Lysine Requirement Research Articles

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.

Standard Body Weight and Serum Estradiol and Progesterone Concentrations in Response to Total Lysine Content in Female Broiler Breeders from 14 to 42 Days after Hatch

ABSTRACT This study was conducted to determine the total lysine requirement for female broiler breeders from days 14 to 42. Two-hundred and ten female broiler breeders were used in a completely randomized design with 6 replicates per treatment and 5 chicks per pen under restricted feeding. The contents of total lysine used in this experiment were 0.68, 0.72, 0.76, 0.80, 0.84, 0.88 and 0.92% in the diet. A basal diet was formulated to meet or to exceed the Ross 308 female broiler breeders’ nutrient specifications except for the lysine. Body weight and feed intake were measured to calculate feed efficiency, and body weight uniformity was defined on a weekly basis. One chick per pen was randomly selected to collect blood samples, organ and an abundance of sexual maturity associated miRNAs (miR-21, mi-26a and mi-375) in the plasma was measured on day 42. Increasing total lysine contents in the diet improved body weight gain and feed conversion ratio from days 14 to 42. The combined values from the two models for BW, average daily gain and feed efficiency were estimated at 1.04, 1.00 and 1.21% total lysine, respectively. Total lysine contents did not affect the ovary weight, serum estradiol-17b, serum progesterone and plasma urea nitrogen or the expression levels of the three miRNAs on day 42. Therefore, the results from the current study indicated that female broiler breeders fed on 0.68% total lysine could achieve the recommended BW, suggested by field practice when data were fitted into the overlapped point of linear-, and quadratic-plateau models.

Performance of EPMp broiler ducks feed with various levels of dietary lysine up to 10 weeks of age

Determining the optimum level of lysine in the ration will be a significant effort to avoid poor growth in duck husbandry. The purpose of this study was to determine the optimum dietary lysine requirement for EPMp broiler ducks, raised up to 10 weeks of age. The study was designed in a completely randomized design (CRD) with 4 dietary treatments, and 4 replicates. Each replicate consisted of 10 ducks. The 4 treatments were diets, containing lysine: 0.60% (T1); 0.70% (T2); 0.80% (T3) and 0.90% (T4). Variables measured included: feed consumption, body weight gain, feed conversion ratio (FCR), carcass and carcass cuts percentages. The results showed that the performance of 10 weeks of age EPMp broiler duck was significantly affected by the level of dietary lysine (P<0.05). The average body weight gain and the FCR of the duck were significantly affected (P<0.05) by dietary lysine level, but not for feed consumption and percentage of carcass (P>0.05). The average body weight gain of EPMp duck with T4 treatment (0.90% lysine) was significantly higher than that T1 (0.60% lysine) but did not significantly difference (P>0.05) with T2 and T3. The average FCR of EPMp duck under T3 and T4 were significantly (P<0.05) higher than that of EPMp duck under T1. It was concluded that the optimum dietary lysine to produce maximum body weight gain of EPMp duck raised up to 10 weeks of age was 0.70%, while for minimum FCR were at the level of 0.80% and 0.90%.

Lysine Requirements of Healthy Pregnant Women are Higher During Late Stages of Gestation Compared to Early Gestation

Lysine is the first limiting amino acid in cereal proteins and is found mainly in animal-derived products. Current Dietary Reference Intake (DRI) recommendations extrapolate lysine requirements during pregnancy from nonpregnant adult data, and may underestimate true requirements. Our objective is to define a quantitative lysine requirement in healthy pregnant women and to determine whether requirements vary between 2 phases of gestation. Fourteen pregnant women in early (12-19 wk) and 19 women in late (33-39 wk) gestation were studied using the indicator amino acid oxidation technique. Individual lysine intakes (6-84 mg · kg-1 · d-1, deficient to excess) were tested on each study day as a crystalline amino acid mixture based on egg protein composition. Isonitrogenous diets maintained protein intake at 1.5 g · kg-1 · d-1 and calorie intake at 1.7 times resting energy expenditure during each study day. Phenylalanine and tyrosine intakes were held constant across all lysine intakes. Breath and urine samples were collected at baseline and isotopic steady state. Lysine requirements were determined by measuring the oxidation of L-[1-13C]-phenylalanine to 13CO2 (F13CO2). Biphase linear regression crossover analysis was used to determine a breakpoint (which represents the estimated average requirement, EAR) in F13CO2. The EAR for lysine during early gestation was determined to be 36.6 mg · kg-1 · d-1 (R2 = 0.484, upper 95% CI = 46.2 mg · kg-1 · d-1), similar to an earlier adult requirement of 36 mg · kg-1 · d-1. The EAR for lysine during late gestation was determined to be 50.3 mg · kg-1 · d-1 (R2 = 0.664, upper 95% CI = 60.4 mg · kg-1 · d-1), 23% higher than the current pregnancy DRI EAR recommendation of 41 mg · kg-1 · d-1. Our results suggest that lysine requirements are higher during late gestation compared to early gestation, and that current dietary lysine recommendations during late stages of pregnancy may be underestimated. The results have implications for populations consuming cereal-based diets as their primary source of protein. This trial was registered at clinicaltrials.gov as NCT01776931.

Effect of High Dietary Level of Some Amino acids and Coccidial Infection on Growth Performance and Health Status of Broiler Chicken

A total of 320 one-day-old Cobb chicks of mixed sex were used to investigate the impact of some amino acids supplementation and coccidial infection of broiler chicken on the growth performance, Immune response, some blood serum biochemical changes and intestinal morphology of broiler chickens. The chicks were randomly allotted into 10 equal groups, the first group were fed on the basal diet contain requirement of lysine (Ly), methionine (Met) and threonine (Thr) according to recommended catalog of the Cobb breed. Group 2 – 4 fed on the basal diet with 30% extra Ly, Met or Thr than recommended requirement respectively. Group 5 fed on the basal diet with extra combination of Ly, Met and Thr. Groups 6 – 10 fed on the same design as described for groups 1 – 5 with coccidial infection. It was found that the excess Ly, Met or Thr non-significantly increased the final body weight and significantly (P≤0.05) improved the feed efficiency and the performance index. Our data revealed that extra amino acids supplementation improved the blood picture and enhanced the immune response via increase the WBCs count and antibodies titer and significantly (P≤0.05) decreased blood serum carotenoids at 20th days of broiler age also reduced the coccidial fecal oocyst output at 14th or 28th days post-infection. It can be concluded that using of 30% extra methionine supplementation during the early age of broiler chickens and using 30% extra lysine supplementation during the grower and finisher period improved the performance and ameliorated the severity of coccidiosis.

Manipulating the immune system for pigs to optimise performance

Disease and enhanced microbial load are considered to be major factors limiting the performance and overall efficiency of feed use by pigs in Australian piggeries. It is recognised that pigs exposed to conventional housing systems with high microbial loads grow 10–20% more slowly than do gnotobiotic pigs or pigs kept in ‘clean’ environments. Consequently, a proportion of pigs in any production cycle are continuously being challenged by their immediate environment, which can cause an immune response to be mounted. Such a process is physiologically expensive in terms of energy and protein (comprised of amino acids), with, for example, the enhanced rate of protein turnover associated with the production of immune cells, antibodies and acute-phase proteins increasing energy expenditure by 10–15% of maintenance needs and protein requirements by 7–10%. The requirements for lysine, tryptophan, sulfur-containing amino acids and threonine can be increased by a further 10%. The over-stimulation of the immune response with excess production of pro-inflammatory cytokines causes excessive production primarily of the prostaglandin E2 (PGE2), which contributes to anorexia, fever and increased proteolysis, and a concomitant reduction in pig performance. Prostaglandin E2 is produced from dietary and cell-membrane phospholipids via secretory phospholipase A2 (sPLA2) to produce arachidonic acid, which is catalysed by the COX-2 enzyme. Negating the negative effects of PGE2 appears not to adversely affect the ability of the immune system to combat pathogens, but improves pig performance. There are negative outcomes for pig health and productivity through both under- and over-stimulation of the immune response. This review briefly outlines the impact of immune stimulation on pigs and discusses strategies to optimise the immune response for pig health and performance.

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.

Relative influence of dietary protein and energy contents on lysine requirements and voluntary feed intake of rainbow trout fry.

The effect of dietary digestible protein (DP) and/or digestible energy (DE) levels on lysine (Lys) requirements, Lys utilisation efficiency and voluntary feed intake (VFI) were studied in rainbow trout fry when Lys was the first limiting indispensable amino acid or in excess in the diet. Two trials were conducted at 11·6°C with eighty-one experimental diets, containing 280 g DP/kg DM (low protein (LP), trial 1), 600 g DP/kg DM (high protein (HP), trial 1) or 440 g DP/kg DM (medium protein (MP), trial 2), 17 MJ DE/kg (low energy (LE)), 19·5 MJ DE/kg (medium energy (ME)) or 22 MJ DE/kg (high energy (HE)), and nine Lys levels from deeply deficient to large excess (2·3-36 g/kg DM). Each diet was given to apparent satiety to one group of fifty fry (initial body weight 0·85 g) for 24 (MP diets, trial 2) or 30 (LP and HP diets, trial 1) feeding days. Based on N gain data fitted with the broken-line model, the relative Lys requirement was significantly different with the dietary DP level, from 13·3-15·7 to 22·9-26·5 g/kg DM for LP and HP diets, respectively, but did not significantly change with the DE level for a same protein level. The Lys utilisation efficiency for protein growth above maintenance was constant across diets, suggesting no effect of either dietary DE or DP levels. In Lys excess, the VFI was markedly decreased by the DP level but not by the extra DE supply. Our results suggest that the relative Lys need is best expressed in terms of percentage of protein content for optimum fish feed formulation, at least in rainbow trout fry.

Estimation of lysine requirements for growing Japanese quails.

This study was conducted to estimate the lysine requirements of growing meat-type Japanese quails based on different growth responses using different regression models. Experimental treatments including five doses of dietary lysine (9.40, 10.9, 12.4, 13.9 and 15.4g/kg of diet) were used in a dose-response platform from 7 to 21day of age. A total of 375, 7-day old quail chicks were randomly allotted to one of five dietary treatments with five replicate pens and 15 birds per pen. Performance traits including feed intake (FI), weight gain (G) and feed:gain (F:G) and carcass criteria including dressing (DRS), breast meat yield (BMY) and leg meat yield (LMY) were measured and used to fit several models (e.g., spline and quadratic polynomial models). Except FI and LMY, other parameters responded to dietary treatments (p<.05), in which G linearly but F:G, DRS and BMY quadratically responded to incremental levels of lysine (p<.05). On the basis of statistical merit, the best estimation of lysine requirements for G, F:G, BMY and DRS was 12.39 (R2 : .93 and Sy.x : 2.35), 12.40 (R2 : .98 and Sy.x : 0.001), 13.64 (R2 : .99 and Sy.x : 0.15) and 13.80 (R2 : .99 and Sy.x : 0.50) g/kg of diet respectively. This study showed that lysine requirements for maximum carcass yield and its attributes (e.g., BMY) might be higher than those needed for maximum growth rate or feed efficiency.

Production of highly nutritious functional food with the supplementation of wheat flour with lysine

Abstract During our research, we added 0.5–2.0% L-lysine to wheat flour in order to increase the quantity of this essential amino acid and the biological value of the wheat protein, producing such a functional, health-protecting, and health-preserving foodstuff that is suitable for satisfying the lysine requirement of humans, assuming normal nutrition. Furthermore, by the increase of the biological value completing the wheat flour with a higher amount of lysine, we could produce such a functional, health-protecting and health-preserving food that is suitable for containing or preventing lysine malnutrition symptoms. During our work, we determined the quantity of the Maillard reaction products (hydroxymethyl-furfural) and the lysine content developed during the baking of the wheat flour used for bread baking and in the bread baked with supplemented or without supplemented lysine, and evaluated the sensory characteristics of the produced functional food and the bread supplemented with lysine.

Lisina em dietas para alevinos de carpa comum

O presente estudo teve por objetivo determinar a exigência de lisina para alevinos de carpa comum (Cyprinus carpio). Foram distribuí­­dos inteiramente ao acaso 280 alevinos de carpa comum com peso e comprimento inicial médio de 0,62 ± 0,05 g e 3,38 ± 0,11 cm respectivamente em 28 tanques-rede quadrados com volume útil de 150 litros, dispostos no interior de um tanque circular de alvenaria com capacidade para 25 m3 de água (sete tratamentos e quatro repetições). Os peixes foram alimentados até a saciedade aparente quatro vezes ao dia com dietas isproteicas e isoenergéticas suplementadas com lisina nas concentrações de 1,58; 1,81; 2,05; 2,29; 2,53; 2,76 e 3,0% da dieta por 57 dias. Ao final do estudo foi avaliado o desempenho produtivo, sobrevivência e composição centesimal da carcaça dos peixes. Os dados obtidos foram submetidos a análise de regressão (p&lt;0,05) e ao teste múltiplo de média Tukey. A análise do platô de resposta linear (LRP) foi aplicado adicionalmente. A suplementação de lisina melhorou (p&lt;0,05) o peso final médio, ganho de peso médio e taxa de crescimento especí­­fico e, a partir de 2,29% de suplementação de lisina na dieta, prejudicou a eficiência alimentar dos peixes. A exigência de lisina para alevinos de carpa comum é de 1,89% da dieta ou 4,73% da proteí­­na bruta para obtenção do melhor crescimento.

561 Effects of ractopamine hydrochloride on lysine utilization by growing cattle

Two separate sets of 6 ruminally cannulated Holstein steers (240 kg) were used to study effects of ractopamine on lysine utilization. Steers were housed in metabolism crates and limit-fed 2.52 kg DM/d of a diet (10.1% CP) containing 82% soybean hulls twice daily. Treatments were arranged as a 2 × 3 factorial with 2 levels of ractopamine-HCl (0 and 200 mg/d) and 3 levels of lysine (0, 6, and 15 g/d) continuously infused abomasally. For each replicate of 6 steers, a completely randomized design was used for main-plot treatments (ractopamine-HCl; 0 vs 200 mg/d). Each steer received subplot treatments (lysine; 0, 6, or 15 g/d) in random sequence, such that each replicate contained concurrent 3 × 3 Latin squares, with each Latin square representing either 0 or 200 mg/d ractopamine-HCl. All steers were continuously infused ruminally with 200 g/d acetic acid, 200 g/d propionic acid, and 50 g/d butyric acid and abomasally with 300 g/d glucose to increase energy supply. Urea (10 g/d) was infused ruminally to ensure adequate ruminal ammonia. Steers were abomasally infused with excess of all essential AA except lysine to ensure lysine was solely limiting. Periods were 6 d with N retention measured on d 3 to 6 and longissimus biopsies and blood collected on d 6. Lysine increased (P<0.01) N retention for both control steers (21.3, 28.6, 33.9 g/d) and ractopamine-fed steers (25.5, 33.2, 38.9 g/d); ractopamine tended (P= 0.07) to increase N retention. Lysine linearly decreased (P<0.01) plasma urea (2.83, 2.04, 1.88 mM), leucine, and valine, but increased (P<0.01) plasma lysine (34, 51, 76 mM), arginine, and alanine. Ractopamine decreased (P<0.05) plasma lysine and arginine concentrations. In longissimus, ractopamine increased (P<0.05) phosphorylation of RPS6 on Ser-235 and Ser-244, and tended to increase (P= 0.08) phosphorylation of AKT on Thr-308 but not Ser-473. Abundance of MAFbx was decreased (P= 0.01) and MURF1 was numerically decreased (P= 0.14) by ractopamine. Lysine supplementation did not affect phosphorylation of RPS6 or AKT or abundance of MAFbx or MURF1. The efficiency of lysine use between 0 and 6 g/d supplemental lysine was 49% for control and 51% for ractopamine-supplemented steers. N retention tended to be improved by ractopamine when lysine supply was limiting, but incremental efficiencies of lysine utilization were not affected by ractopamine, suggesting that ractopamine reduced maintenance requirements for lysine.

English

Synthetic amino acid supplementation has provided facilities in the adjustment of feed formula, making it possible to obtain the required levels of essential amino acids. Lysine is pronounced the second greatest restrictive amino acid in broiler nutrition. The synthetic amino acid lysine is used as the orientation amino acid in poultry for the reason that it is mainly consumed for protein synthesis. In order to characterize the requirements of lysine, 240 male broilers of the lineage Avian Farms were kept in an environment with average temperature of 25.6°C. The 22 to 42 days old broilers presented initial average weight of 541 ± 3.6 g. The basal ration contained 19.57% of crude protein (CP), 3100 kcal of metabolizable energy (ME)/kg and 0.88% of total lysine, which was supplemented with 0.000, 0.076, 0.153, 0.230 and 0.306% de L-lysine hydrochloric acid (HCL), resulting in rations with 0.88, 0.94, 1.00, 1.06 and 1.12% of total lysine. The experimental design was completely randomized with five treatments of total lysine, six repetitions and eight broilers per repetition. During experiments, the temperature was kept at 25.6 ± 0.24°C, relative moisture ate 68.4 ± 6.30%, black globe temperature at 25.7 ± 0.25°C and the wet-bulb globe temperature (WBGT) at 74 ± 0.6°C. Treatments influenced the absolute weight of carcass, breast with bone, leg, thigh, abdominal fat and relative weight of breast with bone. Lysine levels had a quadratic effect over the food conversion (FC), which increased up to the level 1.03% of total lysine. Lysine levels had a quadratic influence over the weight gain (WG), which increased up to the level 1.05% of total lysine. Key words: Chickens for meat production, growth phase, lysine, thermal environment.

Dietary lysine requirement of juvenile dusky kob, Argyrosomus japonicus

To determine dietary lysine requirement of dusky kob, Argyrosomus japonicus, six isonitrogenous and isoenergetic diets (431 g/kg crude protein, 141 g/kg lipid and 20 kJ/kg) were formulated with graded levels of crystalline L-lysine (18–42 g/kg of the dry diet). The protein source in the basal diet comprised fishmeal and soya, where a combination of L-aspartic and L-glutamic acids was maintained at a ratio of 1:1, and all diets were supplemented with a mixture of crystalline essential amino acids to simulate the amino acid profile in dusky kob. Dietary treatments were randomly assigned to triplicate groups of 12 fish (4.5 ± 0.2 g, mean weight; 66.5 ± 1.1 mm, total length ± SD), which were fed to apparent satiation three times daily for 12 weeks. The fish fed dietary L-lysine at 21, 29 and 33 g/kg dry diet showed the highest specific growth rates (SGR) and the lowest feed conversion ratio. For most amino acids, retention in the body of the fish increased with an increase in dietary lysine from 18 to 21 g/kg, and it reached a maximum somewhere between 21 and 33 g/kg, where after amino acid retention decreased with increasing dietary lysine. Based on SGR and using segmented broken-line analysis, the dietary L-lysine requirement of juvenile dusky kob was estimated at 31.7 ± 1.6 g/kg dry diet corresponding to 73.5 g lysine per kg protein.

Digestible lysine requirements of male broilers from 1 to 42 days of age reassessed.

Three experiments were conducted separately to estimate the digestible Lys (dig. Lys) requirements of Cobb × Cobb 500 male broilers using different statistical models. For each experiment, 1,200 chicks were housed in 48 floor pens in a completely randomized design with 6 treatments and 8 replicates. Broilers were fed diets with increasing dig. Lys levels from 1 to 12 d (Exp. 1), from 12 to 28 d (Exp. 2), and 28 to 42 d (Exp. 3). Increasing dig. Lys levels were equally spaced from 0.97 to 1.37% in Exp. 1, 0.77 to 1.17% in Exp. 2, and 0.68 to 1.07% in Exp. 3. The lowest dig. Lys diets were not supplemented with L-Lysine and all other essential AA met or exceeded recommendations. In Exp. 3, six birds per pen were randomly selected from each replication to evaluate carcass and breast yields. Digestible Lys requirements were estimated by quadratic polynomial (QP), linear broken-line (LBL), quadratic broken-line (QBL), and exponential asymptotic (EA) models. Overall, dig. Lys requirements varied among response variables and statistical models. Increasing dietary dig. Lys had a positive effect on BW, carcass and breast yields. Levels of dig. Lys that optimized performance using QP, LBL, QBL, and EA models were 1.207, 1.036, 1.113, and 1.204% for BWG and 1.190, 1.027, 1.100, and 1.172% for FCR in Exp. 1; 1.019, 0.853, 0.944; 1.025% for BWG and 1.050, 0.879, 1.032, and 1.167% for FCR in Exp. 2; and 0.960, 0.835, 0.933, and 1.077% for BWG, 0.981, 0.857, 0.963, and 1.146% for FCR in Exp. 3. The QP, LBL, QBL, and EA also estimated dig. Lys requirements as 0.941, 0.846, 0.925, and 1.070% for breast meat yield in Exp. 3. In conclusion, Lys requirements vary greatly according to the statistical analysis utilized; therefore, the origin of requirement estimation must be taken into account in order to allow adequate comparisons between references.

Energy and lysine requirements and balances of sows during transition and lactation: A factorial approach

This study aimed to quantify daily requirements for metabolizable energy (ME) and standard ileal digestible (SID) lysine in late gestating and lactating sows using a factorial approach. Metabolizable energy and SID lysine required for fetal and mammary growth, colostrum and milk production, uterine components (including uterus wall, placenta and membrane fluids) and maintenance were estimated. It was estimated that maintenance, additional heat loss, colostrum production, fetal growth, mammary growth and uterine components accounted for 66.8%, 19.3%, 7.2%, 5.0%, 1.3% and 0.5% of total ME requirements, respectively, in the last 12 days of gestation. Oxidation/transamination, fetal growth, mammary growth, colostrum production, maintenance and uterine components were estimated to account for 29.5%, 22.7%, 16.8%, 16.1%, 10.4% and 4.5% of total SID lysine requirements, respectively, in the last 12 days of gestation. After parturition, ME and SID lysine requirements increased daily until peak lactation (day 17). At peak lactation, 95% and 72% of total required SID lysine and ME, respectively, were associated with milk production (including oxidation). Relative to day 104 of gestation, ME and SID lysine requirements increased by 60% and 149% at day 115 of gestation, and by 228%, and 338% at peak lactation, respectively. A dietary SID lysine: ME ratio of 0.55 was estimated as the ideal ratio to optimize milk production at peak lactation. It was estimated that the regressing uterus released about 30g SID lysine and 14MJ ME into the endogenous plasma pool during lactation. It was concluded that dramatic changes in energy and lysine requirements and balances occur during transition and lactation; that sows with high milk yield and /or low live weight require high SID lysine: ME ratio and that it would be beneficial to feed sows with two components at each meal to match the daily requirements for maintenance and production.

Effect of varying dietary concentrations of lysine on growth performance of the Pearl Grey guinea fowl

Lysine is the second limiting essential amino acid in poultry nutrition after methionine. Understanding the lysine requirement of poultry is necessary in guiding formulation of least cost diets that effectively meet the nutritional needs of individual birds. The lysine requirement of the Pearl Grey guinea fowl (PGGF) is not known. Therefore, the objective of this study was to assess the appropriate lysine levels required for optimal growth attributes of the PGGF. In a 12-week study, 512 one-day-old Pearl Grey guinea keets were weighed individually and randomly assigned to electrically heated battery brooders. Each battery contained 12 compartments housing 15 birds each. Eight diets fed to the experimental birds consisted of corn-soybean meal and contained 0.80 to 1.22 digestible lysine in 0.06% increments. Feed and water were provided at free choice and the diets were replicated twice. Experimental diets contained 3,100 Kcal metabolizable energy (ME)/kg diet and 23% crude protein (CP), 3,150 ME Kcal ME/kg diet and 21% CP, and 3,100 ME/kg and 17% CP, at zero to 4, 5 to 10, and 11 to 12 weeks of age (WOA), respectively. Birds were provided water ad libitum and a 23:1 and 8:16-hr (light:dark) regimen at zero to 8 and 9 to 12 WOA, respectively. Birds were weighed weekly, and body weight gain, feed consumption, and feed conversions were determined. Data were analyzed using the General Linear Model (GLM) procedures of SAS (2002) with dietary lysine as treatment effect. Females responded better to diets containing 1.04 and 0.8% lysine from hatch to 4 and 5 to 12 WOA, respectively. Males responded better to diets containing 1.10 and 0.8% lysine at hatch to 4 WOA and 5 to 12 WOA, respectively. Therefore, we recommend that PGGF females and males be fed diets containing 1.04 and 1.10%, respectively, at hatch to 4 WOA and 0.80% lysine at 5 to 12 WOA. The diets should be supplied in phases.

Effect of feeding different levels of lysine and protein on the performance of WLH layers

A trial was conducted to evaluate the requirement of digestible lysine at various protein levels in the diet of WLH layers (BV-300) from 25-44 weeks of age. Layers (528) were fed with diets containing two protein levels i.e. 13.36 and 15.78 % each with 5 % concentration variations of lysine (0.50, 0.55, 0.60, 0.65, and 0.70) and a control with 17 % CP and 0.70 % lysine. Each diet was fed to six replicates of eight birds. Egg production, feed intake, body weight were not influenced either by the concentration of lysine or by level of protein in diet. Increased (P d” 0.05) egg weight and egg mass were observed with increasing lysine in diets. Better feed efficiency was observed with increasing lysine concentration. It can be concluded that WLH layers require approximately 0.65% lysine with 13.36% CP or 0.63% lysine with 15.78% CP (i.e. 598.80 vs 570 mg/h/day) in diet.

Estimation of the optimum digestible lysine level for Cherry Valley ducks

The aim of the current study was to determine the digestible lysine (DLys) requirement of Cherry Valley ducks from 1 to 14 d and from 15 to 35 d of age. One-day-old male Cherry Valley ducks (n = 320) were divided randomly and evenly into five treatments with 8 replicates of 8 birds. Ducks were fed adequate levels of digestible amino acid but with graded levels of DLys: 0.80, 0.88, 0.96, 1.04, and 1.12% from 1 to 14 d; 0.60, 0.68, 0.76, 0.84, and 0.92% from 15 to 35 d. At 35 d of age, 8 ducks per treatment were slaughtered for evaluating the yields of abdominal fat, subcutaneous fat, breast meat, and leg meat. Additionally, a 7-d metabolizable experiment was conducted with ducks of the same hatch beginning on d 35 (8 ducks per treatment). The results showed that the DLys level in diet had a quadratic relationship both with the average daily gain (ADG) and feed:gain ratio (F/G). According to the quadratic model, an optimum digestible lysine level was 0.948% from 0 to 14 d and 0.758% from 15 to 35 d based on ADG. The digestible lysine level for obtaining minimum F/G were 0.986% (0 ∼ 14 d) and 0.792% (15 ∼ 35 d), respectively. Breast meat yield (P = 0.110) and subcutaneous fat percentage (P = 0.021) showed a quadratic or linear response to the increasing dietary DLys level. To achieve maximum breast meat yield, the digestible lysine level of 0.961% and 0.761% were needed for the starter period (1 ∼ 14 d) and the growth period (14 ∼ 35 d), respectively. N excretion showed a quadratic response to the increasing dietary DLys level (P = 0.103). The results of the current study suggested that the optimum digestible lysine level was very different with the response criterion. The dietary digestible lysine levels were 0.948, 0.961% in the starter period (1 ∼ 14 d) and 0.758, 0.761% in the growth period (15 ∼ 35 d) for ADG, F/G, respectively.

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.