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Lysine Requirement (lysine + requirement)
Selected AbstractsDietary digestible lysine requirement and essential amino acid to lysine ratio for pacu Piaractus mesopotamicusAQUACULTURE NUTRITION, Issue 4 2010E.G. ABIMORAD Abstract To determine the digestible lysine requirement for pacu juveniles, a dose,response feeding trial was carried out. The fish (8.66 ± 1.13 g) were fed six diets containing the digestible lysine levels: 6.8, 9.1, 11.4, 13.2, 16.1 and 19.6 g kg,1 dry diet. The gradual increase of dietary digestible lysine levels from 6.8 to 13.2 g kg,1 did not influence the average values of the parameters evaluated (P > 0.05). The increase of dietary digestible lysine level to 16.1 g kg,1 significantly improved weight gain (WG), specific growth rate (SGR), protein productive value (PPV), protein efficiency rate (PER), and apparent feed conversion rate (FCR), but was not different from fish fed diets containing 19.6 g kg,1 lysine. Fish fed diets containing 16.1 and 19.6 g kg,1 digestible lysine showed lower body lipid contents than fish in the other treatments. The digestible lysine requirement as determined by the broken-line model, based on average WG values, was 16.4 g kg,1. The other essential amino acid requirements were estimated based on the ideal protein concept and the value determined for lysine. [source] Quantitative l -lysine requirement of juvenile black sea bream (Sparus macrocephalus)AQUACULTURE NUTRITION, Issue 2 2010F. ZHOU Abstract An 8-week feeding experiment was conducted to determine the quantitative l -lysine requirement of juvenile black sea bream Sparus macrocephalus (initial mean weight: 9.13 ± 0.09 g, SD) in eighteen 300-L indoors flow-through circular fibreglass tanks provided with sand-filtered aerated seawater. The experimental diets contained six levels of l -lysine ranging from 20.8 to 40.5 g kg,1 dry diet at about 4 g kg,1 increments. All the experiment diets were formulated to be isoenergetic and isonitrogenous. Each diet was assigned to triplicate groups of 20 fish in a completely randomized design. Weight gain and specific growth rate (SGR) increased with increasing levels of dietary lysine up to 32.5 g kg,1 (P < 0.05) and both showed a declining tendency thereafter. Feed efficiency ratio and protein efficiency ratio was poorer for fish fed the lower lysine level diets (P < 0.05) and showed no significant differences among other treatments (P > 0.05). All groups showed high survival (above 90%) and no significant differences were observed. The whole body crude protein and crude lipid contents were significantly affected (P < 0.05) by dietary lysine level, while moisture and ash showed no significant differences. The composition of muscle and liver also presented similar change tendency. Total essential amino acid and lysine contents in muscle both obtained the highest value when fish fed 32.5 g kg,1 lysine diet (P < 0.05). Serum protein, cholesterol and free lysine concentration were affected by different dietary treatments (P < 0.05), triacylglyceride and glucose contents were more variable and could not be related to dietary lysine levels. Dietary lysine level significantly affected condition factor and intraperitoneal fat ratio of juvenile black sea bream (P < 0.05) except for hepatosomatic index. There were no significant differences in white blood cell count and red blood cell count (P > 0.05), however, haemoglobin level was significantly influenced by different diets (P < 0.05). Analysis of dose (lysine level)-response (SGR) with second order polynomial regression suggested the dietary lysine requirement of juvenile black sea bream to be 33.2 g kg,1 dry diet or 86.4 g lysine kg,1 protein. [source] Dietary lysine requirement of juvenile gilthead seabream Sparus aurata L.,AQUACULTURE NUTRITION, Issue 1 2006P.A. MARCOULI Abstract 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. [source] Lysine deposition responds linearly to marginal lysine intake in Atlantic salmon (Salmo salar L.) parrAQUACULTURE RESEARCH, Issue 2001R C Hauler Abstract This study investigated lysine utilization at marginal lysine intake (mg day,1) in Atlantic salmon (Salmo salar L) parr fed diets similar to those used in dose,response lysine requirement experiments. Duplicate tanks of salmon were fed Diet PL20.1 (20.1 g lysine kg,1 and 19.8 MJ DE kg,1) containing 54% of the lysine in the crystalline (free) form at four intake levels for 50 days. Feed intake levels were measured at 0.59, 0.85, 1.10 and 1.16 (satiation)%BW day,1. In addition, duplicate tanks of salmon were fed to satiation with Diets FML9.1 (9.1 g lysine kg,1) and FML20.7 (20.7 g lysine kg,1) in which lysine was derived almost entirely from fish meal. Feed intakes of FML9.1 (0.70%BW day,1) and FML20.7 (1.21%BW day,1) were significantly lower and higher (P < 0.001) than the satiation intake of the Diet PL20.1, respectively. Over all dietary treatments, lysine deposition was dependent on lysine intake (LI, mg day,1) as described by the equation: lysine deposition (mg day,1) = 0.708LI , 0.035 (r2 = 0.97, n = 12, P < 0.001). Addition of marginal lysine intakes from Atlantic salmon dose,response lysine requirement literature resulted in an equivalent relationship. The linear relationship suggests that lysine utilization remains constant at marginal lysine intake over different dietary formulations and life-stages. Consequently, the lysine requirement (allowance) of Atlantic salmon would be more appropriately estimated by a factorial approach, assuming constant efficiency of lysine utilization and the addition of obligatory lysine loss (maintenance). Efficiency of lysine utilization and obligatory lysine loss was estimated to be 71% and 0.05 mg day,1 from the current experiment and 78% and 0.10 mg day,1 with the addition of the literature data. Based on the constant lysine utilization observed in this study, it is proposed there is a need to re-evaluate lysine requirements expressed as a dietary concentration. [source] | ||||||||||