Schinkel_2015_Effect of 2 net energy feeding programs in combination with ractopamine on grow-finish pig growth performance and carcass characteristics

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The Professional Animal Scientist 31 (2015):504-515; http://dx.doi.org/10.15232/pas.2015-01449 ©2015 American Registry of Professional Animal Scientists Effect of 2 net energy feeding programs in combination with ractopamine on grow-finish pig growth performance and carcass characteristics A. P. Schinckel,*1 PAS, W. Steyn,t E. C. Allen,* C.A.P. Garbossa,* J.M. Eggert,t and B. T. Richert* *Department of Animal Sciences, Purdue University, Lilly Hall, 915 West State Street, West Lafayette, IN 47907-2054; and Norsvin USA, Burnsville, MN 55337 ABSTRACT greater (PEvaluation of high and low net energy diets in pigs 505 needed for maximal protein accretion ported by trailer to the Swine Envi- in the percentage of wheat middlings (Campbell and Taverner, 1988; Wil- ronmental Research Building at the (from 5 to 20%) and soybean hulls (2 liams et al., 1994). A small reduction Animal Science Research and Educa- to 7.9%) from grower 1 to finisher 2 in daily energy intake of barrows may tion Center for trial at 24 d of age, with no RAC. The LE finisher 2 diet improve their efficiency of energy assigned to pens with 10 pigs per pen with RAC contained 4% soybean hulls utilization above 90 kg of BW. (1.83 m X 2.44 m), and fed common and 10% wheat middlings and con- Carcass weight gain is economically nursery diets. Then, after a nursery tained 2,385 kcal/kg. important because most pork proces- period of 34 d, pigs were weighed and The difference in the NE content sors pay producers based on carcass allotted to the experimental treat- of the diets increased from grower 1 weight. One disadvantage of diets ments. A total of 200 crossbred bar- to finisher 2 because based on prior with increased fiber concentrations is rows (TOPIGS Tempo X TOPIGS 20, data, the daily feed and energy in- their effect of reducing carcass weight Topigs Norsvin USA, Burnsville, MN) takes for these pigs is more limiting at gain by reducing DP (Kennelly and were blocked by BW (28.4 ± 0.02 the beginning (grower 1) and less at Aherne, 1980; Pond et al., 1988; Xu kg), housed 5 barrows per pen, and the other phases. The energy concen- et al., 2010a). Ractopamine (RAC) is randomly allocated to 1 of 4 treat- trations of the LE diets were targeted a feed additive that increases carcass ments (10 pens per treatment) in a 2 to result in more optimal NE intakes lean gain and DP (Schinckel et al., X 2 factorial arrangement, with 2 NE relative to that required for maximum 2003b). It is possible that the reduc- levels (control low, LE) and with lean gain and protein deposition at tion of the fiber content of the diets or without 7.5 mg/kg of ractopamine each phase. and feeding of RAC the last 21 d hydrochloride during the last 21 d of The NDF content of the control before market may result in increased the 105-d feeding trial. Within each diets increased from 13.3 to 13.5% carcass weights in pigs previously fed block, pens (1.83 m X 2.44 m) were from grower 1 to finisher 1 diets. The low energy, high fiber diets. randomly assigned to 1 of 4 dietary finisher 2 control diets with 0 and 7.5 The feeding of corn distillers dried treatments. Pens had totally slatted mg/kg of RAC contained 11.44 and grains with solubles (DDGS) has concrete floors with ad libitum access 11.09% NDF. The NDF content of the increased awareness of carcass fat to a single-hole self-feeder and nipple low energy diets increased from 15.44 quality and iodine levels (Whitney waterer. Rooms were mechanically to 20.78% from grower 1 to finisher et al., 2006; White et al., 2009; Xu ventilated, and a minimum tempera- 1 diets. The finisher 2 low energy et al., 2010b). The energy density of ture of 18.3 to 20°C was maintained. diets with 0 and 7.5 mg/kg of RAC the diet, including crude fiber con- There were five 21-d nutritional contained 22.44 and 15.95% NDF, tent, has been shown to affect the phases (grower 1, grower 2, grower 3, respectively. fatty acid composition of fat tissue in finisher 1, and finisher 2 with or with- Individual BW and pen feed intake pigs (Bee et al., 2002). The effect of out RAC). The diets were formulated data were collected every 21 d cor- feeding corn DDGS in combination on equal standardized ileal digestible responding to diet changes. The day with high and low NE diets on belly lysine:NE ratio (Table 1 and 2) for before slaughter, pigs were scanned fat iodine values (IV) has not been each phase using ingredient NE values ultrasonically using an Aloka 500v reported. from the NRC (2012). The lysine:NE linear array ultrasound unit with a The objectives of this study were ratios used were based on previ- 3.5-MHz, 17-cm linear probe (Coro- (1) to evaluate the BW growth, en- ous research on the lysine require- metrics Medical Systems, Wallingford, ergy intakes, and energetic efficiency ments of pigs (TOPIGS, 2013). The CT) to obtain measurements of 10th- of high growth barrows fed high and control grower diets and finisher 1 rib backfat depth and LM area. low energy density diets during the diets contained 20% DDGS and were Pigs were transported to a com- grow-finisher phases; (2) to evaluate typical of those used in the United mercial pork processor at 163 of the effect of feeding RAC when pigs States. The finisher 2 diet contained age, and HCW was recorded. Car- were previously fed either high and 10% DDGS as a means to reduce the casses were measured with an opti- low energy diets; (3) to evaluate the effect of DDGS on fat quality (Xu et cal probe (Fat-O-Meter, Carometec, economic returns of the alternative al., 2010a). The NE content of the Herlev, Denmark) between the third feeding strategies; and (4) to evaluate control diets increased from 2,462 and fourth ribs anterior of the last dietary differences in carcass fat IV. kcal/kg (grower 1) to 2,536 kcal/kg rib. Percent lean was predicted by (finisher 2 with no RAC). The con- the equation percent lean = 54.67 MATERIALS AND METHODS trol diet with RAC was high energy - (0.4125 X backfat depth, mm) - (2,637 kcal/kg) with 4.0% added fat. (0.00656 X carcass weight) + (0.14332 Experimental Design The energy content of the LE diets X muscle depth, mm). decreased from 2,461 kcal/kg (grower At the commercial pork processor All procedures were approved by 1) to 2,319 kcal/kg (finisher 2 with no an approximate 5 cm X 5 cm sample Purdue University Animal Care and RAC). This decrease in NE content was collected from the anterior por- Use Committee. Barrows were trans- was primarily caused by the increase tion of the belly proximal to the mid-506 Schinckel et al. line split and below the teat line. The weight gain was estimated as the final variables up to 84 d on test were sample was cut as thick as possible carcass weight of the pig minus its evaluated for the effect of the dietary to contain only fat tissue and not any initial BW times 0.75. Total feed cost energy treatments. Growth and feed lean tissue. The fat tissue samples and income over feed cost were calcu- intake data from 84 to 105 d, overall were analyzed via near infrared spec- lated for each pen. The carcass price data, and final carcass data were ana- troscopy. Fat IV values were predicted of $1.984/kg was the actual price lyzed as a factorial arrangement (2 X using a Bruker NIR (Bruker Multi- when the pigs were marketed. 2) of energy concentration and RAC Purpose Analyzer; Bruker Daltonics, treatments. Bremen, Germany) integrating sphere Statistical Analysis The BW data were fitted to a gen- using a regression equation developed eralized Michaelis-Menten (GMM) from gas chromatography fatty acid Pen was used as the experimental equation (Lopez et al., 2000; Schinckel analysis. unit (n = 40) for statistical analysis et al., 2009a). The equation has 2 Feed costs were estimated as the of all live animal and carcass mea- alternative forms, = mean prices for each feed ingredient surements. Data were analyzed as a + + + or WT from May to September 2013. Feed complete block design using the GLM = WT₀ + {(WF costs were estimated for each pen for procedure of SAS (SAS Institute Inc., + + where WF is mean each 21-d period and overall. Carcass Cary, NC). Growth and feed intake mature BW, WT₀ is the mean birth Table 1. Diet composition for d 0 to 84 grow-finish diets Control diet Low energy diet Item Grower 1 Grower 2 Grower 3 Grower 1 Grower 2 Grower 3 % Corn NRC 50.120 60.222 66.520 43.795 48.907 49.390 Soybean meal 23.400 15.250 9.850 21.800 12.220 6.950 Soy hulls 0.00 0.00 0.00 2.00 4.00 5.00 DDGS, 7.5% fat 20.00 20.00 20.00 20.00 20.00 20.00 Swine grease 2.70 1.100 0.500 3.650 1.650 0.950 Limestone 1.61 1.470 1.400 1.630 1.470 1.390 Monocal 0.67 0.500 0.410 0.580 0.280 0.080 Vitamin 0.15 0.150 0.125 0.150 0.150 0.125 Trace mineral 0.10 0.100 0.080 0.100 0.100 0.080 Phytase 0.10 0.100 0.100 0.100 0.100 0.080 Salt 0.35 0.350 0.300 0.350 0.350 0.300 Wheat middlings 0.00 0.000 0.000 5.00 10.00 15.00 Lysine-HCL 0.40 0.400 0.420 0.430 0.420 0.400 DL-Methionine 0.080 0.040 0.020 0.090 0.040 0.000 L-Threonine 0.110 0.100 0.090 0.125 0.100 0.080 L-Tryptophan 0.030 0.030 0.035 0.025 0.025 0.025 Chlortetracycline-50 0.100 0.100 0.000 0.100 0.100 0.000 Tylan 40 0.000 0.000 0.050 0.000 0.000 0.050 Rabon 0.025 0.038 0.050 0.025 0.038 0.050 Se 600 0.050 0.050 0.050 0.050 0.050 0.050 Total 100.00 100.00 100.00 100.00 100.00 100.00 Calculated composition ME, kcal/kg 3,414 3,354 3,339 3,410 3,286 3,235 NE, kcal/kg 2,462 2,452 2,469 2,461 2,391 2,366 SID² Lys, % 1.154 0.955 0.837 1.154 0.931 0.802 SID Lys/NE 4.688 3.893 3.390 4.688 3.892 3.391 Ca, % 0.84 0.73 0.67 0.84 0.71 0.64 Available P, % 0.40 0.35 0.32 0.40 0.34 0.31 NDF, % 13.30 13.44 13.49 15.44 17.86 19.71 Fat, % 6.96 5.51 4.99 7.85 6.00 5.39 Cost, $/kg 0.3735 0.3360 0.3225 0.3697 0.3181 0.2934 40 (Elanco Animal Health, Greenville, IN); Rabon (Bayer Health Care, Animal Health Division, Shawnee Mission, KS). = standardized ileal digestible.Evaluation of high and low net energy diets in pigs 507 Table 2. Diet composition for the finisher diets and ractopamine d 84 to 105 Control diets Low energy diets Item Finisher 1 Finisher 2 Finisher 2¹ Finisher 1 Finisher 2 Finisher 2¹ Ingredient,² % Corn 70.590 79.350 68.392 49.280 55.22 63.752 Soybean meal 6.100 7.600 14.430 5.000 5.000 9.460 Soy hulls 0.000 0.000 0.000 6.000 7.900 4.000 DDGS, 7.5% fat 20.00 10.00 10.00 20.00 10.00 10.00 Swine grease 0.500 0.500 4.000 0.510 0.000 0.000 Limestone 1.260 1.030 1.120 1.160 0.960 1.100 Monocal 0.250 0.350 0.450 0.000 0.000 0.180 Vitamin 0.125 0.100 0.150 0.125 0.100 0.150 Trace mineral 0.080 0.050 0.090 0.080 0.050 0.090 Phytase 0.100 0.100 0.100 0.050 0.050 0.080 Salt 0.300 0.300 0.300 0.300 0.300 0.300 Wheat middlings 0.000 0.000 0.000 17.000 20.000 10.000 Lysine-HCL 0.420 0.350 0.390 0.315 0.260 0.380 DL-Methionine 0.010 0.030 0.100 0.000 0.000 0.060 L-Threonine 0.105 0.110 0.160 0.045 0.050 0.135 L-Tryptophan 0.035 0.030 0.030 0.010 0.005 0.025 Chlortetracycline-50 0.000 0.000 0.000 0.000 0.000 0.000 Tylan 40 0.025 0.000 0.000 0.025 0.000 0.000 Rabon 0.050 0.050 0.050 0.050 0.050 0.050 Paylean 7.5 mg/kg 0.000 0.000 0.1875 0.000 0.000 0.1875 Se 600 0.050 0.050 0.050 0.050 0.050 0.050 Total 100.00 100.00 100.00 100.00 100.00 100.00 Calculated composition ME, kcal/kg 3,351 3,366 3,508 3,204 3,157 3,238 NE, kcal/kg 2,505 2,536 2,637 2,343 2,319 2,385 SID³ Lys, % 0.744 0.701 0.894 0.697 0.642 0.808 SID Lys/NE 2.970 2.764 3.390 2.976 2.769 3.389 Ca, % 0.580 0.510 0.580 0.540 0.470 0.540 Available P, % 0.280 0.250 0.280 0.260 0.230 0.260 NDF, % 13.50 11.44 11.09 20.78 20.44 15.95 Fat, % 5.04 4.62 7.90 4.98 4.05 4.04 Cost, $/kg 0.3049 0.3036 0.3874 0.2718 0.2577 0.3274 ¹This set of diets contained ractopamine hydrochloride (Paylean; Elanco Animal Health, Greenville, IN). 40 and Paylean (Elanco Animal Health, Greenville, IN); Rabon (Bayer Health Care, Animal Health Division, Shawnee Mission, KS). = standardized ileal digestible. BW, i is the ith pig, t is days of age, The BW data (all except when where is the residual value of the K is a parameter equal to the days of RAC was fed) were fitted to the ith pig at age t, n is the number of age in which one-half WF is achieved, GMM function using the nonlinear observations, and p is the number of and C is a unitless parameter related mixed (NLMIXED) procedure of SAS. parameters in the model. The NL- to changes in proportional growth and Random effects were added in a MIXED procedure provided predicted shape of the growth curves (Lopez et stepwise order based on Akaike's values for the random effect of each al., 2000). In this function, a mean information criteria values. The R² pig, variance estimates for each value of 1.5 kg was used for birth BW values were calculated as squared random effect, covariance estimates This function has an inflection correlations between the predicted for each pair of random effects, and point age (IP, d) = 1)/(C+ and actual observations. The relative the residual variance. and the BW at the IP = {[1 SD (RSD) was calculated with the The pen daily feed and NE intake + (1/C)]WT₀ + [1 (1/C)]WF}/2. equation data (all data except when RAC was In this function, WF, K, and C were fed) were fitted to a nonlinear func- considered as random effects. RSD , tion of mid-BW of each pen for each508 Schinckel et al. period. The Bridges function DFI ing to decreasing relative to BW is each pig in the pen. The BW gain:NE = C[1 - + was called the inflection point (IP) and is intakes above maintenance were calcu- proposed by Bridges et al. (1986). equal to DFI times F, where F = 1 lated using predicted maintenance Here BW is mid-BW (kg) of the ith exp[(1/A) 1]. The BW at the IP = requirements (NE for maintenance, pen; C is the average mature daily [AM/(A - In this function, Mcal/d = Noblet et al., feed intake (DFI), or NE intake; C, M', and A were considered as pen- 1999). M is the exponential growth decay specific effects. constant; and A is the kinetic order Feed efficiency (G:F) was predicted RESULTS AND DISCUSSION constant. Because the exponential for each pen as the ratio of mean pre- decay parameter was close to zero, dicted ADG (kg/d) for each pig in the The growth performance data for the model was reparametrized (M' pen divided by the pen predicted DFI the first 4 periods (d 0 to 84) are = log M) with the form DFI = (kg/d). Net energy efficiency (gain:NE presented in Table 3. For grower 1, C{1 (Craig intake) was predicted for each pen pigs fed the control diets had 7.8% and Schinckel, 2001; Schinckel et al., as the ratio of mean predicted ADG greater ADG (P = 0.001), 5.56% 2009b). In this function, the BW at (kg/d) for each pig in the pen divided greater ADFI (P = 0.002), and 5.5% which the rate of daily feed, or NE, by the predicted pen daily NE intake greater daily NE intakes (P = 0.002) intake changes from being increas- (kg/d) from the GMM function for than pigs fed the LE diets. For grower 1, both F:G (0.508 0.497, P = 0.11) and NE efficiency were similar for the pigs fed the control and LE Table 3. Effect of dietary net energy level from d 0 to 84 on grow-finish diets (0.2065 0.2022, respectively, pig growth performance P = 0.11). For grower 2, ADFI, ADG, and G:F Item Control Low energy SE Probability were similar (P > 0.15) for pigs fed Grower 1, d 0-21 the control and LE diets. In grower d-0 BW, kg 28.38 28.43 0.023 0.14 2, pigs fed the LE diet had lesser d-21 BW, kg 48.36 47.01 0.284 0.002 NE intakes (6.64 6.82 Mcal/d, P ADG, kg/d 0.950 0.881 0.014 0.001 = 0.043) and greater NE efficiency ADFI, kg/d 1.877 1.778 0.021 0.002 (0.1537 0.1496) than pigs fed the NE intake, Mcal/d 4.62 4.38 0.051 0.002 control diet. G:F 0.508 0.497 0.0045 0.108 For grower 3, pigs fed the control Gain:NE intake 0.2065 0.2032 0.002 0.11 diets had 5.0% greater daily NE in- Grower 2, d 21-42 takes (P = 0.003), 3.3% greater ADG ADG, kg/d 1.038 1.067 0.015 0.18 ADFI, kg/d 2.782 2.776 0.025 0.88 (P = 0.025), and 2.7% greater G:F (P NE intake, Mcal/d 6.82 6.64 0.061 0.043 = 0.059) than pigs fed the LE diets. G:F 0.374 0.384 0.0047 0.15 In periods 3, pigs fed the control and Gain:NE intake 0.1529 0.1609 0.0013 0.006 the LE diets had similar NE efficiency d-42 BW, kg 70.11 69.41 0.383 0.20 (0.1387 0.1407, P = 0.34). Grower 3, 42-63 For finisher 4, pigs fed the control ADG, kg/d 1.098 1.063 0.011 0.025 diets had 9.0% greater ADG (P = ADFI, kg/d 3.220 3.201 0.034 0.69 0.0003), 3.36% greater ADFI (P = NE intake, Mcal/d 7.95 7.57 0.082 0.003 0.059), 10.4% greater daily NE in- G:F 0.342 0.333 0.0035 0.059 Gain:NE intake 0.1387 0.1407 0.0014 0.34 takes (PEvaluation of high and low net energy diets in pigs 509 At the end of 84 d on test, pigs fed For finisher 2, pigs fed RAC had ciency (0.1217 0.1258 kg/Mcal, the control diets were 4.39 kg heaver 24.3% greater ADG (1.128 0.907 respectively, P = 0.20). Pigs fed (114.4 111.0 kg, P = 0.001). kg/d, P = 0.001) and 22.8% greater RAC for finisher 2 phase had 18.9% The pig growth data for finisher 2 G:F (0.336 VS. 0.274, P = 0.001). greater NE efficiency than pigs not period (d 84-105), overall data, and The feeding of RAC had no effect on fed RAC (0.1345 0.1131 kg/Mcal, carcass data are presented in Table 4. ADFI (3.35 3.32 kg/d, P = 0.58), P 0.23) for ADG, G:F, ADFI, and510 Schinckel et al. creases at or less than one unit when Table 5. Parameters for function fitted to BW data RAC is fed from 21 to 28 (Weber et al., 2006; Apple et al., 2007a,b). Parameter Estimate SE R² Relative SD, kg The parameters of the GMM func- Control tion describing the BW growth of WF, kg 295.9 14.8 0.9967 1.895 the pigs are shown in Table 5. Only K 177.3 7.85 a random effect for mature BW C 1.958 0.0367 was significant for the GMM function. 332.5 111 The parameters for the Bridges func- Var(e) 3.52 0.372 tion relating daily NE intakes to BW Low energy are shown in Table 6. Only a random WF, kg 264.9 11.5 0.9967 1.821 K 164.46 6.36 effect for asymptotic NE intake (c, C 1.999 0.0367 for the ith pen) was significant. The 204.0 69.1 relationships of ADG relative to BW Var(e) 3.25 0.342 for the pigs fed the control and LE diets are shown in Figure 1. The generalized Michaelis-Menten equation has the form BW = WT₀ + [(WF - + where WF is mean mature BW, wf, is a random effect for WF, relationships of daily NE intake to is the variance of the wf, values, t is age (d), K is a parameter equal to the BW are shown in Figure 2. As BW days of age in which one-half WF is achieved, C is a unitless parameter related to increased and the difference in NE changes in proportional growth and shape of the growth curves, and is birth density of the control and LE diets weight (1.5 kg). increased, the differences in ADG and daily NE intakes increased. The predicted NE efficiency (ADG:NE intake) and NE efficiency (1.70 1.49 cm, P = 0.005) and LM LM depth (60.15 56.57 mm, P above maintenance relative to BW area (50.8 48.9 cm², P = 0.008) = 0.009). Feeding RAC tended to are shown in Figures 3 and 4. The than pigs fed the LE diets. Pigs fed increase predicted percent lean (52.81 difference in predicted NE efficiency RAC had similar (P = 0.85) ultrason- 52.19%, P = 0.086). The effects was slighter greater at 30 to 40 kg of ic backfat depth as pigs not fed RAC. of RAC to increase carcass weight BW (3 to 4.5%) and then a constant Pigs fed RAC had 6.9% greater LM and LM depth are similar to that of 1.8% from 40 to 130 kg of BW. The area (51.5 48.2 P = 0.001) past research trials (Schinckel et al., efficiency of NE intake above main- than pigs fed diets without RAC. 2003b; Apple et al., 2007b). It should tenance was 4.8% greater for pigs fed There were no significant dietary en- be noted that prediction equations for the LE diets at 40 kg of BW, and the ergy-by-RAC interactions (P = 0.64). percent lean which include fat depth difference decreased to 1.8% at 60 Pigs fed the control diets had 4.54- and LM depth only predict 40 to 50% kg of BW and then increased to 3.1, kg greater carcass weight (102.79 of the actual differences in carcass 4.2, and 5% at 80, 100, and 120 kg of 98.15 kg, P = 0.001) and 1.4% greater lean percentage (Schinckel et al., BW, respectively. Overall from 30 to DP (75.63 74.23%, P = 0.001) 2003a). 130 kg of BW, the functions predicted than pigs fed the LE diets. Pigs fed Belly fat IV values were greater for the LE pigs had approximately a 3% the control diets had 1.46-mm greater pigs fed the LE diets (68.00 65.97, greater efficiency of using NE above optical probe fat depth (24.67 vs. PEvaluation of high and low net energy diets in pigs 511 1.20 BW gain were similar for pigs fed and 1.15 not fed RAC (0.938 0.930 $/kg, 1.10 P = 0.31). There were no significant 1.05 diet energy-by-RAC interactions (P 1.00 > 0.20) for the any of the economic ADG (kg) variables. 0.95 Control Carcass gain value was estimated 0.90 0.85 Low Energy as the predicted carcass weight gain times the carcass weight value per 0.80 kilogram ($1.984/kg). Pigs fed the 0.75 control diets had a $9.08 greater 0.70 carcass weight gain value than pigs 20 40 60 80 100 120 140 fed the LE diets ($161.51 vs. $152.43, Body Weight (kg) P512 Schinckel et al. 0.300 The soybean hulls increased in our 0.280 diets from 2 to almost 8% from the 0.260 grower 1 to finisher 2 diets. These ADG/NEI (kg/Mcal) 0.240 levels of soybean hull inclusion would 0.220 seem to be a less likely explanation for our reduced growth rates as recent 0.200 Control research reported no change in growth 0.180 rate, increased ADFI, and poorer feed 0.160 - Low Energy efficiency when soybean hulls were 0.140 included at 7.5 or 15% of grow-finish 0.120 diets (Goehring et al., 2012). How- 0.100 ever, earlier work by Bowers et al. 20 40 60 80 100 120 140 (2000) reported that when soybean hulls increased to 6 or 9% in the Body Weight (kg) finishing diets, pig ADG and feed effi- Figure 3. The relationship of NE efficiency [ADG/NE intake (NEI), kg/Mcal] to BW ciency were reduced by approximately for pigs fed the control and low energy diets. 6%, which may suggest a similar variability in soybean hull quality as was reported for wheat middlings by Cromwell et al. (2000). The energy concentrations of the 0.55 LE diets were decreased via increased 0.50 fiber content to reduce the energy 0.45 intake of the high feed intake, high growth barrows during the late 0.40 finishing to target the energy intakes G/NE (kg/Mcal) 0.35 needed for maximal protein accre- 0.30 Control tion. In this study, the NE concentra- tions of the LE diets may have been - 0.25 Low Energy decreased too great of an extent; the 0.20 NE values used for the by-products may have been slightly too high. Also, 0.15 the amino acid concentration or avail- 0.10 ability of the by-products may have 20 40 60 80 100 120 140 been overestimated, which reduced Body Weight (kg) the loin muscle areas and subsequent Figure 4. The relationship the efficiency of daily NE intake above maintenance to be predicted protein mass and accretion used for BW growth (G/NE is ADG/NE intake above maintenance, kg/Mcal). rates of the pigs fed the LE diets. There is considerable variability in wheat middlings across the United Table 7. Means for economic variables Control, high energy Low energy mg/kg RAC, mg/kg Probability Item 0 7.5 0 7.5 SE RAC Energy Economics, $/pig Feed cost, $ 100.29 102.98 90.78 95.60 1.29 0.007 0.001 Feed cost, $/kg gain 0.959 0.950 0.917 0.909 0.004 0.31 0.001 Carcass gain value, $ 157.47 165.55 146.86 158.00 2.13 0.001 0.001 57.17 62.56 56.07 62.39 1.54 0.001 0.68 = ractopamine. over feed costs assume carcass value of $1.984 per kilogram of carcass weight.Evaluation of high and low net energy diets in pigs 513 States (Cromwell et al., 2000), and maintenance should be greater for the late finishing phases, which were the values used in this trial for wheat pigs fed the LE diet. For example, fed in late July, August, and early middlings and potentially soybean gilts that had 4.02 mm less backfat September. It is possible that the hulls may have been slightly inac- depth and 3.3% greater fat-free lean increased heat increment of the high curate for the sources used in this percentage (52.9 49.6% fat-free fiber LE diets limited ADFI and ADG experiment lean, Schinckel et al., 2012a,b) had in the finishing phases (Coffey et al., It should be noted that a combina- approximately 13% greater gain:NE 1982; Stahly and Cromwell, 1986). tion of wheat middlings and soybean intake above maintenance. Based on It should be noted for grower 2 and hulls were added to the LE diets to the backfat differences between pigs grower 3 that the DFI were similar be representative of current feeding fed the control and LE diets, pigs fed for the control and LE pigs and for practices. The responses to dietary the LE diets should have approxi- finisher 1; DFI were slightly lower fiber are affected by the types of mately 4.72% greater gain:NE intake for the LE pigs than the control pigs. fiber. Different types of fiber have above maintenance than pigs fed the Although the diets were formulated to different water-holding capacity, rates control diets, yet only a 3% difference have equal standardized ileal digest- of fermentation, and effect on rates in gain:NE intake above maintenance ible Lys:NE content, the LE pigs for of passage, gut fill, and visceral organ was predicted. Most likely the main- the grower 2, grower 3, and finisher size (Kerr and Shurson, 2013; Lind- tenance requirements for energy are 1 phases were both limited in their berg, 2014). Repeating the trial with slightly greater for pigs fed the LE daily intake of both NE and standard- different feed ingredients with differ- diets (Wenk, 2001). Feeding of LE di- ized ileal digestible Lys (and other ent types of dietary fiber would likely ets with increased fiber concentrations essential amino acids). affect the results. can increase endogenous gut losses The income over feed costs on a The effect of RAC to increase (Mariscal-Landin et al., 1995; Nyacho- carcass-value basis were similar for growth rate, feed efficiency, carcass ti et al., 1996). It is also possible that the control and LE diets. Because weight, and LM depth are similar to viscera organ mass increased with the the feeding trial was on a constant that of past research trials (Schinckel feeding of the LE diets. Viscera mass time, the daily returns above feed et al., 2003b; Apple et al., 2007b). has approximately 3-times greater costs were also similar for pigs fed The use of RAC with the high by- maintenance requirement per kilo- the control and LE diets. The LE product based diet sequence improved than muscle mass (Noblet et diets using lower energy feed ingredi- carcass weight to be equal to that of al., 1999). ents including wheat middlings and the pigs fed the control diets through- In a recent large trial, pigs fed soybean hulls resulted in diets that out the grow-finish period and may be high energy, high fat diets (2.62 to were much lower cost per kilogram. a tool to be combined with high by- 2.68 Mcal of NE/kg, 8% fat and 11% The decreased ADG, DP, and carcass product feeding programs. Graham et NDF) had 1.3% greater NE efficiency weight of the pigs fed the LE diets al. (2014) found that RAC improved (ADG:NE intake) than pigs fed must be taken into account in estima- the carcass weights of pigs fed diets LE diets (2.36 to 2.42 Mcal of NE/ tion of the relative value of the low with 30% DDGS and 19% wheat mid- kg, 3.8 to 4% fat and 15.3 to 15.5% energy, high fiber feed ingredients to dlings. However, the carcass weights NDF, Schinckel et al., 2012a,b). The high energy ingredients including corn of pigs fed the diets containing DDGS increased fat percentage in the high and fat. and wheat middlings were still 0.82 kg energy diets in the previous trial Few trials have been published eval- lighter than the pigs fed control-corn- versus similar dietary fat percentages uating the effect of feeding high fiber soybean meal based diets. in the control and LE diets in this diets on fatty acid profiles (Salyer et The objective was to decrease the trial may partially explain the differ- al., 2012). The use of by-products in- ratio of lipid accretion to protein ac- ence in the results. The high energy, cluding DDGS, wheat middlings, and cretion in late finishing phases and high fat diets of the previous trial soybean hulls may increase the IV increase the NE efficiency of BW may have had an advantage in that value of carcass fat. In a recent trial, gain. The ADG was reduced in the the direct deposition of dietary fat the IV value of pigs fed diets based on pigs fed the LE diets in approximate to lipid accretion is an energetically corn and soybean meal was compared proportion to their decreased NE efficient process (about 90%, Noblet with pigs fed diets containing corn, intakes that there were no diet ef- and Milgen, 2004). soybean meal plus 30% DDGS (12.3% fects on net energy efficiency for the In the past trial (Schinckel et al., oil), and 19% wheat middlings. Pigs 2 finishing phases of growth. Overall, 2012a), the pigs fed the LE diets had fed the high fiber diets (19.0% NDF the LE pigs had 1.95% greater NE greater ADFI and similar NE intakes 9.2%) from 41 to 121 kg of BW efficiency, 3% greater NE efficiency (6.33 6.44 Mcal/d). In this trial (90 d) had jowl IV values of 78.5 ver- above maintenance, and 1.46 mm less the pigs fed the LE diets did not sus 68.4 for pigs fed the diets based backfat depth than the control pigs. increase their ADFI to compensate on corn and soybean meal. In the With increased carcass leanness, it is for the decreased NE content of the past, the IV value of carcass fat has expected the gain:NE intake above LE diets. This was especially true for been modeled as a linear function of514 Schinckel et al. the iodine value product of the diets Apple, J. K., P. J. Rincker, F. K. McKeith, titioning in growing pigs. Pages 137-149 in fed (Madsen et al., 1992; Zhu et al., T. A. Carr, P. A. S. Armstrong, and P. D. Modelling Growth in the Pig. EAAP publica- Matzat. 2007b. Review: Meta-analysis of the tion no. 78. EAAP, Rome, Italy. 2012). The effect of dietary fiber may Ractopamine response in finishing swine. be in addition to dietary differences in Prof. Anim. Sci. 23:179-196. de Lange, C. F. M., and H. W. E. Schreurs. iodine value product. Feeding of high 1995. Principles of model application. Pages Asmus, M. D., J. M. DeRouchey, M. D. To- 187-208 in Modelling Growth in the Pig. levels of DDGS with other by-prod- kach, S. S. Dritz, T. A. Houser, J. L. Nelssen, EAAP publication no. 78. EAAP, Rome, ucts and RAC may increase carcass and R. D. Goodband. 2014. Effects of lower- Italy. fat IV values to the point of affecting ing dietary fiber before marketing on finishing pig growth performance, carcass charac- Goehring, D. L., J. M. DeRouchey, S. S. fat quality (Whitney et al., 2006; Xu teristics, carcass fat quality, and intestinal Dritz, M. D. Tokach, R. D. Goodband, and J. et al., 2010b; Zhu et al., 2012). weights. J. Anim. Sci. 92:119-128. L. Nelssen. 2012. The effects of soybean hulls Pork producers are paid on the and their particle size on growth performance Bee, G., S. Gebert, and R. Messikommer. and carcass characteristics of finishing pigs. basis of carcass weight. Feeding the 2002. Effect of dietary energy supply and fat Kansas State University Swine Day Pub- lower cost LE diets reduced carcass source on the fat source on the fatty acid pat- lication, pp. 148-154. Kansas State Univ., weight gain and DP. Reduction of tern of adipose and lean tissues and lipogen- Manhattan. the fiber content of the final diet may esis in the pig. J. Anim. Sci. 80:1564-1574. Graham, A. B., R. D. Goodband, M. D. increase DP and result in increased Bee, G., R. Messikommer, and S. Gebert. Tokach, S. S. Dritz, J. M. De, J. M. Rouchey, carcass weight gain (Xu et al., 2010a; 1999. Dietary fats and energy levels differ- and S. Nitikanchana. 2014. The interactive ently affect tissue lipogenic enzyme activity effects of high-fat, high-fiber diets and racto- Asmus et al., 2014). The carcass in finishing pigs. Lipid/Fett 101:336-342. pamine HCI on finishing pig growth perfor- weights of the pigs fed the LE diets mance, carcass characteristics, and carcass fat and fed RAC was similar to that of Bowers, K. A., C. T. Herr, T. E. Weber, D. quality. J. Anim. Sci. 92:4585-4597. Smith, and B. T. Richert. 2000. Evaluating the pigs fed the control diets and no inclusion levels of soybean hulls in finishing Kennelly, J. J., and F. X. Aherne. 1980. The RAC. The feeding of lower cost diets pig diets. J. Anim. Sci. 78(Suppl. 1):194. effect of fiber addition to diets formulated to for most of grow-finish and then feed- (Abstr.) contain different levels of energy and protein on growth and carcass quality of swine. Can. ing of RAC with diets with reduced Bridges, T. C., U. W. Turner, E. M. Smith, J. Anim. Sci. 60:385-393. fiber content is an alternative feeding T. S. Stahly, and O. J. Loewer. 1986. A strategy that should be researched in mathematical procedure for estimating Kerr, B. J., and G. C. Shurson. 2013. Strate- animal growth and body composition. Trans. gies to improve fiber utilization in swine. J. more depth. Am. Soc. Agric. Eng. 29:1342-1347. Anim. Sci. Biotech. 4:11-22. Campbell, R. G., and M. R. Taverner. 1988. Lindberg, J. E. 2014. Fiber effects in nutri- IMPLICATIONS Genotype and sex effects on the relationship tion and gut health in pigs. J. Anim. Sci. between energy intake and protein deposition Biotech. 5:15-21. The feeding of lower energy feed in growing pigs. J. Anim. Sci. 66:676-686. Lopez, S., J. France, W. J. J. Gerrits, M. S. ingredient by-products results in re- Coffey, M. T., R. W. Seerley, D. W. Funder- Dhanoa, D. J. Humphries, and J. Dijkstra. duced rates of BW and carcass weight burke, and H. C. McCampbell. 1982. Effect 2000. A generalized Michaelis-Menten equa- of heat increment and level of dietary energy tion for the analysis of growth. J. Anim. Sci. gain, increased carcass leanness, and and environmental temperature on the per- 78:1816-1828. slightly increased IV value of the formance of growing-finishing swine. J. Anim. Sci. 54:95-105. Madsen, A., K. Jakobsen, and H. P. carcass fat. If the changes in pig per- Mortensen. 1992. Influence of dietary fat formance are taken into account, pork Craig, B. A., and A. P. Schinckel. 2001. Non- on carcass fat quality in pigs. A review. producers can estimate the relative linear mixed effects model for swine growth. Acta Agric. Scand., Section A-Anim. Sci. value of the lower energy feed ingredi- Prof. Anim. Sci. 17:256-260. 42:220-225. ents. Reduction of the fiber content of Cromwell, G. L., T. R. Cline, J.D. Crenshaw, Mariscal-Landin, G., B. Seve, Y. Colleaux, the last finishing diet and combined T. D. Crenshaw, R. A. Easter, R. C. Ewan, and Y. Lebreton. 1995. Endogenous amino C. R. Hamilton, G. M. Hill, A. J. Lewis, D. nitrogen collected from pigs with end-to- feeding of RAC should be evaluated C. Mahan, J. L. Nelssen, J. E. Pettigrew, T. end ileorectal anastomosis is affected by the to reduce the effect of the LE diets on L. Veum, and J. T. Yen. 2000. Variability method of estimation and altered by dietary carcass weight gain and final IV val- among sources and laboratories in analysis fiber. J. Nutr. 125:136-146. ues of the carcass fat tissues. Research of wheat middlings, NCR-42 committee on swine nutrition. J. Anim. Sci. 78:2652-2658. Noblet, J., C. Karege, S. Dubois, and J. van is needed to estimate the effect of Milgen. 1999. Metabolic utilization of energy dietary fiber on maintenance energy Cromwell, G. L., T. S. Stahly, and H. J. and maintenance requirements in growing Monegue. 1992. Wheat middlings in diets for pigs: Effects of sex and genotype. J. Anim. requirements. growing-finishing pigs. J. Anim. Sci. 70(Sup- Sci. 77:1208-1216. pl. 1):239. (Abstr.) Noblet, J., and J. van Milgen. 2004. Energy LITERATURE CITED Daza, A., A. I. Rey, D. Menoyo, J. M. value of pig feeds: Effect of pig body weight Bautista, A. Olivares, and C. J. López-Bote. and energy evaluation system. J. Anim. Sci. 2007. Effect of level of feed restriction during 82(E. Apple, J. K., C. V. Maxwell, J. T. Sawyer, growth and/or fattening on fatty acid compo- B. R. Kutz, L. K. Rakes, M. E. Davis, Z. B. sition and lipogenic enzyme activity in heavy NRC. 2012. Nutrient Requirements of Swine. Johnson, S. N. Carr, and T. A. Armstrong. pigs. Anim. Feed Sci. Technol. 138:61-74. 11th ed. Natl. Acad. Press, Washington, DC. 2007a. Interactive effect of ractopamine and dietary fat source on quality characteristics of De Greef, K. H., and M. W. A. Verstegen. Nyachoti, C. M., C. F. M. de Lange, B. W. fresh pork bellies. J. Anim. Sci. 85:2682-2690. 1995. Evaluation of a concept on energy par- McBride, and H. Schulze. 1996. Significance of endogenous gut nitrogen losses in theEvaluation of high and low net energy diets in pigs 515 nutrition of growing pigs: A review. Can. J. impact of feeding diets of high or low energy S. Donkin, and M. A. Latour. 2009. Feeding Anim. Sci. 77:149-163. concentration on carcass measurements and conjugated linoleic acid partially recov- the weight of primal and subprimal lean cuts. ers carcass quality in pigs fed dried corn Pond, W. G., H. G. Jung, and V. H. Varel. Asian-australas. J. Anim. Sci. 25:531-540. distillers grains with solubles. J. Anim. Sci. 1988. Effect of dietary fiber on young adult 87:157-166. genetically lean, obese and contemporary Schinckel, A. P., C. T. Herr, B. T. Richert, pigs: Body weight, carcass measurements, J. C. Forrest, and M. E. Einstein. 2003a. Rac- Whitney, M. H., G. C. Shurson, L. J. John- organ weights and digesta content. J. Anim. topamine treatment biases in the prediction ston, D. M. Wulf, and B. C. Shanks. 2006. Sci. 66:699-706. of pork carcass composition. J. Anim. Sci. Growth performance and carcass character- 81:16-28. istics of grower-finisher pigs fed high-quality Salyer, J. A., J. M. DeRouchey, M. D. To- corn distillers dried grain with solubles origi- kach, S. S. Dritz, R. D. Goodband, J. L. Nels- Schinckel, A. P., N. Li, B. T. Richert, P. V. nating from a modern Midwestern ethanol sen, and D. B. Petry. 2012. Effects of dietary Preckel, and M. E. Einstein. 2003b. Devel- plant. J. Anim. Sci. 84:3356-3363. wheat middlings, distillers dried grains with opment of a model to describe the compo- solubles, and choice white grease on growth sitional growth and dietary lysine require- Williams, N. H., T. R. Cline, A. P. Schinckel, performance, carcass characteristics, and ments of pigs fed ractopamine. J. Anim. Sci. and D. J. Jones. 1994. The impact of rac- carcass fat quality of finishing pigs. J. Anim. 81:1106-1119. topamine, energy intake, and dietary fat on Sci. 90:2620-2630. finisher pig growth performance and carcass Schinckel, A. P., D. C. Mahan, T. G. Wise- merit. J. Anim. Sci. 72:3152-3162. Schinckel, A. P., and C. F. De Lange. 1996. man, and M. E. Einstein. 2008. Impact of Characterization of growth parameters alternative energy systems on the estimated Wood, J. D., M. Enser, A. V. Fisher, G. R. needed as inputs for pig growth models. J. feed requirements of pigs with varying lean Nute, P. R. Sheard, R. I. Richardson, S. I. Anim. Sci. 74:2021-2036. and fat tissue growth rates when fed corn and Hughes, and F. M. Whittington. 2008. Fat soybean meal-based diets. Prof. Anim. Sci. deposition, fatty acid composition and meat Schinckel, A. P., M. E. Einstein, S. Jungst, C. 24:198-207. quality: A review. Meat Sci. 78:343-358. Booher, and S. Newman. 2009a. Evaluation of different mixed model nonlinear functions Stahly, T. S., and G. L. Cromwell. 1986. Re- Xu, G., S. K. Baidoo, L. J. Johnston, D. to describe the body weight growth of pigs of sponses to dietary additions of fiber (alfalfa Bibus, J. E. Cannon, and G. C. Shurson. different sire and dam lines. Prof. Anim. Sci. meal) in growing pigs housed in a cold, warm 2010a. The effects of feeding diets containing 25:307-324. or hot thermal environment. J. Anim. Sci. corn distillers dried grains with solubles, and 63:1870-1876. withdrawal period of distillers dried grains Schinckel, A. P., M. E. Einstein, S. Jungst, C. with solubles, on growth performance and Booher, and S. Newman. 2009b. Evaluation TOPIGS. 2013. Feed Manual TOPIGS Fin- pork quality in grower-finisher pigs. J. Anim. of different mixed model nonlinear func- isher. TOPIGS, 5263 LT Vught, the Nether- Sci. 88:1388-1397. tions to describe the feed intakes of pigs of lands. different sire and dam lines. Prof. Anim. Sci. Xu, G., S. K. Baidoo, L. J. Johnston, D. Bi- 25:345-359. Weber, T. E., B. T. Richert, M. A. Belury, bus, J. E. Cannon, and G. C. Shurson. 2010b. Y. Gu, K. Enright, and A. P. Schinckel. Effects of feeding diets containing increas- Schinckel, A. P., M. E. Einstein, S. Jungst, 2006. Evaluation of the effects of dietary fat, ing levels of corn distillers dried grains with J. O. Matthews, C. Booher, T. Dreadin, C. conjugated linoleic acid, and ractopamine on solubles (DDGS) to grower-finisher pigs on Fralick, E. Wilson, R. D. Boyd, and S. New- growth performance, pork quality, and fatty growth performance, carcass composition, and man. 2012a. Feed and energy intake, growth acid profiles in genetically lean gilts. J. Anim. pork fat quality. J. Anim. Sci. 88:1398-1410. rate and diet energy efficiency of pigs from Sci. 84:720-732. four sire lines fed high or low energy diets. Zhu, Y., S. Arnold, B. Richert, A. Schinckel, Asian-Australas. J. Anim. Sci. 25:410-420. Wenk, C. 2001. The role of dietary fibre in and M. A. Latour. 2012. Impact of high the digestive physiology of the pig. Anim. iodine value diet composed of distillers dried Schinckel, A. P., M. E. Einstein, S. Jungst, Feed Sci. Technol. 90:21-33. grains with solubles and restaurant grease J. O. Matthews, B. Fields, C. Booher, T. White, H. M., B. T. Richert, J. S. Radcliffe, on pork loin quality. J. Agric. Biodiv. Res. Dreadin, C. Fralick, S. Tabor, A. Sosnicki, A. P. Schinckel, J. R. Burgess, S. L. Koser, S. 1:102-115. E. Wilson, and R. D. Boyd. 2012b. The