L-lysine HCl Research Articles

EFFECT OF FEEDING LOW-PROTEIN, L-LYSINE AND DL-METHIONINE-SUPPLEMENTED DIETS ON THE GROWTH PERFORMANCE AND CARCASS CHARACTERISTICS OF BROILERS

Two hundred day-old unsexed broiler (Cobb 500) chicks wererandomly distributed to four groups. The first (control) group was fedon starter (22% CP, 3100 Kcal/kg ME, 1.10% Lysine, and 0.48%Methionine) and finisher (20% CP, 3200 Kcal/Kg ME, 0.90% Lysine,and 0.35% Methionine) diets. The other three groups were fed onthree starter and finisher isocaloric isonitrogenou diets with 2% lowerprotein content than the diets of control group with addition of gradedlevels of L-lysine HCl and DL-methionine to give 120%, 140%, and160% of the NRC (2000), At the end of starting period, the increasedLysine and Methionine content of the low-protein starter's rationsdidn't affect body weight and gain but increased the feed consumptionand decreased the feed conversion ratio of the birds. At the end offinishing period, body weight, body gain, feed intake, and breast meatyield increased significantly with the increasing of synthetic aminoacids in the diets, while the best feed conversion ratio was obtainedwith 120% amino acids level. Plasma uric acid level increased with feeding broiler on low protein diets and with increasing of syntheticamino acids supplementation to the diets. Plasma Creatinineincreased in the birds fed on low-protein diet supplemented with thehighest synthetic amino acids level (160%). Plasma Calcium wasn'taffected by the treatment while phosphorus increased in the birds fedon low-protein, DL-Methionine and L-lysine supplemented dietscompared with the control group, which might be as indicator forenhanced growth of these groups. It could be concluded that theminimum levels of protein (20% and 18% for starting and finishingperiods, respectively) in the broiler's diets supplemented with 120% ofNRC requirements for Lysine and Methionine requirements ensure anoptimum body weights, body gains, and feed conversion ratios withreduced plasma level of Uric acid but were inadequate to produce thehighest breast meat yield.

Effects of increasing standardized ileal digestible lysine:calorie ratio on the growth performance of growing-finishing pigs (2009)

A total of 1,080 pigs (PIC TR4 × 1050) were used in four 28-d experiments to determine the lysine requirements of growing-finishing pigs reared in the new Kansas State University finishing barn. Low- and high-lysine corn-soybean meal-based diets with no added fat were formulated for each experiment by varying the amounts of corn, soybean meal, L-lysine HCl, DL-methionine, and L-threonine. Six lysine levels were evaluated in each experiment, with intermediate lysine levels obtained by blending the low- and high-lysine diets. There were 6 pens containing an equal number of barrows and gilts for each treatment, with 6 or 8 pigs per pen. Pens were blocked by initial count and BW. In Exp. 1, 252 pigs (initially 80.7 lb) were fed diets with standardized ileal digestible lysine:calorie (SID lys:cal) ratios of 2.09, 2.39, 2.69, 2.99, 3.29, or 3.59 g/Mcal ME. Increasing the SID lys:cal ratio improved (linear; P < 0.04) ADG and F/G. Optimum performance and income over feed cost (IOFC) was observed at 2.69 g SID lys/Mcal, or a dietary level of 1.01% total lysine and 0.90% SID lysine. In Exp. 2, 288 pigs (initially 122.9 lb) were fed diets with SID lys:cal ratios of 2.12, 2.35, 2.58, 2.81, 3.04, or 3.27 g/Mcal. Increasing the SID lys:cal ratio tended (quadratic; P < 0.12) to increase ADG and improved (linear; P < 0.02) F/G. Optimum performance and IOFC was observed at 2.35 g SID lys/Mcal, or a dietary level of 0.88% total and 0.78% SID lysine. In Exp. 3, 252 pigs (initially 177.2 lb) were fed diets with SID lys:cal ratios of 1.49, 1.79, 2.09, 2.39, 2.69, or 2.98 g/Mcal. Increasing the SID lys:cal ratio tended (linear; P < 0.06) to improve ADG and improved (linear; P < 0.001) F/G. Optimum performance and IOFC was observed at 2.09 g SID lys/Mcal, or a dietary level of 0.80% total and 0.70% SID lysine. In Exp. 4, 288 pigs (initially 224.3 lb) were fed the same SID lys:cal ratios as in Exp. 3. Increasing the SID lys:cal ratio decreased (linear; P < 0.04) ADFI, F/G, carcass yield, and IOFC. Despite a linear improvement in F/G, ADG did not improve above 1.79 g SID lys/Mcal, which resulted in the best IOFC. This requirement is equivalent to 0.69% total and 0.60% SID lysine. These experiments agree with previous recommendations for growing-finishing pigs of this genotype. For pigs weighing 80 to 143 lb, 123 to 190

Nivel óptimo de lisina digestible en dietas para gallinas de postura de primer ciclo

The optimum biological digestible lysine level in laying hens past production peak was determined in a 7-wk trial using diets with different digestible lysine levels. A total of 336 Isa Babcock B-300 laying hens (32 wk old) housed in cages were distributed randomly in seven treatments with four replicates each and 12 hens per replicate. The basal diet was based on sorghum, soybean and sesame meal, contained 15 % crude protein and 0.50 % digestible lysine. Six experimental diets were formulated with digestible lysine levels ranging from 0.50 % to 0.74 %, L-lysine HCl was added to increase lysine levels by 0.04 % in each successive diet. Production variable data were recorded weekly: average egg weight, egg mass, feed conversion and feed intake. At 3.5 weeks, egg component variable data (percentage albumen, yolk and shell) were collected. Data were analyzed using a multivariate analysis with the principal components technique, and a regression analysis with quadratic transformation. The principal components exhibited a quadratic effect (P<0.01), with egg mass (0.899) having a greater effect on digestible lysine requirements than other components, such as egg weight (0.590). Egg mass was thus used to calculate the optimum biologically digestible lysine level requirement for the studied laying hens, which was 0.659 %, or 12.14 mg lysine per gram egg mass.

Comparison of Synthetic Lysine Sources on Growth Performance, Nutrient Digestibility and Nitrogen Retention in Weaning Pigs

We compared the effects of supplementing L-lysine.SO 4 to L-lysine-HCl on growth performance, nutrient digestibility and nitrogen retention in weaning pigs. A total of 96 crossbred pigs, weaned at 21±3 days of age and with an average initial body weight (BW) 6.23±0.01 kg, were given one of 4 treatments, which translated into 6 replicates of 4 pigs in each pen. The animals were randomly assigned to four dietary treatments according to a randomized completely block design (RCBD) as follows: 1) control-no synthetic lysine, lysine deficient (0.80% total lysine); 2) L-C (= 0.2% L-lysine·HCl); 3) K-L-S (= 0.332% L-lysine·SO 4 , A company); 4) C-L-S (= 0.332% L-lysine·SO 4 , B company). Diets were formulated with corn, soy bean meal, and corn gluten meal as the major ingredients, and all nutrients except the lysine met or exceeded NRC requirements (1998). The lysine content of supplemented synthetic lysine was the same in all treatment groups except the control. No clinical health problems associated with the dietary treatments were observed. During the entire experimental period, body weight, average daily gain (ADG) and feed efficiency (G:F ratio) increased (p<0.01) in pigs fed the experimental diets supplemented with L-lysine-HCl or L-lysine·SO 4 produced by A company, irrespective of the two synthetic lysine sources. Although the supplementation of L-lysine·SO 4 produced by B company tended to improve the ADG and G:F ratio, significant differences were not seen among all treatments and tended to be lower than the L-C (L-lysine·HCl) and K-L-S (L-lysine·SO 4 groups using the product from A company). The digestibility of crude protein (CP) was increased by the supplementation of synthetic lysine (p<0.05), irrespective of the L-lysine source (L-C, K-L-S, C-L-S). The results of this study showed that ADG, G:F ratio, and CP digestibility improved when L-lysine·SO 4 or L-lysine·HCl was supplemented into the weaning pigs' diet. There was a clear difference in efficacy between the two lysine·SO 4 products based upon the growth performance of weaning pigs. Consequently, the bioavailability of lysine·SO 4 products should be evaluated before supplementation of synthetic lysine in swine diets.

Effects of increasing standardized ileal digestible lysine:calorie ratio on gilts grown in a commercial finishing environment (2008)

A total of 2,165 commercial gilts (PIC 337 × 1050) were used in two 4-wk studies to determine the lysine requirement for growing and finishing gilts. All diets were corn-soybean meal based and contained 0.15% L-lysine HCl and 3% added fat. Desired lysine levels were achieved by altering the corn and soybean meal level in the diet. Each experiment consisted of 6 treatments with 7 pens per treatment and 24 to 27 pigs per pen. In Exp. 1, 1,085 gilts (initially 84.2 lb) were used with standardized ileal digestible (SID) lysine:calorie ratios of 2.01, 2.30, 2.58, 2.87, 3.16, and 3.45 g/Mcal. Both ADG and F/G improved (quadratic, P < 0.003) with increasing SID lysine:calorie ratio, with the greatest improvement in performance through 3.16 g SID lysine/Mcal ME and a smaller increase to the highest SID lysine:calorie level. Daily SID lysine intake increased (linear, P < 0.001) and SID lysine intake per pound of gain increased (quadratic, P < 0.001) as expected with increasing dietary lysine. Income over feed costs (IOFC) and feed cost per pound of gain also followed a similar pattern (quadratic, P < 0.001). In Exp. 2, 1,080 gilts (initially 185.3 lb) were used with SID lysine:calorie ratios of 1.55, 1.75, 1.95, 2.05, 2.35, and 2.55 g/Mcal. As SID lysine:calorie ratio increased, ADG, F/G, daily SID lysine intake, SID lysine intake per pound of gain, IOFC, and feed cost per pound of gain improved (linear, P < 0.001) through the highest lysine:calorie level of 2.55 g/Mcal. These studies indicate that feeding higher levels of lysine than previously thought to be optimal offers significant economic and biologic improvements in growing and finishing gilts. More research is needed to validate the ideal SID lysine:calorie ratio for today’s evolving genetics.; Swine Day, 2008, Kansas State University, Manhattan, KS, 2008

Effects of increasing standardized ileal digestible lysine:calorie ratio for 120- to 180-lb gilts grown in a commercial finishing environment (2008)

A 28-d growth trial was conducted to estimate the lysine requirement for 120- to 180-lb gilts. A total of 1,092 gilts (initially 121.7 lb, PIC 337 × 1050) were allotted to treatment diets with standardized ileal digestible (SID) lysine/ME ratios of 1.89, 2.12, 2.35, 2.58, 2.81, and 3.04 g/Mcal. All diets contained 0.15% L-lysine HCl and 3% choice white grease and were formulated to meet or exceed all other requirements. Seven replicate pens per treatment were used; there were approximately 26 pigs per pen. Gilts were vaccinated with 2 doses of commercial porcine circo virus type 2 (PCV2) vaccine while in the nursery. As the SID lysine content of the diet increased, both ADG and F/G improved (linear, P < 0.001) with the greatest values at the SID lysine/ME ratio of 2.58 g/Mcal. Daily SID lysine intake and SID lysine intake per pound of gain increased (linear, P < 0.001) as lysine density of the diet increased. Diet did not in-fluence (P > 0.25) feed cost per pound of gain; however, there was a tendency for improved (linear, P < 0.06) income over marginal feed cost (IOMFC) as SID lysine level increased in the diet. The SID lysine/ME ratio that yielded the greatest IOMFC value, 2.58 g/Mcal, corresponded to the treatment with the greatest growth response. On the basis of this trial, 2.58 g SID lysine/Mcal ME appears to provide the greatest biological and economical response for 120- to 180-lb gilts.; Swine Day, 2008, Kansas State University, Manhattan, KS, 2008

Influences of dietary conjugated linoleic acid (CLA) and total lysine content on growth, carcass characteristics and meat quality of heavy pigs

To assess the effects of dietary CLA, lysine and sex on performance, blood metabolites, carcass characteristics, meat quality and skeletal development, seventy-two pigs (initially 105.3 ± 6.6 kg live weight) barrows and gilts, were assigned to one of four diets in a 2 × 2 × 2 factorial arrangement. The diets contained 0% or 0.75% CLA, and 0% or 0.16% of l-lysine–HCl. All pigs were slaughtered at an average weight of 153.4 ± 11.0 kg. Neither CLA nor lysine supplementation influenced growth, blood metabolites or carcass characteristics. CLA reduced ( P < 0.05) pH 24 and increased ( P < 0.01) yellowness ( b ∗) of the Longissimus muscle. Lysine increased ( P < 0.01) pH 24 and reduced ( P < 0.01) muscle ash content. CLA reduced ( P < 0.05) collagen synthesis, and lysine increased (P < 0.05) collagen synthesis in Longissimus muscle, but no influence on intramuscular collagen maturity or muscle hydroxylysylpyridinoline crosslink concentration were observed. In addition, metacarpal bone diameter was reduced ( P < 0.05) by CLA. Barrows had higher ADG, final weight ( P < 0.01), carcass weight, lean percentage ( P < 0.05), serum cholesterol ( P < 0.05) and triacylglycerol ( P < 0.001) than gilts. Metatarsal diameter was larger in gilts than barrows ( P < 0.05).

Efeito da ractopamina e de métodos de formulação de dietas sobre o desempenho e as características de carcaça de suínos machos castrados em terminação

Foi realizado um experimento com o objetivo de avaliar o efeito de métodos de formulação e da suplementação de ractopamina (RAC) na dieta sobre o desempenho e as características de carcaça de suínos machos castrados em terminação. Foram utilizados 60 suínos distribuídos em delineamento de blocos ao acaso, em esquema fatorial 2 &lt;FONT FACE=Symbol&gt;´&lt;/FONT&gt; 3, com dois níveis de RAC e três métodos de formulação das dietas. A suplementação de RAC melhorou o peso final, o ganho de peso diário (GPD) e a conversão alimentar (CA) dos animais. A adição de RAC melhorou também as características de carcaça por reduzir a espessura de toucinho no ponto P1 e aumentar a taxa de deposição diária de carne magra. Dietas formuladas com base no conceito de proteína ideal ou pelo aumento do farelo de soja proporcionaram melhores resultados de CA, mas não influenciaram significativamente o consumo diário de ração, o GPD e as características de carcaça. Suínos machos castrados em terminação sob suplementação com RAC durante 21 ou 28 dias apresentaram melhor desempenho e qualidade de carcaça. Dietas formuladas para atender o nível de lisina digestível pela inclusão de L-lisina-HCl com o ajuste dos demais aminoácidos para relação ideal (proteína ideal) ou pela maior inclusão de farelo de soja (aumento do teor de PB) proporcionam melhores resultados de conversão alimentar em suínos machos castrados em terminação sob suplementação com RAC durante 28 dias.

Lysine Requirement of Broiler Chickens Fed Low-density Diets under Tropical Conditions

Two experiments were conducted to determine the lysine requirement of straight-run broiler chickens (Hubbardx Hubbard) during the period 4-21 (Exp. 1) and 21-40 (Exp. 2) days of age. Experiments were conducted during the summer months (June-August) in open-sided houses, thus exposing chicks to chronic heat stress. Daily min-max temperature averaged 28-40°C (Exp. 1) and 23-36°C (Exp. 2). Lysine deficient basal diets were formulated to contain low-nutrient-density, i.e., 2,700 kcal per kg ME, 18.6% CP (Exp. 1), and 2,750 kcal per kg ME, 17.1% CP (Exp. 2), to mimic typical commercial broiler diets used in Pakistan. Diets were supplemented with L-lysine HCl to provide total lysine level ranging from 0.85 to 1.10% (six increments) and 0.72 to 1.02% (six increments), respectively in Exp. 1 and 2. Live performance data were subjected to quadratic analysis and requirement was defined as the level achieving 95% of maximum or minimum values. Lysine requirements were found to be 0.98 and 0.97% total lysine, respectively, for gain and feed efficiency during 4-21 days, and 0.87% total lysine for both gain and feed efficiency during 21-40 days of age. Calculated on a digestible lysine basis, the estimates were 0.85 and 0.84%, respectively, for gain and feed efficiency during 4-21 days of age; and 0.75% for gain and feed efficiency during 21-40 days of age.

Comparative Bioefficacy of Lysine from l-Lysine Hydrochloride or l-Lysine Sulfate in Basal Diets Containing Graded Levels of Canola Meal for Female Broiler Chickens

A broiler growth assay was conducted to compare the efficacy of l-lysine HCl and l-lysine sulfate at a graded addition of canola meal (CM). A total of 1,440 1-d-old female Hubbard broiler chicks were allotted randomly to 6 dietary treatments each in 4 replicates of 60 birds per pen. The 2 lysine sources (l-lysine HCl and l-lysine sulfate) and the 3 CM levels (10, 15, and 20%) were used in 2 × 3 factorial arrangement in isonitrogenous (19% CP) and equicaloric (2,700 kcal of ME/kg) diets containing 0.96% digestible lysine. The experiment lasted for 42 d, and a single mash diet was used throughout the experiment. The feed intake during the starter phase (1 to 28 d) decreased linearly as the dietary CM level increased with diets containing l-lysine HCl, whereas feed intake increased linearly with increasing dietary CM level with that of lysine sulfate. Gizzard weight as percentage of carcass weight increased linearly (P ≤ 0.016) as dietary CM level increased. No significant effect of lysine sources or CM was observed on body weight gain, feed:gain, mortality, carcass weight, breast and thigh yield, and abdominal fat. In conclusion, l-lysine HCl can be replaced with l-lysine sulfate for broiler diets, and CM can be used as up to 20% of the starter (1 to 28 d) and finisher (29 to 42 d) diets without having any adverse effects of broiler performance.

Determination of the fourth-limiting amino acid in swine diets containing nutridense® corn (2007)

Two studies were conducted to determine the fourth-limiting amino acid in swine diets containing NutriDense® corn. Both experiments were conducted at a commercial swine research facility in southwest Minnesota. In Exp. 1, 1,259 pigs (initially 82.1 lb, PIC) were used in a 28-d study. Pigs were blocked by weight, and were randomly allotted to one of six dietary treatments. Pigs were fed NutriDense corn-soybean meal-based diets. The treatments were 1) a positive control diet containing 0.15% L-lysine HCl and 0.015% added L-threonine; 2) a negative control diet with 0.45% L-lysine HCl, 0.085% added DLmethionine, and 0.15% added L-threonine; 3) treatment 2 with 0.05% L-isoleucine; 4) treatment 2 with 0.05% L-valine; 5) treatment 2 with 0.05% L-tryptophan; and 6) treatment 2 with a combination of 0.05% L-isoleucine, 0.05% L-tryptophan, and 0.05% L-valine. Pigs fed the positive control and the diet with the combination of added isoleucine, tryptophan, and valine had greater ADG (P<0.05) than all other treatments. Also, pigs fed added isoleucine or tryptophan had greater ADG (P<0.05) than pigs fed the negative control with those fed added valine being intermediate. Pigs fed the diet with the combination of added isoleucine, tryptophan, and valine had greater ADFI (P<0.05) then pigs fed the negative control. There were no significant differences in F/G.

Comparison of the bioavailability of lysine in blood meals of various origins to that of l-lysine HCL for rainbow trout ( Oncorhynchus mykiss)

The bioavailability of lysine in blood meals from various origins was examined in rainbow trout. Bioavailability of lysine of the blood meals was assessed in comparison to that of l-lysine HCL using a slope ratio assay experimental design. A corn gluten meal-based diet, deficient in lysine (1.5% diet), was used as the basal diet. Two levels of spray-dried poultry blood meal (SDBM), flash-dried bovine blood meal (FDBM), disc-dried poultry blood meal (DDBM), and lysine-HCL substituted corn gluten meal in the basal diet to produce experimental diets containing 1.8 or 2.2% lysine. These diets were pair-fed to rainbow trout (initial body weight = 25 g/fish) reared at 15 °C for 12 weeks. Weight gain, feed efficiency ratio (FER, gain: feed), retained nitrogen (RN), and recovered energy (RE) increased significantly ( P < 0.05) with increasing lysine levels. Diets containing SDBM and FDBM recorded significantly greater weight gain, FER, RN and RE compared to DDBM ( P < 0.05). At the 1.8% lysine level, the diet containing FDBM recorded significantly greater weight gain, and RN than the diet supplemented with l-lysine HCl. The weight gain, FER and RN of the fish fed diets containing SDBM was not significantly different from that of the fish fed the diets with l-lysine HCl, at both lysine levels. At the 2.2% lysine level, feeding diets containing FDBM and DDBM resulted in significantly lower weight gain than diet supplemented with l-lysine HCl, suggesting that other nutrients may have become more limiting than lysine at high levels (20%) of blood meal. Results suggest that the bioavailability of lysine in SDBM or FDBM is slightly greater than that of l-lysine HCL. Bioavailability of lysine in the DDBM used in this study appeared to be significantly lower than that of spray-dried or flash-dried blood meals.

Exigência de lisina para poedeiras semipesadas durante o pico de postura

Objetivando determinar as exigências nutricionais de lisina para 252 poedeiras semipesadas, foi conduzido um experimento em delineamento inteiramente ao acaso, com sete tratamentos, constituídos de seis repetições de seis aves. As dietas, isoprotéicas (17,1% de PB) e isocalóricas (2.800 kcal/kg-EM), foram formuladas para atender às exigências das aves em todos os nutrientes, exceto lisina, que foi suplementada com L-lisina • HCl (78,4% de lisina), resultando nos seguintes níveis: 0,79; 0,83; 0,87; 0,91; 0,95; 0,99 e 1,03% de lisina total. As características de desempenho foram avaliadas no período de 30 a 46 semanas de idade, que corresponde ao pico de postura. Foi observado efeito quadrático dos níveis de lisina sobre a produção, o peso e a conversão alimentar por dúzia de ovos. As exigências de lisina total foram de 0,92; 0,91 e 0,90%, que correspondem, respectivamente, a 0,84; 0,83 e 0,82% de lisina digestível. Recomenda-se 0,92 ou 0,84%, ou 996 ou 910 mg, de lisina total e digestível/ave/dia para poedeiras semipesadas durante o pico de postura.

The dietary valine requirement for prolific lactating sows does not exceed the National Research Council estimate12

Two studies were conducted to determine the effect of increasing the valine:lysine (V:L) ratio in diets of lactating sows above the minimum proposed by the NRC (1998). The first experiment involved 189 PIC, Camborough product sows (parity 1 to 4) that were allotted to 1 of 3 dietary treatments. Diets were formulated to achieve total dietary V:L ratios of 0.90, 1.05, or 1.25:1, respectively, and were corn and soybean meal-based. The second experiment involved 279 PIC, Camborough sows (parity 1 to 5) that were allotted to 1 of 4 treatments. Diets 1 and 3 were formulated using corn and a fixed inclusion of soybean meal (16.7%), with 0.27% L-lysine HCl. The V:L ratios in diets 1 and 3 were 0.73 and 1.25:1, respectively. Diets 2 and 4 were typical corn-soybean meal diets containing 0.05% L-lysine HCl, with a fixed inclusion of soybean meal (22.7%). The V:L ratios in diets 2 and 4 were 0.86 and 1.25:1, respectively. In both experiments, each litter was standardized to a minimum of 10 pigs, which achieved litter growth rates of 2.22 and 2.56 kg/d in Exp. 1 and 2, respectively. In Exp. 1, increasing the dietary V:L ratio beyond 0.90:1 did not improve (P > 0.10) the number of pigs weaned, survival rate, or piglet growth rate, even though sows were nursing more than 10 pigs per litter for 19 d. In Exp. 2, total lysine intake was similar among treatments and ranged from 52.1 to 55.3 g/d. Valine intake increased as the diet valine concentration increased (diet 1 vs. 3 and diet 2 vs. 4, P < 0.001), ranging from 40.0 to 66.1 g/d. Litter gain tended to improve (P = 0.14) when the 0.27% L-lysine HCl control (0.73 V:L) was supplemented with valine to achieve a 1.25:1 V:L ratio. In contrast, no aspect of sow or litter response was improved when the practical control diet containing 0.05% L-lysine HCl (0.86 V:L) was supplemented with valine to achieve a 1.25:1 V:L ratio. Collectively, this research shows that a V:L ratio in excess of 0.86 does not conserve maternal tissue loss or improve piglet growth rate, but a V:L ratio of 0.73 may compromise litter growth rate.

Exigências de lisina digestível para juvenis de tilápia-do-nilo

Este estudo foi realizado com o objetivo de determinar a exigência de lisina digestível para juvenis de tilápia-do-nilo. Noventa e seis peixes revertidos sexualmente e com peso vivo inicial de 5,72 ± 0,10 g foram alimentados por 42 dias com quatro rações (29.51% de PB e 3.235 kcal de energia digestível/kg) contendo diferentes níveis de L-lisina HCl (0,1; 0,3; 0,5 e 0,7%, correspondendo a rações com 1,04; 1,27; 1,51 e 1,741% de lisina digestível, respectivamente). Os peixes foram distribuídos em 16 tanques com capacidade de 1.000 L cada um, em um delineamento inteiramente casualizado, com quatro tratamentos, três repetições e seis peixes por unidade experimental. Não foi observado efeito dos níveis de lisina sobre o índice hepato-somático, a gordura visceral, a sobrevivência e os teores de água e extrato etéreo na carcaça. A análise de Linear Response Plateau do ganho de peso e da conversão alimentar versus níveis de lisina digestível demonstrou estimativa de exigência de 1,56 e 1,44% de lisina digestível, respectivamente. Foi observado efeito quadrático sobre o rendimento de carcaça, que aumentou até o nível de 1,61% de lisina digestível. Considerando o desempenho, recomenda-se que dietas para juvenis de tilápia-do-nilo devem conter 1,44% de lisina digestível (5,23% da proteína da dieta).

Solid-State35/37Cl NMR Spectroscopy of Hydrochloride Salts of Amino Acids Implicated in Chloride Ion Transport Channel Selectivity: Opportunities at 900 MHz

The results of a detailed systematic chlorine solid-state NMR study of several hydrochloride salts of amino acids implicated in chloride ion transport channel selectivity are reported. (35)Cl and (37)Cl NMR spectra have been obtained for stationary and/or magic-angle spinning powdered samples of the following compounds on 500 and/or 900 MHz spectrometers: DL-arginine HCl monohydrate, L-lysine HCl, L-serine HCl, L-glutamic acid HCl, L-proline HCl, L-isoleucine HCl, L-valine HCl, L-phenylalanine HCl, and glycine HCl. Spectral analyses provide information on the anisotropic properties and relative orientations of the chlorine electric field gradient and chemical shift (CS) tensors, which are intimately related to the local molecular and electronic structure. Data obtained at 900 MHz provide unique examples of the effects of CS anisotropy on the NMR spectrum of a quadrupolar nucleus. The range of chlorine quadrupolar coupling constants (C(Q)) measured, -6.42 to 2.03 MHz, demonstrates the sensitivity of this parameter to the chloride ion environment and suggests the applicability of chlorine solid-state NMR as a novel experimental tool for defining chloride binding environments in larger ion channel systems. Salts of hydrophobic amino acids are observed to tend to exhibit larger values of C(Q) than salts of hydrophilic amino acids. A simple model for rationalizing the observed trend in C(Q) is proposed. For salts for which neutron diffraction structures are available, we identify a quantum chemical method which reproduces experimental values of C(Q) with a root-mean-square deviation of 0.1 MHz and a correlation coefficient of 0.9998. On the basis of this, chlorine NMR tensors are predicted for the Cl(-) binding site in ClC channels.

Dietary lysine requirement of juvenile gilthead seabream Sparus aurata L.*

The dietary lysine requirement of juvenile gilthead seabream was determined by the growth response of duplicate groups of fish (3.5 g initial weight) fed on six isonitrogenous (427 g kg−1) and isolipidic (135 g kg−1) diets containing graded levels of crystalline l-lysine HCl, with dietary lysine content ranging from 36.3 to 79.7 g kg−1 of protein. The final indispensable amino acid profile of the diets except for lysine was formulated so as to resemble that of wild seabream whole body. Except for the reduced growth performance of fish groups fed the lysine-deficient diets no other deficiency signs were apparent. Survival observed throughout the feeding period of 6 weeks was excellent. Weight gain (in %), specific growth rate, feed efficiency and daily protein deposition (DPD) were significantly improved in response to the increasing levels of dietary lysine up to 52.7 g kg−1 of protein and remained nearly constant thereafter. Whole-body protein content followed a similar pattern as growth parameters in relation to dietary lysine level. Non-linear regression analysis of DPD against dietary lysine level using the four-parameter saturation kinetic model indicated a lysine requirement of 50.4 g kg−1 of protein for this species to support growth.

Determining the total sulfur amino acid to lysine requirement of the lactating sow (2006)

A total of 163 sows were used in a study to determine the requirement for total sulfur amino acids (TSAA), relative to lysine, during lactation. All experimental diets were cornsoybean meal-based and formulated to contain 0.88% true ileal digestible (TID) lysine (0.97% total lysine). The experimental diets contained 0.37% L-lysine HCl, with other crystalline amino acids added to ensure that TSAA was first limiting. The dietary TID TSAA rates were formulated to 0.44, 0.48, 0.53, 0.57, and 0.62%, corresponding to 50, 55, 60, 65, and 70% of lysine, respectively. Sows farrowed in six farrowing groups, and were randomly allotted to the dietary treatments on the basis of parity. Over the entire lactation period, there were no differences (P>0.14) in ADFI, weight loss, backfat loss, or plasma urea nitrogen among sows fed increasing TSAA:Lys ratios. Increasing TSAA, relative to lysine, had no effect (P>0.25) on litter weaning weight or preweaning mortality. In summary, there were no differences in litter performance with increasing TID TSAA:Lys ratio. These results suggest that the requirement for TID TSAA is no more than 50% of lysine. Additional research is needed to confirm this relatively low TSAA requirement, and that the relatively high feed (and amino acid) intake of sows, coupled with possible tissue breakdown as a source of TSAA, did not decrease the dietary requirement.

Effect of increased dietary lysine on growth performance of gilts fed ractopamine HCL (paylean) in a commercial facility (2006)

A total of 1,915 gilts (PIC L337 × C22) were used in two 21-d experiments in a commercial research barn to evaluate the effects of lysine rates on pig growth and carcass performance when fed ractopamine HCl. There were 7 replicates per treatment and 21 to 24 pigs per pen in both experiments. In both experiments, treatments included a control diet formulated to 0.65% TID lysine without ractopamine HCl, and diets containing 0.75, 0.85, 0.95, 1.05, and 1.15% TID lysine with 5 ppm ractopamine. There were 983 (initially 217.4 lb) and 932 (initially 226.2 lb) gilts in Exp. 1 and 2, respectively. All diets were based on corn-soybean meal and contained high concentrations of synthetic amino acids (0.325% of L-lysine HCl with added threonine, methionine, and tryptophan) in Exp. 1, but only 0.075% L-lysine HCl in Exp. 2. As lysine increased in the diet, ADG increased and F/G decreased (linear; P<0.05), with the greatest response through 1.05% TID lysine in Exp. 1 and through 0.95% TID lysine in Exp. 2. In both experiments, pigs fed ractopamine HCl had increased (P<0.003) ADG and F/G, compared with performance of pigs fed the control diet. For carcass data, average backfat and FFLI were improved (linear; P<0.03) in Exp. 2 with increasing rates of TID lysine, but were not changed in Exp. 1. These experiments suggest that pigs fed ractopamine HCl require at least 0.95% or 26 g/d of TID lysine and at least 25 g of TID lysine/kg of gain.; Swine Day, 2006, Kansas State University, Manhattan, KS, 2006

Rumen lysine escape, rumen fermentation, and productivity of early lactation dairy cows fed free lysine

The primary objective was to quantitate forestomach escape of lysine fed to cows in a free form. However, since it was expected that a large proportion of the lysine would be degraded in the rumen, other objectives were to determine if lysine impacted ruminal fermentation as well as determine effects on performance of the cows. Four multiparous Holstein cows, fitted with large diameter rumen cannulae between 6 and 8 weeks prior to their projected calving date, were assigned in a 4 × 4 Latin square design experiment between 2 and 4 weeks post-partum. All cows were fed the same total mixed ration (TMR) and treatment differences were achieved by manually incorporating l-lysine HCl into each cow's individually weighed allocation of TMR at the time of feeding to deliver 0, 1, 2 or 3 g of l-lysine from l-lysine HCl/kg of dry matter (DM) intake, although actually delivered lysine values were about 16% higher. As expected, average rumen free lysine concentrations increased linearly (P=0.05) due to increased feeding levels of lysine. Rumen pH, N and volatile fatty acid concentrations, as well as other organic components of rumen ingesta, including those of isolated rumen bacteria, were unaffected by lysine feeding. Intake of DM, neutral detergent fibre and crude protein were not influenced by increased feeding of l-lysine, as were production of milk and its components. Feeding increasing levels of free lysine to lactating dairy cows, in three levels up to 71 g/day, resulted in an estimated forestomach escape of lysine of 35 g/kg of lysine fed, a level that is only about 1/6 of those reported in previous studies based upon short term pulse dosing and/or feeding studies.