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Effect of increasing dried blood cells in corn-soybean meal diets on growth performance of weanling and growing pigs1
The Professional Animal Scientist 27 (2011):65–72
©2011 American Registry of Professional Animal Scientists
E fcells fect of increasing dried blood in corn-soybean meal
diets on growth performance of weanling and growing pigs1 A. M. Waguespack, D. W. Dean, T. D. Bidner, and L. L. Southern,2 PAS School of Animal Sciences, Louisiana State University Agricultural Center, Baton Rouge 70803
ABSTRACT Dried blood cells (DBC) contain low levels of Ile relative to Lys, and thus Ile may become limiting in pig diets supplemented with DBC. Therefore, 3 experiments were conducted to evaluate the effect of increasing DBC in corn-soybean meal–based diets in weanling (7 to 13 kg, Exp. 1 and 2) and grower (24 to 46 kg, Exp. 3) pigs. Treatments were replicated with 4 to 6 pens of 4 to 6 pigs per pen. In Exp. 1 and 2 (14 d), all diets contained 0.10% l-Lys·HCl and DBC were added at 2% increments from 0 to 8%. In Exp. 1, all diets contained 1.40% total dietary Lys. All diets in Exp. 2 contained 1.185% apparent ileal digestible Lys. In Exp. 1, increasing dietary DBC resulted in a linear decrease in ADFI (P < 0.05) and a quadratic decrease (P < 0.10) in ADG. Gain:feed was not affected by DBC addition (P > 0.10). In Exp. 2, increasing dietary DBC resulted in a decrease in ADG (linear and quadratic, P < 0.01) and a linear decrease in ADFI and G:F (P < 0.05). Experiment 3 was conducted for 28 d to determine the Approved for publication by the director of the Louisiana Agricultural Experimental Station as manuscript No. 2010-230-5240. 2 Corresponding author: lsouthern@ agcenter.lsu.edu 1
effect of graded levels of DBC. In Exp. 3, DBC were added to the diets at 2% increments from 0 to 8%. All diets contained 1.00% total dietary Lys. In Exp. 3, increasing dietary DBC resulted in a decrease in ADG and ADFI (linear, P < 0.01). Feed efficiency was not significantly affected by the increasing levels of DBC. The results of these 3 experiments indicate that ADG can be maintained with up to 4% DBC, but DBC fed above 2% may have a negative effect on feed efficiency of weanling and grower pigs. The maximum inclusion level of DBC that can be added in a diet for weanling and growing pigs without reducing growth performance is dependent on the Ile:Lys. Key words: blood cell, grower pig, weanling pig
INTRODUCTION Feed costs and environmental concerns are an important consideration for most nutritionists and result in the need for cost effective and efficiently utilized protein sources for pigs. Blood products such as blood cells or blood meal are by-products of the commercial slaughter industry. Diets supplemented with blood products are commonly fed in the first 3 wk postweaning.
Based on the nutrient profile, blood cells contain 12 to 13% Leu and less than 1% Ile. Because blood cells are deficient in Ile, researchers have investigated their use in estimating the Ile requirement of pigs (Bergström et al., 1996a,b; James et al., 2000; Parr et al., 2003; Kendall et al., 2004; Kerr et al., 2004a; Parr et al., 2004; Dean et al., 2005; Fu et al., 2005, 2006c; Barea et al., 2009; Wiltafsky et al., 2009). Maximizing supplementation of dried blood cells (DBC) in the diet without limiting performance is also a research area of interest. Frugé et al. (2009) reported that a maximum of 2% DBC could be provided in the diet for finishing pigs without decreasing growth performance. Blood cells are a readily available protein source high in Lys, and with the changes in the cost of ingredients, they may be a cost effective source of Lys. Therefore, the objective of this research was to determine the optimal level of DBC inclusion that would not cause a reduction in performance in weanling and growing pigs.
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MATERIALS AND METHODS General All experimental animal use was in compliance with the Louisiana State University Agricultural Center Animal Care and Use Committee. Pigs (Yorkshire, Yorkshire × Landrace, and Yorkshire × Landrace × Duroc) were obtained from the Louisiana State University Agricultural Center Swine Unit. In Exp. 1 and 2, weanling pigs were housed in a temperaturecontrolled nursery building in 0.97× 1.47-m pens with plastic slotted flooring, one nipple waterer, and a 4-hole stainless steel self-feeder. In Exp. 3, grower pigs were housed in a completely enclosed building in 1.32- × 2.44-m pens with metal slotted floors, one nipple waterer, and a 2-hole stainless steel feeder with lids. In all experiments, pigs were allotted to treatments in randomized complete block designs based on initial BW. Feed in meal form and water were available on an ad libitum basis. Dietary treatments were formulated to meet or exceed NRC (1998) recommendations for all nutrients. In Exp. 1, the total amino acid (AA) values for DBC (Innovative Proteins, Brentwood, MO) were based on NRC (1998) values. In Exp. 2, the AA values for DBC (APC Inc., Ankeny, IA) were based on the supplier’s analyzed AA and apparent ileal digestible (AID) values. In Exp. 3, the AA nutrient values for DBC (APC Inc.) were based on analyzed values. Amino acid composition of the DBC was determined after acid hydrolysis (Method 982.30 E[a]; AOAC, 2000). Total sulfur AA content was determined after performic acid oxidation followed by acid hydrolysis (Method 982.30 E[b]; AOAC, 2000). Tryptophan content was determined after alkaline hydrolysis (Method 982.30 E[c]; AOAC, 2000). The nutrient values used in formulation of the dietary treatments for granular whey were provided by the ingredient supplier (International Ingredient Corporation, St. Louis, MO). All other nutrient values used in formulation of the di-
Waguespack et al.
etary treatments were based on NRC (1998).
Experiment 1 Experiment 1 was conducted to determine the effect of increasing DBC on growth performance of weanling pigs. Weanling pigs (n = 115) were allotted to 5 treatments. Each treat-
ment had 5 replicates with 4 or 5 pigs each, consisting of 2 barrows and 2 gilts or 3 gilts and 2 barrows, respectively. Treatment 1 (positive control) was a corn-soybean meal (C-SBM) diet with no DBC. Treatments 2 to 5 contained 2, 4, 6, or 8% DBC, respectively (Table 1). As incremental additions of DBC were increased in the diets, the amount of soybean
Table 1. Composition of diets fed to 7- to 13-kg weanling pigs in Exp. 1, as-fed basis Dried blood cells, % Item
0
2
4
6
8
Ingredient, % Corn 48.91 52.67 56.36 60.00 63.65 Soybean meal, 47.5% CP 28.26 22.30 16.35 10.40 4.45 Whey, granular1 10.00 10.00 10.00 10.00 10.00 — 2.00 4.00 6.00 8.00 Dried blood cells2 Fish meal, menhaden 5.00 5.00 5.00 5.00 5.00 Dry fat3 3.00 3.00 3.00 3.00 3.00 Monocalcium phosphate 1.16 1.27 1.38 1.49 1.60 Limestone 0.71 0.71 0.71 0.71 0.72 0.75 0.75 0.75 0.75 0.75 Antibiotic4 Vitamin premix5 0.50 0.50 0.50 0.50 0.50 Sodium chloride 0.50 0.50 0.50 0.50 0.50 Sodium bentonite6 0.50 0.50 0.50 0.50 0.50 Zinc oxide 0.28 0.28 0.28 0.28 0.28 0.10 0.10 0.10 0.10 0.10 Trace mineral premix7 Choline chloride 0.05 0.05 0.05 0.05 0.05 Flavor8 0.08 0.08 0.08 0.08 0.08 l-Lys·HCl 0.10 0.10 0.10 0.10 0.10 l-Thr 0.05 0.08 0.11 0.14 0.17 0.06 0.11 0.15 0.20 0.24 dl-Met l-Trp 0.01 0.02 0.02 0.03 0.04 l-Ile — — 0.06 0.17 0.27 Calculated nutrient composition, % ME, kcal/kg 3,401 3,416 3,432 3,450 3,467 CP 22.02 21.40 20.82 20.27 19.72 Ca 0.90 0.90 0.90 0.90 0.90 P 0.80 0.80 0.80 0.80 0.80 Total Lys 1.40 1.40 1.40 1.40 1.40 Total Met 0.44 0.47 0.50 0.53 0.55 Total Met+Cys 0.80 0.81 0.81 0.81 0.81 Total Thr 0.92 0.92 0.92 0.92 0.92 Total Trp 0.27 0.27 0.27 0.27 0.27 Total Ile 0.95 0.84 0.79 0.79 0.78 Total Val 1.05 1.10 1.15 1.20 1.25 Total Leu 1.87 1.94 2.01 2.08 2.16 Total Ile:total Lys 0.68 0.60 0.56 0.56 0.56 SID Lys9 1.26 1.27 1.28 1.30 1.31 SID Met 0.41 0.44 0.46 0.50 0.52 SID Met+Cys 0.72 0.73 0.74 0.76 0.76 SID Thr 0.80 0.81 0.81 0.82 0.83 SID Trp 0.25 0.25 0.25 0.25 0.25 Continued
Increasing blood cells in weanling and grower pigs
Table 1 (Continued). Composition of diets fed to 7- to 13-kg weanling pigs in Exp. 1, as-fed basis Dried blood cells, % Item
0
2
4
6
8
SID Ile SID Val SID Leu
0.84 0.93 1.68
0.74 0.99 1.77
0.70 1.05 1.86
0.71 1.11 1.95
0.71 1.17 2.04
1
Granular whey provided by International Ingredient Corporation, St. Louis, MO.
Innomax Porcine red blood cells provided by Innovative Proteins, a division of PMI Nutrition International LLC, Brentwood, MO.
2
3
Fat Pak 100, Milk Specialties Co., Dundee, IL.
Neo-Terra 10/10, oxytetracycline (from oxytetracycline quaternary salt) equivalent to oxytetracycline hydrochloride providing 22 g/kg premix or 0.165 g/kg of diet, and neomycin sulfate providing 15.43 g/kg premix of neomycin or 0.116 g/kg of diet; Nutra Blend Corporation, Neosho, MO.
4
5 Provided the following per kilogram of diet: vitamin A, 11,023 IU; vitamin D3, 3,307 IU; vitamin E, 88 IU; menadione (menadione dimethylpyrimidinol bisulfite), 8.3 mg; riboflavin, 13 mg; pantothenic acid, 50 mg; niacin, 88 mg; vitamin B12, 61 μg; biotin, 441 μg; folic acid, 3.3 mg; pyridoxine, 4.4 mg; thiamin, 4.4 mg; and vitamin C, 110 μg. 6
AB-20 provided by Prince Agri Products Inc., Quincy, IL.
Provided the following per kilogram of diet: Zn, 127 mg; Fe, 127 mg; Mn, 20 mg; Cu, 12.7 mg; I, 0.80 mg; and Se, 0.30 mg, as zinc sulfate, ferrous sulfate, manganese sulfate, copper sulfate, calcium iodate, and sodium selenite, respectively, with calcium carbonate as the carrier.
7
8
Dried strawberry, Feed Flavors Inc., Wheeling, IL.
Standardized ileal digestible (SID) amino acid values were calculated using NRC coefficients with the exception of dried blood cells, in which Stein (2008) values were used.
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Treatment 1 (positive control) was a C-SBM diet with no DBC. Treatments 2 to 5 contained 2, 4, 6, or 8% DBC, respectively. All dietary treatments were formulated to contain 1% total dietary Lys (Table 3). The ratios of total AA to Lys were 0.57, 0.64, 0.54, and 0.18 for Met+Cys, Thr, Ile, and Trp, respectively.
Statistical Analysis For all experiments, data were analyzed by ANOVA as randomized complete block designs using the GLM procedures of SAS (SAS Inst. Inc., Cary, NC). Pigs were allotted to treatments by using initial weight as a blocking factor. The pen of pigs was the experimental unit in all experiments. Treatment differences were considered significant with an α = 0.10. The PDIFF option of SAS was used to compare individual diets to the control diet, and orthogonal contrasts were used to determine significant linear and quadratic effects of DBC on response variables.
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RESULTS AND DISCUSSION Experiment 1
meal decreased and supplemental AA increased with the exception of crystalline Lys. All diets were formulated to contain 1.40% total dietary Lys with 0.10% Lys provided as l-Lys·HCl. The ratios of total AA to Lys were 0.57, 0.65, 0.56, and 0.19 for Met+Cys, Thr, Ile, and Trp, respectively.
Experiment 2 Experiment 2 was conducted in a similar manner to Exp. 1 with the exception that diets were formulated to contain 1.18% AID Lys (Table 2). Each treatment had 6 replicates with 5 or 6 pigs each, consisting of 2 barrows and 3 gilts or 3 gilts and 3 barrows, respectively. The ratios of AID AA to Lys were 0.57, 0.61, 0.54, and 0.18 for Met+Cys, Thr, Ile, and Trp, respectively. At the termination of the experiment, blood was collected
from the anterior vena cava from 3 randomly selected pigs per pen. Blood was collected (2 mL) and placed into 10-mL tubes containing sodium heparin (BD Vacutainer, Franklin Lakes, NJ). Blood samples were placed on ice before centrifugation at 3,000 × g at 0°C for 20 min. After centrifugation, plasma was removed and kept frozen until analysis to determine plasma urea nitrogen concentration (Mathies, 1964).
Overall (d 0 to 14), ADG was increased by the 4% DBC addition (P < 0.07, quadratic) but decreased by the 8% addition (Table 4). Daily feed intake was decreased (P < 0.05, linear) by the DBC additions. Daily feed intake for pigs fed the 4% DBC diet was similar to that of pigs fed the control diet, whereas pigs fed 2, 6, or 8% DBC had decreased ADFI compared with pigs fed the control diet. Gain:feed was not affected by DBC addition (P > 0.10).
Experiment 3
Experiment 2
Experiment 3 was conducted to determine the effect of increasing DBC on growth performance of grower pigs. Grower pigs (n = 120) were allotted to 5 treatments. Each treatment had 4 replicates with 6 pigs per pen. Two of the 4 replicates contained 6 gilts per pen, and the remaining 2 replicates contained 6 barrows per pen.
Overall (d 0 to 14), ADG and ADFI were decreased (P < 0.01 to 0.04, linear and quadratic) with increasing levels of DBC in the diet (Table 4). Daily gain was not negatively affected by DBC until the 8% level of inclusion. Daily feed intake was increased by the intermediate levels of DBC but
68 decreased by the 8% inclusion level. Gain:feed was decreased (P < 0.01, linear) by the DBC. Plasma urea nitrogen was decreased (P < 0.01, linear) in pigs fed the DBC, which is an indication of the decrease in CP content of the diet as DBC increased (Frugé et al., 2009). Experiments 1 and 2 indicate that ADG can be maintained with up to 6% DBC; however, G:F was decreased by the 4% DBC in Exp. 2 but not affected in Exp. 1. Kerr et al. (2004b) reported that 6% DBC addition to a C-SBM diet without Ile supplementation decreased growth performance in 9- to 15-kg pigs. DeRouchey et al. (2002) reported that ADG of weanling pigs was decreased with 7.5% inclusion of DBC, which was due to decreased feed intake, but only in the first week of the trial (0 to 7 d). These results indicate a decrease in ADG with 8% inclusion of DBC. This decrease in gain was a direct result of decreased feed intake. The results suggest that feeding DBC above a 2% inclusion level may reduce G:F of weanling pigs. These results are in agreement with Zhang et al. (1999), who reported that 2.7% DBC inclusion did not reduce growth performance of phase I (d 0 to 14; 6.1 kg initial BW) weanling pigs. Although G:F was not affected, Zhang et al. (1999) also reported that 3.6% DBC addition to a C-SBM diet decreased ADG and ADFI of weanling pigs. DeRouchey et al. (2002) reported that feed efficiency of weanling pigs (7 to 10 kg) was improved with up to 7.5% inclusion of DBC. The results of Exp. 1 agree with the results of DeRouchey et al. (2002), but the results of Exp. 2 indicated a reduction in G:F as DBC increased. The discrepancy in the results of Exp. 2 and in the data of DeRouchey et al. (2002) may be a result of the way the diets were formulated. In Exp. 1 and in DeRouchey et al. (2002), the diets were formulated on a total AA basis, and in Exp. 2, they were formulated on an AID basis. Because the AID of Lys in DBC is higher than in corn or soybean meal, the amount of soybean meal decreased more with each increment of DBC in
Waguespack et al.
Exp. 2 compared with Exp. 1. This may have resulted in the more negative effect of feeding DBC in Exp. 2 than in Exp. 1. Another possible reason for the discrepancy in the data between Exp. 1 and 2 could be the ratio of Ile to
Lys. DeRouchey et al. (2002) had a total Ile to total Lys ratio of 0.60 in their diets. Our DBC diets contained a total Ile to total Lys ratio of 0.55 in Exp. 1 and AID Ile to AID Lys ratio of 0.54 in Exp. 2. Recent research suggests that the ratio of Ile to Lys
Table 2. Composition of diets fed to 7- to 13-kg weanling pigs in Exp. 2, as-fed basis Dried blood cells, % Item
0
2
4
6
8
Ingredient, % Corn 48.85 53.65 58.37 63.05 67.73 Soybean meal, 47.5% CP 28.31 21.31 14.30 7.30 0.30 Whey, granular1 10.00 10.00 10.00 10.00 10.00 — 2.00 4.00 6.00 8.00 Dried blood cells2 Fish meal, menhaden 5.00 5.00 5.00 5.00 5.00 Dry fat3 3.00 3.00 3.00 3.00 3.00 Monocalcium phosphate 1.16 1.29 1.42 1.55 1.68 Limestone 0.71 0.71 0.71 0.71 0.72 0.75 0.75 0.75 0.75 0.75 Antibiotic4 Vitamin premix5 0.50 0.50 0.50 0.50 0.50 Sodium chloride 0.50 0.50 0.50 0.50 0.50 Sodium bentonite6 0.50 0.50 0.50 0.50 0.50 Zinc oxide 0.28 0.28 0.28 0.28 0.28 0.10 0.10 0.10 0.10 0.10 Trace mineral premix7 Choline chloride 0.05 0.05 0.05 0.05 0.05 Flavor8 0.08 0.08 0.08 0.08 0.08 l-Lys·HCl 0.10 0.10 0.10 0.10 0.10 l-Thr 0.05 0.07 0.10 0.13 0.16 0.06 0.10 0.14 0.18 0.22 dl-Met l-Trp 0.01 0.02 0.03 0.03 0.04 l-Ile — — 0.07 0.18 0.29 Calculated nutrient composition, % ME, kcal/kg 3,401 3,416 3,432 3,449 3,466 CP 22.04 21.00 20.01 19.04 18.08 Ca 0.90 0.90 0.90 0.90 0.90 P 0.80 0.80 0.80 0.80 0.80 AID Lys 1.18 1.18 1.18 1.18 1.18 AID Met+Cys 0.67 0.67 0.67 0.67 0.67 AID Thr 0.72 0.72 0.72 0.72 0.72 AID Trp 0.22 0.22 0.22 0.22 0.22 AID Ile 0.79 0.69 0.64 0.64 0.64 AID Val 0.86 0.91 0.96 1.01 1.06 AID Ile:AID Lys 0.67 0.58 0.54 0.54 0.54 Total Lys 1.40 1.37 1.34 1.31 1.29 Total Met+Cys 0.80 0.79 0.77 0.76 0.75 Total Thr 0.93 0.90 0.88 0.86 0.84 Total Trp 0.28 0.27 0.27 0.25 0.24 Total Ile 0.95 0.82 0.76 0.74 0.72 Total Val 1.07 1.08 1.11 1.14 1.17 SID Lys9 1.26 1.25 1.23 1.22 1.20 SID Met+Cys 0.72 0.72 0.71 0.71 0.70 SID Thr 0.80 0.78 0.78 0.77 0.76 SID Trp 0.25 0.24 0.24 0.23 0.23 Continued
Increasing blood cells in weanling and grower pigs
Table 2 (Continued). Composition of diets fed to 7- to 13-kg weanling pigs in Exp. 2, as-fed basis Dried blood cells, % Item
0
2
4
6
8
SID Ile SID Val
0.84 0.93
0.73 0.97
0.68 1.01
0.67 1.05
0.66 1.10
1
Granular whey provided by International Ingredient Corporation, St. Louis, MO.
AP 301G, APC Inc., Ankeny, IA. The amino acid (AA) nutrient values for dried blood cells were based on the supplier’s AA analyzed values, which were on an apparent ileal digestible (AID) basis. The AA nutrient values used in formulating the diets were as follows: 8.51% Lys, 3.31% Thr, 0.78% Met, 0.56% Cys, 1.12% Trp, 7.5% His, 0.47% Ile, 13% Leu, 8.92% Val, 3.76% Arg, 6.82% Phe, 1.89% Tyr, and 7.37% Ala.
2
3
Fat Pak 100, Milk Specialties Co., Dundee, IL.
Neo-Terra 10/10, oxytetracycline (from oxytetracycline quaternary salt) equivalent to oxytetracycline hydrochloride providing 22 g/kg premix or 0.165 g/kg of diet, and neomycin sulfate providing 15.43 g/kg premix of neomycin or 0.116 g/kg of diet; Nutra Blend Corporation, Neosho, MO.
4
5 Provided the following per kilogram of diet: vitamin A, 11,023 IU; vitamin D3, 3,307 IU; vitamin E, 88 IU; menadione (menadione dimethylpyrimidinol bisulfite), 8.3 mg; riboflavin, 13 mg; pantothenic acid, 50 mg; niacin, 88 mg; vitamin B12, 61 μg; biotin, 441 μg; folic acid, 3.3 mg; pyridoxine, 4.4 mg; thiamin, 4.4 mg; and vitamin C, 110 μg. 6
AB-20 provided by Prince Agri Products Inc., Quincy, IL.
Provided the following per kilogram of diet: Zn, 127 mg; Fe, 127 mg; Mn, 20 mg; Cu, 12.7 mg; I, 0.80 mg; and Se, 0.30 mg, as zinc sulfate, ferrous sulfate, manganese sulfate, copper sulfate, calcium iodate, and sodium selenite respectively, with calcium carbonate as the carrier.
7
8
Dried strawberry, Feed Flavors Inc., Wheeling, IL.
Standardized ileal digestible (SID) amino acid values were calculated using NRC coefficients with the exception of dried blood cells, in which Stein (2008) values were used.
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is not more than 0.54 in 8- to 25-kg pigs (Wiltafsky et al., 2009) or not more than 0.50 in 12- to 25-kg pigs (Barea et al., 2009). However, Dean et al. (2005) and Fu et al. (2005, 2006c) reported that the required Ile:Lys was greater in pigs fed DBC than in those fed only C-SBM diets. Hinson et al. (2007) also reported that levels of DBC as high as 6% could be included in weanling pig diets as long as the diets were formulated to contain a minimum standardized ileal digestible (SID) Ile to Lys ratio of 0.62.
Experiment 3 For d 0 to 14, ADG and G:F were increased by 2 and 4% DBC additions but decreased (P < 0.03, linear and quadratic) by the 8% addition (Table 5). Daily feed intake followed a similar
response, but the quadratic effect was not significant (P < 0.04, linear). For d 14 to 28, ADG and ADFI were decreased (P < 0.05, linear) by incremental DBC addition. Gain:feed was not affected by DBC additions (P > 0.10). Overall (d 0 to 28), ADG and ADFI were decreased (P < 0.01, linear) by DBC. Feed efficiency was not affected linearly or quadratically by DBC, but pigs fed the 2% DBC diet had increased (P < 0.10) G:F compared with pigs fed the control diet. The results of Exp. 3 indicate that ADG can be maintained with up to 4% DBC. Gain:feed was increased by the 2% DBC addition and was not negatively affected by DBC of higher levels. Positive growth performance can be achieved with up to 2% DBC
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inclusion in C-SBM diets for 24- to 46-kg pigs. The results of all 3 experiments suggest that inclusion of more than 2% DBC in pig diets may negatively affect G:F of weanling or growing pigs, even with Ile supplementation at levels that would be adequate in a C-SBM diet. These data are in agreement with Dean et al. (2005) and Fu et al. (2006a). As the percentage of DBC in the diet increases, the ratios between Leu+Val to Ile increase, which results in an imbalance in the branch-chained AA (BCAA). Wiltafsky et al. (2010) reported that feeding levels with a SID Leu to Ile ratio above 2.33 or SID Leu to Val ratio above 1.79 decreases growth performance of pigs. Fu et al. (2006b) suggested that decreased growth performance from feeding diets containing supplemental DBC is due to AA interactions from the excess Leu, His, and Phe in the diet. In late finishing pigs, growth performance was restored and AA imbalance was corrected by adding Ile to a C-SBM diet containing the excess levels of Leu, Val, His, and Phe that are in a DBC diet (Fu et al., 2006b). Many researchers have reported that feeding pigs increased dietary Leu increases Leu and decreases Val and Ile concentration in the blood (Oestemer et al., 1973; Langer et al., 2000; Wiltafsky et al., 2010). The changes in the blood chemistry profile suggest that excess Leu increases BCAA catabolism. Increased catabolism of BCAA with excess dietary Leu has also been shown in rats (Block and Harper, 1984; Harper and Benjamin, 1984). Calvert et al. (1982) reported increased catabolism of Val and Ile when chicks were fed excess Leu. Wiltafsky et al. (2010) reported increased branch-chain α-keto acid dehydrogenase in pigs fed increasing levels of Leu, but there was no effect on the mRNA of BCAA catabolism genes. Furthermore, they suggested that the increase in catabolism might be due to posttranslational modification. Supplementation of Ile and Val reversed the negative growth effects of feeding a diet with excess Leu to
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Waguespack et al.
Table 3. Composition of diets fed to 24- to 46-kg grower pigs in Exp. 3, as fed basis Dried blood cells, % Item Ingredient, % Corn Soybean meal, 47.5% CP Dried blood cells1 Monocalcium phosphate Limestone Vitamin premix2 Sodium chloride Sodium bentonite3 Trace mineral premix4 l-Lys·HCl l-Thr dl-Met l-Ile Calculated nutrient composition, % ME, kcal/kg CP Ca P Total Lys Total Met+Cys Total Thr Total Trp Total Ile Total Val Total Leu Total Ile:Total Lys SID Lys5 SID Met+Cys SID Thr SID Trp SID Ile SID Val SID Leu
0
73.00 23.15 — 1.12 1.10 0.38 0.50 0.50 0.10 0.14 — — — 3,284 17.19 0.70 0.60 1.00 0.59 0.64 0.19 0.70 0.81 1.57 0.70 0.89 0.52 0.55 0.17 0.62 0.71 1.42
2
73.97 20.20 2.00 1.21 1.09 0.38 0.50 0.50 0.10 0.05 — — — 3,300 17.62 0.70 0.60 1.00 0.58 0.64 0.21 0.65 0.92 1.71 0.65 0.91 0.52 0.57 0.19 0.57 0.82 1.58
4
6
75.88 16.21 4.00 1.31 1.08 0.38 0.50 0.50 0.10 — 0.02 0.02 — 3,315 17.70 0.70 0.60 1.00 0.57 0.64 0.21 0.58 1.00 1.83 0.58 0.92 0.52 0.61 0.20 0.50 0.90 1.71
79.07 10.75 6.00 1.45 1.07 0.38 0.50 0.50 0.10 — 0.06 0.06 0.06 3,331 17.31 0.70 0.60 1.00 0.57 0.64 0.21 0.54 1.06 1.90 0.54 0.95 0.53 0.64 0.20 0.47 0.97 1.81
8
82.22 5.29 8.00 1.59 1.06 0.38 0.50 0.50 0.10 — 0.10 0.10 0.17 3,348 16.95 0.70 0.60 1.00 0.57 0.64 0.20 0.54 1.11 1.97 0.54 0.97 0.54 0.67 0.20 0.48 1.03 1.90
AP 301G provided by APC Co., Ankeny, IA. The analyzed amino acid (AA) values on a percentage as-fed basis were Lys, 8.47; Trp, 1.65; Thr, 3.78; Ile, 0.26; Met+Cys, 1.62; Leu, 12.55; Val, 8.25; Phe+Tyr, 9.17; His, 6.37; and Arg, 3.49.
1
2 Provided the following per kilogram of diet: vitamin A, 8,378 IU; vitamin D3, 2,513 IU; vitamin E, 67 IU; menadione (menadione dimethylpyrimidinol bisulfite), 6.3 mg; riboflavin, 10.1 mg; pantothenic acid, 37.7 mg; niacin, 67 mg; vitamin B12, 46 μg; biotin, 335 μg; folic acid, 2.5 mg; pyridoxine, 3.4 mg; thiamin, 3.4 mg; and vitamin C, 84 μg. 3
AB-20 provided by Prince Agri Products Inc., Quincy, IL.
Provided the following per kilogram of diet: Zn, 127 mg; Fe, 127 mg; Mn, 20 mg; Cu, 12.7 mg; I, 0.80 mg; and Se, 0.30 mg, as zinc sulfate, ferrous sulfate, manganese sulfate, copper sulfate, calcium iodate, and sodium selenite respectively, with calcium carbonate as the carrier.
4
Standardized ileal digestible (SID) amino acid values were calculated using NRC coefficients with the exception of dried blood cells, in which Stein (2008) values were used.
5
chicks or pigs (Calvert et al., 1982; Fu et al., 2006b). However, Wiltafsky et al. (2010) did not report an improvement in growth performance as a result of providing additional Val and Ile in a diet with excess Leu. Further
research needs to be conducted to determine how supplementation of Ile and Val might improve the growth performance of pigs fed diets with excess Leu.
IMPLICATIONS Our results indicate that daily gain can be maintained with up to 4% DBC in C-SBM diets for 7- to 13-kg or 24- to 46-kg pigs. However, feeding
71
Increasing blood cells in weanling and grower pigs
Table 4. Growth performance of 7- to 13-kg weanling pigs fed increasing amounts of dried blood cells in Exp. 1 and 21,2 Dried blood cells additions, % Response Exp. 1 ADG,3 g ADFI, g G:F,3 g:g Exp. 2 ADG, g ADFI, g G:F, g:g PUN,5 mg/dL
0
443 673 0.694 383 598 0.645 8.51
2
4
438 6094 0.697 398 6434 0.620 6.964
P<
6
469 672 0.713 366 600 0.6114 5.354
8
433 6184 0.686 366 613 0.5974 3.624
SEM
4024 6014 0.688 3054 5624 0.5414 2.654
11.4 19.8 0.01 9.1 14.5 0.01 0.28
Linear
0.11 0.05 0.44 0.01 0.04 0.01 0.01
Quadratic
0.07 0.77 0.28 0.01 0.02 0.13 0.32
For Exp. 1, data are the means of 5 replicates with 4 or 5 pigs per pen. Average initial BW, 7-d BW, and 14-d BW were 6.9, 9.7, and 13.1 kg, respectively.
1
For Exp. 2, data are the means of 6 replicates with 5 or 6 pigs per pen. Average initial BW, 7-d BW, and 14-d BW were 7.49, 9.59, and 12.58 kg, respectively.
2
After allocation to treatment, there was a significant overall treatment P-value (P = 0.05; SEM = 0.13) for initial BW. Thus, initial BW was used as a covariate when it was significant. The initial BW means for pigs fed 0 to 8% DBC were 7.20, 6.67, 7.01, 6.72, and 7.05, respectively.
3
4
Significantly different (P < 0.10) from the control.
Plasma urea nitrogen. Nitrogen intake was used as a covariate and found to be not significant (P > 0.10); therefore, it was removed from the model. Means of 6 replicates with 3 randomly selected pigs per pen.
5
Table 5. Growth performance of 24- to 46-kg grower pigs fed increasing amounts of dried blood cells in Exp. 31 Dried blood cell additions, % Item
0
Response Initial BW, kg 24.26 14-d BW, kg 33.79 28-d BW, kg 45.67 Growth performance Day 0 to 14 ADG, g 682 ADFI, g 1,544 G:F, g/g 0.443 Day 14 to 28 ADG, g 849 ADFI, g 2,271 G:F, g/g 0.378 Day 0 to 28 ADG, g 765 ADFI, g 1,908 G:F, g/g 0.404
2
24.32 34.772 46.56 747 1,580 0.473 842 2,0792 0.407 795 1,830 0.4352
4
24.26 34.41 45.42 722 1,574 0.459 787 2,137 0.376 754 1,855 0.410
1
Data are the means of 4 replicates with 6 pigs per pen.
2
Significantly different (P < 0.10) from the control.
P<
6
24.26 33.13 44.102 636 1,4372 0.444 792 2,0082 0.401 712 1,7102 0.418
8
24.26 32.612 43.582 5972 1,480 0.4052 783 2,0192 0.398 6892 1,7502 0.400
SEM
Linear
Quadratic
0.07 0.39 0.62 27.1 36.7 0.01 26.2 57.0 0.02 22.3 37.6 0.01
0.78 0.01 0.01 0.01 0.04 0.03 0.05 0.01 0.54 0.01 0.01 0.56
0.84 0.02 0.22 0.02 0.41 0.02 0.57 0.33 0.91 0.23 0.64 0.19
72
Waguespack et al.
DBC above a 2% inclusion level may reduce feed efficiency. The optimal inclusion level of DBC is dependent on the minimum ratio of Ile to Lys in the diet.
LITERATURE CITED AOAC. 2000. Official Methods of Analysis of AOAC International. 17th ed. AOAC, Gaithersburg, MD. Barea, R., L. Brossard, N. Le Floc’h, Y. Primot, and J. van Milgen. 2009. The standardized ileal digestible isoleucine-to-lysine requirement ratio may be less than fifty percent in eleven- to twenty-three-kilogram piglets. J. Anim. Sci. 87:4022. Bergström, J. R., J. L. Nelssen, M. D. Tokach, R. D. Goodband, S. S. Dritz, J. A. Loughmiller, R. E. Musser, and W. B. Nessmith Jr 1996a. Determining the optimal isoleucine:lysine ratio in diets for the segregated early-weaning pig. Kansas State Univ. Ext., Rep. Prog. 772:26. Bergström, J. R., J. L. Nelssen, M. D. Tokach, R. D. Goodband, S. S. Dritz, J. A. Loughmiller, R. E. Musser, and W. B. Nessmith Jr 1996b. Determining the optimal isoleucine:lysine ratio for the 25 to 50 lb pig. Kansas State Univ. Ext., Rep. Prog. 772:30. Block, K. P., and A. E. Harper. 1984. Valine metabolism in vivo: Effects of high dietary levels of leucine and isoleucine. Metabolism 33:559. Calvert, C. C., K. C. Klasing, and R. E. Austic. 1982. Involvement of food intake and amino acid catabolism in the branch-chain amino acid antagonism in chicks. J. Nutr. 112:627. Dean, D. W., L. L. Southern, B. J. Kerr, and T. D. Bidner. 2005. Isoleucine requirement of 80- to 120-kilogram barrows fed corn-soybean meal or corn-blood cell diets. J. Anim. Sci. 83:2543. DeRouchey, J. M., M. D. Tokach, J. L. Nelssen, R. D. Goodband, S. S. Dritz, J. C. Woodworth, and B. W. James. 2002. Comparison of spray-dried blood meal and blood cells in diets for nursery pigs. J. Anim. Sci. 80:2879.
Frugé, E. D., T. D. Bidner, and L. L. Southern. 2009. Effect of incremental levels of red blood cells on growth performance and carcass traits of finishing pigs. J. Anim. Sci. 87:2853. Fu, S. X., R. W. Fent, G. L. Allee, and J. L. Usry. 2006a. Branched chain amino acid interactions and isoleucine imbalance in late-finishing pigs. J. Anim. Sci. 84(Suppl. 1):283. (Abstr.) Fu, S. X., R. W. Fent, G. L. Allee, and J. L. Usry. 2006b. Branched chain amino acid interactions increases isoleucine requirement in late-finishing pigs. J. Anim. Sci. 84(Suppl. 1):283. (Abstr.) Fu, S. X., R. W. Fent, P. Srichana, G. L. Allee, and J. L. Usry. 2005. Effects of protein source on true ileal digestible (TID) isoleucine:lysine ratio in late-finishing barrows. J. Anim. Sci. 83(Suppl. 2):67. (Abstr.) Fu, S. X., A. M. Gaines, R. W. Fent, G. L. Allee, and J. L. Usry. 2006c. True ileal digestible isoleucine requirement and ratio in 12 to 22 kg pigs. J. Anim. Sci. 84(Suppl. 1):283. (Abstr.) Harper, A. E., and E. Benjamin. 1984. Relationship between intake and rate of oxidation of leucine and α-ketoisocaproate in vivo in the rat. J. Nutr. 114:431. Hinson, R. B., G. L. Allee, and J. D. Crenshaw. 2007. Use of spray-dried red blood cells and isoleucine supplementation in pig starter diets. J. Anim. Sci. 85(Suppl. 2):93. (Abstr.) James, B. W., R. D. Goodband, M. D. Tokach, J. L. Nelssen, and J. M. DeRouchey. 2000. The optimum isoleucine:lysine ratio in starter diets to maximize growth performance of the early weaned pig. Kansas State Univ. Ext., Rep. Prog. 858:20. Kendall, D. C., B. J. Kerr, R. W. Fent, S. X. Fu, J. L. Usry, and G. L. Allee. 2004. Determination of the true ileal digestible isoleucine requirement for 90 kg barrows. J. Anim. Sci. 82(Suppl. 2):67. (Abstr.) Kerr, B. J., M. T. Kidd, J. A. Cuaron, K. L. Bryant, T. M. Parr, C. V. Maxwell, and J. M. Campbell. 2004a. Isoleucine requirements and ratios in starting (7 to 11 kg) pigs. J. Anim. Sci. 82:2333. Kerr, B. J., M. T. Kidd, J. A. Cuaron, K. L. Bryant, T. M. Parr, C. V. Maxwell, and
E. Weaver. 2004b. Utilization of spray-dried blood cells and crystalline isoleucine in nursery pig diets. J. Anim. Sci. 82:2397. Langer, S., P. W. D. Scislowski, D. S. Brown, P. Dewey, and M. F. Fuller. 2000. Interactions among the branched-chain amino acids and their effects on methionine utilization in growing pigs: Effects on plasma amino- and keto-acid concentrations and branched-chain keto-acid dehydrogenase activity. Br. J. Nutr. 83:49. Mathies, J. C. 1964. Adaptation of the Berthelot color reaction for the determination of urea nitrogen in serum and urine to an ultramicro system. Clin. Chem. 10:366. NRC. 1998. Nutrient Requirements of Swine. 10th ed. National Academy Press, Washington, DC. Oestemer, G. A., L. E. Hanson, and R. J. Meade. 1973. Leucine-isoleucine interrelationship in the young pig. J. Anim. Sci. 36:674. Parr, T. M., B. J. Kerr, and D. H. Baker. 2003. Isoleucine requirement of growing (25 to 45 kg) pigs. J. Anim. Sci. 81:745. Parr, T. M., B. J. Kerr, and D. H. Baker. 2004. Isoleucine requirement for late finishing (87 to 100 kg) pigs. J. Anim. Sci. 82:1334. Stein, H. H. 2008. Standardized ileal digestibility of crude protein and amino acids in feed ingredients. Accessed Oct. 1, 2010. http://nutrition.ansci.illinois.edu/sites/default/files/AA%20digestibility.pdf. Wiltafsky, M. K., J. Bartelt, C. Relandeau, and F. X. Roth. 2009. Estimation of the optimum ratio of standardized ileal digestible isoleucine to lysine for eight- to twenty-fivekilogram pigs in diets containing spray-dried blood cells or corn gluten feed as a protein source. J. Anim. Sci. 87:2554. Wiltafsky, M. K., M. W. Pfaffl, and F. X. Roth. 2010. The effects of branch-chain amino acid interactions on growth performance, blood metabolites, enzyme kinetics and transcriptomics in weaned pigs. Br. J. Nutr. 103:964. Zhang, Q., T. L. Veum, and D. Bollinger. 1999. Spray dried animal blood cells in diets for weanling pigs. J. Anim. Sci. 77(Suppl. 1):62. (Abstr.)
©2011 American Registry of Professional Animal Scientists
E fcells fect of increasing dried blood in corn-soybean meal
diets on growth performance of weanling and growing pigs1 A. M. Waguespack, D. W. Dean, T. D. Bidner, and L. L. Southern,2 PAS School of Animal Sciences, Louisiana State University Agricultural Center, Baton Rouge 70803
ABSTRACT Dried blood cells (DBC) contain low levels of Ile relative to Lys, and thus Ile may become limiting in pig diets supplemented with DBC. Therefore, 3 experiments were conducted to evaluate the effect of increasing DBC in corn-soybean meal–based diets in weanling (7 to 13 kg, Exp. 1 and 2) and grower (24 to 46 kg, Exp. 3) pigs. Treatments were replicated with 4 to 6 pens of 4 to 6 pigs per pen. In Exp. 1 and 2 (14 d), all diets contained 0.10% l-Lys·HCl and DBC were added at 2% increments from 0 to 8%. In Exp. 1, all diets contained 1.40% total dietary Lys. All diets in Exp. 2 contained 1.185% apparent ileal digestible Lys. In Exp. 1, increasing dietary DBC resulted in a linear decrease in ADFI (P < 0.05) and a quadratic decrease (P < 0.10) in ADG. Gain:feed was not affected by DBC addition (P > 0.10). In Exp. 2, increasing dietary DBC resulted in a decrease in ADG (linear and quadratic, P < 0.01) and a linear decrease in ADFI and G:F (P < 0.05). Experiment 3 was conducted for 28 d to determine the Approved for publication by the director of the Louisiana Agricultural Experimental Station as manuscript No. 2010-230-5240. 2 Corresponding author: lsouthern@ agcenter.lsu.edu 1
effect of graded levels of DBC. In Exp. 3, DBC were added to the diets at 2% increments from 0 to 8%. All diets contained 1.00% total dietary Lys. In Exp. 3, increasing dietary DBC resulted in a decrease in ADG and ADFI (linear, P < 0.01). Feed efficiency was not significantly affected by the increasing levels of DBC. The results of these 3 experiments indicate that ADG can be maintained with up to 4% DBC, but DBC fed above 2% may have a negative effect on feed efficiency of weanling and grower pigs. The maximum inclusion level of DBC that can be added in a diet for weanling and growing pigs without reducing growth performance is dependent on the Ile:Lys. Key words: blood cell, grower pig, weanling pig
INTRODUCTION Feed costs and environmental concerns are an important consideration for most nutritionists and result in the need for cost effective and efficiently utilized protein sources for pigs. Blood products such as blood cells or blood meal are by-products of the commercial slaughter industry. Diets supplemented with blood products are commonly fed in the first 3 wk postweaning.
Based on the nutrient profile, blood cells contain 12 to 13% Leu and less than 1% Ile. Because blood cells are deficient in Ile, researchers have investigated their use in estimating the Ile requirement of pigs (Bergström et al., 1996a,b; James et al., 2000; Parr et al., 2003; Kendall et al., 2004; Kerr et al., 2004a; Parr et al., 2004; Dean et al., 2005; Fu et al., 2005, 2006c; Barea et al., 2009; Wiltafsky et al., 2009). Maximizing supplementation of dried blood cells (DBC) in the diet without limiting performance is also a research area of interest. Frugé et al. (2009) reported that a maximum of 2% DBC could be provided in the diet for finishing pigs without decreasing growth performance. Blood cells are a readily available protein source high in Lys, and with the changes in the cost of ingredients, they may be a cost effective source of Lys. Therefore, the objective of this research was to determine the optimal level of DBC inclusion that would not cause a reduction in performance in weanling and growing pigs.
66
MATERIALS AND METHODS General All experimental animal use was in compliance with the Louisiana State University Agricultural Center Animal Care and Use Committee. Pigs (Yorkshire, Yorkshire × Landrace, and Yorkshire × Landrace × Duroc) were obtained from the Louisiana State University Agricultural Center Swine Unit. In Exp. 1 and 2, weanling pigs were housed in a temperaturecontrolled nursery building in 0.97× 1.47-m pens with plastic slotted flooring, one nipple waterer, and a 4-hole stainless steel self-feeder. In Exp. 3, grower pigs were housed in a completely enclosed building in 1.32- × 2.44-m pens with metal slotted floors, one nipple waterer, and a 2-hole stainless steel feeder with lids. In all experiments, pigs were allotted to treatments in randomized complete block designs based on initial BW. Feed in meal form and water were available on an ad libitum basis. Dietary treatments were formulated to meet or exceed NRC (1998) recommendations for all nutrients. In Exp. 1, the total amino acid (AA) values for DBC (Innovative Proteins, Brentwood, MO) were based on NRC (1998) values. In Exp. 2, the AA values for DBC (APC Inc., Ankeny, IA) were based on the supplier’s analyzed AA and apparent ileal digestible (AID) values. In Exp. 3, the AA nutrient values for DBC (APC Inc.) were based on analyzed values. Amino acid composition of the DBC was determined after acid hydrolysis (Method 982.30 E[a]; AOAC, 2000). Total sulfur AA content was determined after performic acid oxidation followed by acid hydrolysis (Method 982.30 E[b]; AOAC, 2000). Tryptophan content was determined after alkaline hydrolysis (Method 982.30 E[c]; AOAC, 2000). The nutrient values used in formulation of the dietary treatments for granular whey were provided by the ingredient supplier (International Ingredient Corporation, St. Louis, MO). All other nutrient values used in formulation of the di-
Waguespack et al.
etary treatments were based on NRC (1998).
Experiment 1 Experiment 1 was conducted to determine the effect of increasing DBC on growth performance of weanling pigs. Weanling pigs (n = 115) were allotted to 5 treatments. Each treat-
ment had 5 replicates with 4 or 5 pigs each, consisting of 2 barrows and 2 gilts or 3 gilts and 2 barrows, respectively. Treatment 1 (positive control) was a corn-soybean meal (C-SBM) diet with no DBC. Treatments 2 to 5 contained 2, 4, 6, or 8% DBC, respectively (Table 1). As incremental additions of DBC were increased in the diets, the amount of soybean
Table 1. Composition of diets fed to 7- to 13-kg weanling pigs in Exp. 1, as-fed basis Dried blood cells, % Item
0
2
4
6
8
Ingredient, % Corn 48.91 52.67 56.36 60.00 63.65 Soybean meal, 47.5% CP 28.26 22.30 16.35 10.40 4.45 Whey, granular1 10.00 10.00 10.00 10.00 10.00 — 2.00 4.00 6.00 8.00 Dried blood cells2 Fish meal, menhaden 5.00 5.00 5.00 5.00 5.00 Dry fat3 3.00 3.00 3.00 3.00 3.00 Monocalcium phosphate 1.16 1.27 1.38 1.49 1.60 Limestone 0.71 0.71 0.71 0.71 0.72 0.75 0.75 0.75 0.75 0.75 Antibiotic4 Vitamin premix5 0.50 0.50 0.50 0.50 0.50 Sodium chloride 0.50 0.50 0.50 0.50 0.50 Sodium bentonite6 0.50 0.50 0.50 0.50 0.50 Zinc oxide 0.28 0.28 0.28 0.28 0.28 0.10 0.10 0.10 0.10 0.10 Trace mineral premix7 Choline chloride 0.05 0.05 0.05 0.05 0.05 Flavor8 0.08 0.08 0.08 0.08 0.08 l-Lys·HCl 0.10 0.10 0.10 0.10 0.10 l-Thr 0.05 0.08 0.11 0.14 0.17 0.06 0.11 0.15 0.20 0.24 dl-Met l-Trp 0.01 0.02 0.02 0.03 0.04 l-Ile — — 0.06 0.17 0.27 Calculated nutrient composition, % ME, kcal/kg 3,401 3,416 3,432 3,450 3,467 CP 22.02 21.40 20.82 20.27 19.72 Ca 0.90 0.90 0.90 0.90 0.90 P 0.80 0.80 0.80 0.80 0.80 Total Lys 1.40 1.40 1.40 1.40 1.40 Total Met 0.44 0.47 0.50 0.53 0.55 Total Met+Cys 0.80 0.81 0.81 0.81 0.81 Total Thr 0.92 0.92 0.92 0.92 0.92 Total Trp 0.27 0.27 0.27 0.27 0.27 Total Ile 0.95 0.84 0.79 0.79 0.78 Total Val 1.05 1.10 1.15 1.20 1.25 Total Leu 1.87 1.94 2.01 2.08 2.16 Total Ile:total Lys 0.68 0.60 0.56 0.56 0.56 SID Lys9 1.26 1.27 1.28 1.30 1.31 SID Met 0.41 0.44 0.46 0.50 0.52 SID Met+Cys 0.72 0.73 0.74 0.76 0.76 SID Thr 0.80 0.81 0.81 0.82 0.83 SID Trp 0.25 0.25 0.25 0.25 0.25 Continued
Increasing blood cells in weanling and grower pigs
Table 1 (Continued). Composition of diets fed to 7- to 13-kg weanling pigs in Exp. 1, as-fed basis Dried blood cells, % Item
0
2
4
6
8
SID Ile SID Val SID Leu
0.84 0.93 1.68
0.74 0.99 1.77
0.70 1.05 1.86
0.71 1.11 1.95
0.71 1.17 2.04
1
Granular whey provided by International Ingredient Corporation, St. Louis, MO.
Innomax Porcine red blood cells provided by Innovative Proteins, a division of PMI Nutrition International LLC, Brentwood, MO.
2
3
Fat Pak 100, Milk Specialties Co., Dundee, IL.
Neo-Terra 10/10, oxytetracycline (from oxytetracycline quaternary salt) equivalent to oxytetracycline hydrochloride providing 22 g/kg premix or 0.165 g/kg of diet, and neomycin sulfate providing 15.43 g/kg premix of neomycin or 0.116 g/kg of diet; Nutra Blend Corporation, Neosho, MO.
4
5 Provided the following per kilogram of diet: vitamin A, 11,023 IU; vitamin D3, 3,307 IU; vitamin E, 88 IU; menadione (menadione dimethylpyrimidinol bisulfite), 8.3 mg; riboflavin, 13 mg; pantothenic acid, 50 mg; niacin, 88 mg; vitamin B12, 61 μg; biotin, 441 μg; folic acid, 3.3 mg; pyridoxine, 4.4 mg; thiamin, 4.4 mg; and vitamin C, 110 μg. 6
AB-20 provided by Prince Agri Products Inc., Quincy, IL.
Provided the following per kilogram of diet: Zn, 127 mg; Fe, 127 mg; Mn, 20 mg; Cu, 12.7 mg; I, 0.80 mg; and Se, 0.30 mg, as zinc sulfate, ferrous sulfate, manganese sulfate, copper sulfate, calcium iodate, and sodium selenite, respectively, with calcium carbonate as the carrier.
7
8
Dried strawberry, Feed Flavors Inc., Wheeling, IL.
Standardized ileal digestible (SID) amino acid values were calculated using NRC coefficients with the exception of dried blood cells, in which Stein (2008) values were used.
67
Treatment 1 (positive control) was a C-SBM diet with no DBC. Treatments 2 to 5 contained 2, 4, 6, or 8% DBC, respectively. All dietary treatments were formulated to contain 1% total dietary Lys (Table 3). The ratios of total AA to Lys were 0.57, 0.64, 0.54, and 0.18 for Met+Cys, Thr, Ile, and Trp, respectively.
Statistical Analysis For all experiments, data were analyzed by ANOVA as randomized complete block designs using the GLM procedures of SAS (SAS Inst. Inc., Cary, NC). Pigs were allotted to treatments by using initial weight as a blocking factor. The pen of pigs was the experimental unit in all experiments. Treatment differences were considered significant with an α = 0.10. The PDIFF option of SAS was used to compare individual diets to the control diet, and orthogonal contrasts were used to determine significant linear and quadratic effects of DBC on response variables.
9
RESULTS AND DISCUSSION Experiment 1
meal decreased and supplemental AA increased with the exception of crystalline Lys. All diets were formulated to contain 1.40% total dietary Lys with 0.10% Lys provided as l-Lys·HCl. The ratios of total AA to Lys were 0.57, 0.65, 0.56, and 0.19 for Met+Cys, Thr, Ile, and Trp, respectively.
Experiment 2 Experiment 2 was conducted in a similar manner to Exp. 1 with the exception that diets were formulated to contain 1.18% AID Lys (Table 2). Each treatment had 6 replicates with 5 or 6 pigs each, consisting of 2 barrows and 3 gilts or 3 gilts and 3 barrows, respectively. The ratios of AID AA to Lys were 0.57, 0.61, 0.54, and 0.18 for Met+Cys, Thr, Ile, and Trp, respectively. At the termination of the experiment, blood was collected
from the anterior vena cava from 3 randomly selected pigs per pen. Blood was collected (2 mL) and placed into 10-mL tubes containing sodium heparin (BD Vacutainer, Franklin Lakes, NJ). Blood samples were placed on ice before centrifugation at 3,000 × g at 0°C for 20 min. After centrifugation, plasma was removed and kept frozen until analysis to determine plasma urea nitrogen concentration (Mathies, 1964).
Overall (d 0 to 14), ADG was increased by the 4% DBC addition (P < 0.07, quadratic) but decreased by the 8% addition (Table 4). Daily feed intake was decreased (P < 0.05, linear) by the DBC additions. Daily feed intake for pigs fed the 4% DBC diet was similar to that of pigs fed the control diet, whereas pigs fed 2, 6, or 8% DBC had decreased ADFI compared with pigs fed the control diet. Gain:feed was not affected by DBC addition (P > 0.10).
Experiment 3
Experiment 2
Experiment 3 was conducted to determine the effect of increasing DBC on growth performance of grower pigs. Grower pigs (n = 120) were allotted to 5 treatments. Each treatment had 4 replicates with 6 pigs per pen. Two of the 4 replicates contained 6 gilts per pen, and the remaining 2 replicates contained 6 barrows per pen.
Overall (d 0 to 14), ADG and ADFI were decreased (P < 0.01 to 0.04, linear and quadratic) with increasing levels of DBC in the diet (Table 4). Daily gain was not negatively affected by DBC until the 8% level of inclusion. Daily feed intake was increased by the intermediate levels of DBC but
68 decreased by the 8% inclusion level. Gain:feed was decreased (P < 0.01, linear) by the DBC. Plasma urea nitrogen was decreased (P < 0.01, linear) in pigs fed the DBC, which is an indication of the decrease in CP content of the diet as DBC increased (Frugé et al., 2009). Experiments 1 and 2 indicate that ADG can be maintained with up to 6% DBC; however, G:F was decreased by the 4% DBC in Exp. 2 but not affected in Exp. 1. Kerr et al. (2004b) reported that 6% DBC addition to a C-SBM diet without Ile supplementation decreased growth performance in 9- to 15-kg pigs. DeRouchey et al. (2002) reported that ADG of weanling pigs was decreased with 7.5% inclusion of DBC, which was due to decreased feed intake, but only in the first week of the trial (0 to 7 d). These results indicate a decrease in ADG with 8% inclusion of DBC. This decrease in gain was a direct result of decreased feed intake. The results suggest that feeding DBC above a 2% inclusion level may reduce G:F of weanling pigs. These results are in agreement with Zhang et al. (1999), who reported that 2.7% DBC inclusion did not reduce growth performance of phase I (d 0 to 14; 6.1 kg initial BW) weanling pigs. Although G:F was not affected, Zhang et al. (1999) also reported that 3.6% DBC addition to a C-SBM diet decreased ADG and ADFI of weanling pigs. DeRouchey et al. (2002) reported that feed efficiency of weanling pigs (7 to 10 kg) was improved with up to 7.5% inclusion of DBC. The results of Exp. 1 agree with the results of DeRouchey et al. (2002), but the results of Exp. 2 indicated a reduction in G:F as DBC increased. The discrepancy in the results of Exp. 2 and in the data of DeRouchey et al. (2002) may be a result of the way the diets were formulated. In Exp. 1 and in DeRouchey et al. (2002), the diets were formulated on a total AA basis, and in Exp. 2, they were formulated on an AID basis. Because the AID of Lys in DBC is higher than in corn or soybean meal, the amount of soybean meal decreased more with each increment of DBC in
Waguespack et al.
Exp. 2 compared with Exp. 1. This may have resulted in the more negative effect of feeding DBC in Exp. 2 than in Exp. 1. Another possible reason for the discrepancy in the data between Exp. 1 and 2 could be the ratio of Ile to
Lys. DeRouchey et al. (2002) had a total Ile to total Lys ratio of 0.60 in their diets. Our DBC diets contained a total Ile to total Lys ratio of 0.55 in Exp. 1 and AID Ile to AID Lys ratio of 0.54 in Exp. 2. Recent research suggests that the ratio of Ile to Lys
Table 2. Composition of diets fed to 7- to 13-kg weanling pigs in Exp. 2, as-fed basis Dried blood cells, % Item
0
2
4
6
8
Ingredient, % Corn 48.85 53.65 58.37 63.05 67.73 Soybean meal, 47.5% CP 28.31 21.31 14.30 7.30 0.30 Whey, granular1 10.00 10.00 10.00 10.00 10.00 — 2.00 4.00 6.00 8.00 Dried blood cells2 Fish meal, menhaden 5.00 5.00 5.00 5.00 5.00 Dry fat3 3.00 3.00 3.00 3.00 3.00 Monocalcium phosphate 1.16 1.29 1.42 1.55 1.68 Limestone 0.71 0.71 0.71 0.71 0.72 0.75 0.75 0.75 0.75 0.75 Antibiotic4 Vitamin premix5 0.50 0.50 0.50 0.50 0.50 Sodium chloride 0.50 0.50 0.50 0.50 0.50 Sodium bentonite6 0.50 0.50 0.50 0.50 0.50 Zinc oxide 0.28 0.28 0.28 0.28 0.28 0.10 0.10 0.10 0.10 0.10 Trace mineral premix7 Choline chloride 0.05 0.05 0.05 0.05 0.05 Flavor8 0.08 0.08 0.08 0.08 0.08 l-Lys·HCl 0.10 0.10 0.10 0.10 0.10 l-Thr 0.05 0.07 0.10 0.13 0.16 0.06 0.10 0.14 0.18 0.22 dl-Met l-Trp 0.01 0.02 0.03 0.03 0.04 l-Ile — — 0.07 0.18 0.29 Calculated nutrient composition, % ME, kcal/kg 3,401 3,416 3,432 3,449 3,466 CP 22.04 21.00 20.01 19.04 18.08 Ca 0.90 0.90 0.90 0.90 0.90 P 0.80 0.80 0.80 0.80 0.80 AID Lys 1.18 1.18 1.18 1.18 1.18 AID Met+Cys 0.67 0.67 0.67 0.67 0.67 AID Thr 0.72 0.72 0.72 0.72 0.72 AID Trp 0.22 0.22 0.22 0.22 0.22 AID Ile 0.79 0.69 0.64 0.64 0.64 AID Val 0.86 0.91 0.96 1.01 1.06 AID Ile:AID Lys 0.67 0.58 0.54 0.54 0.54 Total Lys 1.40 1.37 1.34 1.31 1.29 Total Met+Cys 0.80 0.79 0.77 0.76 0.75 Total Thr 0.93 0.90 0.88 0.86 0.84 Total Trp 0.28 0.27 0.27 0.25 0.24 Total Ile 0.95 0.82 0.76 0.74 0.72 Total Val 1.07 1.08 1.11 1.14 1.17 SID Lys9 1.26 1.25 1.23 1.22 1.20 SID Met+Cys 0.72 0.72 0.71 0.71 0.70 SID Thr 0.80 0.78 0.78 0.77 0.76 SID Trp 0.25 0.24 0.24 0.23 0.23 Continued
Increasing blood cells in weanling and grower pigs
Table 2 (Continued). Composition of diets fed to 7- to 13-kg weanling pigs in Exp. 2, as-fed basis Dried blood cells, % Item
0
2
4
6
8
SID Ile SID Val
0.84 0.93
0.73 0.97
0.68 1.01
0.67 1.05
0.66 1.10
1
Granular whey provided by International Ingredient Corporation, St. Louis, MO.
AP 301G, APC Inc., Ankeny, IA. The amino acid (AA) nutrient values for dried blood cells were based on the supplier’s AA analyzed values, which were on an apparent ileal digestible (AID) basis. The AA nutrient values used in formulating the diets were as follows: 8.51% Lys, 3.31% Thr, 0.78% Met, 0.56% Cys, 1.12% Trp, 7.5% His, 0.47% Ile, 13% Leu, 8.92% Val, 3.76% Arg, 6.82% Phe, 1.89% Tyr, and 7.37% Ala.
2
3
Fat Pak 100, Milk Specialties Co., Dundee, IL.
Neo-Terra 10/10, oxytetracycline (from oxytetracycline quaternary salt) equivalent to oxytetracycline hydrochloride providing 22 g/kg premix or 0.165 g/kg of diet, and neomycin sulfate providing 15.43 g/kg premix of neomycin or 0.116 g/kg of diet; Nutra Blend Corporation, Neosho, MO.
4
5 Provided the following per kilogram of diet: vitamin A, 11,023 IU; vitamin D3, 3,307 IU; vitamin E, 88 IU; menadione (menadione dimethylpyrimidinol bisulfite), 8.3 mg; riboflavin, 13 mg; pantothenic acid, 50 mg; niacin, 88 mg; vitamin B12, 61 μg; biotin, 441 μg; folic acid, 3.3 mg; pyridoxine, 4.4 mg; thiamin, 4.4 mg; and vitamin C, 110 μg. 6
AB-20 provided by Prince Agri Products Inc., Quincy, IL.
Provided the following per kilogram of diet: Zn, 127 mg; Fe, 127 mg; Mn, 20 mg; Cu, 12.7 mg; I, 0.80 mg; and Se, 0.30 mg, as zinc sulfate, ferrous sulfate, manganese sulfate, copper sulfate, calcium iodate, and sodium selenite respectively, with calcium carbonate as the carrier.
7
8
Dried strawberry, Feed Flavors Inc., Wheeling, IL.
Standardized ileal digestible (SID) amino acid values were calculated using NRC coefficients with the exception of dried blood cells, in which Stein (2008) values were used.
9
is not more than 0.54 in 8- to 25-kg pigs (Wiltafsky et al., 2009) or not more than 0.50 in 12- to 25-kg pigs (Barea et al., 2009). However, Dean et al. (2005) and Fu et al. (2005, 2006c) reported that the required Ile:Lys was greater in pigs fed DBC than in those fed only C-SBM diets. Hinson et al. (2007) also reported that levels of DBC as high as 6% could be included in weanling pig diets as long as the diets were formulated to contain a minimum standardized ileal digestible (SID) Ile to Lys ratio of 0.62.
Experiment 3 For d 0 to 14, ADG and G:F were increased by 2 and 4% DBC additions but decreased (P < 0.03, linear and quadratic) by the 8% addition (Table 5). Daily feed intake followed a similar
response, but the quadratic effect was not significant (P < 0.04, linear). For d 14 to 28, ADG and ADFI were decreased (P < 0.05, linear) by incremental DBC addition. Gain:feed was not affected by DBC additions (P > 0.10). Overall (d 0 to 28), ADG and ADFI were decreased (P < 0.01, linear) by DBC. Feed efficiency was not affected linearly or quadratically by DBC, but pigs fed the 2% DBC diet had increased (P < 0.10) G:F compared with pigs fed the control diet. The results of Exp. 3 indicate that ADG can be maintained with up to 4% DBC. Gain:feed was increased by the 2% DBC addition and was not negatively affected by DBC of higher levels. Positive growth performance can be achieved with up to 2% DBC
69
inclusion in C-SBM diets for 24- to 46-kg pigs. The results of all 3 experiments suggest that inclusion of more than 2% DBC in pig diets may negatively affect G:F of weanling or growing pigs, even with Ile supplementation at levels that would be adequate in a C-SBM diet. These data are in agreement with Dean et al. (2005) and Fu et al. (2006a). As the percentage of DBC in the diet increases, the ratios between Leu+Val to Ile increase, which results in an imbalance in the branch-chained AA (BCAA). Wiltafsky et al. (2010) reported that feeding levels with a SID Leu to Ile ratio above 2.33 or SID Leu to Val ratio above 1.79 decreases growth performance of pigs. Fu et al. (2006b) suggested that decreased growth performance from feeding diets containing supplemental DBC is due to AA interactions from the excess Leu, His, and Phe in the diet. In late finishing pigs, growth performance was restored and AA imbalance was corrected by adding Ile to a C-SBM diet containing the excess levels of Leu, Val, His, and Phe that are in a DBC diet (Fu et al., 2006b). Many researchers have reported that feeding pigs increased dietary Leu increases Leu and decreases Val and Ile concentration in the blood (Oestemer et al., 1973; Langer et al., 2000; Wiltafsky et al., 2010). The changes in the blood chemistry profile suggest that excess Leu increases BCAA catabolism. Increased catabolism of BCAA with excess dietary Leu has also been shown in rats (Block and Harper, 1984; Harper and Benjamin, 1984). Calvert et al. (1982) reported increased catabolism of Val and Ile when chicks were fed excess Leu. Wiltafsky et al. (2010) reported increased branch-chain α-keto acid dehydrogenase in pigs fed increasing levels of Leu, but there was no effect on the mRNA of BCAA catabolism genes. Furthermore, they suggested that the increase in catabolism might be due to posttranslational modification. Supplementation of Ile and Val reversed the negative growth effects of feeding a diet with excess Leu to
70
Waguespack et al.
Table 3. Composition of diets fed to 24- to 46-kg grower pigs in Exp. 3, as fed basis Dried blood cells, % Item Ingredient, % Corn Soybean meal, 47.5% CP Dried blood cells1 Monocalcium phosphate Limestone Vitamin premix2 Sodium chloride Sodium bentonite3 Trace mineral premix4 l-Lys·HCl l-Thr dl-Met l-Ile Calculated nutrient composition, % ME, kcal/kg CP Ca P Total Lys Total Met+Cys Total Thr Total Trp Total Ile Total Val Total Leu Total Ile:Total Lys SID Lys5 SID Met+Cys SID Thr SID Trp SID Ile SID Val SID Leu
0
73.00 23.15 — 1.12 1.10 0.38 0.50 0.50 0.10 0.14 — — — 3,284 17.19 0.70 0.60 1.00 0.59 0.64 0.19 0.70 0.81 1.57 0.70 0.89 0.52 0.55 0.17 0.62 0.71 1.42
2
73.97 20.20 2.00 1.21 1.09 0.38 0.50 0.50 0.10 0.05 — — — 3,300 17.62 0.70 0.60 1.00 0.58 0.64 0.21 0.65 0.92 1.71 0.65 0.91 0.52 0.57 0.19 0.57 0.82 1.58
4
6
75.88 16.21 4.00 1.31 1.08 0.38 0.50 0.50 0.10 — 0.02 0.02 — 3,315 17.70 0.70 0.60 1.00 0.57 0.64 0.21 0.58 1.00 1.83 0.58 0.92 0.52 0.61 0.20 0.50 0.90 1.71
79.07 10.75 6.00 1.45 1.07 0.38 0.50 0.50 0.10 — 0.06 0.06 0.06 3,331 17.31 0.70 0.60 1.00 0.57 0.64 0.21 0.54 1.06 1.90 0.54 0.95 0.53 0.64 0.20 0.47 0.97 1.81
8
82.22 5.29 8.00 1.59 1.06 0.38 0.50 0.50 0.10 — 0.10 0.10 0.17 3,348 16.95 0.70 0.60 1.00 0.57 0.64 0.20 0.54 1.11 1.97 0.54 0.97 0.54 0.67 0.20 0.48 1.03 1.90
AP 301G provided by APC Co., Ankeny, IA. The analyzed amino acid (AA) values on a percentage as-fed basis were Lys, 8.47; Trp, 1.65; Thr, 3.78; Ile, 0.26; Met+Cys, 1.62; Leu, 12.55; Val, 8.25; Phe+Tyr, 9.17; His, 6.37; and Arg, 3.49.
1
2 Provided the following per kilogram of diet: vitamin A, 8,378 IU; vitamin D3, 2,513 IU; vitamin E, 67 IU; menadione (menadione dimethylpyrimidinol bisulfite), 6.3 mg; riboflavin, 10.1 mg; pantothenic acid, 37.7 mg; niacin, 67 mg; vitamin B12, 46 μg; biotin, 335 μg; folic acid, 2.5 mg; pyridoxine, 3.4 mg; thiamin, 3.4 mg; and vitamin C, 84 μg. 3
AB-20 provided by Prince Agri Products Inc., Quincy, IL.
Provided the following per kilogram of diet: Zn, 127 mg; Fe, 127 mg; Mn, 20 mg; Cu, 12.7 mg; I, 0.80 mg; and Se, 0.30 mg, as zinc sulfate, ferrous sulfate, manganese sulfate, copper sulfate, calcium iodate, and sodium selenite respectively, with calcium carbonate as the carrier.
4
Standardized ileal digestible (SID) amino acid values were calculated using NRC coefficients with the exception of dried blood cells, in which Stein (2008) values were used.
5
chicks or pigs (Calvert et al., 1982; Fu et al., 2006b). However, Wiltafsky et al. (2010) did not report an improvement in growth performance as a result of providing additional Val and Ile in a diet with excess Leu. Further
research needs to be conducted to determine how supplementation of Ile and Val might improve the growth performance of pigs fed diets with excess Leu.
IMPLICATIONS Our results indicate that daily gain can be maintained with up to 4% DBC in C-SBM diets for 7- to 13-kg or 24- to 46-kg pigs. However, feeding
71
Increasing blood cells in weanling and grower pigs
Table 4. Growth performance of 7- to 13-kg weanling pigs fed increasing amounts of dried blood cells in Exp. 1 and 21,2 Dried blood cells additions, % Response Exp. 1 ADG,3 g ADFI, g G:F,3 g:g Exp. 2 ADG, g ADFI, g G:F, g:g PUN,5 mg/dL
0
443 673 0.694 383 598 0.645 8.51
2
4
438 6094 0.697 398 6434 0.620 6.964
P<
6
469 672 0.713 366 600 0.6114 5.354
8
433 6184 0.686 366 613 0.5974 3.624
SEM
4024 6014 0.688 3054 5624 0.5414 2.654
11.4 19.8 0.01 9.1 14.5 0.01 0.28
Linear
0.11 0.05 0.44 0.01 0.04 0.01 0.01
Quadratic
0.07 0.77 0.28 0.01 0.02 0.13 0.32
For Exp. 1, data are the means of 5 replicates with 4 or 5 pigs per pen. Average initial BW, 7-d BW, and 14-d BW were 6.9, 9.7, and 13.1 kg, respectively.
1
For Exp. 2, data are the means of 6 replicates with 5 or 6 pigs per pen. Average initial BW, 7-d BW, and 14-d BW were 7.49, 9.59, and 12.58 kg, respectively.
2
After allocation to treatment, there was a significant overall treatment P-value (P = 0.05; SEM = 0.13) for initial BW. Thus, initial BW was used as a covariate when it was significant. The initial BW means for pigs fed 0 to 8% DBC were 7.20, 6.67, 7.01, 6.72, and 7.05, respectively.
3
4
Significantly different (P < 0.10) from the control.
Plasma urea nitrogen. Nitrogen intake was used as a covariate and found to be not significant (P > 0.10); therefore, it was removed from the model. Means of 6 replicates with 3 randomly selected pigs per pen.
5
Table 5. Growth performance of 24- to 46-kg grower pigs fed increasing amounts of dried blood cells in Exp. 31 Dried blood cell additions, % Item
0
Response Initial BW, kg 24.26 14-d BW, kg 33.79 28-d BW, kg 45.67 Growth performance Day 0 to 14 ADG, g 682 ADFI, g 1,544 G:F, g/g 0.443 Day 14 to 28 ADG, g 849 ADFI, g 2,271 G:F, g/g 0.378 Day 0 to 28 ADG, g 765 ADFI, g 1,908 G:F, g/g 0.404
2
24.32 34.772 46.56 747 1,580 0.473 842 2,0792 0.407 795 1,830 0.4352
4
24.26 34.41 45.42 722 1,574 0.459 787 2,137 0.376 754 1,855 0.410
1
Data are the means of 4 replicates with 6 pigs per pen.
2
Significantly different (P < 0.10) from the control.
P<
6
24.26 33.13 44.102 636 1,4372 0.444 792 2,0082 0.401 712 1,7102 0.418
8
24.26 32.612 43.582 5972 1,480 0.4052 783 2,0192 0.398 6892 1,7502 0.400
SEM
Linear
Quadratic
0.07 0.39 0.62 27.1 36.7 0.01 26.2 57.0 0.02 22.3 37.6 0.01
0.78 0.01 0.01 0.01 0.04 0.03 0.05 0.01 0.54 0.01 0.01 0.56
0.84 0.02 0.22 0.02 0.41 0.02 0.57 0.33 0.91 0.23 0.64 0.19
72
Waguespack et al.
DBC above a 2% inclusion level may reduce feed efficiency. The optimal inclusion level of DBC is dependent on the minimum ratio of Ile to Lys in the diet.
LITERATURE CITED AOAC. 2000. Official Methods of Analysis of AOAC International. 17th ed. AOAC, Gaithersburg, MD. Barea, R., L. Brossard, N. Le Floc’h, Y. Primot, and J. van Milgen. 2009. The standardized ileal digestible isoleucine-to-lysine requirement ratio may be less than fifty percent in eleven- to twenty-three-kilogram piglets. J. Anim. Sci. 87:4022. Bergström, J. R., J. L. Nelssen, M. D. Tokach, R. D. Goodband, S. S. Dritz, J. A. Loughmiller, R. E. Musser, and W. B. Nessmith Jr 1996a. Determining the optimal isoleucine:lysine ratio in diets for the segregated early-weaning pig. Kansas State Univ. Ext., Rep. Prog. 772:26. Bergström, J. R., J. L. Nelssen, M. D. Tokach, R. D. Goodband, S. S. Dritz, J. A. Loughmiller, R. E. Musser, and W. B. Nessmith Jr 1996b. Determining the optimal isoleucine:lysine ratio for the 25 to 50 lb pig. Kansas State Univ. Ext., Rep. Prog. 772:30. Block, K. P., and A. E. Harper. 1984. Valine metabolism in vivo: Effects of high dietary levels of leucine and isoleucine. Metabolism 33:559. Calvert, C. C., K. C. Klasing, and R. E. Austic. 1982. Involvement of food intake and amino acid catabolism in the branch-chain amino acid antagonism in chicks. J. Nutr. 112:627. Dean, D. W., L. L. Southern, B. J. Kerr, and T. D. Bidner. 2005. Isoleucine requirement of 80- to 120-kilogram barrows fed corn-soybean meal or corn-blood cell diets. J. Anim. Sci. 83:2543. DeRouchey, J. M., M. D. Tokach, J. L. Nelssen, R. D. Goodband, S. S. Dritz, J. C. Woodworth, and B. W. James. 2002. Comparison of spray-dried blood meal and blood cells in diets for nursery pigs. J. Anim. Sci. 80:2879.
Frugé, E. D., T. D. Bidner, and L. L. Southern. 2009. Effect of incremental levels of red blood cells on growth performance and carcass traits of finishing pigs. J. Anim. Sci. 87:2853. Fu, S. X., R. W. Fent, G. L. Allee, and J. L. Usry. 2006a. Branched chain amino acid interactions and isoleucine imbalance in late-finishing pigs. J. Anim. Sci. 84(Suppl. 1):283. (Abstr.) Fu, S. X., R. W. Fent, G. L. Allee, and J. L. Usry. 2006b. Branched chain amino acid interactions increases isoleucine requirement in late-finishing pigs. J. Anim. Sci. 84(Suppl. 1):283. (Abstr.) Fu, S. X., R. W. Fent, P. Srichana, G. L. Allee, and J. L. Usry. 2005. Effects of protein source on true ileal digestible (TID) isoleucine:lysine ratio in late-finishing barrows. J. Anim. Sci. 83(Suppl. 2):67. (Abstr.) Fu, S. X., A. M. Gaines, R. W. Fent, G. L. Allee, and J. L. Usry. 2006c. True ileal digestible isoleucine requirement and ratio in 12 to 22 kg pigs. J. Anim. Sci. 84(Suppl. 1):283. (Abstr.) Harper, A. E., and E. Benjamin. 1984. Relationship between intake and rate of oxidation of leucine and α-ketoisocaproate in vivo in the rat. J. Nutr. 114:431. Hinson, R. B., G. L. Allee, and J. D. Crenshaw. 2007. Use of spray-dried red blood cells and isoleucine supplementation in pig starter diets. J. Anim. Sci. 85(Suppl. 2):93. (Abstr.) James, B. W., R. D. Goodband, M. D. Tokach, J. L. Nelssen, and J. M. DeRouchey. 2000. The optimum isoleucine:lysine ratio in starter diets to maximize growth performance of the early weaned pig. Kansas State Univ. Ext., Rep. Prog. 858:20. Kendall, D. C., B. J. Kerr, R. W. Fent, S. X. Fu, J. L. Usry, and G. L. Allee. 2004. Determination of the true ileal digestible isoleucine requirement for 90 kg barrows. J. Anim. Sci. 82(Suppl. 2):67. (Abstr.) Kerr, B. J., M. T. Kidd, J. A. Cuaron, K. L. Bryant, T. M. Parr, C. V. Maxwell, and J. M. Campbell. 2004a. Isoleucine requirements and ratios in starting (7 to 11 kg) pigs. J. Anim. Sci. 82:2333. Kerr, B. J., M. T. Kidd, J. A. Cuaron, K. L. Bryant, T. M. Parr, C. V. Maxwell, and
E. Weaver. 2004b. Utilization of spray-dried blood cells and crystalline isoleucine in nursery pig diets. J. Anim. Sci. 82:2397. Langer, S., P. W. D. Scislowski, D. S. Brown, P. Dewey, and M. F. Fuller. 2000. Interactions among the branched-chain amino acids and their effects on methionine utilization in growing pigs: Effects on plasma amino- and keto-acid concentrations and branched-chain keto-acid dehydrogenase activity. Br. J. Nutr. 83:49. Mathies, J. C. 1964. Adaptation of the Berthelot color reaction for the determination of urea nitrogen in serum and urine to an ultramicro system. Clin. Chem. 10:366. NRC. 1998. Nutrient Requirements of Swine. 10th ed. National Academy Press, Washington, DC. Oestemer, G. A., L. E. Hanson, and R. J. Meade. 1973. Leucine-isoleucine interrelationship in the young pig. J. Anim. Sci. 36:674. Parr, T. M., B. J. Kerr, and D. H. Baker. 2003. Isoleucine requirement of growing (25 to 45 kg) pigs. J. Anim. Sci. 81:745. Parr, T. M., B. J. Kerr, and D. H. Baker. 2004. Isoleucine requirement for late finishing (87 to 100 kg) pigs. J. Anim. Sci. 82:1334. Stein, H. H. 2008. Standardized ileal digestibility of crude protein and amino acids in feed ingredients. Accessed Oct. 1, 2010. http://nutrition.ansci.illinois.edu/sites/default/files/AA%20digestibility.pdf. Wiltafsky, M. K., J. Bartelt, C. Relandeau, and F. X. Roth. 2009. Estimation of the optimum ratio of standardized ileal digestible isoleucine to lysine for eight- to twenty-fivekilogram pigs in diets containing spray-dried blood cells or corn gluten feed as a protein source. J. Anim. Sci. 87:2554. Wiltafsky, M. K., M. W. Pfaffl, and F. X. Roth. 2010. The effects of branch-chain amino acid interactions on growth performance, blood metabolites, enzyme kinetics and transcriptomics in weaned pigs. Br. J. Nutr. 103:964. Zhang, Q., T. L. Veum, and D. Bollinger. 1999. Spray dried animal blood cells in diets for weanling pigs. J. Anim. Sci. 77(Suppl. 1):62. (Abstr.)