Standardized Ileal Digestible Lysine Requirement Research Articles

23 The effects of dietary net energy level on grow-finish performance and carcass characteristics of intact male market pigs managed with Improvest

Abstract Improvest is a gonadotropin releasing factor (GnRF) analogue-diphtheria toxoid conjugate product approved for temporary suppression of testicular function and reduction of boar taint in intact male pigs (Zoetis Canada Inc.). Objectives for this study were to determine the effects of dietary net energy (NE) level during the grow-finish period on live performance and carcass characteristics of intact male pigs managed with Improvest/immunological castration (IC) when compared with physically castrated (PC) male pigs. The 101-d study began when 1,008 pigs (504 intact male pigs and 504 PC male pigs; 10 wk old) were allocated by body weight to 48 pens with 21 intact males or 21 PC males per pen. Three dietary NE treatments were fed to pigs using five dietary phases to provide an average of 2,212 kcal/kg (Low NE), 2,337 kcal/kg (Medium NE), or 2,462 kcal/kg (High NE). Dietary programs were formulated according to standardized ileal digestible lysine requirements of IC males or PC males. The experiment was designed and analyzed as a 2 × 3 factorial with main effects of Improvest management and NE. For the overall study period, there were no significant interactions between Improvest management and NE (P ≥ 0.19) for average daily feed intake (ADFI), average daily gain (ADG), or gain to feed ratio (G:F; Table). There were also no significant interactions between Improvest management and NE (P ≥ 0.06) for carcass characteristics. Immunologically castrated male pigs consumed less feed (5.3% less ADFI; P < 0.01), grew faster (5.1% greater ADG; P < 0.01), and were more efficient (11.2% greater G:F; P < 0.01) compared with PC male pigs. Hot carcass weight (HCW) did not differ (P = 0.16) between IC males and PC males (attributed to 1.6 percentage unit less dressing percentage for IC males; P < 0.01); however, IC males were leaner (0.9 mm less backfat and 0.65% greater predicted lean yield; P < 0.01) compared with PC males. For the overall study period, pigs fed Low NE and Medium NE diets consumed more feed than pigs fed High NE diets, and pigs fed Low NE diets grew slower than pigs fed Medium NE and High NE diets. This resulted in pigs fed Low NE diets having 4.4% less G:F than pigs fed Medium NE and 8.6% less G:F than pigs fed High NE diets (P < 0.01). Pigs fed Low NE had 3.0 kg lighter (P < 0.01) HCW compared with Medium NE, while High NE had intermediate HCW that did not differ from the other two treatments. Overall, typical Improvest response levels were sustained for each of the NE treatments in this study; however, consideration should be provided to the known production impacts of low NE diets when male market pigs are managed with Improvest.

The effects of dietary net energy on grow-finish performance and carcass characteristics of male market pigs managed with immunological castration (Improvest).

The objective was to determine the effects of dietary net energy (NE) during the grow-finish period on live performance and carcass characteristics of intact male pigs managed with immunological castration (Improvest) compared with physically castrated (PC) male pigs. The 101-d study began when 1,008 pigs (504 intact male pigs and 504 PC male pigs; 10wk old) were allocated by weight to 48 pens with 21 intact males or 21 PC males per pen. Three dietary NE treatments were fed to pigs using five dietary phases (dietary programs were formulated according to standardized ileal digestible lysine requirements of Improvest males or PC males) to provide an average of 2,212 kcal/kg (low NE), 2,337 kcal/kg (medium NE), or 2,462 kcal/kg (high NE). The experiment was designed and analyzed as a 2 × 3 factorial with main effects of Improvest management and NE. For the overall study period, there were no significant interactions between Improvest management and NE (P ≥ 0.19) for average daily feed intake (ADFI), average daily gain (ADG), or gain:feed (G:F). There were also no significant interactions between Improvest management and NE (P ≥ 0.06) for carcass characteristics. Improvest males consumed less feed (5.3% lower ADFI; P < 0.01), grew faster (5.1% greater ADG; P < 0.01), and were more efficient (11.2% greater G:F; P < 0.01) compared with PC males. Hot carcass weight (HCW) did not differ (P = 0.16) between Improvest males and PC males (attributed to 1.6 percentage unit lower dressing percentage for Improvest males; P < 0.01); however, Improvest males were leaner (0.9mm less backfat and 0.65% greater predicted lean yield; P < 0.01) compared with PC males. For the overall study period, pigs fed low NE and medium NE diets consumed 7.5% and 4.6% more feed (P < 0.01) than pigs fed high NE diets, respectively, and pigs fed low NE diets grew 1.7% slower (P < 0.02) than pigs fed medium NE and high NE diets. This resulted in pigs fed low NE diets having 4.4% lower G:F compared with pigs fed medium NE and 8.6% lower G:F compared with pigs fed high NE diets (P < 0.01). Pigs fed low NE had 3.0kg lighter (P < 0.01) HCW compared with medium NE, while high NE had intermediate HCW that did not differ from the other two treatments. Overall, typical Improvest response levels for live performance and carcass characteristics when compared with PC males were achieved for each of the NE treatments evaluated in this study.

The effects of dietary net energy on grow-finish performance and carcass characteristics of market gilts managed with immunological suppression of ovarian function and estrus (Improvest).

The objective was to determine the effects of net energy (NE) during the grow-finish period on live performance and carcass characteristics of market gilts managed with immunological suppression of ovarian function and estrus (Improvest®; IMP) compared with market gilts not managed with Improvest (CON). The 104-d study began when 1,008 gilts (11wk old; average starting weight of 30.8kg) were allocated by weight to 48 pens with 21 gilts/pen. Half of the pens were randomly selected to be managed with Improvest while the other half of the pens were not managed with Improvest. Three dietary programs differing in their NE were formulated over five dietary phases (according to standardized ileal digestible lysine requirements) to provide an average of 2,218 kcal/kg (low NE), 2,343 kcal/kg (medium NE), or 2,468 kcal/kg (high NE). The experiment was designed as a 2 × 3 factorial with main effects of Improvest management and NE. For the overall study period, there were no significant interactions (P ≥ 0.20) for average daily feed intake (ADFI), average daily gain (ADG), or Gain:Feed (G:F). There were also no significant interactions between Improvest management and NE (P ≥ 0.30) for carcass characteristics. However, IMP gilts consumed more feed (6.8% greater ADFI; P < 0.01), grew faster (5.0% greater ADG; P < 0.01), were less efficient (1.8% lower G:F; P < 0.01), heavier (3.5kg hot carcass weight; P < 0.01), and fatter (1.9mm greater backfat thickness and 1.26% less predicted lean carcass yield; P < 0.01). No difference (P = 0.21) in carcass dressing percentage between IMP and CON gilts was reported. For the overall study period, gilts fed low NE and medium NE diets consumed more feed compared with gilts fed high NE diets (6.8% more ADFI for low NE and 5.7% more for medium NE; P < 0.01), and gilts fed low NE diets grew 2.5% slower (P < 0.01) than gilts fed medium NE diets, while gilts fed high NE diets were intermediate and not different from the other NE treatments. This resulted in gilts fed Low NE diets being the least efficient (3.8% lower G:F than medium NE and 7.1% lower G:F than High NE; P < 0.01). Overall, these data indicate that typical Improvest response levels were sustained at each of the NE treatments evaluated in this study as there were no significant interactions for Improvest management and NE; however, consideration should still be provided to the known production impacts of low NE diets.

Standardized ileal digestible lysine requirement of pregnant sows under commercial conditions.

The present experiment aimed to determine standardized ileal digestible (SID) lysine (Lys) requirements for pregnant sows individually housed under commercial farm conditions. Two hundred multiparous sows (parity = 5.1±2.0) on day 42 of gestation were randomly allocated to five dietary treatments with a balanced parity. Experimental diets were formulated to contain 0.22%, 0.32%, 0.42%, 0.52%, and 0.62% of SID Lys for the mid-gestation period (days 42 to 76) and 0.36%, 0.46%, 0.56%, 0.66%, and 0.76% of SID Lys for the late gestation period (days 77 to 103). All indispensable amino acids except Lys were provided at 110% of their requirement estimates. Daily feed allowance per sow was determined based on the back-fat thickness and body condition score at the second pregnancy check and on day 90 of gestation. Three different statistical models were used to estimate the SID Lys requirement. Total born piglets alive per litter increased linearly and quadratically (p<0.001) as dietary SID Lys increased. For total born piglets alive per litter, the SID Lys requirement estimates ranged from 9.69 to 12.4 g/d for the mid-gestation period (1.19 to 1.52 g/Mcal metabolizable energy; 0.39% to 0.49%) and 14.6 to 17.4 g/d for the late gestation period (1.62 to 1.93 g/Mcal metabolizable energy; 0.52% to 0.62%). The mean values of the SID Lys requirement for the mid-gestation period and the late gestation period are 11.1 and 16.1 g/d (1.36 and 1.79 g/Mcal metabolizable energy; 0.44% and 0.58%), respectively, for maximal total born piglets alive per litter.

Prediction of the daily nutrient requirements of gestating sows based on sensor data and machine-learning algorithms.

Precision feeding is a strategy for supplying an amount and composition of feed as close that are as possible to each animal's nutrient requirements, with the aim of reducing feed costs and environmental losses. Usually, the nutrient requirements of gestating sows are provided by a nutrition model that requires input data such as sow and herd characteristics, but also an estimation of future farrowing performances. New sensors and automatons, such as automatic feeders and drinkers, have been developed on pig farms over the last decade, and have produced large amounts of data. This study evaluated machine-learning methods for predicting the daily nutrient requirements of gestating sows, based only on sensor data, according to various configurations of digital farms. The data of 73 gestating sows was recorded using sensors such as electronic feeders and drinker stations, connected weight scales, accelerometers, and cameras. Nine machine-learning algorithms were trained on various dataset scenarios according to different digital farm configurations (one or two sensors), in order to predict the daily metabolizable energy and standardized ileal digestible lysine requirements for each sow. The prediction results were compared to those predicted by the InraPorc model, a mechanistic model for the precision feeding of gestating sows. The scenario predictions were also evaluated with or without the housing conditions and sow characteristics at artificial insemination usually integrated into the InraPorc model. Adding housing and sow characteristics to sensor data improved the mean average percentage error by 5.58% for lysine and by 2.22% for energy. The higher correlation coefficient values for lysine (0.99) and for energy (0.95) were obtained for scenarios involving an automatic feeder system (daily duration and number of visits with or without consumption) only. The scenarios including an automatic feeder combined with another sensor gave good performance results. For the scenarios using sow and housing characteristics and automatic feeder only, the root mean square error was lower with Gradient Tree Boosting (0.91 MJ/d for energy and 0.08g/d for lysine) compared with those obtained using linear regression (2.75 MJ/d and 1.07g/d). The results of this study show that the daily nutrient requirements of gestating sows can be predicted accurately using data provided by sensors and machine-learning methods. It paves the way to simpler solutions for precision feeding.

Standardized ileal digestible lysine requirements of 21–28 days old male broilers

The objective of this study was to estimate the standardized ileal digestible (SID) lysine (Lys) requirement for male broiler chickens at the age of 21–28 days. A total of 240 (21 days old) Ross 308 broilers (842 ± 43.9 g; mean ± SD) were allocated to six different dietary treatments in a randomized complete block design with eight replicate cages per treatment. The six experimental diets were formulated based on corn, soybean meal, and synthetic amino acids to contain dietary SID Lys equally increased from 7.5 g/kg to 12.5 g/kg, with a consistent concentration of all amino acids except for Lys. As the SID Lys increased in the experimental diet, the weight gain, feed intake, and G:F increased linearly (P < 0.05) and quadratically (P < 0.05). The Lys intake linearly (P < 0.01) increased as the SID Lys concentration increased. The SID Lys requirements for weight gain and G:F were 10.6 g/kg and 10.9 g/kg for the one-slope broken-line, 11.6 g/kg and 12.1 g/kg for the quadratic line, and 11.0 g/kg and 11.5 g/kg for 95 % of the upper asymptote of the quadratic model, respectively. In summary, the dietary SID Lys for optimum body weight gain and G:F of 21–28 days old male broilers were 10.7 g/kg and 10.9 g/kg, respectively. In addition, the SID Lys for maximum body weight gain and G:F were 11.6 g/kg and 12.1 g/kg, respectively.

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.

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%.

PSIII-34 Standardized ileal digestible lysine requirements for 7- to 15-kg weanling pigs with high-lean genetics fed a corn-soybean meal-based diet

Abstract Continued genetic improvement necessitates the verification of nutrient requirements for newly developed pig genotypes. Therefore, the objective was to determine the standardized ileal digestible (SID) lysine requirements for 7- to 15-kg high-lean piglets (TN Tempo × TN70) fed a corn-soybean meal-based diet. A total of 144 piglets (6.51 ± 0.56 kg BW) were assigned to 1 of 6 diets in a randomized complete block design based on BW to give 8 replicate pens each with 3 pigs over a 21-d period. Sex was balanced as 4 replicates for each male and female. Diets contained 1.00, 1.16, 1.32, 1.48, 1.64, or 1.80% SID lysine, achieved by adding crystalline L-Lysine·HCl at the expense of cornstarch. Other indispensable AA were provided to meet the requirements. Individual BW and feed disappearance were recorded weekly and blood was sampled on d 1, 14, and 21. Data were analyzed using MIXED procedure of SAS including the SID lysine concentration as the fixed effect and the block as the random effect. Sex effect was not significant, thus was excluded from the model. The SID Lys requirements were estimated for linear and quadratic broken-line using NLIN procedure of SAS. Lysine content did not affect ADG and ADFI during wk 1, but quadratically increased (P &amp;lt; 0.05) G:F. From d 14 to 21, ADG and G:F increased (P &amp;lt; 0.05) quadratically by increasing dietary lysine content. Overall, increasing dietary lysine content quadratically increased (P &amp;lt; 0.05) ADG and G:F; whereas, plasma urea nitrogen quadratically decreased (P &amp;lt; 0.05). In conclusion, the SID lysine requirements for optimal growth performance of 7- to 15-kg piglets fed corn-soybean meal-based diets based on linear and quadratic broken-line models were 1.27 and 1.38% for ADG and 1.36 and 1.46% for G:F, respectively, thus giving an overall average value of 1.37%.

78 Evaluation of the growth performance of finishing pigs (Genesus genetics) to titrated levels of dietary lysine

Abstract A total of 1,000 Genesus (Oakville, Manitoba, Canada) genetics pigs (51.8 kg body weight) were used to estimate the standardized ileal digestible (SID) lysine requirement by dietary phase. Pigs were penned by sex at 25 pigs per pen. Pens were allotted to one of five dietary treatments in a completely randomized design with eight replicate pens (four barrow, four gilt) per treatment. Growth performance was evaluated in four independent phases in which pens were re-allotted to dietary treatment between phases. Dietary SID Lys concentrations evaluated were 0.78, 0.88, 0.98, 1.08, and 1.18% for phase 1, 0.68, 0.77, 0.86, 0.95, and 1.04% for phase 2, 0.60, 0.67, 0.75, 0.83 and 0.90% for phase 3, and 0.53, 0.60, 0.67, 0.74, and 0.81% for phase 4. Diets were formulated to be isoenergetic within each phase. During phase 1 (52-64 kg), average daily gain (ADG) and gain to feed ratio (G:F) increased (P &amp;lt; 0.01) quadratically with increasing SID Lys. Breakpoint analysis estimated the SID Lys requirement for ADG and G:F for phase 1 at 0.99 and 1.02%, respectively. During phase 2 (64-82 kg), ADG increased (P &amp;lt; 0.10) quadratically as dietary SID Lys increased with a plateau observed above 0.86% SID Lys. Gain:feed increased linearly (P &amp;lt; 0.01) with increasing SID Lys. During phase 3 (82-97 kg) cost of gain was a quadratic response (P &amp;lt; 0.10) with the breakpoint being at 0.76% SID Lys. During phase 4 (97-131 kg), a linear response (P &amp;lt; 0.02) in G:F was observed with increasing SID Lys but with no improvement above 0.67% SID Lys. These data indicate the SID lysine requirement for Genesus finishing pigs to be approximately 0.99% (23.0 g/d) for 52-64 kg, 0.86% (21.9 g/d) for 64-82 kg, 0.76% (20.2 g/d) for 82-97 kg, and 0.67% (21.6 g/d) 97-131 kg.

Dynamic modeling of nutrient use and individual requirements of lactating sows1.

Nutrient requirements of sows during lactation are related mainly to their milk yield and feed intake, and vary greatly among individuals. In practice, nutrient requirements are generally determined at the population level based on average performance. The objective of the present modeling approach was to explore the variability in nutrient requirements among sows by combining current knowledge about nutrient use with on-farm data available on sows at farrowing [parity, BW, backfat thickness (BT)] and their individual performance (litter size, litter average daily gain, daily sow feed intake) to estimate nutrient requirements. The approach was tested on a database of 1,450 lactations from 2 farms. The effects of farm (A, B), week of lactation (W1: week 1, W2: week 2, W3+: week 3 and beyond), and parity (P1: 1, P2: 2, P3+: 3 and beyond) on sow performance and their nutrient requirements were evaluated. The mean daily ME requirement was strongly correlated with litter growth (R2 = 0.95; P < 0.001) and varied slightly according to sow BW, which influenced the maintenance cost. The mean daily standardized ileal digestible (SID) lysine requirement was influenced by farm, week of lactation, and parity. Variability in SID lysine requirement per kg feed was related mainly to feed intake (R2 = 0.51; P < 0.001) and, to a smaller extent, litter growth (R2 = 0.27; P < 0.001). It was lowest in W1 (7.0 g/kg), greatest in W2 (7.9 g/kg), and intermediate in W3+ (7.5 g/kg; P < 0.001) because milk production increased faster than feed intake capacity did. It was lower for P3+ (6.7 g/kg) and P2 sows (7.3 g/kg) than P1 sows (8.3 g/kg) due to the greater feed intake of multiparous sows. The SID lysine requirement per kg of feed was met for 80% of sows when supplies were 112 and 120% of the mean population requirement on farm A and B, respectively, indicating higher variability in requirements on farm B. Other amino acid and mineral requirements were influenced in the same way as SID lysine. The present modeling approach allows to capture individual variability in the performance of sows and litters according to farm, stage of lactation, and parity. It is an initial step in the development of new types of models able to process historical farm data (e.g., for ex post assessment of nutrient requirements) and real-time data (e.g., to control precision feeding).

Optimal dietary standardized ileal digestible lysine and crude protein concentration for growth and carcass performance in finishing pigs weighing greater than 100 kg1,2.

Three experiments were conducted to determine the optimal dietary standardized ileal digestible (SID) lysine and CP concentrations for finishing pigs over 100 kg BW. In Exp. 1, 253 pigs (DNA 600 × 241, initially 102.0 kg) were used in a 23-d trial with 7 to 8 pigs per pen and 8 pens per treatment. Dietary treatments contained 4 SID lysine concentrations (0.45, 0.55, 0.65, or 0.75%). To formulate the experimental diets, a corn-soybean meal diet with 0.45% SID lysine was formulated without L-lysine HCl. Then, a corn-soybean meal diet containing 0.75% SID lysine was formulated including 0.23% L-lysine HCl. The 0.45 and 0.75% SID lysine diets were blended to provide the 0.55 and 0.65% SID lysine diets. Increasing SID lysine increased (quadratic, P < 0.05) ADG and ADFI with pigs fed 0.55% SID lysine having the greatest final BW. Marginal improvements in gain:feed (G:F; quadratic, P = 0.058) and carcass yield (linear, P = 0.051) and reduction in backfat (quadratic, P = 0.074) were also observed with increasing SID lysine. The quadratic polynomial models predicted maximum ADG and G:F at 0.62 and 0.63% SID lysine, respectively. The broken-line linear model predicted no further improvement in G:F over 0.55% SID lysine. In Exp. 2, 224 pigs (PIC 327 × 1050, initially 109.4 kg) were used in a 20-d trial with 7 pigs per pen and 7 to 8 pens per treatment. Dietary treatments included 4 concentrations of CP (10, 11, 12, or 13%) that were formed by reducing the amount of L-lysine HCl in a corn-soybean meal diet. Increasing CP increased (linear, P < 0.05) ADG and ADFI with the greatest responses observed in pigs fed the diet with 12% CP. Increasing dietary CP also improved (linear, P < 0.05) G:F, final BW, and hot carcass weight (HCW). In Exp. 3, 238 pigs (DNA 600 × 241, initially 111.8 kg) were used in a 26-d trial with 7 to 8 pigs and 6 pens per treatment. Dietary treatments included 5 concentrations of CP (9, 10, 11, 12, or 13%). Increasing CP improved (quadratic, P < 0.05) ADG and G:F with the greatest response observed in pigs fed 13% CP. Increasing CP marginally increased (quadratic, P < 0.074) HCW, with the greatest response observed in pigs fed 12% CP. In conclusion, the SID lysine requirement for pigs from 100 to 122 kg was 0.55 to 0.63% depending on the response criteria with performance maximized with diets containing 12 to 13% CP.

Evaluation of standardized ileal digestible lysine requirement for 8-20kg pigs fed low crude protein diets.

Two experiments were conducted to determine the standardized ileal digestible lysine (SID Lys) requirement for weaned pigs fed with low crude protein (CP) diet. In Experiment 1, 144 pigs were fed a normal CP (20%) diet with 12.3g/kg SID Lys and five low CP (18.5%) diets providing SID Lys levels of 9.8, 11.1, 12.3, 13.5, and 14.8g/kg, respectively, for 28days. Reducing dietary CP from 20% to 18.5% enhanced (p<0.05) the growth performance. The average daily gain (ADG) and gain to feed ratio (G:F) increased (linear and quadratic; p<0.05), serum urea nitrogen (SUN) decreased (linear and quadratic; p<0.05) as SID Lys increased. The SID Lys levels required to maximize ADG and optimize G:F were 12.8 and 13.1g/kg using a curvilinear plateau model, and to minimize SUN was 13.4g/kg using a two-slope broken-line model, which averaged 13.1g/kg SID Lys. In Experiment 2, 18 pigs were used in a 12-day N balance trial and received the same diets of Experiment 1. Total N excretion was decreased when dietary CP reduced and further decreased when SID Lys increased. Collectively, 1.5% dietary CP reduction improved the growth performance and decreased the N excretion; the optimal SID Lys requirement was at 13.1g/kg of 8-20kg pigs fed with 18.5% CP diet.

Standardized ileal digestible lysine requirement of male broilers at the age of 0–10 days

Two experiments were conducted to determine the standardized ileal digestible (SID) lysine requirement for 10-day-old male broilers. In experiment 1, 3 experimental diets including 2 diets composed of corn or soybean meal as the sole source of amino acids and an N-free diet were used to investigate standardized ileal digestibility of amino acids in corn and soybean meal for 11-day-old broilers. A total of 480 birds were allocated to the 3 treatments with a randomized complete block design, and each treatment included 8 cages per treatment and 20 birds per cage. In experiment 2, a total of 720 1-day-old birds were used for 10 days. The birds were allocated to 6 diets and 8 blocks with a randomized complete block design to estimate the SID lysine requirements. The 6 experimental diets were based on corn-soybean meal, and the concentrations of SID lysine in the diets increased equally from 9.8 g/kg to 14.8 g/kg with a consistent ratio of other indispensable amino acids. As the SID lysine increased, the average daily gain and gain:feed ratio increased linearly and quadratically (P < 0.05). The SID lysine requirements for average daily gain and gain:feed ratio were 13.27 g/kg and 12.89 g/kg for the one-slope broken-line, 15.33 g/kg and 13.99 g/kg for the quadratic broken-line, 14.56 g/kg and 13.24 g/kg for 95% of the upper asymptote of the quadratic model, and 14.18 g/kg and 13.56 g/kg for the first intercept between the plateau of the one-slope broken-line and quadratic models, respectively. In conclusion, the SID lysine requirements for 10-day-old broiler chicks fed corn-SBM-based diets ranged from 13.27 g/kg to 15.33 g/kg for average daily gain and from 12.89 g/kg to 13.99 g/kg for gain:feed ratio.

Evaluation of the standardized ileal digestible lysine requirement of nursery pigs from 28 to 63 d of age in a three-phase feeding program

The objective of this study was to determine the standardized ileal digestible lysine (SID Lys) requirement of nursery pigs from 28 to 63 d of age fed a multi-phase feeding (PF) program and its possible adaptation to SID Lys-deficient diets. Ninety-six commercial hybrid piglets (Topigs Norsvin, 46 castrated males and 50 females) that had been weaned at 28 d of age with an initial body weight of 8.82 ± 0.28 kg were distributed in a randomized block design composed of four treatments, with eight replicates per treatment and three animals per replicate. The treatments were as follows: PF1, SID Lys levels of 1.05, 0.95, and 0.85%; PF 2, SID Lys levels of 1.15, 1.05, and 0.95%; PF 3, SID Lys levels of 1.25, 1.15, and 1.05%; and PF 4, SID Lys levels of 1.35, 1.25, and 1.15% from 28 to 35, 36 to 49, and 50 to 63 d of age, respectively. From 28 to 63 d of age, the average daily feed intake (ADFI) and average daily gain (ADG) were not affected by the SID Lys levels tested; however, final body weight (fBW) was affected, with PF1 having the lowest fBW. The SID Lys levels tested had a significant effect on the feed conversion ratio (FCR), which varied linearly from 28 to 35 d of age. In the period from 28 to 63 d of age, pigs fed PF4 had the highest FCR results. The protein deposition ratio (PDR) was also affected by the SID Lys levels tested, with PF3 and PF4 having the highest PDR results. Therefore, the optimal SID Lys requirement for nursery pigs from 28 to 35 d of age that provided better performance results was 1.25%, corresponding to a daily Lys intake of 4.13 g/d. PF3 provided the best performance and PDR results for piglets from 28 to 63 days of age.

Standardized ileal digestible lysine requirement of white commercial layers in peak egg production

This study was conducted to determine the standardized ileal digestible lysine (SID Lys) requirements for white commercial layers in peak egg production phase. A total of two hundred eighty-eight 24 week-old Hy-Line W-36 layers were randomly assigned to one of six treatments groups, with eight replicates of six hens each. A basal diet, SID Lys-deficient, was graded supplemented with L-Lysine HCl (78.4%) in order to produce experimental treatments (6.0, 6.6, 7.2, 7.8, 8.4 and 9.0 g SID Lys/kg diet). Throughout the 16-week-feeding trial (24 to 40 weeks of age) hens had free access to water and mash feed. Data were analyzed as one-way ANOVA and optimum SID Lys level for each dependent variable assessed were estimated using polynomial and linear broken-line regression model. Feed intake and SID Lys intake were both linearly enhanced by graded SID Lys levels. According to linear broken-line regression model, the breakpoint for egg production, egg weight, and egg mass occurred at 8.14, 8.56 and 8.35 g SID Lys/kg diet, respectively. The breakpoint for feed conversion per egg mass (kg/kg) and per dozen of eggs (kg/dozen) occurred at 8.48 and 7.80 g SID Lys/kg diet, respectively. Eggshell weight and albumen weight were unaffected by dietary SID Lys supply. Weight gain and yolk weight reached optimum values at 8.33 and 8.03 g SID Lys/kg diet, respectively, according to linear broken-line regression model. In conclusion, SID Lys requirement for white commercial layers in peak egg production phase is 8.48 g/kg diet, which corresponds to an average daily SID Lys intake of 813 mg/hen.

SID lysine requirement of immunologically and physically castrated male pigs during the grower, early and late finisher periods.

The main objective of this experiment was to determine the standardized ileal digestible (SID) Lys requirement of immunologically castrated (IC) and physically castrated (PC) male pigs during 3 growth phases. An additional objective was to compare the ADFI of PC and IC after the second anti-gonadotropin releasing factor (GnRF) injection. Three hundred male pigs (PIC 359 × C29), 150 each of IC and PC, were allotted to 1 of 5 treatments: 80, 90, 100, 110, or 120% of the estimated Lys requirement using the modeling program. Pigs remained on the same treatment throughout each of the 3 phases. Lysine requirements were determined at 3 stages of growth starting at a BW of 30.0 ± 0.8, 64.7 ± 1.4, and 111.9 ± 1.9 kg for IC and 32.4 ± 0.6, 69.8 ± 1.0, and 114.5 ± 1.3 kg for PC. Anti-GnRF injections were administered to IC at 11.5 and 19 wk (average BW = 96.3 ± 1.8 kg) of age. The one-slope broken line regression and quadratic plateau models were used, and the best model was selected based on the Akaike information criterion. The IC SID Lys requirements based on ADG were 1.03, 0.97, and 0.55% and for G:F, the requirements were 0.99, 0.72, and 0.55% for phases 1, 2, and 3, respectively. For PC, the SID Lys requirements based on ADG were 0.86, 0.62, and 0.47% and for G:F were 0.86, 0.58, and 0.47% for phases 1, 2, and 3, respectively. Immunologically castrated pigs had greater SID Lys requirements for phases 1 and 2 compared to PC (0.17 and 0.35% points greater for ADG and 0.13 and 0.14% points greater for G:F for phases 1 and 2, respectively). After the second injection, when IC pigs are believed to become physiologically more similar to PC pigs, the SID Lys requirements continue to be greater for IC (0.55 vs. 0.47% for both ADG and G:F). The ADFI of IC increased 4 d after the second injection relative to PC. By 2 wk post second injection, the ADFI of IC exceeded that of PC ( < 0.05). Adopting immunological castration as a management tool requires an understanding that IC need to be fed differently compared to PC, to maximize growth performance. Immunologically castrated pigs have a greater SID Lys requirement throughout the grower and finishing periods compared to the PC.

408 Determining the standardized ileal digestible lysine requirement of 6.8 to 15.9 kg pigs

Citation: Vier, C. M., De Souza, I. B., De Jong, J. A., Goncalves, M. A. D., Jones, A. M., Goodband, R. D., . . . Dritz, S. S. (2016). Determining the standardized ileal digestible lysine requirement of 6.8 to 15.9 kg pigs. Journal of Animal Science, 94, 191-191. doi:10.2527/msasas2016-408

Dietary lysine requirement for 7–16 kg pigs fed wheat–corn–soybean meal‐based diets

Two experiments were conducted to determine the lysine requirement of weaned pigs [Duroc×(Yorkshire×Landrace)] with an average initial BW of 7kg and fed wheat-corn-soybean meal-based diets. The experiments were conducted for 21days during which piglets had free access to diets and water. Average daily gain (ADG), average daily feed intake (ADFI) and gain to feed ratio (G:F) were determined on day 7, 14 and 21. Blood samples were collected on day 0 and 14 to determine plasma urea nitrogen (PUN) concentration. In experiment 1, 96 weaned pigs were housed four per pen and allocated to four dietary treatments with six replicates per treatment. The diets contained 0.99%, 1.23%, 1.51% and 1.81% standardized ileal digestible (SID) lysine, respectively, corrected analysed values. The rest of the AA were provided to meet the ideal AA ratio for protein accretion. Increasing dietary lysine content linearly increased (p<0.05) ADG and G:F. In experiment 2, 90 piglets were housed three per pen and allocated to five dietary treatments with six replicates per treatment. The five diets contained 1.03%, 1.25%, 1.31%, 1.36% and 1.51% SID lysine, respectively, corrected analysed values. Increasing dietary lysine content linearly increased (p<0.05) G:F, linearly decreased (p<0.05) day-14 PUN and quadratically (p<0.05) increased ADG and ADFI. The ADG data from experiment 2 were subjected to linear andquadratic broken-lines regression analyses, and the SID lysine requirement was determined to be 1.29% and 1.34% respectively. On average, optimal dietary SID lysine content for optimal growth of 7-16kg weaned piglets fed wheat-corn-SBM-based diets was estimated to be 1.32%; at this level, the ADG and ADFI were 444 and 560g, respectively, thus representing an SID lysine requirement, expressed on daily intake basis as, 7.4g/day or 16.76mg/g gain.

Estimation of the standardized ileal digestible lysine requirement for primiparous pregnant sows.

This experiment was conducted to determine the optimal standardized ileal digestible lysine (SID Lys) level in diets fed to primiparous sows during gestation. A total of 150 (Landrace×Large White) crossbred gilts (weighing 149.9±3.1kg) were fed gestation diets (12.55 MJ of ME/kg) containing SID Lys levels of 0.43, 0.52, 0.60, 0.70 or 0.80% respectively. Gilts were fed 2.0kg/day from day 1 to 80 and 3.0kg/day from day 80 to 110 of gestation respectively. Gilts were allocated to treatments based on their body weight on the day of breeding. Weight gain from day 80 to 110 increased with increasing dietary SID Lys levels (p=0.044). Fitted broken-line (p=0.031) and quadratic plot (p=0.047) analysis of body weight gain indicated that the optimal SID Lys level for primiparous sows was 0.70 and 0.69% respectively. During gestation, neither backfat thickness nor loin eye area was affected by dietary SID Lys level. Increasing dietary Lys had no effect on the litter size at birth or pigs born alive per litter. Litter weight at birth was not affected by dietary SID Lys level. The litter weight variation at birth quadratically decreased with increasing dietary SID Lys (p=0.021) and was minimized at 0.70% dietary SID Lys. Gilts fed the 0.70% SID Lys diet had the highest dry matter (p=0.031) and protein (p=0.044) content in colostrum. On day 110 of gestation, gilts fed the 0.70% SID Lys diet tended to have the highest serum prolactin (p=0.085) and serum insulin (p=0.074) levels. The data demonstrate that the optimal dietary SID Lys was 0.70% for pregnant gilts, which is similar to the recommendation of 0.69% that was estimated by the NRC (2012).