Digestible Lysine Requirement Research Articles

Lysine requirement of weaned piglets

Lysine, often referred to as the ‘first limiting amino acid’ in pig nutrition, plays a pivotal role in growth performance. Variability in lysine requirements arises due to factors such as age, sex and environmental conditions. Optimising pig health and production efficiency and minimising nitrogen excretion require accurate knowledge of estimated lysine requirements accounting for factors such as genetics, feeding practices, scientific advancements, and environmental considerations. This study aimed to determine standardised ileal digestible (SID) lysine requirements of weaned piglets (5–30 kg) based on a literature review using meta-analytical approaches. The literature review yielded 344 studies that were screened for title and abstract. In total, 41 experiments met the inclusion criteria, resulting in a dataset of 206 treatment means. Linear, quadratic and linear-plateau models were used to gain insight into the effect of SID lysine addition on average daily gain and feed efficiency for the combined dataset and separately for the individual experiments. Regression analysis showed a predominant linear increase in average daily gain and feed efficiency as an overall response to increasing lysine levels across both the combined dataset and individual experiments. Breakpoint estimation from the linear-plateau models was inconclusive, indicating that the optimal SID lysine requirement to maximise piglet growth performance likely exceeded the upper lysine levels tested in most studies, thus surpassing 1.3 g SID lysine per MJ net energy. This review indicates high values for the lysine requirement to achieve maximum growth performance. Results may suggest that piglet feed formulation should focus on an optimal dietary SID lysine to CP ratio, rather than SID lysine per kg of diet or unit of net energy. However, more research is needed to investigate this suggestion.

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.

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 &amp;gt; 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.

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.

Requirement for digestible lysine in Nile tilapias (Oreochromis niloticus) with live weight between 500 and 600 g

The present study was carried out with the objective of determining the requirements for digestible lysine in Nile tilapia during the 500 to 600 g live weight stage. Isocaloric and isonitrogenous diets were tested with increasing amounts of digestible lysine. L-lysine HCl (78%) were used to replace glutamic acid at increasing levels, resulting in treatments of 9.3, 12.3, 15.3, 18.3 and 21.3 g kg-1 of digestible lysine. Three hundred Nile tilapias with an average weight of 519 ± 27.23 g were used and distributed among 25 tanks. The physical and chemical parameters of the water were pH, dissolved oxygen, salinity, conductivity and temperature. The mortality rate was registered daily. Two slaughters were performed at 28 and 50 days after the beginning of the experiment. It was estimated that an amount of 13.1 g kg-1 of digestible lysine was ideal for obtaining higher WG. Fish slaughtered after 50 days, the digestible lysine requirements were determined to be 14.5 g kg-1 for the lowest carcass humidity and 14.6 g kg-1 for the greatest carcass ethereal extract. Nile tilapias with live weight between 500 and 600 grams require 13.1 g kg-1 of digestible lysine in the diet for greater WG (90.53 g) and better FCR (2.55).

Standardized ileal digestible lysine requirements based on growth performance and histochemical characteristics of male broilers from 10 to 21d of age.

The growth performance and histochemical characteristics of breast muscle fibers were used to estimate the standardized ileal digestible (SID) Lys requirements for 10- to 21-d-old male broilers. Three hundred and sixty 10-d-old Ross 308 broilers (290±16.6g) were allocated to 6 diets in a randomized complete block design with 6 replicate cages per treatment and 10 birds per cage. The 6 experimental diets were formulated to contain equally spaced increasing levels of SID Lys from 0.86% to 1.36%. The data were analyzed using the MIXED procedure of SAS. The Lys requirements were estimated by the NLIN procedure of SAS. An increase in dietary SID Lys from 0.86% to 1.36% resulted in a quadratic increase (P<0.05) in body weight gain (BWG), gain to feed ratio (G:F), breast weight, muscle cross-sectional area (MCSA), and fiber area. The SID Lys requirements based on the one-slope broken-line, quadratic line, the first intercept between the plateau of the one-slope broken-line and quadratic-line models and 95% of the upper asymptote of the quadratic-line model were estimated to be 1.01%, 1.19%, 1.08%, and 1.13% for BWG, 1.06%, 1.22%, 1.11%, and 1.16% for G:F, 1.10%, 1.29%, 1.19%, and 1.22% for breast weight, 1.06%, 1.22%, 1.12%, and 1.16% for MCSA, and 1.14%, 1.22%, 1.16%, and 1.16% for breast muscle fiber area, respectively. It was concluded that the SID Lys requirements for broilers at the age of 10 to 21d depended on the response variables used for estimation, and that histochemical characteristics of breast muscle fibers could be good indicators for estimating SID Lys requirements.

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.

Influence of diet formulation technique on requirement of digestible lysine for growing Japanese quail: A practical reflection

This work aimed to investigate the influence of two diet formulation techniques: supplementation and dilution, on estimates of digestible lysine requirements in growing Japanese quail. For this, 492 Japanese quails (10 to 36 days old) with initial weight of 33.7 ± 0.42 g were used, housed in overlapping cages, and distributed in a completely randomized design in a 2 × 5 factorial arrangement. Two formulation techniques (supplementation technique and dilution technique) and five levels of lysine (0.80; 0.90; 1.00; 1.10 and 1.20%) were used, thus composing 10 treatments and 6 repetitions with 8 birds each. Performance parameters, nutrient gain, and carcass components were evaluated. There was interaction (p <0.05) between the formulation techniques and the levels of digestible lysine tested for feed intake, weight gain, protein gain, fat gain, chilled carcass weight, breast weight and thigh percentage, in addition to the isolated effect of the formulation technique on feed conversion, and isolated effect of the levels of digestible lysine on feed conversion and thigh weight. The digestible lysine requirement values estimated for better performance and efficiency in nutrient deposition were 1.028% or 133 mg/day by the supplementation technique, and 1.063% or 140 mg/day by the dilution technique. It can be concluded that the requirement for digestible lysine in Japanese quail is influenced by the formulation technique, and the supplementation technique had better results.

Determining the digestible lysine requirement of Cobb MV × Cobb 500 FF broilers from 28-41 days of age and the effect of feeding varying digestible lysine levels on performance, processing, and economics

Determining the digestible lysine requirement of Cobb MV × Cobb 500 FF broilers from 28-41 days of age and the effect of feeding varying digestible lysine levels on performance, processing, and economics

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.

Evaluating the digestible lysine requirements of male Cobb MV × Cobb 500 broilers during the first fourteen days of age and the carryover effect of feeding varying levels of digestible lysine on performance and processing

Digestible lysine ( dLys ) requirements in broilers is heavily researched due to lysine's importance in diet formulation, body protein accretion, and dietary protein cost. As such, when novel broiler strains are established, it is important to evaluate their dLys requirements. The current objective was to determine the dLys requirement of male Cobb MV × Cobb 500 broilers from d 0 to 14 and evaluate the carryover effect (d 14–41) of feeding varying starter levels of dLys. Two basal diets were formulated (0.88% dLys and 1.44% dLys), then blended to create 6 intermediate dLys treatments (ranging from 0.96 to 1.36% dLys), creating a total of 8 dLys experimental diets. A control diet (treatment 9–1.28% dLys) was separately made to confirm blending techniques. Treatments were arranged as a randomized complete block design ( RCBD ) to 96 pens, with each pen having 14 male chicks. In general, increasing dLys resulted in improvements in performance metrics and processing weights. From d 0 to 14, feeding ≥1.20% dLys increased BW and BWG, feeding ≥0.96% dLys increased FI, with an exception in birds fed 1.44% dLys; stepwise reductions in FCR were observed as dLys increased from 0.88 until 1.20% dLys. Estimated dLys requirements ranged from 1.17 to 1.30% for BWG and 1.29 to 1.49% for FCR (using multiple regression methods). In general, carryover effect data (d 0–41) demonstrated that increasing starter dLys improved performance and d 42 processing. Future research should evaluate higher dLys levels than those used in this study and the dLys requirements of female Cobb MV × Cobb 500 broilers during the starter phase.

Impact of Rearing Strategies on the Metabolizable Energy and SID Lysine Partitioning in Pigs Growing from 90 to 200 kg in Body Weight.

Simple SummaryThe nutritional recommendations for pigs largely focus on pigs with lean genotypes fed ad libitum until reaching up to 140 kg in body weight (BW). Under different rearing conditions, it is still unclear whether existing recommendations apply to pigs that weigh more than 140 kg in BW, especially in heavy pig production systems. In the current study, pigs growing from 90 to 200 kg in BW were raised with different feeding strategies. We observed that energy restriction had a negligible effect on pigs’ estimated metabolizable energy requirements at heavier BW under different feeding conditions. Under energy and protein restrictions, a value of 0.73 could be assumed as the maximum marginal efficiency of standardized ileal digestible lysine (SID lysine) utilization for protein deposition irrespective of BW, which corresponds to 9.8 g of SID lysine per 100 g of protein deposition as a minimum requirement.The current nutrient recommendations focus on pigs fed ad libitum up to 140 kg in body weight (BW). It remains unclear whether this applies to pigs weighing above 140 kg in BW under different rearing conditions. This study aimed to estimate protein (Pd) and lipid (Ld) depositions and the metabolizable energy (ME), standardized ileal digestible lysine (SID lysine) requirement and partitioning in 224 C21 Goland pigs (90–200 kg in BW). The control pigs (C) received diets limiting ME up to 170 kg in slaughter weight (SW) at 9 months of age (SA); older (OA) pigs had restricted diets limiting ME and SID lysine up to 170 kg in SW at >9 months SA; younger (YA) pigs were fed nonlimited amounts of ME and SID lysine up to 170 kg in SW at <9 months SA; and greater weight (GW) pigs were fed as the YA group, with 9 months SA at >170 kg in SW. The estimated MEm averaged 1.03 MJ/kg0.60. An 11% increase in MEm was observed in OA pigs compared to the controls. Energy restriction had negligible effects on the estimated MEm. The marginal efficiency of SID lysine utilization for Pd averaged 0.725, corresponding to a SID lysine requirement of 9.8 g/100 g Pd.

Standardized Ileal Digestible Lysine Requirement of 20 to 40-kilogram Philippine Black Tiaong Native Pigs (Sus scrofa domesticus)

Twenty growing Philippine black Tiaong native pigs were randomly allotted to 1 of 4 dietary treatments using a randomized complete block design to determine whether there were differences in SID Lys Requirements. There were five (5) replicate pigs per treatment. Diets were formulated with 0.717, 0.865, 1.010, and 1.156% SID Lys, respectively, which corresponded to SID Lys:ME ratios of 2.11, 2.54, 2.97, and 3.40 g/Mcal. All pigs were offered ad libitum intake from d 0 to 35. Overall (d 0 to 35), Philippine black Tiaong native pigs fed with 1.01% SID Lys had better performance than pigs not fed with 1.001%SID Lys. Moreover, pigs fed with increasing % SID Lys had quadratic relationships in ME efficiency at d 0 to 3(P=0.01). However, no significant differences (P&gt;0.05) were observed in carcass and meatquality characteristics. Meanwhile, a quadratic relationship (P=0.02) was observed in the kidney, whereas a linear response (P=0.004) was noted in the liver with increasing graded levels of % SID Lys. Additionally, a quadratic response was observed in the value of gain/pig(P=0.02), feed cost/kg gain (P=0.02), and margin over feed cost (MOFC)/pig (P=0.01) on a live weight basis and there is a linear relationship were revealed in carcass basis (feed cost/pig, P=0.009; feed cost/kg gain, P=0.006) and live weight basis (feed cost/pig, P=0.009). From the results of this study, it is concluded that diets containing 1.01% SID Lys and alysine: ME ratio of 2.97 g/Mcal are recommended for use in the feeding of Philippine black Tiaong native pigs at 20 to 40-kg.

Assessment of digestible lysine requirements in lipopolysaccharide-challenged pigs.

To evaluate the effect of an Escherichia coli lipopolysaccharide (LPS) challenge on the digestible lysine (Lys) requirement for growing pigs, a nitrogen (N) balance assay was performed. Seventy-two castrated male pigs (19 ± 1.49 kg body weight [BW]) were allocated in a 2 × 6 factorial design composed of two immune activation states (control and LPS-challenged) and six dietary treatments with N levels of 0.94, 1.69, 2.09, 3.04, 3.23, and 3.97% N, as fed, where Lys was limiting, with six replicates and one pig per unit. The challenge consisted of an initial LPS dose of 30 μg/kg BW via intramuscular (IM) injection and a subsequent dose of 33.6 μg/kg BW after 48 h. The experimental period lasted 11 d and was composed of a 7-d adaptation and a subsequent 4-d sampling period in which N intake (NI), N excretion (NEX), and N deposition (ND) were evaluated. Inflammatory mediators and rectal temperature were assessed during the 4-d collection period. A three-way interaction (N levels × LPS challenge × time, P < 0.05) for IgG was observed. Additionally, two-way interactions (challenge × time, P < 0.05) were verified for IgA, ceruloplasmin, transferrin, haptoglobin, α-1-acid glycoprotein, total protein, and rectal temperature; and (N levels × time, P < 0.05) for transferrin, albumin, haptoglobin, total protein, and rectal temperature. LPS-challenged pigs showed lower (P < 0.05) feed intake. A two-way interaction (N levels × LPS challenge, P < 0.05) was observed for NI, NEX, and ND, with a clear dose-response (P < 0.05). LPS-challenged pigs showed lower NI and ND at 2.09% N and 1.69 to 3.97% N (P < 0.05), respectively, and higher NEX at 3.23% N (P < 0.05). The parameters obtained by a nonlinear model (N maintenance requirement, NMR and theoretical maximum N deposition, NDmaxT) were 152.9 and 197.1 mg/BWkg0.75/d for NMR, and 3,524.7 and 2,077.8 mg/BWkg0.75/d for NDmaxT, for control and LPS-challenged pigs, respectively. The estimated digestible Lys requirements were 1,994.83 and 949.16 mg/BWkg0.75/d for control and LPS-challenged pigs, respectively. The daily digestible Lys intakes required to achieve 0.68 and 0.54 times the NRmaxT value were 18.12 and 8.62 g/d, respectively, and the optimal dietary digestible Lys concentration may change depending on the feed intake levels. Based on the derived model parameters obtained in the N balance trial with lower cost and time, it was possible to differentiate the digestible Lys requirement for swine under challenging conditions.

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

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

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%.