Standardized Ileal Digestible Lys Research Articles

214 Effects of Reducing Digestible Lysine and Tryptophan to Lysine Ratio on Growth Performance of Grow-finish Pigs

Abstract Due to packing plant closures or slow-downs, many producers needed to examine ways to reduce average daily gain (ADG) of finishing pigs. Therefore, a total of 1,080 pigs (L337 × 1050, PIC; initially 32.0 kg) were used in a 119-d trial to evaluate the effects of reducing dietary standardized ileal digestibility (SID) Lys and SID Trp:Lys ratio to slow growth of finishing pigs in a commercial setting. Pigs were randomly allotted in weight blocks to 1 of 4 dietary regimens with 27 pigs/pen and 10 replications/regimen. Pigs were fed a control regimen (100% of the estimated SID Lys requirement for pigs in this facility) formulated to contain 1.10, 1.01, 0.91, 0.83, 0.79, 0.71 and 0.67% SID Lys from 32 to 42, 42 to 51, 51 to 72, 72 to 85, 85 to 97, 97 to 112, and, 112 to 130 kg, respectively. Two other regimens contained 90 or 80% of the Lys estimate. These 3 regimes were formulated to a SID Trp:Lys ratio of 19% except for the last dietary phase that contained 17% SID Trp:Lys ratio. The fourth regimen contained 80% of the SID Lys estimate with 16% SID Trp:Lys in all phases. The statistical model included fixed effects of treatment, random effect of block, linear and quadratic effects of SID Lys and pairwise comparison of the two 80% treatments. Overall, decreasing SID Lys decreased (linear, P < 0.01) ADG and final body weight (BW) and tended (P < 0.10) to decrease gain:feed ratio (G:F). Reducing the Trp:Lys ratio decreased (P = 0.014) ADG and final BW compared to pigs fed diets with 80% SID Lys with higher SID Trp:Lys. In summary, decreasing SID Lys reduced ADG and feeding a reduced SID Trp:Lys ratio resulted in a further decrease in ADG of grow-finish pigs.

165 Effects of Digestible Lysine Level on Growth Performance and Economics of Grow-finish Pigs

Abstract A total of 2,124 barrows and gilts (PIC 1050′DNA 600, initially 48.9 kg) were used in a 32-d study to determine the optimal dietary standardized ileal digestibility (SID) Lys level in a commercial setting. Pigs were randomly allotted to 1 of 5 dietary treatments with 24 to 27 pigs/pen and 16 replications/treatment. Similar number of barrows and gilts were placed in each pen. Diets were fed over 3 phases (48.9 to 58.6, 58.6 to 70.9, and 70.9 to 80.8 kg respectively). Dietary treatments were corn-soybean meal-based and contained 10 (phase 1 and 2) or 5% (phase 3) distillers dried grains with solubles. Diets were formulated to 85, 95, 103, 110, or 120% of the current Pig Improvement Company (PIC, Hendersonville, TN) SID Lys gilt recommendations with phase 1 SID Lys levels of 0.90, 1.01, 1.09, 1.17 and 1.27%, phase 2 levels of 0.79, 0.87, 0.94, 1.03, and 1.10%, and phase 3 levels of 0.71, 0.78, 0.85, 0.92, and 0.99%, respectively. Dose response curves were evaluated using linear (LM), quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic (BLQ) models. For each response variable, the best-fitting model was selected using the Bayesian information criterion. Overall (d 0 to 32), increasing SID Lys increased (linear, P< 0.001) BW, ADG, G:F, Lys intake/d, and Lys intake/kg of gain. Modeling margin over feed cost (MOFC), BLL and QP estimated the requirement at 105.8% and 113.7% respectively. In summary, while growth increased linearly up to 120% of the PIC current feeding level, the optimal MOFC was 106% to 114% depending on the model used.

264 Effects of Low Dietary Crude Protein Diets Containing Coarse Wheat Bran as an Alternative to Zinc Oxide in Nursery Pig Diets

Abstract An experiment was conducted to determine the effect of reduced crude protein (CP) in diets containing coarse wheat bran (CWB) without pharmacological levels of Zn (ZnO) on growth performance and fecal dry matter (DM) of nursery pigs. A total of 650 pigs (DNA 241′600; initially 6.6 kg), were used with 5 pigs/pen and 26 replicate pens/treatment. Pens were assigned to 1 of 5 treatments in a RCB design based on BW. Treatments were fed for 13-d, contained 4% CWB, and consisted of: 1) diet with pharmacological ZnO (2,000 mg/kg Zn) and 21% CP formulated to 1.35% standardized ileal digestible (SID) Lys; 2) a diet with 110 ppm added Zn and 21% CP (1.35% SID Lys); 3) a diet with 110 ppm added Zn formulated to 18% CP (1.20% SID Lys); 4) an 18% CP diet with 110 ppm added Zn formulated to 1.35% SID Lys by the addition of increased levels of feed grade amino acids; and 5) diet 4 with addition of non-essential amino acids (NEAA; glycine and glutamic acid). Data were analyzed using the lmer function in R. Overall, pigs fed 21% CP with ZnO had increased (P < 0.05) ADG compared to those fed 18% CP (1.35% SID Lys) with high levels of feed grade amino acids or those fed the reduced SID Lys (1.2%) diet. Gain-to-feed ratio was increased (P < 0.05) for pigs fed 21% CP diets and those fed the 18% CP diet with NEAA compared to pigs fed 1.2% SID Lys and pigs fed high levels of feed grade amino acids. Fecal DM was increased (P < 0.05) for pigs fed reduced SID Lys diet. In conclusion, reducing CP (subsequently SID Lys) in diets without ZnO decreased growth performance but increased fecal DM.

218 Ileal Digestibility of Amino Acids Is Greater in Sunflower Expellers Than in Sunflower Meal When Fed to Growing Pigs

Abstract An experiment was conducted to test the null hypothesis that country of origin and oil extraction method does not affect the standardized ileal digestibility (SID) of AA in sunflower co-products. Six sources of sunflower meal (SFM) and one source of sunflower expeller (SFE) were obtained from Ukraine, Hungary, Italy, and the United States. Eight barrows (initial BW: 28.5 ± 2.4 kg) that had a T-cannula installed in the distal ileum were housed individually and allotted to an 8 × 8 Latin square design with 8 diets and eight 7-d periods. Each source of SFM or SFE was included in one diet as the only source of CP and AA. A nitrogen-free diet was also used. Data for SFM were analyzed using PROC MIXED of SAS with the fixed effect of ingredient and the random effects of animal and period. A contrast statement was used to compare results for SFM and SFE. Pig was the experimental unit and an alpha value of 0.05 was used. Results indicated that the SID of most AA in SFM sources 2 and 6 were greater (P < 0.05) than in source 4, but the SID of Lys, Met, and Trp were not different among the 6 sources of sunflower meal (Table 1). The SID of all AA, except Trp, was greater (P < 0.05) in SFE compared with SFM. In conclusion, differences in the SID of all AA except Lys, Met, and Trp in SFM sourced from Ukraine, Hungary, Italy, or the United States were observed, but the SID of all AA, except Trp, was greater in SFE than in SFM indicating that country of origin or site of production as well as oil extraction method influence SID of AA.

172 Effects of Dietary Valine, Isoleucine, and Tryptophan Supplementations to Diets Containing Excess Leucine from Corn Protein on Growth Performance of Growing Pigs

Abstract An experiment was conducted to test the hypothesis that addition of Val, Ile, or Trp alone or in combination will reduce the negative effects of excess Leu in diets for growing pigs. A total of 288 growing pigs (28.6 ± 2.5 kg) were randomly assigned to 1 of 9 dietary treatments in a randomized complete block design. There were 2 barrows and 2 gilts in each pen and 8 replicate pens per treatment. A control diet based on corn and soybean meal and 8 diets based on corn and a high-protein corn product (48% crude protein) with 2 levels of crystalline L-Val (0 or 0.10%), L-Ile (0 or 0.10%), and L-Trp (0 or 0.05%) were formulated. The crystalline L-Val, L-Ile, and L-Trp increased standardized ileal digestible (SID) Val:Lys from 70 to 80%, SID Ile:Lys from 53 to 63%, and SID Trp:Lys from 18 to 23%, respectively. All diets were formulated to contain 1.00% SID Lys and the 8 diets containing corn protein contained 171% SID Leu:Lys. Individual pig weights were recorded at the beginning and at the conclusion of the 28-d experiment. Data were analyzed using the PROC MIXED of SAS with a pen as the experimental unit. Diet was the fixed effect and block and replicate within block were random effects. Results indicated that final body weight and average daily gain were not different between pigs fed the control diet and pigs fed the diet with Val and Trp addition, but greater (P < 0.001) than for pigs fed the diet with Val addition, Ile addition, Trp addition, Val and Ile addition, Ile and Trp addition, or Val, Ile, and Trp addition (Table 1). In conclusion, addition of Val and Trp to diets with excess Leu may prevent negative effects of excess Leu in diets for growing pigs.

166 Optimal tryptophan:lysine Ratio for 25–40 Kg Growing Pigs Fed Diets Containing 35 % Distillers Dried Grains with Solubles

Abstract Distillers dried grains with solubles (DDGS) has a high concentration of Leu, and the Trp requirement for growing pigs may be increased if diets contain excess Leu. Therefore, the objective of this experiment was to determine the optimum standardized ileal digestible (SID) Trp:Lys ratio in growing pigs fed diets with excess Leu from DDGS. A diet based on corn, soybean-meal, and 35% DDGS was formulated to be deficient in Trp and Lys, according to NRC requirements (0.13% SID Trp; 0.88% SID Lys; 15% SID Trp:Lys ratio). Four diets were prepared by adding L-Trp to the basal diet, which resulted in analyzed SID Trp:Lys ratios of 18, 20, 23, and 24% in these diets. One-hundred and twenty growing pigs (26.3 ± 2.0 kg) were allotted to one of the 5 dietary treatments with 3 pigs per pen and 8 pen replicates in a completely randomized design. Diets were fed for 21d and blood samples were collected on d-21. Data were analyzed by linear and quadratic contrasts in SAS. The optimal SID Trp:Lys ratio was estimated using linear broken-line (LBL) and quadratic broken-line (QBL) regressions for ADG and G:F, using NLIN procedure in SAS. Results indicated that average daily feed intake, ADG, G:F, and final body weight increased (linear and quadratic, P < 0.01) and plasma-urea-nitrogen decreased (linear and quadratic, P < 0.05) as dietary SID Trp:Lys increased (Table 1). The SID Trp:Lys ratio to optimize ADG was 20.9 and 23.4% by LBL and QBL, respectively. The G:F was optimized at 18.7 and 20.2% by LBL and QBL, respectively. The average SID Trp:Lys ratio for the 4 measurements was 20.8% which is greater than the current NRC requirement (SID 17.3%). In conclusion, diets formulated with 35% DDGS may need more dietary Trp than current NRC values.

170 Meta-analysis to Determine the Standardized Ileal Digestible Lysine Requirements of Growing-finishing Pigs from 11- to 150-kg

Abstract A meta-analysis was conducted to determine the standardized ileal digestible (SID) lysine (Lys) recommendations for 11–150 kg PIC pigs housed under commercial conditions. Data from 29 trials dating from 2013 to 2020 utilizing 48,338 pigs were recorded in a database. Number of pens/treatment and pigs/trial ranged from 9 to 16 and 12 to 25, respectively. Sire lines were PIC 337 in 25 trials, PIC 327 in 3 trials, and PIC TR4 and 327 in 1 trial. Dam lines were PIC Camborough in 18 trials and PIC Camborough 29 in 9 trials. The SID Lys to calorie ratio curves were built for both metabolizable energy (ME) and net energy (NE) systems using the feed ingredient composition in NRC (2012) for energy levels. The response variables average daily gain (ADG) and feed efficiency (G:F) were analyzed using generalized linear and non-linear mixed models with heterogeneous variance (Gonçalves et al., 2016). Each treatment mean within a trial (n = 288) was considered the experimental unit and each trial was used as a random effect. The models were developed for mixed gender pigs and the PIC 337 growth curves were used to estimate the recommendations for barrows and gilts. There was no evidence for an interaction between sire lines or dam lines and treatment (P > 0.10). The SID Lys to calorie recommendations are based on the average for ADG and G:F (Table 1). At these levels, approximately 100% of maximum ADG and 99.4% of maximum G:F are achieved. The NE to ME ratio that results in a similar SID Lys recommendation as a percentage of the diet ranged from approximately 0.72 to 0.74. The updated biological requirements for PIC pigs remained similar compared to previous PIC recommendations (Gonçalves et al., 2017). However, the requirement estimates have been adjusted for late nursery and late finishing phases.

168 Effects of Increasing Dietary Standardized Ileal Digestible Lysine Levels on Growth Performance of 12- to 26-kg Pigs Sired by High Index Boars

Abstract Our objective was to determine the effects of increasing dietary standardized ileal digestible (SID) lysine (Lys) on the growth performance of late nursery pigs. A total of 1,125 pigs (PIC 337×Camborough, initially 12.0±0.66 kg) were used in a 21-d study. The pigs used in the study were sired by boars ranked in the top 15% of a selected PIC elite boar stud based on index. Pens of pigs were blocked by body weight and randomly allotted to 1 of 5 treatments containing 0.95, 1.10, 1.20, 1.35, and 1.50% of SID Lys. Diets were corn-soybean meal-based and contained 2,480 Kcal of NE/kg. Treatments were achieved with increasing feed-grade amino acids. There were 9 mixed gender pens per treatment and 25 pigs per pen. Data were analyzed using generalized linear and nonlinear mixed models with pen as the experimental unit. Competing models included linear, quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic (BLQ). Increasing SID Lys concentration improved average daily gain (ADG, linear, P < 0.001) and gain to feed ratio (G:F, quadratic, P = 0.011). The best-fitting models for ADG were QP and BLL. The QP model estimated the maximum ADG at 1.43% (95% CI: 1.12 to >1.50%), with 99% of maximum ADG achieved at 1.27%. The BLL plateau was estimated at 1.31% (95%CI: 1.06 to >1.50%). The best-fitting models for G:F were QP, BLL, and BLQ. The QP model estimated the maximum G:F at 1.48% (95%CI: 1.23 to >1.50%), with 99% of maximum G:F achieved at 1.24%. The BLL plateau was estimated at 1.30% (95% CI: 1.18 to 1.41%), whereas the BLQ plateau was estimated at 1.36% (95%CI: 1.14 to >1.50%). In conclusion, the estimated optimum SID Lys concentration for 12- to 26-kg pigs sired by high index boars ranged from 1.30 to 1.48%, depending on the response criteria and statistical model.

36 Evaluation of Compensatory Growth of 90-kg Finishing Pigs Previously Fed a Low Lysine Diet

Abstract A total of 346 pigs (241×600, DNA, Columbus, NE; initially 88.6 kg) were used in a 44-day trial to evaluate compensatory growth of pigs previously fed very low lysine diets. Two diets [control and corn (98% corn and 2% vitamins and minerals)] were arranged into 4 nutritional strategies. One group of pigs (control) was fed the control diet from d 0 to 44. The other three groups of pigs were fed the corn diet for 14, 21, or 28-d and then fed the control diet until day 44. The control and corn diets contained 0.70 and 0.18% standardized ileal digestible Lys, respectively. Pens were assigned to nutritional strategies in a randomized complete block design based on initial BW with 9 pens per treatment. On average, pigs fed the corn diet grew 49% slower than the control. Pigs previously fed the corn diet had 28% increased (P < 0.05) ADG during the first week of switching to the control diet and 12% faster (P < 0.05) ADG than the control for the rest of the trial. Despite this increase in ADG, final BW on d 44 was lower (P < 0.05) compared to the control for pigs fed the corn diet for 21 or 28-d. From d 0 to 44, control pigs and pigs fed the corn diet for only 14-d had increased (P < 0.05) ADG compared to pigs fed the corn diet for 21 and 28-d. Feed efficiency was decreased (P < 0.05) when the corn diet was fed and increased (P < 0.05) during the period of compensatory growth; however, overall G:F decreased (P < 0.05) as pigs were fed the corn diet longer. The data suggest that compensatory growth was observed when pigs fed the corn diet for 21 or 28-d followed by the control diet within a 6-week-period, but overall growth performance was still reduced compared to the control.

215 Effects of Increasing Dietary Standardized Ileal Digestible Lysine Levels on Growth Performance of 39- to 119-kg Pigs Sired by High Index Boars

Abstract Our objective was to determine the effects of increasing dietary standardized ileal digestible (SID) lysine (Lys) on the growth performance of grow-finish pigs. A total of 1,120 pigs (PIC 337×Camborough, initially 39.0±0.82 kg) were used in a 77-d study. Pigs used in the study were sired by boars ranked in the top 15% of a selected PIC elite boar stud based on index. Pens of pigs were blocked by body weight and randomly allotted to 1 of 5 treatments, which consisted of 85, 95, 105, 115, and 125% of the PIC2016 SID Lys recommendations within each phase. Diets were corn-soybean meal-based and formulated to be iso-caloric. Treatments were achieved with increasing feed-grade amino acids. There were 9 mixed-gender pens per treatment and 24 or 25 pigs per pen. Data were analyzed using generalized linear and nonlinear mixed models with pen as the experimental unit. Competing models included linear, quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic (BLQ). Increasing dietary SID Lys from 85 to 125% marginally improved overall average daily gain (ADG, quadratic, P = 0.056), gain to feed ratio (G:F, quadratic, P = 0.062), and final body weight (linear, P = 0.075). There was no evidence for treatment effects on mortality and removals (P > 0.10). The best-fitting models for ADG were QP and BLL. The QP model estimated the maximum ADG at 110.6% (95% CI: 93 to >125%), with 99% of maximum ADG achieved at 97.4%. The BLL plateau was estimated at 105.0% (95% CI: 74 to 136%). The best-fitting model for G:F was QP, estimating the maximum G:F at 107.8% (95% CI: 92 to >125%). In conclusion, the estimated optimum overall SID Lys for 39- to 119-kg pigs sired by high index boars ranged from 105.0 to 110.6% of PIC2016 SID Lys recommendation within each phase, depending on the response criteria and statistical model.

151 A Web Application to Establish Customized Feeding Program and Nutrient Specifications for Highly Prolific Sows

Abstract A web application was developed to provide a dynamic feeding program for PIC maternal dam lines during gilt development, gestation, peri-partum, lactation and wean-to-service interval (WSI). These recommendations for each production phase are based on peer-reviewed large-scale commercial research. The tool was developed using the Shiny package of R and includes CSS themes, html widgets, and JavaScript actions. Inputs, include pigs weaned per sow per year (PWSY), farrowing rate (FR), total born (TB), replacement rate, the existing feeding program of the breeding herd and the diet energy and standardized ileal digestible (SID) lysine (Lys) levels. Outputs include the feeding program, nutrient specifications and estimates of economic opportunity and performance improvement. The feeding program is based on user-defined energy and SID Lys levels for the gestation and lactation diets and the PIC nutrient recommendations for the breeding herd. Correspondingly, recommended specifications of other nutrients in the diets are provided and calculated based on the recommended feeding program. The tool provides economic and productivity opportunity analysis by comparing the PIC recommendations and the current user feeding programs. Improvement in PWSY is driven by the energy intake impact on caliper score during breeding and farrowing and consequently to FR and TB. This web application can be used by nutritionists and production managers to compare their current feeding practices to PIC recommendations for highly prolific sows. This will aid in their decision-making process regarding nutrition and feeding programs considering productivity and profitability outcomes.

Influence of the energy and digestible lysine contents of the diet on performance and egg quality traits of brown-egg laying hens from 19 to 59 weeks of age

The influence of nutrient density and standardized ileal digestible lys (DLys) content of the diet on egg production and egg quality traits, was studied in brown-egg laying hens from 19 to 59 wk of age. The experimental design was completely randomized with eight treatments arranged as a 2×4 factorial with two AMEn concentrations (2,680 and 2,780 kcal/kg) and four levels of DLys (0.68, 0.72, 0.76, and 0.80%). Each treatment was replicated nine times and the experimental unit was a cage with nine hens. Hen production, egg components (proportion of albumen, yolk, and shell), egg quality traits (Haugh units, egg shell strength, and incidence of broken, dirty, and shell-less eggs) were measured by period (28 d) and cumulatively. Data were analyzed as a completely randomized design with energy concentration, level of DLys, and their interactions as main effects. In addition, the effects of the level of DLys on the variables studied, were partitioned into its linear and quadratic components. No interactions between AMEn and DLys content of the diet were detected for any of the traits studied and therefore, only main effects are presented. An increase in the AMEn concentration of the diet from 2,680 to 2,780 kcal/kg increased energy intake (P < 0.05) and egg weight (P < 0.001) and improved feed conversion ratio (P < 0.05). An Increase in DLys from 0.68 to 0.80% did not affect the number of eggs produced but increased linearly egg weight (P < 0.01) and egg mass production (P < 0.05). Diet did not affect egg quality. In conclusion, an increase in the AMEn content of the diet from 2,680 to 2,780 kcal/kg increased egg weight and improved feed efficiency. Laying hens require no more than 744 mg DLys/d (corresponding to 0.68% DLys) to optimize egg production. However, when the objective is to maximize egg weight, hens should consume at least 843 mg DLys/d (corresponding to 0.76% D Lys).

Modeling standardized ileal digestible lysine requirements during gestation on gilts and sows

The objective of this study was to model daily standardized ileal digestible (SID) Lys-requirements in gestating sows. Data from 877 females (459 gilts, 418 sows; Camborough®, PIC, Hendersonville, TN) was collected and modeled using Dourmad et al. (2008) equations. Individual feed intake and body weight (BW) were recorded daily throughout gestation. Dietary treatments included 11, 13.5, 16, and 18.5 g/d SID Lys-intake throughout gestation. Data were divided into 2 parity groups: gilts and sows, and gestation was divided into 3 stages: d 5 to 39 (early), 40 to 74 (mid), and 75 to 108 (late). The model follows the principle that energy is partitioned between maintenance, growth of conceptus (fetus, placenta, and fluids), and maternal protein and lipid deposition. Requirements for SID Lys-were estimated based on predicted whole body protein deposition. After dividing energy requirements into tissue pools for maintenance, products of conceptus, and maternal reserves, the greatest portion of the energy requirement was for maintenance. Estimated protein retention of the conceptus increased in each sequential stage of gestation (P < 0.05) but there were no differences (P > 0.05) among treatments. Regardless of parity or stage of gestation, increasing SID Lys-increased estimated maternal protein deposition (linear, P < 0.001), but it decreased in each sequential stage of gestation (P < 0.001). Estimated maternal lipid deposition increased with increasing SID Lys (linear, P = 0.076) and decreased in each sequential stage of gestation (P < 0.05), with gilts having to mobilize maternal lipid in late gestation. For gilts and sows, estimated SID Lys-requirements increased in each sequential stage of gestation (P < 0.05). Estimated SID Lys-balance (SID Lys-intake - SID Lys-requirement) increased with increasing SID Lys-in the diet (quadratic, P < 0.054), and decreased (P < 0.05) in each sequential stage of gestation. Overall, the model shows how changes in protein retention of the conceptus and maternal protein deposition differ by parity and stage of gestation for a single gestation phase. Based on predicted changes in protein deposition, and SID Lys-balance, providing females with 11.0 g/d SID Lys-throughout gestation adequately meets Lys-requirements for most of gestation; however, gilts and sows were in a negative SID Lys-balance for the last 5- to 10 d of gestation and this can be prevented by providing gilts and sows with 13.5 g/d SID Lys.

Effects of different diet alternatives to replace the use of pharmacological levels of zinc on growth performance and fecal dry matter of weanling pigs.

A total of 300 weanling pigs (Line 400 × 200, DNA, Columbus, NE, initially 4.83 kg) were used in a 46-d trial to evaluate the effects of different nutritional strategies to replace pharmacological levels of Zn, provided by zinc oxide (ZnO), in nursery diets on growth performance and fecal dry matter (DM). Six treatments with 10 replicate pens per treatment and 5 pigs per pen were used. Diets consisted of: (1) positive control (ZnO providing 3,000 mg/kg added Zn from d 0 to 7 and 2,000 mg/kg added Zn from d 8 to 25 and 21% crude protein, CP); (2) negative control (NC; no added ZnO); (3) NC plus 1.2% Na diformate; (4) NC with 4% coarse ground wheat bran; (5) NC but formulated to 18% CP; and (6) the combination of NC with 18% CP, 1.2% Na diformate, and 4% coarse ground wheat bran. The diets formulated to 18% CP contained 1.2% standardized ileal digestible (SID) Lys from d 0 to 25, whereas the 21% CP diets contained 1.4% SID Lys from d 0 to 7 and 1.35% SID Lys from d 7 to 25. From d 25 to 46, all pigs were fed a common diet. From d 0 to 7, no differences in any variables were observed between treatments. From d 7 to 25, pigs fed the diet with added ZnO had greater (P < 0.01) average daily gain (ADG) and average daily feed intake (ADFI) than all other treatments. Pigs fed the diet formulated to 18% CP had decreased (P < 0.01) ADG when compared with pigs fed the other diets. From d 25 to 46, no previous treatment effects on ADG or gain to feed ratio (G:F) were observed. Overall (d 0 to 46), pigs fed the diet with added ZnO from d 0 to 25 had greater (P < 0.01) ADG, ADFI, and final body weight than pigs fed added Na Diformate, or 4% coarse ground wheat bran, or with the 18% CP diet, or with pigs fed the combination of the additives intermediate. There was no evidence for differences in overall G:F. Pigs fed the NC diet had the lowest fecal DM and highest fecal scores (P < 0.05), indicating the greatest incidence of loose stools. Pigs fed added ZnO had greater fecal DM than pigs fed the NC, 4% added wheat bran, or 18% CP diets, or with pigs fed the combination of additives intermediate (P < 0.01). These results suggest that adding pharmacological levels of Zn from ZnO improves nursery pig performance and increases DM content of feces when compared with pigs fed diets with either Na diformate, 4% course wheat bran, or 18% CP alone. However, a combination of all three alternatives appeared to be additive and partially restored growth performance similar to adding pharmacological levels of Zn.

Effects of feeding diets containing low crude protein and coarse wheat bran as alternatives to zinc oxide in nursery pig diets.

Two experiments were conducted to determine the effects of crude protein (CP) level in diets containing coarse wheat bran (CWB) with or without pharmacological levels of Zn (provided by zinc oxide: ZnO) on growth performance and fecal DM of nursery pigs. In experiment 1, 360 barrows (Line 200 × 400, DNA, Columbus, NE, initially 5.6 kg) were allotted to 1 of 6 dietary treatments from d 0 to 21 after weaning with 5 pigs per pen and 12 pens per treatment. Treatments included a positive control diet (21% CP) with 3,000 mg/kg Zn in phase 1 and 2,000 mg/kg in phase 2; negative control (21% CP) with 110 mg/kg added Zn, and 4 diets containing 4% CWB and 110 mg/kg added Zn formulated to contain 21%, 19.5%, 18%, or 16.5% CP. The 2 control diets and 21% CP CWB diet contained 1.40% standardized ileal digestible (SID) Lys in phase 1 and 1.35% SID Lys in phase 2, while the 19.5%, 18%, and 16.5% CP diets contained 1.33, 1.25 and 1.20% Lys, respectively, in both phases. Pigs fed the positive control diet containing pharmacological ZnO had increased (P < 0.05) ADG and G:F compared with the negative control and the 21% CP CWB diet. Reducing CP (concurrently with SID Lys) in diets containing CWB decreased ADG and G:F (linear, P = 0.002); however, fecal DM increased (linear, P = 0.005). In experiment 2, two groups of 300 and 350 pigs, initially 7.0 and 6.2 kg, respectively, were used with 5 pigs per pen and 26 pens per treatment. The objective was to determine if adding back essential AA would improve growth performance of pigs fed the low CP diets. All dietary treatments were fed for 13 days, contained 4% CWB, and consisted of: (1) positive control with 2,000 mg/kg of Zn and 21% CP (1.35% SID Lys); (2) no ZnO and 21% CP; and 3 diets with no ZnO formulated to 18% CP and (3) 1.2% SID Lys; (4) 1.35% SID Lys by the addition of feed grade amino acids (AA), and (5) diet 4 with non-essential amino acids (NEAA; Gly and Glu). Pigs fed 21% CP with ZnO had increased (P = 0.001) ADG compared to those fed 18% CP (1.35% SID Lys) with high levels of feed grade amino acids or those fed the reduced SID Lys (1.2%) diet. Overall, G:F was improved (P < 0.001) for pigs fed 21% CP diets and those fed the 18% CP diet with NEAA compared to pigs fed 1.2% SID Lys and pigs fed high levels of feed grade amino acids. Fecal DM was increased for pigs fed the reduced SID Lys diet. In summary, pharmacological levels of Zn improve pig growth performance, but reducing CP (and subsequently SID Lys) decreased nursery pig growth performance.

Effects of Standardized Ileal Digestible Lysine on Growth Performance and Economic Return of 108 to 178 lb Grow-Finish Pigs

A total of 2,124 barrows and gilts (PIC 1050 × DNA 600; initially 107.9 ± 1.31 lb) were used in a 32-d study to determine the optimal level of dietary standardized ileal digestibility (SID) Lys for 108 to 178 lb pigs in a commercial setting. Pigs were randomly allotted to 1 of 5 dietary treatments with 24 to 27 pigs per pen and 16 replications pen treatment. A similar number of barrows and gilts were placed in each pen. Diets were fed over 3 phases (108 to 129, 129 to 156, and 156 to 178 lb, respectively). Dietary treatments were corn-soybean meal-based and contained 10% (phase 1 and 2) or 5% (phase 3) DDGS. Diets were formulated to 85, 95, 103, 110, or 120% of the 2016 PIC SID Lys gilt recommendations as follows: phase 1 SID Lys levels of 0.90, 1.01, 1.09, 1.17 and 1.27%; phase 2 levels of 0.79, 0.87, 0.94, 1.03, and 1.10%; and phase 3 levels of 0.71, 0.78, 0.85, 0.92, and 0.99%, respectively. Overall (d 0 to 32), increasing SID Lys increased (linear, P < 0.001) ADG, final body weight, Lys intake/d, and Lys intake/kg of gain with an improvement in F/G (quadratic, P = 0.047). Additionally, feed cost per pig, feed cost per lb of gain, total revenue per pig, and income over feed cost (IOFC) increased (linear, P ≤ 0.002) as SID Lys increased. Projecting IOFC, broken line linear and quadratic polynomial models estimated the maximum IOFC at 105.8% and 113.7% SID Lys, respectively. In summary, while growth performance increased linearly up to 120% of the 2016 PIC recommended Lys requirement, the optimal IOFC was 106% to 114%.

Evaluating the standardized ileal digestible lysine requirement of 7- to 15-kg weanling pigs fed corn-soybean meal-based diets

Continued genetic improvement necessitates the verification of nutrient requirements for newly developed pig genotypes. Therefore, the objective of this research was to determine the standardized ileal digestible (SID) lysine (Lys) requirement of 7- to 15-kg weanling pigs (TN70 × TN Tempo; Topigs Norsvin) fed a corn-soybean meal-based diet. A total of 144 piglets with an initial BW of 6.51 ± 0.56 kg (mean ± SD) were assigned to one of six diets using a randomized complete block design based on BW to give eight replicate pens with three pigs per pen. The six diets contained 1.00, 1.16, 1.32, 1.48, 1.64, and 1.80% SID Lys, achieved by adding crystalline l-Lys·HCl at the expense of cornstarch. Other indispensable amino acids were provided to meet the requirements. Piglets had free access to diets and water for 21 days. Individual BW of pigs and feed disappearance were recorded weekly and blood samples were collected on day 1, 14, and 21. Average daily gain (ADG) and average daily feed intake were not affected by dietary SID Lys content during the first 7 days. However, the addition of dietary SID Lys quadratically increased (P < 0.05) gain:feed (G:F) during the first 7 days of the experiment. A quadratic increase (P < 0.05) was found in both ADG and G:F when SID Lys content increased in the diets from day 14 to 21. During the overall experimental period, increasing dietary Lys content quadratically increased (P < 0.05) ADG and G:F, whereas plasma urea nitrogen quadratically decreased (P < 0.05) as SID Lys content increased. The SID Lys requirements were estimated for linear and quadratic broken-line models. In conclusion, the SID Lys requirement for optimal growth performance of 7- to 15-kg weanling pigs fed corn-soybean meal-based diets based on linear and quadratic broken-line models were 1.27% (95% confidence interval (CI): [1.01, 1.53]) and 1.30% (95% CI: [0.94, 1.66]) for ADG and 1.27% (95% CI: [1.14, 1.40]) and 1.43% (95% CI: [1.11, 1.75]) for G:F, respectively, thus giving an overall average value of 1.32%.

Effects of lysine biomass supplementation on growth performance and clinical indicators in broiler chickens

Production of crystalline amino acids (AA) through microbial fermentation concomitantly provides an AA-enriched biomass that may serve as a cost-effective supplement for broiler chickens. We investigated the effects of feeding a fermentation biomass product containing approximately 62% Lys on growth performance, organ growth, and clinical outcomes of broilers. Beginning at 2 d post-hatch, a total of 360 Ross 308 chicks were randomly assigned to 1 of 5 treatments provided to 12 replicate cages of 6 birds. Practical corn-soybean meal-based dietary treatments included: negative control (NC; no supplementation of L-Lys, 1.01 and 0.86% standardized ileal digestible Lys in starter and grower phases, respectively), NC + 0.23% L-Lys HCl (positive control; PC), and NC supplemented with 0.30, 0.90, or 1.50% Lys biomass (LB) in both phases. Feed and water were provided ad libitum throughout the study. Individual bird and feeder weights were recorded on study day 0, 10, 21, and 35. At study conclusion, birds from each treatment were randomly selected to collect blood and tissue samples. The PC and 0.30% LB diets elicited similar overall (day 0–35) body weight gain and birds were heavier (P < 0.001) than the NC and other LB treatments. The PC, 0.30% LB, and 0.90% LB groups had better (P < 0.001) overall feed conversion ratio than NC. Some LB-supplemented treatments elicited increased (P < 0.001) relative spleen and ileum weight compared with NC and PC. Heterophils were increased (P < 0.001) in LB treatments compared with PC and NC. Lymphocytes were decreased (P < 0.001) in LB treatments compared with NC, and 1.50% LB was similar to PC. This resulted in an increased (P < 0.001) heterophil-to-lymphocyte ratio in some LB treatments, which may have resulted from general AA supplementation or the LB product. Collectively, these results suggest that addition of up to 0.30% LB restored growth performance when added to a Lys-deficient practical diet and elicited results identical to the Lys-adequate PC diet with no negative clinical effects.

Effects of a low allergenic soybean variety on gut permeability, microbiota composition, ileal digestibility of amino acids, and growth performance in pigs

Soybeans are the ‘gold standard’ protein source in pig diets, with lower inclusion levels in weaned pig diets due to transient gut hypersensitivity. The objective was to determine the impact of weaned pig diets containing a Triple Null (TN) soybean (low trypsin inhibitors, lectins, and P34 protein) in both meal (TNSBM), and full fat ground (TNGR) forms on intestinal permeability and gut microbial composition, ileal digestibility of protein and amino acids, and growth performance, in comparison to conventional soybean meal (CONSBM) and animal proteins (ANIM). In Exp. 1, 60 weaned barrows (6.65 ± 0.3 kg, n=12/diet) were randomly assigned to one of five experimental diets containing one of five test proteins (CONSBM, CONGR, TNSBM, TNGR, and ANIM). Gut permeability measurements were collected over 4d (1 pig/diet per d), beginning at d 11. No differences were detected in ileal or jejunal permeability among dietary treatments. In Exp. 2, 10 ileal-cannulated barrows (17.63 ± 1.18 kg BW) were used in a cross-over design to determine standardized ileal digestibility (SID) of four test ingredients [fishmeal (FM), CONSBM, TNSBM, TNGR]. Each pig received 3 of the 5 diets (1 diet/coll for a total of n = 6 per diet. The SID of crude protein and amino acids was greater (P < 0.05) in FM than soy products. There were minor differences in ileal digestibility between soy products where SID of Lys, Met, and His were greater (P < 0.05) in TNSBM than CONSBM. Growth performance (Exp. 3) was determined in 112 weaned pigs (7.30 ± 0.43 kg BW; 2 barrows and 2 gilts per pen) assigned to one of four dietary treatments in 2 phases (Ph1 = 5d, Ph2 = 13d). The control diet contained FM (7.25%, Ph1; 6%, Ph2); TNSBM, TNGR, and CONSBM replaced FM to supply equivalent dietary crude protein (CP). Pigs received a common Ph3 diet (18d). Overall daily gain was greater (P < 0.01) in TNGR-fed pigs compared to TNSBM, but not different from FM- or SBM-fed pigs. Overall daily intake tended to be greater (P < 0.10) in SBM-fed pigs compared to FM and TNSBM but was not different from TNGR. There was a tendency for greater (P < 0.10) overall G:F in TNGR- versus TNSBM-fed pigs. Low allergenic ground soybeans may be a suitable alternative protein source in weaned pig diets due to similar impact on intestinal permeability and growth performance compared to FM.

PSIX-14 Evaluation of high-protein distillers dried grains on growth performance and carcass characteristics of growing-finishing pigs

Abstract A total of 1,890 growing-finishing pigs (PIC; 359 × 1050; initially 27.1 kg) were used in a 124-d growth trial to compare the effects of pigs fed diets with high-protein dried distillers grains (HPDDG) or conventional dried distillers grains with solubles (DDGS) on growth performance and carcass characteristics. Conventional DDGS contained 29.0% CP, 0.48% standardized ileal digestible (SID) Lys and 9.2% oil, whereas HPDDG contained 39.3% CP, 0.68% SID Lys and 11.1% oil. All diets were formulated on an equal SID Lys-basis with diets containing HPDDG having less soybean meal than diets with conventional DDGS. There were 27 pigs per pen and 14 pens per treatment. Treatments were arranged in a 2×2 + 1 factorial with main effects of DDG source (conventional DDGS or HPDDG) and level (15 or 30%). A corn-soybean meal-based diet served as the control and allowed linear and quadratic level effects to be determined within each DDG source. Pens were assigned to treatments in a randomized complete block design with initial weight as the blocking factor. Data were analyzed using lme4 package in R (version 3.5.2) with pen as experimental unit. Overall, there were no differences observed in ADG between pigs fed either DDG source. Pigs fed HPDDG had decreased (P&amp;lt; 0.001) ADFI and increased (P&amp;lt; 0.001) G:F compared with those fed conventional DDGS. Increasing either conventional DDGS or HPDDG decreased carcass yield and HCW (linear, P&amp;lt; 0.02); however, there were no differences between pigs fed HPDDG or conventional DDGS. Iodine value (IV) was greater (P&amp;lt; 0.001) in pigs fed HPDDG than conventional DDGS, and IV increased (linear, P&amp;lt; 0.02) with increasing DDG. These data suggest that pigs fed HPDDG had greater G:F and IV compared with pigs fed conventional DDGS, probably due to the difference in oil content.