice-Hall; 1988. p. 108–16.

19. Grant RJ, Albright JL. Feeding behavior. D’Mello JFP, editorFarm animal metabolism and nutrition. New York, NY: CABI Publishing; 2000. p. 365–82.
crossref
20. Plascencia A, Bermúdez R, Cervantes M, et al. Influence of processing method on comparative digestion of white corn vs. conventional steam-flaked yellow dent corn in finishing diets for feedlot steers. J Anim Sci 2011; 89:136–41.
crossref pmid
21. Committee on Nutrient Requirement of Beef Cattle, National Research Council. Nutrient requirements of beef cattle. 7th rev edWashington, DC: National Academy Press; 2000.

TOOLS
METRICS Graph View
  • 1 Crossref
  •  0 Scopus
  • 4,833 View
  • 98 Download
Related articles


Editorial Office
Asian-Australasian Association of Animal Production Societies(AAAP)
Room 708 Sammo Sporex, 23, Sillim-ro 59-gil, Gwanak-gu, Seoul 08776, Korea   
TEL : +82-2-888-6558    FAX : +82-2-888-6559   
E-mail : jongkha@hotmail.com               

Copyright © 2020 by Asian-Australasian Journal of Animal Sciences. All rights reserved.

Close layer
prev next