Standardized Ileal Digestible Lys Levels Research Articles

141 Determination of the optimum standardized ileal digestible lysine for nursery pigs fed high levels of dietary fiber

Abstract An experiment was conducted to determine the optimum standardized ileal digestible (SID) Lys for nursery swine-fed high levels of dietary fiber. A total of 2,525 pigs [PIC 337 × 1050, initial body weight (BW) = 6.5 kg], placed in pens of 36 mixed-sex pigs, were used in a 42-d trial. Pigs were allotted to 1 of 5 dietary treatments with 14 replicates per treatment. Increasing dietary SID Lys concentrations of 1.14, 1.22, 1.30, 1.38, and 1.45% were obtained by blending the 1.14% and the 1.45% SID Lys diets via Big Dutchman DryExact Pro feeding system (Big Dutchman, Holland, MI). The different SID Lys levels were obtained by changing the inclusion rate of soybean meal, which ranged from 15 to 28%. The experimental diets contained sugar beet pulp and soy hulls, resulting in an NDF level of 10.5%. Experimental diets were fed for 17 d and followed by a common corn, soybean meal, and 10% DDGS diet with 1.30% SID Lys from d 17 to 42. Pigs were weighed on d 0, 17, and 42 to calculate average daily gain (ADG), average daily feed intake (ADFI) and gain to feed ratio (G:F). From d 0 to 17, a quadratic (P < 0.05) improvement in ADG and ADFI was observed for pigs fed increasing SID Lys up to 1.38%, plateauing thereafter. Pigs fed increasing SID Lys had linearly (P = 0.001) improved G:F (Table 1). From d 17 to 42, there was no evidence (P > 0.10) for differences in ADG, yet ADFI increased linearly (P = 0.004) while G:F decreased linearly (P = 0.001) for pigs previously fed increasing concentrations of SID Lys. Overall (d 0 to 42) for pigs fed increasing SID Lys, ADG and ADFI increased quadratically (P < 0.05) up to 1.38% SID Lys, whereas G:F increased linearly (P = 0.001) up to 1.45% SID Lys. Mortality and removal rate was quadratically influenced (P < 0.05) by feeding increasing SID Lys. Our findings suggest feeding weaned pigs from d 0 to 17 a diet containing 1.38% SID Lys is optimal for growth performance while minimizing mortality and removal rate.

31 Effects of dietary standardized ileal digestible (SID) lysine (Lys) levels and dietary SID tryptophan to Lys ratios on growth performance and behavior of late-nursery to finish maternal barrows

Abstract The objective was to determine the effects of dietary standardized ileal digestible (SID) lysine (Lys) levels and SID tryptophan (Trp) to Lys ratios on growth performance and behavior of late-nursery to finish maternal barrows. A total of 2,293 barrows (PIC Camborough, initially 11.9 ± 0.35 kg) were used in this trial with 96 mixed-sex pens and 23 to 25 pigs/pen. There was a total of 6 dietary phases: P1:11.9-29.5 kg; P2:29.5-49.6 kg; P3:49.6-62.6 kg; P4:62.6-80.3 kg; P5:80.3-103.3 kg; and P6:103.3-137.8 kg. Pens were blocked by body weight and randomly allotted to 1 of 6 treatments:T1: 100% Lys (dietary SID Lys levels meet PIC SID Lys recommendation) and 21.0% of SID Trp:Lys ratio; T2: 100% Lys and 18.5% of SID Trp:Lys ratio; T3: 100% Lys and 16.0% of SID Trp:Lys ratio; T4: 80% Lys (dietary SID Lys levels meet 80% of PIC SID Lys recommendation) and 21.0% of SID Trp:Lys ratio; T5: 80% Lys and 18.5% of SID Trp:Lys ratio; and T6: 80% Lys and 16.0% of SID Trp:Lys ratio for P1-P2 and then 100% Lys and 18.5% of SID Trp:Lys ratio for P3-P6. Ear lesion (EL) was monitored during P2-P5. Data were analyzed using a linear mixed model in R Studio (Version 3.5.2, R Core Team; Vienna, Austria). Pigs fed T1 and T2 showed improved average daily gain than T6 (P < 0.05), with other treatments intermediate (Table 1). Pigs fed T2 showed improved average daily feed intake as compared with T6 (P < 0.05), with other treatments intermediate. There was no evidence for significant difference on feed-to-gain ratio or mortality. Removal was significantly greater for pigs fed T6 compared with all other treatments (P < 0.05). Pigs fed T2 had significantly greater hot carcass weight than T4, with other treatments intermediate. There was no evidence for significant differences on carcass yield or lean percentage. Pig fed T6 had significantly greater incidence of EL in P2 than all other treatments (P < 0.05). Pigs fed T4 and T6 had greater incidence of EL in P3 than T1 (P < 0.05), with other treatments intermediate. Pigs fed T5 and T6 had significantly greater incidence of EL in P4 than T1, T2, and T3 (P < 0.05), with T4 intermediate. During P5, pigs fed T4 and T5 had the greatest incidence of EL (P < 0.05), while pigs fed T6 had significant greater incidence of EL than T3 (P < 0.05), with T1 and T2 intermediate. In conclusion, dietary SID Lys and SID Trp:Lys ratio less than PIC recommendation during late-nursery-to-grower phase resulted in compromised overall growth performance of maternal barrows, even with restored dietary SID Lys and SID Trp:Lys levels in finish phase. Dietary SID Lys level and/or SID Trp:Lys ratios lower than PIC recommendation may result in greater incidence of aggression behavior in maternal barrows.

132 The Effects of Increasing Dietary Standardized Ileal Digestible Lysine Levels on Growth Performance and Carcass Characteristics of 11- to 133-kg Late-Nursery-to-Finish Pigs Sired by PIC 800 Boars

Abstract Our objective was to determine the effects of increasing standardized ileal digestible (SID) lysine (Lys) levels on growth performance and carcass characteristics of late-nursery-to-finish pigs sired by PIC 800 boars. Barrows and gilts [n = 1,00; PIC800×Camborough, initial body weight (BW) = 10.9 ± 0.39 kg] were used in a 142-d growth trial with 40 mixed sex pens, 10 pens per treatment, and 25 pigs per pen. At the beginning of the trial, pens were blocked by BW and randomly allotted to one of four treatments (overall dietary SID Lys level as 87, 95, 102, or 110% of PIC SID Lys recommendations) in a randomized complete block design. Diets were corn-soybean meal (SBM)-based, and treatments were achieved through the inclusion of SBM with adjustments of corn and choice white grease. Diets were fed in 7 phases (11-17, 17-34, 34-44, 44-57, 57-77, 77-95, and 95-133 kg) and formulated to be iso-caloric across treatments for each phase. Within each phase, only the diets of the least and greatest SID Lys levels were manufactured, and the diets of intermediate SID Lys levels were blended by the automatic feeding system in the research facility. Growth performance data were analyzed using the GLIMMIX procedure in SAS (Version 9.4, SAS Institute, Inc., Cary, NC) and considered pen as the experimental unit. The statistical model considered fixed effects of SID Lys levels and random effects of the block. Mortality and removals were also analyzed using the GLIMMIX procedure and specified a binomial distribution. All data are reported as least square means and considered statistically significant at P < 0.05 and marginally significant at P < 0.10. Increasing overall dietary SID Lys levels reduced overall average daily feed intake (linear, P = 0.045) and increased overall gain-to-feed ratio (linear, P = 0.002), but there was no evidence for a difference across treatments for overall average daily gain (P > 0.10) or overall removal and mortality rate (Table 1; P >0.10). Pigs fed overall SID Lys level as 102% of PIC recommendation had significantly greater carcass yield compared with those fed 95 or 110% (P < 0.05), with the pigs fed 87% being intermediate. Increasing overall dietary SID Lys levels reduced backfat depth (linear, P< 0.001) and increased lean yield (linear, P = 0.012), but there was no evidence for a difference among treatments for loin depth (P > 0.10). In conclusion, increasing overall dietary SID Lys level beyond PIC recommendations through increasing SBM levels resulted in improved feed efficiency, backfat depth, and lean yield of 11 to 133 kg pigs sired by PIC 800 boars.

133 The Effects of Increasing Dietary Standardized Ileal Digestible Lysine Levels on Growth Performance and Carcass Characteristics of 24- to 130-kg Grow-Finish Pigs Sired by PIC 800 Boars

Abstract Our objective was to determine the effects of increasing overall standardized ileal digestible (SID) lysine (Lys) levels on growth performance and carcass characteristics of grow-finish pigs sired by PIC 800 boars. A total of 1,715 barrows and gilts (PIC800×Camborough, initially 23.7±0.58 kg) were used in a 117-d growth trial with 70 mixed sex pens in two rooms (35 pens per room), 14 pens per treatment, and 23 to 25 pigs per pen. At the beginning of the trial, pens within each room were blocked by body weight and randomly allotted to one of five treatments (overall dietary SID Lys level as 80, 88, 94, 100, or 110% of PIC SID Lys recommendations) in a randomized complete block design. Diets were corn-soybean meal (SBM)-based, and treatments were achieved through the inclusion of SBM with adjustments of corn and choice white grease inclusion rates. Diets were fed in 6 phases (24-47, 47-63, 63-75, 75-95, 95-113, and 113-130 kg) and formulated to be iso-caloric across treatment for each phase. Within each phase, only the diets of the lowest and highest SID Lys levels were manufactured, and the diets of intermediate SID Lys levels were blended by the automatic feeding system in the research facility. Growth performance data were analyzed using the GLIMMIX procedure in SAS (Version 9.4, SAS Institute, Inc., Cary, NC) and considered pen as the experimental unit. The statistical model considered fixed effects of SID Lys levels and random effects of the block. Mortality and removals were also analyzed using the GLIMMIX procedure and specified a binomial distribution. All data are reported as least square means and considered statistically significant at P < 0.05 and marginally significant at P < 0.10. Increasing overall dietary SID Lys levels marginally reduced average daily feed intake (linear, P = 0.108) and increased gain-to-feed ratio (linear, P < 0.001), but there was no evidence for difference among treatments for average daily gain (P >0.10) or removal and mortality rate (Table 1; P > 0.10). There was no evidence for increasing overall dietary SID Lys levels affect hot carcass weight, carcass yield, backfat depth, loin depth, or lean yield. In conclusion, increasing overall dietary SID Lys level over PIC recommendations through increasing SBM levels resulted in improved feed efficiency of 24 to 130 kg pigs sired with PIC 800 boars, but there was no evidence for difference in the carcass characteristics.

214 Effects of Dietary Standardized Ileal Digestible (SID) Lysine (Lys) Levels and Dietary SID Tryptophan to Lys Ratios on Growth Performance of Late-Nursery Maternal Barrows

Abstract The objective was to determine the effects of dietary standardized ileal digestible (SID) lysine (Lys) levels and SID tryptophan (Trp) to Lys ratios on the growth performance of late-nursery maternal barrows. A total of 2,293 barrows (PIC Camborough, initially 11.9 ± 0.35 kg) were used in a 28-day trial with 96 mixed-sex pens in two rooms (48 pens/room), 16 pens/treatment, and 23 to 25 pigs/pen. Pens were blocked by body weight (BW) and randomly allotted to 1 of 6 treatments in a 2×3 factorial arrangement. Treatment factors were: 1) Dietary SID Lys levels: meet PIC SID Lys recommendation at 1.234% (PIC LYS) or below PIC SID Lys recommendation at 0.988% (BELOW LYS); 2) Dietary SID Trp to Lys ratios: 21.0, 18.5, and 16.0. Data were analyzed using a linear mixed model in R Studio (Version 3.5.2, R Core Team; Vienna, Austria). Dietary SID Lys levels, dietary SID Trp to Lys ratios, and their interaction were included as fixed effects, and room and weight block were included as random effects in the model. Pigs fed with PIC LYS diets showed significantly improved average daily gain (ADG; 672 vs. 594 g; P < 0.001), average daily feed intake (ADFI; 1227 vs. 1179 g; P < 0.001), gain-to-feed ratio (G:F; 550 vs. 508 g/kg; P = 0.002), and greater amount of SID Lys intake (22.5 vs. 19.5; P < 0.05) or Trp intake (4.2 vs. 3.6; P < 0.05) per kg of BW gain comparing to BELOW LYS diets. Significant interactive effects were observed between dietary SID Lys levels and dietary SID Trp and Lys ratios on final BW, ADG, ADFI, and G:F (P < 0.05; Table 1). For final BW and ADG, when feeding PIC LYS diets, decreasing dietary SID Trp to Lys ratios increased final BW and ADG (quadratic, P < 0.05); but when feeding BELOW LYS diets the decreasing ratios reduced final BW and ADG (quadratic, P < 0.05). For ADFI, when feeding PIC LYS diets, there was no evidence that decreasing dietary SID Trp to Lys ratios impacted ADFI (P > 0.05); but when feeding BELOW LYS diets the decreasing ratios reduced ADFI (quadratic, P < 0.05). When feeding PIC LYS diets, the decreasing dietary SID Trp to Lys ratios decreased and then increased G:F (quadratic, P < 0.05); but when feeding BELOW LYS diets, the decreasing ratios increased and then decreased G:F (quadratic, P < 0.05). In conclusion, late-nursery maternal barrows fed the PIC LYS diet had improved growth performance compared with those fed BELOW LYS diet; and decreasing dietary SID Trp to Lys ratios from 21.0 to 16.0 had deleterious impacts on growth performance when dietary SID Lys level was below PIC recommendation, but not when dietary SID Lys level met PIC recommendation.

134 Meta-Analysis to Determine the Standardized Ileal Digestible Lysine Requirements of Growing-Finishing Pigs from 11- to 150-kg Utilizing the Ingredients Database of Inra

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 utilizing the INRA feed ingredients database. Data from 29 trials dating from 2013 to 2020 utilizing 48,338 pigs were recorded in a database. Number of pens/treatment and pigs/pen 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 levels reported in each trial were used, and 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 INRA for energy levels. The response variables, average daily gain (ADG) and feed efficiency (G:F), were analyzed within 7 phases using generalized linear and non-linear mixed models with heterogeneous variance (Gonçalves et al., 2016). Phases consisted of the following body weight ranges: 11-23, 23-41, 41-59, 59-77, 77-104, 104-127, and 127-150 kg . Each treatment mean within a trial (n = 288) was considered the experimental unit and each trial was used as a random effect. 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 of the requirement estimates for ADG and G:F. At these levels, approximately 100% of maximum ADG and 99.7% of maximum G:F are achieved. After determining the requirement estimates within each of the 7 weight breaks, a quadratic equation of Lys to calorie ratio was fit for each energy system. The equations are described as: g of SID Lys:Mcal of ME = 0.0001381709 × (weight, kg)2 - 0.0366272129 × (weight, kg) + 4.6073086522; and g of SID Lys:Mcal of NE = 0.0000400092 × (weight, kg)2 - 0.0235648387 × (weight, kg) + 6.2762350341. These data provide the estimated SID Lys requirements for maximal growth performance for PIC pigs from 11- to 150-kg based on the ingredients database of INRA.

208 Effect of SID LYS Level with Constant Non-Essential Amino Acids

Abstract Many investigations on the effect of low protein diets reduce crude protein (CP) and have a constant standardized ileal digestible (SID) LYS resulting in reductions in ADG, ADFI, and gain:feed is some cases. This experiment was conducted to determine the impact of maintaining constant non-essential amino acids and changing SID LYS and other essential amino acids. For the experiment, 288 pigs (~22 d of age, 6.61 ± 0.95 kg, 8 replicates/treatment, 6 pigs/pen) were stratified by body (BW) and randomly allotted to one of 6 treatments in a randomized complete block design. Non-essential amino acids were fixed in all diets and synthetic amino acids were added to increase SID LYS from 1.15% to 1.4% while maintaining constant ratios of MET+CYS, THR, TRP, VAL, and ILE to LYS. Diets were corn, wheat, barley, and soy based with 1.1% corn starch in the least SID LYS diet. Synthetic amino acids were added to the diet at the expense of corn starch to maintain non-essential amino acid levels. The CP ranged from 17.8% when SID LYS was 1.15% and 18.6% when SID LYS was 1.4%. Experimental diets were fed for 21 d. Body weight, feed disappearance, visual fecal scores, and visual piglet scores were measured. Visual fecal scores (1 = normal to 4 = watery) and visual pig appearance scores (1 = pale and hairy to 4 = normal color and well-rounded muscle) were assessed on ordered likert scales to determine the probabilities of observing a more normal stool quality and a worse visual appearance, respectively. Performance data were analyzed as a general linear model. Stool quality and visual appearance were analyzed as a generalized linear mixed model. Contrasts were used to test linear and quadratic effects of dietary SID LYS. Results of the experiment are presented in Table 1. Increasing SID LYS with constant non-essential amino acids did not affect ADG or BW. The ADFI was linearly decreased (P < 0.1) and gain:feed was linearly increased (P < 0.0001) with increasing SID LYS (Table 1). Stool quality was not affected. Visual appearance of the pigs was quadratically affected (P < 0.05) by changing SID LYS. Pigs that had consumed diets with the lowest or highest SID LYS had the best visual appearance (lowest probability). The results of the current experiment differ suggest SID LYS may regulate feed intake and nutrient efficiency, but BW gain is not affected when non-essential amino acids are held constant. This differs from cases where CP is reduced, which results are decreased growth in many cases.

Effects of standardized ileal digestible lysine level on growth performance and economic return for 18 to 128 kg Duroc-sired pigs.

The recent shift of the U.S. swine industry toward improved pork quality, such as color, marbling, and firmness, has led to increased use of Duroc-sired pigs in the marketplace. Our objective was to determine the standardized ileal digestible (SID) Lys requirement estimates for Duroc-sired (600 × 241, DNA, Columbus, NE) pigs from 18 to 128 kg BW. We conducted a series of experiments using corn-soybean meal-based diets with pigs allotted to 6 or 7 treatments in randomized complete block designs. In all experiments an equal number of barrows and gilts were used within a pen. In experiment 1, 300 pigs (initially 18.4 ± 0.50 kg) were used with 5 pigs per pen and 10 pens per treatment with 6 SID Lys levels from 1.00% to 1.50%. Increasing SID Lys increased (linear, P < 0.040) final BW, ADG, G:F, and Lys intake/kg of gain, and decreased (linear, P = 0.012) ADFI. In experiment 2, 608 pigs (initially 36.3 ± 0.91 kg) were used with 7 to 9 pigs per pen and 12 pens per treatment with 6 SID Lys levels from 0.80% to 1.20%. Increasing SID Lys increased (linear, P ≤ 0.036) ADG, G:F, and Lys intake/kg of gain. In experiment 3, 700 pigs (initially 53.2 ± 0.86 kg) were used with 8 to 10 pigs per pen and 12 pens per treatment with 6 SID Lys levels from 0.65% to 1.00%. Increasing SID Lys increased (linear, P < 0.001) final BW, ADG, and Lys intake/kg of gain, decreased (quadratic, P = 0.004) ADFI, and improved (quadratic, P < 0.001) G:F. In experiment 4, 616 pigs (initially 76.4 ± 1.25 kg) were used with 8 to 10 pigs per pen and 5, 6, or 11 pens per treatment with 7 SID Lys levels from 0.58% to 1.00%. Increasing SID Lys increased (linear, P ≤ 0.022) ADG, Lys intake per kilogram of gain, and G:F. In experiment 5, 679 pigs (initially 103.8 ± 1.32 kg) were used with 8 to 10 pigs per pen and 11 or 12 pens per treatment with 6 SID Lys levels from 0.43% to 0.78%. Increasing SID Lys increased (linear, P ≤ 0.043) final BW, ADG, and Lys intake per kilogram of gain, and improved (quadratic, P ≤ 0.032) G:F. Using results from all experiments, the quadratic equation of Lys:calorie ratio, g of SID Lys/Mcal of NE = 0.0002611 × BW2 - 0.0711037 × BW + 7.284 was developed to reflect the requirement for maximal growth performance from 18 to 128 kg BW. Maximal income over feed cost (IOFC) is best described by the quadratic equation: Lys:calorie ratio, g of SID Lys/Mcal of NE = 0.0001558 × BW2 - 0.04030769 × BW + 5.410. These data provide updated SID Lys estimates for Duroc-sired grow-finish pigs.

6 Effects of Plans on Growth Performance and Behaviors of 32- to 128-kg Grow-Finish Pigs

Abstract A total of 1,900 pigs (PIC337×Camborough, initially 32.0 ± 0.52kg) were used to determine the effects of different nutrition plans on growth performance and behaviors of 32- to 128-kg grow-finish pigs. Pens of pigs were weighed, blocked by body weight, and randomly allotted to 1 of 5 treatments that consisted: TRT1) Single-phase program (30-135kg), standardized ileal digestible (SID) lysine:NE ratio at 107% of PIC recommendation at the mid-point of the weight range (referred as “PIC mid-point recommendation”); TRT2) Single-phase program (30-135kg), SID lysine:NE ratio at 125% of PIC mid-point recommendation; TRT3) Two-phase program (30-75 and 75-135kg), SID lysine:NE ratio at 96% and 106% of PIC mid-point recommendation, respectively; TRT4) Two-phase program (30-75 and 75-135kg), SID lysine:NE ratios at 101% of PIC mid-point recommendation in both phases; TRT5) Four-phase program (30-50, 50-75, 75-100, and 100-135kg), SID lysine:NE ratios at 100% of PIC mid-point recommendation in each phase. Dietary amino acids to lysine ratios were below PIC recommendations in TRT1 and TRT3, and met or were above PIC recommendations in TRT2, TRT4, and TRT5. Pigs and feeders were weighed, and ear and tail lesion were scored and recorded every 2 to 3 weeks. From 32- to 81-kg, pigs fed TRT1 diet had reduced average daily gain (ADG, P &amp;lt; 0.05) and gain to feed ratio (G:F, P &amp;lt; 0.05) compared with all other groups (Table 1). Overall, pigs fed TRT2 diet had the greatest ADG, G:F, and lean percentage (P &amp;lt; 0.05). Pig fed TRT1 diet had a greater overall incidence rate of ear and flank lesions compared with the ones in other treatments (P &amp;lt; 0.05). In the current experiment, grow-finish pigs fed with a single-phase nutrition plan containing lower SID Lys levels and amino acid ratios compared with PIC recommendations had reduced performance during the grower phase and greater overall incidence rate of vices.

159 Effects of Dietary Energy and Standardized Ileal Digestible Lysine Levels on Growth Performance of Grow-Finish Maternal Barrows

Abstract Our objective was to determine the effects of dietary energy and standardized ileal digestible (SID) lysine (Lys) on growth performance of grow-finish maternal barrows. A total of 1,056 barrows (L02 ′ L03, initially 35.2 kg±0.29) were used in a 107-d study. Pens of pigs were weighed, blocked by body weight (BW), and randomly allotted to treatments in a 2×2 factorial design in a randomized complete block design structure. Treatments consisted of 2 energy concentrations: 3,175 and 3,300 kcal ME/kg, and 2 levels of SID Lys: 93 or 105% of PIC recommendations. Diets were corn-soybean-meal-DDGS-based, and energy treatments were achieved increasing corn oil and lysine treatments were achieved increasing soybean meal levels. There were 11 pens per treatment and 24 barrows per pen. Data were analyzed using linear mixed models in SAS with pen as the experimental unit. Overall, there was no evidence for a significant interaction between energy and lysine for average daily gain (ADG, P &amp;gt;0.10, Table 1) and average daily feed intake (ADFI, P &amp;gt;0.10). Pigs fed 3,175 kcal ME/kg had significantly greater ADFI compared with those fed 3,300 kcal ME/kg. Pigs fed SID Lys at 105% of PIC recommendations had improved gain to feed (G:F, Lys×ME, P = 0.002) and marginally greater final BW (Lys×ME, P = 0.09) compared with those fed at 93% when dietary ME was 3,300 kcal ME/kg, but not when dietary ME was 3,175 kcal ME/kg. There was no evidence for dietary SID Lys or ME levels impact on ADG or removal and mortality (P &amp;gt;0.10). Under the conditions of the current experiment, feeding PIC maternal barrows with increased SID Lys levels (105% vs. 93% of PIC recommendations) improved G:F and final BW only when dietary ME level was at 3,300 kcal/kg but not at 3,175 kcal/kg.

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.

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.

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.

280 Effects of metabolizable energy and standardized ileal digestible lysine levels on lactating sow and litter performance

Abstract The objective was to determine the effects of metabolizable energy (ME) and standardized ileal digestible (SID) lysine (Lys) levels on lactating sows and litter performance. A total of 600 sows (Camborough; PIC, Hendersonville, TN) were blocked by parity (P1, P2, P3+) on d 112 of gestation and allotted to 1 of 6 treatments arranged in a 2 x 3 factorial with the main effect of ME (3.2 and 3.4 Mcal/kg) and SID Lys (0.70, 0.85, and 1.00 %). Corn-soybean meal-based diets were fed from farrowing until weaning (d 21±2.3). Litters were cross-fostered until 48-h after farrowing to equalize litter size. Sows were weighed at d 112 of gestation and at weaning. Litter size and weight were collected at 24-h post-farrow and weaning. Daily feed intake was recorded from 48-h post-farrow until weaning. Data were analyzed using the GLIMMIX procedure of SAS with sow as the experimental unit. There was no evidence of interaction between ME and SID Lys for any response criteria. There was no evidence for an ME effect on sow performance. There was a quadratic effect (P&amp;lt; 0.05) of SID Lys on sow average daily feed intake, with the greatest intake at 0.85% SID Lys. Increasing SID Lys levels increased sow BW change (linear, P&amp;lt; 0.05). Litters from sows fed 3.4 Mcal of ME/kg had greater (P&amp;lt; 0.05) daily gain compared to those from sows fed 3.2 Mcal of ME/kg. Increasing SID Lys levels increased (linear, P&amp;lt; 0.05) litter weight at weaning and piglet daily gain. Wean-to-estrus interval, percentage of sows bred after weaning, total born on the subsequent parity, litter size at weaning, and percent of piglet removals were not influenced by dietary treatments. In summary, increasing ME levels did not affect sow performance, but improved litter and piglet daily gain. Increasing SID Lys levels improved both litter and sow performance.

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.

Standardized ileal digestible lysine and valine-to-lysine requirements for optimal performance of 4 to 9-week-old Piétrain cross piglets

Reduction of crude protein (CP) content in swine diets must be associated with an adequate quantitative and qualitative provision of amino acids (AA). In piglet diets, the fifth limiting AA is Val, where deficiency has been proven to reduce feed intake. In addition, depending on the overall level of CP and AA, diets high or low in standardized ileal digestible (SID) Lys will have different branched chain amino acid (BCAA) balances, which may in turn affect the feed intake response. Therefore, two Lys dose response trials (Exp. 1 and 2) were performed to study the influence of different AA concentrations on feed intake and overall performance. CP levels differed between the two experiments (201–210 g/kg in Exp. 1 and 180 g/kg in Exp. 2). Next, one Val dose response (Exp. 3) was carried out to establish the optimal SID Val:Lys ratio for 4 to 9-week-old Piétrain piglets. In Exp. 1, raising dietary SID Lys from 8.50 to 13.50 g/kg resulted in a significant linear and quadratic increase of average daily gain (ADG) and gain to feed (G:F) (P < 0.001 and P < 0.01 respectively), while average daily feed intake (ADFI) showed a linear increase with increasing SID Lys levels (P < 0.001), with a tendency to a quadratic effect (P = 0.08). In Exp. 2, ADG and G:F responded linearly and quadratically to SID Lys levels from 8.50 to 13.50 g/kg (P < 0.001), and ADFI showed a quadratic (P < 0.001) but not linear (P = 0.144) response to increased dietary SID Lys. For Exp. 1, the break points were above the tested SID range. For Exp. 2, quadratic polynomial (QP) and broken line quadratic (BLQ) model for ADG gave an optimal SID Lys of 12.05 and 11.39 g/kg, respectively, the QP ADFI reached an optimum of 11.33 g/kg of SID Lys. For G:F an optimal SID Lys level of 13.23, 11.72, and 13.28 g/kg SID Lys were estimated with a QP, broken line linear (BLL), and BLQ respectively. In Exp. 3, increasing the dietary SID Val:Lys level resulted in a linear and quadratic increase of ADG and ADFI (P < 0.001), but not G:F (P = 0.626 and P = 0.114). For ADG and ADFI it was possible to fit a QP and a BLQ model, with an optimal SID Val:Lys of 0.74 for the QP and 0.68 for the BLQ model, respectively, for the two response variables. In conclusion, SID Lys requirements of 4 to 9-week-old piglets are estimated to be equal or greater than 11.4 g/kg (1.14%), and SID Val:Lys requirements were found to be between 68 and 74% for optimal growth and feed intake.

PSV-1 Effects of the protein level on growth performance and carcass grading in fattening pig fed ad libitum

Abstract Reducing dietary crude protein (CP) with synthetic amino acids (AA) supplementation is beneficial for sustainable swine industry. However some discrepancies regarding the consequences on growth performance are observed. Therefore, this trial aimed to assess the effect of dietary CP level on growth performance of pigs from 35 to 113 kg BW. Growth performance of 63 pigs fed ad libitum and allocated to three groups (HH, MM and LL) was compared. Each group received one level of CP (‘H’ for High, ‘M’ for Medium and ‘L’ for Low) during growing (d0–d35) and finishing (d35–slaugther day) periods: 15.1%, 16.2%, 17.2% and 13.0%, 14.0%, 15.1% respectively. Diets were mostly based on wheat, corn and soybean meal. Within each feeding phase, diets were formulated to be similar in apparent total tract digestible phosphorus, net energy and standardized ileal digestible (SID) essential AA, the SID Lys levels being 0.95% and 0.78% during the growing and finishing period respectively. Data were analyzed using a linear model (R, 3.1.2) with individual as the experimental unit as feed intake, body weight and carcass grading were individually recorded. From d0 to d14 and from d35 to d63, average daily gain (ADG) and Growth:Feed ratio (G:F) were significantly reduced as the CP level decreased (P &lt; 0.05) while average daily feed intake (ADFI) remained unaffected by the dietary treatments. From d14 to d35 and in late finishing period (d63-slaugther day), growth performance was not significantly affected by the dietary CP level. Over the 82-d of the experiment, G:F was significantly higher for ‘HH’ pigs (P &lt; 0.01). Overall, ADG tended to be reduced as CP levels decreased (P = 0.10). There was no difference among treatments for parameters concerning carcass grading (lean meat percentage and meat yield). In conclusion, reducing CP levels while maintaining essential AA levels impaired growth performances of pigs.

PSVII-21 Revision of the model estimating real-time Lys requirements in individual growing-finishing pigs

Abstract The objective of this study was to review the calibration of the model estimating real-time Lys requirements individual in growing-finishing pigs. Two 28 d growth experiments were performed with 110 pigs distributed in a complete randomized design with growing (25 kg BW ± 2.1, n = 60; 10 pigs per treatment) and finishing (68 kg BW ± 1.8, n = 60; 10 pigs per treatment) barrows. Pigs were fed with 60, 70, 80, 90, 100, or 110% of the pig’s estimated individual standardized ileal digestible (SID) Lys (SIDLys) requirements. Body composition was measured by dual-energy X-ray densitometry on days 1 and 28 of the trial. Pigs were housed in the same pen but fed individually using computerized feeding stations. The Mixed and NLIN procedures of SAS were used to analyze the data and estimate optimal SIDLys requirements. In the growing and finishing trials protein in gain (17 to 19%; 13 to 16%) and N efficiency (52 to 65%; 40 to 55%) increased linearly (P &lt; 0.01) with the increasing levels of SIDLys. Maximum ADG (0.98 kg/d) and protein deposition (PD; 170 g/d) were observed in growing pigs fed at 100% of the estimated SIDLys requirements (P &lt; 0.001). Finishing pigs had maximal ADG (1.2 kg/d) when fed at 100% of the estimated SIDLys requirements, but PD increased linearly (P &lt; 0.05) with SIDLys levels without reaching a plateau at the higher levels of Lys intake. The proposed model correctly estimates the level of SIDLys that maximizes PD and ADG in growing (25 to 50 kg of BW), and ADG in finishing pigs (65 to 100 kg BW); still, there is an opportunity for increasing PD in older pigs fed using precision feeding techniques.

The effect of crude protein reduction on performance and nitrogen metabolism in piglets (four to nine weeks of age) fed two dietary lysine levels1.

Lowering the CP level in piglet diets reduces the risk of postweaning diarrhea and N excretion to the environment. The question remains at what point CP becomes limiting. An experiment was designed with 2 standardized ileal digestible (SID) Lys levels (10 and 11 g) and 6 CP levels (140, 150, 160, 170, 180, 190 g/kg) in a 2 × 6 factorial design (with 6 pens of 6 animals each per treatment). Linear and quadratic (QP) mixed models of performance in function of CP were fitted to study the effect of SID Lys and CP and their interaction. To determine optima, QP models and broken line models with linear (BLL) or quadratic (BLQ) ascending portions were fitted through the data. It was hypothesized 1) that the response to a decreasing digestible CP level could be described with broken line models and 2) that the break point of these models is dependent on the dietary SID Lys level. Decreasing the CP level decreased ADG (P < 0.001). For G:F, the effect of decreasing CP level depended on the SID Lys level (P of the interaction = 0.028 in the linear model and P = 0.002 in the QP model). According to the BLL model, with 11 g SID Lys in the diet, G:F started to decline with CP levels < 176 g CP [SID Lys:CP = 0.062, SID Lys:apparent total tract digestible (ATTD) CP = 0.077], and with 10 g SID Lys, CP levels < 165 g/kg (SID Lys:CP = 0.061, SID Lys:ATTD CP = 0.075) depressed performance. Serum creatinine levels showed a linear decrease with increasing SID Lys:CP levels (P < 0.001). Across both SID Lys levels, when fitting a BLL model, minimal serum urea levels were reached at an SID Lys:CP ratio of 0.064. This seems to be the point where CP and not Lys limits muscle deposition. The small difference in break point between serum urea level and performance suggests that the composition of nonessential AA may also be at stake. The effect of decreasing CP level depends on SID Lys, and using a maximal SID Lys:CP ratio may be useful for optimizing the AA profile of dietary CP. When the SID Lys:CP ratio exceeds 0.064 (SID Lys:ATTD CP > 0.079), protein and not individual AA limits growth in most piglets between 4 and 9 wk of age.

Evaluation of the optimal standardized ileal digestible tryptophan:lysine ratio in lactating sow diets.

Three hundred and fifteen primiparous and multiparous sows were evaluated in a study to determine the effect of standardized ileal digestible (SID) Trp:Lys ratio in lactating sow diets. Camborough sows (PIC USA, Hendersonville, TN) ranging from first parity to eighth parity were blocked by parity and randomly allotted to 1 of 4 experimental diets containing different levels of added L-Trp (0.006, 0.026, 0.045, and 0.064%, respectively) while soybean meal, 30% corn dried distiller's grain with solubles (DDGS), and L-Lys levels were held constant. The SID Lys level for the rations was 0.95% so that the SID Trp:Lys ratios were formulated to be 14, 16, 18, and 20%, respectively. All diets were formulated to have 3.2 Mcal ME/kg and to contain vitamins and minerals that exceeded NRC (1998) recommendations. Sows were fed twice a day with a Howema computerized feed system and were allowed a maximum intake (5.9 kg/d). Average daily feed intake had a tendency to be quadratically improved when the SID ratio was increased (5.11, 5.28, 5.24, 5.21 kg/d, P = 0.09). In addition, sow wean to estrus (6.71, 5.53, 5.58, 6.33, P < 0.02) was quadratically improved as SID Trp:Lys ratio increased. Percent of sows bred by 10 d (84.39, 90.82, 90.28, 90.61) was not linearly (P = 0.25) or quadratically (P = 0.40) improved. There was no difference in litter gain (2.44, 2.52, 2.60, 2.57 kg/d, P = 0.16). Based on a broken-line quadratic model, when sows are fed 30% DDGS, the SID Trp:Lys ratio of 17.6 is required for optimal sow average daily feed intake and 17.2 for wean to estrus interval.