Dietary Standardized Ileal Digestible Lysine Research Articles

29 Effects of using different dietary standardized ileal digestible lysine plans on growth performance and carcass characteristics of PIC 337 or PIC 800 sired grow-finish pigs

Abstract The present study aimed to evaluate the impact of using different dietary standardized ileal digestible (SID) lysine (Lys) plans on growth performance of PIC 337 and PIC 800 sired grow-finish pigs. A total of 2,016 gilts and barrows were placed in 2 separate rooms with 48 single sex pens each (21 pigs/pen; 0.69 m2/pig). Pens were blocked by body weight (BW) and randomly allotted in a 2 × 2 × 2 factorial arrangement with genetic line (PIC 337 or 800), sex (barrows or gilts), and nutrition plan (current SID Lys curve recommendation for PIC 800 as % of PIC 337 SID Lys curve or alternative SID Lys curve) as factors. Pigs (27.4 ± 1.41 kg BW) were followed during the grower-finisher phase until slaughter. Pigs were fed either the current recommendation or an alternative SID Lys curve for PIC 800, in a 5 phase feeding program: phase 1 (23-40 kg; 97 vs 100%, respectively); phase 2 (40-60 kg; 97 vs 95%, respectively); phase 3 (60-80 kg; 97 vs 95%, respectively); phase 4 (80-105 kg; 97 vs 95%, respectively); and phase 5 (105-135 kg; 97 vs 90%, respectively). Pigs were fed isoenergetic diets. Performance and carcass traits, and removals and mortality were recorded. Data were analyzed using mixed models in R, and considering pen as the experimental unit for performance traits and individual carcasses for carcass traits. There was no evidence of interaction between genetic line and nutrition plan factors. Overall, PIC 337 vs 800 pigs did not differ on average daily gain (ADG; P > 0.05), but PIC 337 pigs consumed 150 g/d less and were 0.1 more feed efficient than PIC 800 pigs (P < 0.05; Table 1). Moreover, PIC 337 pigs had 1.9 kg less of hot carcass weight, but 2.1 mm more of loin depth compared with PIC 800 pigs (P < 0.05; Table 1). Regarding nutrition plan, no significant differences were observed for overall performance and carcass traits between pigs fed the current or alternative SID Lys curve (P > 0.05; Table 1). Additionally, no significant differences were observed for overall removals and mortality by genetic line or nutrition plan (P > 0.05; Table 1). In summary, different genetic sire line (PIC 337 and PIC 800) differed on performance and carcass traits. Further research is needed to continue studying the genetic evolution and nutrition plan for each genetic sire line in the grower-finisher period to understand their nutrient requirements.

30 Effects of using different dietary standardized ileal digestible lysine plans on growth performance and carcass characteristics of grow-finish pigs from high or low breeding value boars

Abstract The present study aimed to evaluate the impact of using different dietary standardized ileal digestible (SID) lysine (Lys) plans on growth performance and carcass characteristics of grow-finish pigs coming from high or low breeding value boars. A total of 2,080 pigs (PIC 800 × PIC Camborough) were housed in 20 mixed sex pens (26 pigs/pen), blocked by body weight (BW), and randomly allotted in a 2 × 2 factorial arrangement with boar breeding value (high or low) and nutrition Lys plan (current SID Lys curve recommendation for PIC 800 as % of PIC 337 SID Lys curve or alternative SID Lys curve). Pigs were weaned at 21 d of age (6.1 ± 0.05 kg BW) and followed during the wean-to-finish period until reach the market slaughter weight. Pigs were fed either the current recommendation or an alternative SID Lys curve for PIC 800, in a 6 phase feeding program: phase 1 (6-11 kg; 100 vs 100%, respectively); phase 2 (11-23 kg; 97 vs 100%, respectively); phase 3 (23-45 kg; 97 vs 100%, respectively); phase 4 (45-73 kg; 97 vs 95%, respectively); phase 5 (73-102 kg; 97 vs 95%, respectively); and phase 6 (102-132 kg; 97 vs 90%, respectively). Pigs were fed isoenergetic diets. Performance and carcass traits, and removals and mortality were recorded. Data were analyzed using mixed models in R, and considering pen as the experimental unit for performance traits and individual carcasses for carcass traits. There was no evidence of interaction between boar breeding value and nutrition plan factors. Overall, high breeding value pigs had greater average daily gain (ADG; 0.84 ± 0.005 g/d) compared with low breeding value pigs (0.82 ± 0.005 kg/d; P < 0.01), which was driven by increased average daily feed intake (ADFI; 1.92 ± 0.011 and 1.89 ± 0.011 kg/d, respectively; P < 0.05; Table 1). Moreover, high breeding value pigs had greater hot carcass weight (HCW; 97.8 ± 1.09 kg), carcass yield (74.1 ± 0.23%), backfat thickness (16.3 ± 0.29 mm) and lower lean meat % (57.0 ± 0.21%) compared with low breeding value pigs (96.0 ± 1.09 kg; 73.7 ± 0.23 %; 15.4 ± 0.28; 57.5 ± 0.21%, respectively; P < 0.05; Table 1). Regarding nutrition plan, no significant differences were observed for overall performance traits between pigs fed the current or alternative SID Lys curve (P > 0.05; Table 1). Nevertheless, pigs fed the alternative SID Lys curve had heavier HCW (97.3 ± 1.09 kg) compared with pigs fed the current SID Lys curve (96.6±1.09 kg; P < 0.05; Table 1). No significant differences were observed for overall removals and mortality by breeding value or nutrition Lys plan (P > 0.05). In summary, grow finish pigs from high breeding value boars have an improved productive performance. PIC 800 pigs may achieve the same productive performance with lower lysine levels at the end of the grow-finish period.

14 Effects of increasing daily dietary standardized ileal digestible lysine intake of gilts and sows during d 35 to 112 of gestation on reproductive performance

Abstract Our objective was to determine the effects of increasing daily dietary standardized ileal digestible (SID) lysine (Lys) intake during d 35 to 112 of gestation on sow and litter performance. A total of 704 gilts and sows (PIC Camborough) were used. Females were group-housed after d 35 of gestation and individually fed with electronic sow feeders (ESF). At d 35 of gestation, females were balanced for body weight (BW) and caliper scores within parity categories, and randomly allotted to 1 of 4 treatments. Treatments consisted of increasing daily dietary SID Lys intake (11.1, 13.5, 16.1, and 18.5 g/d). Both gilts and sows received 2.37 kg/d of a gestation diet containing 3.17 Mcal of ME/kg, which was estimated to avoid feeding females below their maintenance requirements throughout the entire gestation. Treatments were achieved by different blend of low (0.47% SID Lys) and high (0.78% SID Lys) Lys diets via ESF based on the set feed allowance for females. Sow was the experimental unit and data were analyzed using generalized linear mixed models with the lmer and glmerfunctions of R, considering treatment, parity, and their interaction as fixed effects. There was no evidence (P > 0.10) of treatment and parity interaction for any response criteria. Body weight at d 112 of gestation and BW change from d 35 to 112 of gestation increased (linear; P < 0.05) with increasing daily dietary SID Lys intake (Table 1). No evidence for SID Lys treatment differences were observed for BW at weaning or BW change during lactation (P > 0.10). There was no evidence (P > 0.10) for treatment differences on caliper score (CS) at d 35 of gestation, d 112 of gestation, at weaning, or CS changes during gestation and lactation. There was no evidence for treatment difference on total born, percentage stillbirth and percentage of mummified fetuses (P > 0.10). However, there was a marginal reduction in percentage born alive piglets (quadratic, P = 0.056), with the least proportion of piglets born alive observed in females receiving 16.1g of daily SID Lys intake from d35 to d112 of gestation. Increasing daily dietary SID Lys intake during d 35 to 112 of gestation did not affect piglet birth weight, piglet average daily gain during lactation, proportion of removed pigs, and proportion of dead pigs during lactation. In summary, increasing daily dietary SID Lys intake during d35-to-112 of gestation increased female BW; however, no evidence of benefits was observed for female reproductive performance and litter performance during lactation.

25 Effects of dietary standardized ileal digestible lysine on growth performance, carcass characteristics, and economics of pigs from 100 to 130 kg

Abstract A total of 1,570 finishing pigs (337 × 1050, PIC; initially 103.4 ± 0.85 kg) were used in a 28-d trial to determine the effects of feeding increasing standardized ileal digestible (SID) Lys to pigs between 100 to 130 kg on growth performance, carcass characteristics, and economics. Before the beginning of the study, the 3 heaviest pigs per pen were removed and marketed with all remaining pigs marketed 28-d later at the end of the study. Pigs were housed in mixed sex pens, with 20 pigs per pen and 20 pens per treatment. The experiment was a randomized complete block design with four dietary treatments: 0.63, 0.68, 0.75, and 0.82% SID Lys. Diets were corn-soybean meal-based and fed in meal form. Dietary treatments were similar in NE and increasing SID Lys was achieved by increasing soybean meal and feed grade amino acids. For the first 14 d from 100 to approximately 118 kg, there was a linear tendency for increased (P = 0.074) average daily gain (ADG), a linear improvement (P < 0.05) in gain to feed ratio (G:F), and increase (P < 0.001) in SID lysine intake per kg of gain as SID Lys increased (Table). For the second 14 d from 118 to 128 kg, SID Lys intake per kg of gain increased (P < 0.001) as SID Lys increased, however; there was no evidence for difference (P > 0.10) for any growth performance traits. Overall, there was a linear increase (P = 0.018) in G:F and increase (P < 0.001) in SID lysine intake per kg of gain as SID Lys increased. Increasing SID Lys also linearly increased (P < 0.05) percentage lean and decreased (P < 0.05) backfat depth with no evidence for differences (P > 0.10) in other carcass criteria. For economics, feed cost and feed cost per kg of gain linearly increased (P < 0.05) as SID Lys increased in both low and high-price scenarios. Income over feed cost linearly decreased (P < 0.05) as dietary SID Lys increased in a low-price scenario, but there was no difference between treatments in a high-price scenario (P > 0.10). In conclusion, increasing dietary SID lysine in the last 28-d of the finisher period linearly increased G:F and SID Lys intake per kg of gain without significantly influencing other growth performance traits. Feed cost per kg of gain was linearly increased for both low and high-price scenarios with a detriment for IOFC with increasing SID Lys in the low-price scenario.

146 Comparing feeding strategies during heat stress in finishing pigs using a stochastic swine model

Abstract Nutritionists may feed standard diets or increase dietary net energy (NE) and/or standardized ileal digestible lysine (SIDLys) to counter reduced average daily feed intake (ADFI) due to heat stress in the late finishing phase. The objective of this work was to develop a set of statistical tools to analyze different grow-finish feeding strategies using the simulations from a proprietary stochastic swine model (Watson) when heat stress occurs during the last 2 wk of the finishing phase. Financial considerations were excluded from the study. Nutrient recommendations for maximum feed efficiency were derived from Watson and used to formulate a grower diet for 25 to 60 kg body weight (BW), and four finisher diets for 60 to 135 kg BW: a) thermoneutral (10 MJ NE/kg, 7.9 g/kg SIDLys), b) high AA (10 NE/kg, 9.2 g/kg SIDLys), c) high NE (10.5 MJ/kg NE, 7.9 g/kg SIDLys), and d) high NE and high AA (10.5 MJ NE/kg, 8.3 g/kg SIDLys). The grow-finish period was simulated by feeding the grower diet followed by the finisher diets in 5 different scenarios: 1) thermoneutral, diet a; 2) heat stress, diet a; 3) heat stress, diet a, and b during last 2 wk; 4) heat stress, diet a, and c during last 2 wk; 5) heat stress, diet a, and d during last 2 wk. Performance results were obtained by running each scenario 100 times, generating a new population per simulation. Results from scenarios 1) and 2 showed that heat stress in the last 2 wk reduced (P < 0.05) ADFI and average daily gain of pigs fed diet a by 790 g/d and 310 g/d, respectively. This resulted in a decrease of 4.79 kg in final BW, an increase of 0.64% lean yield, and a decrease of 0.80 mm back-fat at slaughter (P < 0.05). An increased dietary SIDLys (3), NE (4), or both (5) during heat stress did not affect BW compared with scenario 2 (P > 0.05). An increased NE (4) or NE and SIDLys (5) did not affect lean yield and back fat compared with scenario 2 (P > 0.1). But increased SIDLys during heat stress (3), increased lean yield (P = 0.04) and a trend in less back fat (P = 0.07) compared with scenario 2. In conclusion, pig performance was reduced with heat stress in the late finishing period. With the developed statistical tools, we determined from the simulations that none of the proposed strategies significantly increased final BW compared with the baseline (2). But feeding greater SIDLys will likely result in significantly greater lean yield and less back fat. When formulating diets with greater nutrient density attention to ingredient cost and pig prices should be considered.

130 Effects of Increasing Dietary Standardized Ileal Digestible Lysine Levels on Growth Performance of 102- to 127-kg Immunocastred Gilts and Boars

Abstract Our objective was to determine the effects of increasing dietary standardized ileal digestible (SID) lysine (Lys) on growth performance of immunocastrated gilts and boars. A total of 3,519 split gender pigs [PIC 337×Camborough, initial body weight (BW) = 101.7 ± 3.89 kg] were used in a 21-d trial in 2 replicates. Following the immunization against gonadotropin-releasing hormone (administrated with Vivax, Zoetis, São Paulo, SP, Brazil) in both genders, pens of pigs were weighed, blocked by BW, and randomly allotted to 1 of 5 treatments. Treatments consisted of 1.69, 1.90, 2.11, 2.32, and 2.53 g of SID Lys:Mcal of ME, which corresponded to 80, 90, 100, 110, and 120% of PIC SID Lys recommendations for mixed gender between barrow and gilts. This resulted in 0.56, 0.63, 0.70, 0.77, and 0.84% SID Lys given that the treatment diets were corn-soybean-meal-based and contained 3,300 Kcal of ME/kg. There were 6 split gender pens∙treatment-1∙replicate-1 and 29 pigs/pen. Data were analyzed using generalized linear and nonlinear mixed models with a pen as the experimental unit. Competing models included linear, quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic (BLQ). There was no evidence of linear or quadratic SID Lys concentration by gender interaction (Table). Increasing SID Lys concentration improved average daily gain (ADG; quadratic, P < 0.01) and gain-to-feed ratio (G:F; quadratic, P < 0.01). The QP, BLL, and BLQ had a similar fit for the ADG and G:F. In the QP model, 95% and 100% of the ADG were achieved at 0.64 and 0.76% of SID Lys, respectively, and at 0.61 and 0.75% for G:F. The BLL and BLQ models estimated the breakpoint at 0.70% (95% CI: 0.65-0.74%) and 0.68% SID Lys (95% CI: 0.50-0.85%), for ADG, respectively. For G:F, the BLL, and BLQ models estimated the breakpoint at dietary SID Lys of 0.69% (95% CI: 0.52-0.86%) and 0.68% (95% CI: 0.58-0.78%), respectively. There was no evidence that increasing dietary SID Lys levels impacted the average daily feed intake or the removal and mortality rate. In the current trial the estimated optimum SID Lys:Mcal of ME ratio for 102- to 127-kg immunocastrated gilts and boars ranged from 2.06-2.30 (0.68-0.76% SID Lys based on a 3,300 kcal of ME/kg diet), depending on the statistical model.

135 Effects of Increasing Dietary Standardized Ileal Digestible Lysine Levels on Growth Performance of PIC 337 × Camborough Commercial Pigs that were Sired by High Index Boars

Abstract Our objective was to determine the effects of increasing dietary standardized ileal digestible lysine levels on the growth performance of PIC 337 × Camborough commercial pigs that were sired by high-index boars. A total of 2,200 barrows and gilts (PIC 337 × Camborough) were used in six experiments covering body weight ranges of 11-25 kg (Exp.1), 26-46 kg (Exp.2), 45-66 kg (Exp.3), 63-85 kg (Exp.4), 86-110 kg (Exp.5), and 108-134 kg (Exp.6). Pigs were placed in two rooms with 45 pens in Room 1 and 43 pens in Room 2, and there were 25 pigs/pen (12 or 13 gilts and 13 or 12 barrows) for both rooms. Room 1 was used in Exp. 1, 3, and 5; Room 2 was used in Exp. 2, 4, and 6. At the beginning of each trial, on-test pens were blocked by body weight and randomly allotted to one of five treatments (90, 100, 105, 110, or 120% of PIC SID Lys recommendations for Exp.1 to Exp. 5; whereas 80, 90, 100, 110, or 120% of PIC SID Lys recommendations for Exp. 6) in a randomized complete block design. Off-test pens were fed a common wash-out diet between trials, and common diets were formulated to meet PIC nutrient requirements according to the specific weight range. Data were analyzed using generalized linear mixed model with pen as the experimental unit in R Studio (Version 3.5.2, R Core Team; Vienna, Austria). Dietary SID Lys levels were included as fixed effects, and weight block was included as random effects in the model. All data are reported as least square means and considered statistically significant at P < 0.05 and marginally significant at P < 0.10. Increasing SID Lys improved average daily gain (ADG; linear, P = 0.003) and gain-to-feed ratio (G:F; quadratic, P = 0.007) in Exp.1; improved ADG (quadratic, P = 0.045) in Exp.4; improved ADG (quadratic, P = 0.009) and G:F (quadratic, P = 0.002) in Exp.5; and improved ADG (linear, P = 0.037) and G:F (linear, P = 0.030) in Exp.6 (Table 1). However, there was no evidence for difference among treatments on growth performance in Exp.2 and 3. With increasing dietary SID Lys levels, gram of SID Lys per kilogram of bodyweight gain increased in a quadratic manner in Exp.1 (P = 0.025) and 5 (P = 0.002); and increased in a linear manner in Exp.2, 3, 4, and 6 (P < 0.001). In conclusion, increasing dietary SID Lys levels improved the growth performance of PIC 337 × Camborough commercial pigs sired by high-index boars when the bodyweight was below 25 kg or beyond 63 kg.

Effects of dietary standardized ileal digestible lysine to net energy ratio and wheat level on growth performance, meat quality, intestinal microbiota and body metabolism of finishing pigs

Lowing lysine (Lys): energy ratio based on corn-soybean diets could increase intramuscular fat (IMF) content, the effectiveness of it in enhancing IMF content when corn is partially substituted by wheat is unclear. This study aimed to determine the effects of dietary wheat levels and standardized ileal digestible (SID) Lys: net energy (NE) ratio on growth performance and meat quality, alteration in gut microbiota and body metabolism, as well as its correlation with meat quality are revealed via combined microbiome and metabolomic methods. A total of 72 pigs were randomly divided into four groups and fed with high SID Lys:NE ratio (HR) diets containing 25% wheat (W25HR), low SID Lys:NE ratio (LR) diets containing 25% wheat (W25LR), HR diets containing 55% wheat (W55HR) or LR diets containing 55% wheat (W55LR). Increasing dietary wheat level impaired feed utilization during 65–90 kg phase (P < 0.05) and enhanced meat color values (P < 0.05) of longissimus dorsi (LD) in finishing pigs. Enhancing dietary wheat level decreased relative abundance of Lactobacillus and Coprococcus (P < 0.05), and inhibited microbial carbohydrate metabolism capacity (P < 0.05) in colon of finishing pigs. Changes in microbial composition and carbohydrate metabolism capacity caused by wheat level led to alteration in meat color. LR diets improved feed utilization (P < 0.05), affected amino acid and lipid metabolism, and increased IMF content in LD (P < 0.05). Reducing SID Lys:NE ratio changed the concentrations of PA, delta-tocopherol, L-arginine, AzA, BA, and L-carnitine at the 25% wheat level and ARA, SDA, Glu, fructose-6-phosphate, and isorhamnetin at the 55% wheat level in the serum (P < 0.05, VIP > 1), which could serve as key biomarkers for predicting meat quality. LR diets upregulated mRNA expression levels of CCAAT/enhancer binding protein (C/EBP) α (P < 0.05), C/EBPβ (P < 0.01), sterol regulatory element-binding transcription factor 1c, fatty acid synthase (FAS) (P < 0.05), while downregulated mRNA abundance of adipose triglyceride lipase (ATGL) (P < 0.05) in liver at the 25% wheat level. The mRNA expression levels of C/EBPβ (P < 0.01), FAS, acetyl-coA carboxylase and fatty acid binding protein 1 (P < 0.05) were higher in the W55LR than W55HR groups, whereas mRNA abundance of ATGL was lower (P < 0.05). These results indicated that lowering SID Lys:NE ratio promoted lipogenesis, inhibited lipolysis and improved IMF deposition in LD via altering serum metabolism in different manner at two wheat level. LR diets containing 25% wheat was recommended to enhance the growth performance of finishing pigs, while concurrently achieving higher IMF content and improved meat color in the LD.

Optimal dietary standardized ileal digestible lysine level for pigs during the grower, early and late finisher periods

BackgroundLysine (Lys) is the first limiting amino acid for pigs fed corn-soybean meal diets. Three experiments were conducted to estimate the optimal standardized ileal digestible (SID) Lys requirement for growing (Exp. 1), early finishing (Exp. 2), and late finishing (Exp. 3) pigs under commercial conditions.Results and conclusionsIn Exp. 1, a total of 650 growing pigs (32.21 ± 0.33 kg bodyweight), were allocated to 5 dietary treatments supplemented with 0.75, 0.85, 0.94, 1.03, and 1.13% SID Lys. Each treatment had 5 replicate pens with 26 pigs per pen. The lowest feed to gain ratio (F:G) was obtained by pigs fed the 1.03% Lys diet and F:G showed both a linear and a quadratic response with increasing Lys (P < 0.05). Based on broken-line and quadratic analysis models, dietary SID Lys levels for the minimum F:G were 0.94%. In Exp. 2, 650 finishing pigs (57.24 ± 2.00 kg bodyweight) were allotted to 5 dietary treatments providing SID Lys of 0.63, 0.71, 0.79, 0.87, and 0.95%. Each treatment had 5 replicates, 26 pigs per replication. The highest final bodyweight was achieved by 0.79% Lys while the highest average daily gain (ADG) and average daily feed intake (ADFI) was achieved by pigs consuming the 0.87% Lys diet (P < 0.05). Additionally, the lowest F:G was obtained by pigs fed the 0.79 and 0.87% Lys diet (P < 0.05). Based on broken-line and quadratic analysis models, the optimum Lys was 0.81 and 0.82% for ADG and F:G, respectively. In Exp. 3, 600 late finishing pigs (92.22 ± 2.41 kg bodyweight), were divided into 5 treatments providing Lys levels of 0.53, 0.60, 0.66, 0.73, and 0.79%. Each treatment had 5 replicates, 24 pigs per replication. Results showed that final bodyweight, ADG, ADFI, and F:G was not affected by increasing dietary Lys level, suggesting that the lowest SID Lys (0.53%) was sufficient for this group of pigs. Taken together, the SID Lys requirement for pigs from 30 to 60 kg, 60 to 90 kg, 90 to 120 kg was 0.94%, 0.81 to 0.82, and 0.53%, respectively, depending on the response criteria with performance maximized.

254 Effects of Increasing Daily Dietary Standardized Ileal Digestible Lysine Intake of Gilts and Sows During day 35-to-112 of Gestation on Reproductive Performance

Abstract Our objective was to determine the effects of increasing daily dietary standardized ileal digestible (SID) lysine (Lys) intake during d35-to-112 of gestation on sow and litter performance. A total of 583 gilts and sows (PIC Camborough) were used. Females were group-housed after d35 of gestation and individually fed with electronic sow feeders (ESF). At d35 of gestation, females were randomly allotted to 1 of 4 treatments that were balanced for body weight (BW) and caliper scores (CS) within parity categories. Treatments consisted of increasing daily dietary SID Lys intake (11.1, 13.5, 16.1, and 18.5 g/d). Both gilts and sows received 1.85 kg/d of a gestation diet containing 2.38 Mcal of NE/kg. Treatments were achieved by different blends of low (0.60% SID Lys) and high (1.00% SID Lys) Lys diets via ESF. Sow was the experimental unit and data were analyzed using generalized linear mixed models with the lmer and glmer functions of R. Body weight and CS at d112 of gestation increased (linear, P&amp;lt; 0.05) with increasing daily dietary SID Lys intake. There was no evidence for treatment difference on d112 backfat depth (BD), or changes of BW, CS, and BD during lactation. There was no evidence for treatment difference on total born, percentage born alive and stillbirth, but there was a marginal reduction (linear, P=0.086) on mummified fetuses. Increasing daily dietary SID Lys intake during d35-to-112 of gestation did not affect piglet birth weight, percentage of piglets born with less than 900g, pre-weaning mortality, or piglet average daily gain. In summary, increasing daily dietary SID Lys intake during d35-to-112 of gestation increased female BW and CS, without changing BD, indicating that more lean tissue had been deposited. However, there was no evidence for treatment differences on reproductive performance.

144 Effects of Increasing Dietary Standardized Ileal Digestible Lysine Levels on Growth Performance of 15- to 23-Kg Maternal Barrows

Abstract Our objective was to determine the effects of increasing dietary standardized ileal digestible (SID) lysine (Lys) on growth performance of late nursery pigs. A total of 1,125 barrows (L02 ′ L03, initially 15.4 kg ± 0.003) were used in a 14-d study. Pens of pigs were weighed, blocked by location in the barn, and randomly allotted to 1 of 6 treatments that contained 1.05, 1.16, 1.23, 1.29, 1.39, and 1.52% of dietary SID Lys. Diets were corn-soybean meal-based and contained 3,300 Kcal of ME/kg, with treatments achieved by increasing the inclusion of synthetic lysine. There were 9 pens per treatment and 25 barrows 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 &amp;lt; 0.05) and gain to feed ratio (G:F; quadratic, P &amp;lt; 0.05). Although no model provided better fit to the ADG data compared with the linear model, the greatest improvement in growth rate was observed as SID Lys increased from 1.05 to 1.41%. The best-fitting models for G:F were QP and BLL. The QP and BLL models estimated the plateau or breakpoint at dietary SID Lys of 1.45% (95% CI: 1.21 to &amp;gt;1.52%) and 1.41% (95% CI: 1.40 to 1.42%), respectively. There was no evidence that increasing dietary SID Lys levels impacted average daily feed intake or the removal and mortality rate (P &amp;gt; 0.10). Increasing SID Lys concentration increased (linear; P &amp;lt; 0.05) the grams of SID Lys intake per kg of gain. In the current trial, the estimated optimum SID Lys concentration for 15- to 23-kg maternal barrows ranged from 1.41 to 1.46%, depending on the statistical model.

142 Effects of Increasing Dietary Standardized Ileal Digestible Lysine Levels on Growth Performance of 11- to 25-Kg Pigs Sired by PIC 337 High Index Boars

Abstract Our objective was to determine the effects of increasing dietary standardized ileal digestible (SID) lysine (Lys) on growth performance of late nursery pigs. A total of 1,116 pigs (PIC 337×Camborough, initially 11.1±0.11 kg) were used in a 21-d study. The pigs 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 that contained 1.13, 1.26, 1.32, 1.38, and 1.51% of dietary SID Lys (corresponding to 90, 100, 105, 110, and 120% of PIC SID Lys recommendations). Diets were corn-soybean meal-based and contained 2,385 Kcal of NE/kg. 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 SID Lys concentration improved average daily gain (ADG, linear, P = 0.001) and gain to feed ratio (G:F, quadratic, P = 0.011, Table 1). Although the best fitting model for ADG was the linear, the greatest improvement was observed as SID Lys level increased from 1.13 to 1.32%. The best-fitting models for G:F were BLL, BLQ, and QP. The BLL and BLQ models estimated the breakpoint at 1.31% (95% CI: 1.24 to 1.37%) and 1.30% (95% CI: 1.24 to 1.37%), respectively. The QP model estimated the maximum G:F at 1.44% (95% CI: 1.35 to &amp;gt;1.51%), with 98.7% of maximum G:F achieved at 1.30%. Increasing dietary SID Lys levels marginally reduced removal and mortality rate (linear, P = 0.061). In conclusion, the estimated optimum SID Lys concentration for 11- to 25-kg pigs sired by high index boars ranged from 1.30 to 1.44%, depending on the response criteria and statistical model.

145 Effects of Increasing Dietary Standardized Ileal Digestible Lysine Levels on Growth Performance of 12- to 23-Kg Boars and Gilts

Abstract Our objective was to determine the effects of increasing dietary standardized ileal digestible (SID) lysine (Lys) on growth performance of late nursery boars and gilts. A total of 1,920 pigs (PIC 337×Camborough, initially 12.1±1.34kg) were used in a 21-d trial. Pens of pigs were weighed, blocked by body weight, and randomly allotted to 1 of 5 treatments containing 1.10, 1.16, 1.29, 1.42, and 1.48% SID Lys (corresponding to 85, 90, 100, 110 and 115.0% of PIC SID Lys recommendations). Diets were corn-soybean-meal-based and contained 3,300 Kcal of ME/kg. There were 6 split gender pens/treatment and 32 pigs/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). There was no evidence of linear or quadratic SID Lys concentration by gender interaction. Increasing SID Lys concentration improved average daily gain (ADG; quadratic, P &amp;lt; 0.05) and gain to feed ratio (G:F; quadratic, &amp;lt; 0.01). The QP, BLL, and BLQ had similar fit for the ADG and G:F. In the QP model, 95% and 100% of the ADG were at 1.18 and 1.36% of SID Lys, respectively, and 1.17 and 1.35% for G:F. The BLL and BLQ models estimated the breakpoint at 1.20% (95% CI: 1.06-1.35%) and 1.22% SID Lys (95% CI: 0.97-1.47%), for ADG, respectively. For G:F, the BLL and BLQ models estimated the breakpoint at dietary SID Lys of 1.20% (95% CI: 1.07-1.33%) and 1.20% (95% CI: 1.03-1.38%), respectively. There was no evidence that increasing dietary SID Lys levels impacted average daily feed intake or the removal and mortality rate. In the current trial with dietary ME level at 3,300 kcal/kg, the estimated optimum SID Lys concentration for 12- to 23-kg boars and gilts ranged from 1.20-1.36%, depending on the statistical model.

Limiting Dietary Lysine Increases Body Weight Variability by Restricting Growth Potential of the Lightest Growing Pigs.

Simple SummaryFinding strategies to manage variability in growing pig operations is of major importance to avoid the extra costs associated with inefficient barn usage or penalties at the processing plants when pigs are not correctly sorted. The aim of this study was to determine whether dietary amino acid density can have an impact on body weight variability in a population of growing pigs. Feeding diets with a reduced amino acid density had a negative effect because they increased body weight variability of pens composed of the smallest pigs. For instance, in those pigs, the coefficient of variation, which is used as a measure of variability, increased significantly at the end of the experiment when dietary amino acid density was reduced. It was observed that this effect was explained by a growth restriction that was more severe the lightest the pigs were at the start of the trial. Hypothesizing that posteriorly there would be no differences in growth between those restricted pigs and the normally fed ones, the differences in growth would result in around 5–10 additional days to reach marketing weight. In conclusion, severe nutritional restrictions can negatively affect growing pigs’ body weight variability.The goal of this experiment was to determine the implications of dietary standardized ileal digestible lysine (SID Lys:NE) on body weight variability of growing pigs grouped in three initial body weight categories (BWCAT). Animals (N = 1170) were individually weighed and classified in 3 BWCAT (Lp: 32.1 ± 2.8 kg, Mp: 27.5 ± 2.3 kg, and Sp: 23.4 ± 2.9 kg). Afterward, pens were randomly allocated to five dietary SID Lys:NE treatments (3.25 to 4.88 g/Mcal) that were fed over 47 days. Pen coefficient of variation of Sp at day 47 was linearly increased when reducing SID Lys:NE (p < 0.01), from 9.8% to 15.4% between the two extreme dietary levels. The linear effect was different in Sp compared to Lp (p < 0.05) as no effect of SID Lys:NE was reported in the latter BWCAT (p = 0.992). Further analysis showed that this effect was explained by a growth restriction that was more severe the lightest the pigs were at the start of the trial. To summarize, swine body weight variability can be negatively affected when SID Lys requirements are not fulfilled.

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 &amp;gt; 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 &amp;gt;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 &amp;gt;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.

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 &amp;lt; 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 &amp;gt;1.50%), with 99% of maximum ADG achieved at 1.27%. The BLL plateau was estimated at 1.31% (95%CI: 1.06 to &amp;gt;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 &amp;gt;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 &amp;gt;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.

80 Effects of dietary standardized ileal digestible lysine level in the nursery period and number of dietary phases in the grow-finish period on wean-to-finish growth performance of pigs

Abstract The objective was to determine if feeding differing levels of dietary standardized ileal digestible lysine (SID Lys) during the nursery phase influenced the growth performance response to the number of dietary phases fed in the grow-finish period. A split-plot design was used with a 3×2 factorial arrangement of the following treatments: 1) SID Lys level nursery period: Control (SID Lys at requirement) vs. Restricted (0.2 g/kg SID Lys below Control) vs. Excess (0.1 g/kg SID Lys above Control; 2) Number of Dietary Phases in grow-finish: 3 vs. 5. Diets were formulated to meet NRC (2012) requirements, except for SID Lys during the nursery period. The study was carried out over the nursery [weaning (21±2 d; 5.8 ± 0.05 kg BW) to wk 9 post-weaning] and grow-finish [wk 9 to 19 post-weaning (112 ± 3.7 kg BW)] periods using 4,356 pigs housed in single-sex groups of 44 pigs, at a floor space of 0.30 m2/pig and 0.62 m2/pig in nursery and grow-finish periods, respectively. Data were analyzed using PROC MIXED of SAS; pen was the experimental unit. The model included fixed effects of SID Lys level (main plot), Number of Dietary Phases (split plot), their interaction, and random effects of block and block by SID Lys level interaction. There were no treatment interactions (P &amp;gt; 0.05). The Restricted Lys treatment reduced (P &amp;lt; 0.05) ADG and G:F in the nursery period compared to other treatments, but had no effect on these measurements in the grow-finish or wean-to-finish periods. There was no effect (P &amp;gt; 0.05) of the number of dietary phases on growth performance in grow-finish. In conclusion, feeding low levels of Lys in the nursery reduced nursery but not wean-to-finish growth performance; reducing the number of dietary phases in grow-finish from 5 to 3 had no impact on growth performance.

198 Effects of different dietary standardized ileal digestible lysine specifications on growth performance of grow-finish pigs

Abstract The objective was to determine the effects of different standardized ileal digestible (SID) lysine (Lys) specifications on performance of grow-finish pigs. A total of 2,106 pigs (PIC 359×Camborough, initially 22.0±0.43 kg) were used in a 72-d growth trial with 27 pigs per pen and 13 pens per treatment in a randomized complete block design. Pigs were fed corn-soybean-meal-based diets in three phases from 22-41, 41-62, and 62-91 kg body weight (BW). Treatments consisted of low (L) or high (H) SID Lys in each phase: LLL (1.05, 0.88, and 0.73%); LLH (1.05, 0.88, and 0.82%); LHH (1.05, 0.99, and 0.82%); HLL (1.18, 0.88, and 0.73%); HHL (1.18, 0.99, and 0.73%); and HHH (1.18, 0.99, and 0.82%). Lysine curves from PIC2008 and PIC2016 nutrient specification manuals were used to estimate SID Lys levels for L or H diets, respectively. Data were analyzed using generalized linear mixed models with pen as the experimental unit. From 22-41 kg, feeding high Lys improved (P&amp;lt; 0.10) average daily gain (ADG), feed efficiency (G:F), and final BW compared to low Lys. From 22-62 kg, feeding HH Lys increased (P&amp;lt; 0.05) ADG compared feeding LL or HL Lys. Pigs fed HH Lys or LH Lys had improved (P&amp;lt; 0.05) G:F compared to those fed LL Lys. Pigs fed LH or HH Lys had greater (P&amp;lt; 0.05) final BW compared to pigs fed HL. Pigs fed HH Lys had greater (P&amp;lt; 0.05) feed intake compared to pigs fed HL. From 22-91 kg, there was no evidence for differences in ADG, feed intake, G:F, or final BW. In summary, pigs fed 1.18% SID Lys had improved ADG, G:F, and final BW compared to pigs fed 1.05% SID Lys from 22-41 kg. Feeding a range of Lys specifications resulted in similar growth performance from 22-91 kg.

202 Determining the effects of increasing dietary standardized ileal digestible lysine levels on growth performance and carcass characteristics of growing-finishing pigs from 29- to 129-kg

Abstract Our objective was to determine the effects of increasing standardized ileal digestible (SID) lysine (Lys) levels on growth performance and carcass characteristics of growing-finishing pigs. A total of 1,013 barrows and gilts (PIC337×Camborough, initially 29.2±0.21 kg) were used in a 112-d growth trial with 25 or 26 pigs per pen and 13 pens per treatment in a randomized complete block design. Diets were corn-soybean meal (SBM)-dried distillers grains with solubles-based, and treatments were achieved through the inclusion of SBM at the expense of corn. Diets were fed in 6 phases and formulated to be iso-caloric within each phase. Treatments consisted of: 1) Low Lys: overall dietary SID Lys levels as 87% of PIC2016 Lys requirement; 2) Medium Lys: overall dietary SID Lys levels as 97% of PIC2016 Lys requirement; 3) High Lys: overall dietary SID Lys levels as 106% of PIC2016 Lys requirement. Experimental data were analyzed using generalized linear mixed models with pen as the experimental unit. Pigs fed High or Medium Lys had greater (P&amp;lt; 0.01) average daily gain compared to pigs fed Low Lys. There was no evidence (P &amp;gt;0.10) for the difference between treatments for average daily feed intake. Pigs fed High Lys had the greatest (P&amp;lt; 0.01) feed efficiency (G:F) followed by Medium Lys, with pigs fed Low Lys with the lowest G:F. Pigs fed High or Medium Lys had greater (P&amp;lt; 0.01) hot carcass weight, loin depth, and lean percentage compared to pigs fed Low Lys. There was no evidence (P &amp;gt;0.10) for treatment effect on carcass yield and backfat. Pigs fed Low Lys had greater removal and mortality rate than those fed High or Medium Lys (P&amp;lt; 0.01). In conclusion, increasing SID Lys over PIC2016 recommendations through increasing SBM levels resulted in increased growth performance and carcass characteristics, and reduced removal and mortality rate of 29- to- 129 kg pigs.

Effects of different standardized ileal digestible lysine: net energy proportion in growing and finishing pigs.

This experiment was performed to evaluate the optimal proportion of dietary standardized ileal digestible lysine (SID Lys) to net energy (NE) proportion in growing to finishing pigs. A total of seventy-two pigs were used at phase 1 (initial body weight 37.23 ± 0.23 kilogram, for 42 d) and at phase 2 (initial body weight 54.16 ± 0.20 kilogram, for 77 d). They were arbitrarily assigned to three treatments groups consisting of four duplicates per treatment (six pigs in duplicates, respectively). Diet treatments were as follows: CON = basal diets (phase 1, crude protein (CP): 19.1%; SID Lys: 0.94%; SID Lys: NE proportion: 0.91 g/MJ / phase 2, CP: 17.0%; SID Lys: 0.84%; SID Lys: NE proportion: 0.79 g/MJ), TRT1 (phase 1, CP: 18.0%; SID Lys: 0.92%; SID Lys: NE proportion: 0.89 g/MJ / phase 2, CP: 15.8%; SID Lys: 0.8%; SID Lys: NE proportion: 0.75 g/MJ), TRT2 (phase 1, CP: 17.3%; SID Lys: 0.82%; SID Lys: NE proportion: 0.79 g/MJ / phase 2, CP: 14.8%; SID Lys: 0.7%; SID Lys: NE proportion: 0.65 g/MJ). In phase 1 and 2, growth performance did not meaningfully be affected when SID Lys: NE proportion decreased with reducing CP content. In phase 2, the nitrogen digestibility of CON group in 11 week was higher (p < 0.05) than other treatments. Also, marbling and firmness scores of TRT2 group diets increased (p < 0.05) compared with those of CON group, but dissimilarities of other meat qualities did not be detected among treatments. In conclusion, introduction of NE system can reduce negative problems introduced when dietary CP decreased. Also, 0.79 and 0.65 g/MJ of SID Lys: NE proportion is the optimal Lys: NE proportion to achieve improved pork quality without impairing the growth performance in growing-finishing pigs, respectively.