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In order to control and optimize chicken quality products, it is necessary to improve the description of the responses to dietary amino acid (AA) concentration in terms of carcass composition and meat quality, especially during the finishing period. The aim of this study was to investigate the effects of Lysine (Lys, i.e. a limiting AA used as reference in AA nutrition) and AA other than Lys (AA effect). In total, 12 experimental diets were formulated with four levels of digestible Lys content (7, 8.5, 10 and 11.5 g/kg) combined with either a low (AA-), adequate control (AAc) and high (AA+) amount of other essential AA (EAA) expressed as a proportion of Lys. They were distributed to male Ross PM3 from 3 to 5 weeks of age. No significant AA×Lys interaction was found for growth performance or carcass composition. Body weight and feed conversion ratio were significantly improved by addition of Lys but were impaired in broilers receiving the AA- diets, whereas breast meat yield and abdominal fat were only affected by Lys. No additional benefit was found when the relative amount of other EAA was increased. There was a significant AA×Lys interaction on most of the meat quality traits, including ultimate pH, color and drip loss, with a significant effect of both AA and Lys. For example, AA- combined with reduced Lys level favored the production of meat with high ultimate pH (gt;6.0), dark color and low drip loss whereas more acid, light and exudative meat (lt;5.85) was produced with AA+ combined with a low Lys level. In conclusion, growth performance, carcass composition and meat quality are affected by the levels of dietary Lys and AA in finishing broilers. In addition, interactive responses to Lys and AA are found on meat quality traits, leading to great variations in breast pHu, color and drip loss according AA balance or imbalance.

On commercial farms, young growing pigs are frequently affected by health problems from multifactorial origins (e.g. environmental changes, biosecurity, management, and feed) that result in inflammation and activation of body defenses. Inflammation states alter animal metabolism in such a way that nutrients (particularly amino acids) are diverted from the use for growth towards the production of defense-related proteins and low-molecular-weight compounds (e.g., nitric oxide, H2S, and glutathione) for supporting the activity of rapidly dividing cells such as immune cells and enterocytes. Furthermore, amino acids may act specifically as signaling molecules to regulate metabolic pathways during inflammation. Thus, new knowledge on the specific role and metabolism of each amino acid is needed to refine nutritional recommendations for pigs of different phenotypes and genotypes, with the objective of maintaining animal health and performance under sub-optimal rearing conditions. This paper aims at summarizing recent advances in research on the functional roles of amino acids related to swine health. Specifically, the review highlights current knowledge on the impact of inflammation on the intake and metabolism of amino acids; their relevance for the physical gut mucosal barrier and antioxidant defense, as well as their roles in the syntheses of defense molecules and in the regulation of immune response. Practical implications for feeding strategies adapted to various health conditions of growing pigs are also discussed along with our general perspectives on related research.

Traditional AA dose-response studies utilize many animals for evaluation of growth performance, and it is hypothesized that a new experimental design based on modem analytical techniques can reduce the number of used animals. The objective was to evaluate a short-term approach with a low number of pigs based on plasma metabolites as a method to determine the dietary Ile, Leu, and Val requirements. Three separate 6 x 6 Latin square experiments having 6 replicates per treatment were conducted with 6 diets containing increasing concentrations of Ile, Leu, and Val which were fed to 6 pigs (BW 8-9 kg) for 2 days, each without a wash-out period for a period of 12 days. The diets were prepared and used in 3 previous traditional-design dose-response studies and had been stored at 20 degrees C. Blood samples were collected at the end of each 2-day period, and plasma was analyzed for AA and other metabolites using a metabolomics approach. Out of the 18 analyzed plasma AA, 11, 16, and 3 AA for Ile, Leu, or Val, respectively, showed linear or quadratic responses (P < 0.05) which could be linked to animal growth. The same was found for 4 non-AA metabolites in the Ile, and for 7 non-AA metabolites in the Leu study. 3-Methyl-2-oxovaleric acid, ketohexanoic acid, and a-ketoisovaleric acid were discriminating metabolites for both Ile and Leu. It was possible to fit least squares means of 5, 14, and 2 metabolites in the Ile, Leu, and Val experiments to curvilinear-plateau, broken-line, or quadratic models and thereby estimate an optimum dietary BCAA level. The average optimum BCAA levels across metabolites and models were 0.54 standardized ileal digestible (SID) Ile:Lys, 1.04 SID Leu:Lys, and 0.68 SID Val:Lys which were close to optimums of 0.52, 0.93, and 0.70 found in the previous dose response studies based on animal growth performance. In conclusion, certain plasma metabolites could be used to estimate Ile, Leu, and Val requirements, and 2 days of adaptation to a new diet was sufficient to reflect relevant biological changes in the blood to different levels of dietary AA in the current study.

Besides being incorporated into proteins, Trp, an indispensable AA, is involved in numerous metabolic pathways. Previous data showed that Trp conversion into kynurenine (Kyn) and nicotinamide (Nam) differs among studies, and such differences cannot be explained by different dietary niacin supplies. We hypothesized that pig genotype influences Trp metabolism and thus the conversion of Trp into its metabolites. The objective of this study was to compare plasma appearance of Trp and related metabolites in 12 Duroc and 12 Piétrain crossbred postweaning pigs fed 2 contrasting dietary Trp levels. Within each genotype, 6 pigs were fed a basal (B-Trp: 17% and 15% standardized ileal digestible [SID] Trp:Lys for starter and prestarter diets) or supplemented (S-Trp: 24% and 23% SID Trp:Lys for starter and prestarter diets) Trp diet. Growth was monitored, and plasma fasted concentrations were measured over 4 wk, and then pigs were fitted with a jugular catheter for frequent blood samplings. After overnight fasting, 350 g of the experimental diets were offered to each pig, and plasma concentrations of Trp, Kyn, Nam, and 5-hydroxytryptamine (5-HT) were measured for 6 h. The activities of Trp-degrading enzymes were measured in different tissues collected after pig slaughtering. Plasma Trp fasted concentrations did not differ between B-Trp and S-Trp diets and increased from weaning to 2 and 4 wk after weaning for Piétrain but not for Duroc crossbred pigs (time × genotype, = 0.001). Plasma Kyn concentrations were greater 4 wk after weaning ( = 0.002) than at weaning and for Piétrain compared to Duroc genetics ( = 0.008). Plasma Nam concentrations were greater for pigs fed the S-Trp diet than for those fed the B-Trp diet ( = 0.0001) and for Duroc than for Piétrain genetic lines ( = 0.001); this difference tends to be greater at weaning than after ( = 0.055). Our data showed an increase in plasma concentrations of Trp, Kyn, Nam, and 5-HT according to time after a meal and to the dietary Trp content. However, postprandial plasma concentrations of Trp metabolites and enzyme activities were not significantly different between Duroc and Piétrain crossbred pigs. In conclusion, our results suggest that Nam endogenous synthesis capacity from Trp is greater in Duroc than in Piétrain crossbred pigs, but this was apparent only at weaning.

Eighteen multiparous Large White sows were used to determine the effects of dietary protein content and lactation stage on milk composition during a 28-d lactation under humid tropical climatic conditions. This study was conducted at the INRA facilities in Guadeloupe, French West Indies (latitude 16°N, longitude 61°W). The average minimum and maximum ambient temperatures and average daily relative humidity during the trial were 22.7 and 29.4°C, and 93.7%, respectively. The dietary experimental treatments were a normal protein (NP, 17.3%) diet and a low protein (LP, 14.1%) diet supplemented with essential amino acids. The ADFI tended to be higher for the sows fed the LP diets when compared with the NP treatment (i.e., +9%, P0.10). The treatments did not influence (P>0.10) sow body weight loss during lactation. The sows fed LP diets tended to show lower backfat thickness losses when compared to the sows fed NP diets (2.4 vs. 6.3 mm, respectively; P0.10). Milk dry matter and ash contents linearly increased according to lactation stage (17.6 to 19.9%, and 0.72 vs. 97%, respectively from d 7 to d 27; P0.10) by lactation stage. Maternal BW loss during lactation was negatively correlated with the average daily feed intake (r=-0.76; P

Reducing the CP level of the diet allows for a reduction in N excretion without limiting performance as long as the amino acid (AA) requirements are covered. The availability of crystalline AA has permitted for a considerable reduction in the CP level of diets, practically used in pig nutrition. The adoption of low CP diets and the extent to which the CP content can be reduced further depends on the knowledge of the minimum levels of indispensable AA that maximize growth. The standardized ileal digestible (SID) Phe : Lys and Tyr : Lys requirements and the possibility to substitute Tyr by Phe have never been studied in piglets. The objectives of this study were to estimate these requirements in 10 to 20 kg pig as well as to determine the extent to which Phe can be used to cover the Tyr requirement. In three dose–response studies, six pigs within each of 14 blocks were assigned to six low CP diets (14.5% CP) sub-limiting in Lys at 1.00% SID. In experiment 1, the SID Phe : Lys requirement estimate was assessed by supplementing a Phe-deficient diet with different levels of L-Phe to attain 33%, 39%, 46%, 52%, 58%, and 65% SID Phe : Lys. Because Phe can be used for Tyr synthesis, the diets provided a sufficient Tyr supply. A similar approach was used in experiment 2 with six levels of L-Tyr supplementation to attain 21%, 27%, 33%, 39%, 45% and 52% SID Tyr : Lys. Phenylalanine was supplied at a level sufficient to sustain maximum growth (estimated in experiment 1). The SID Phe : Lys and SID Tyr : Lys requirements for maximizing daily gain were 54% and 40% using a curvilinear-plateau model, respectively. A 10% deficiency in Phe and Tyr reduced daily gain by 3.0% and 0.7%, respectively. In experiment 3, the effect of the equimolar substitution of dietary SID Tyr by Phe to obtain 50%, 57%, and 64% SID Phe : (Phe +Tyr) was studied at two limiting levels of Phe +Tyr. From 57% to 64% SID Phe : (Phe +Tyr), performance was slightly reduced. In conclusion, it is recommended not to use a Phe +Tyr requirement in the ideal AA profile but rather use a SID Phe : Lys of 54% and a SID Tyr : Lys of 40% to support maximal growth.

Several aspects of tryptophan (Trp) metabolism are dependent upon pyridoxine (B 6 ) status. The present experiment aimed to determine if Trp metabolism and the eventual growth responses to dietary supplementation of Trp is modulated by dietary B 6 . Exploratory measurements related to the modulation of the immune system were also made. Piglets weaned at 15 to 18 days of age ( n = 544) were grouped in 32 pens of 17 animals and distributed in a factorial arrangement of treatments with two dietary additions of B 6 [0 (B 6 −) or 5 mg/kg (B 6 +)] and two dietary additions of synthetic Trp [0 (Trp−) or 0.5 g/kg (Trp+)]. Basal dietary concentrations of B 6 varied according to age, between 2.1 and 3.5 mg/kg, and for Trp, between 1.9 and 2.5 g/kg. Growth performance was recorded every week from 2 to 9 weeks of age. Blood samples were taken from two piglets in each pen at 2, 4, 6 and 8 weeks of age. Another piglet in each pen was immunized twice with ovalbumin emulsified with incomplete Freund adjuvant to evaluate the antibody response. No treatment effect was observed on feed intake, body weight gain or feed conversion ratio for the whole experimental period but feed conversion increased more drastically in Trp− than in Trp+ piglets during the last week of experiment (B 6 × Trp × age, P 6 vitamer, was 19% lower in red blood cells of B 6 − than B 6 + piglets (B 6 × age, P 6 + than in B 6 − piglets. The percentage of B lymphocyte population at 4 and 6 weeks of age dropped in B 6 − animals whereas it remained stable in B 6 + piglets (B 6 × age, P 6 × Trp × age), the results indicate that, globally, within the present dietary levels, pyridoxine is not a major factor for Trp metabolism and therefore, for Trp requirements of post-weaning piglets. The absence of interaction between B 6 and Trp on the present immunological indicators suggest that each nutrient modulates the immune response through independent mechanisms.

International audience; The branched-chain amino acids (BCAA) valine (Val) and isoleucine (Ile) are considered to be among the next-limiting amino acids for growth in piglets. In earlier studies, we estimated the standardized ileal digestible (SID) Val : Lys (lysine) requirement to be at least 70%, whereas the Ile : Lys requirement may be as low as 50%. Because the BCAA partially share a common route of catabolism, the supply of one BCAA may affect the availability of the other BCAA. Four experiments were conducted to determine the response of 6-week-old piglets to the Val supply in relation to the other BCAA. A deficient supply of Val or Ile typically results in a reduction in average daily feed intake (ADFI). Experiment 1 was designed to determine the effect of a limiting Val supply, independent of the effect on feed intake. In a dose–response study using restrictively fed piglets, nitrogen retention did not increase for an SID Val : Lys supply greater than 64%. In the remaining experiments, piglets were offered feed ad libitum using ADFI, average daily gain (ADG) and gain-to-feed ratio as response criteria. The interaction between the Val and leucine (Leu) was studied in Experiment 2 in a 2 × 2 factorial design (60% and 70% SID Val : Lys, and 111% and 165% SID Leu : Lys). Performance was considerably lower in piglets receiving 60% Val : Lys compared with those receiving 70% Val : Lys and was lowest in piglets receiving the diet with low Val and high Leu content. To further evaluate the interaction between Val and Leu, a dose–response study was carried out in which the response to Val supply was studied in combination with high Leu supply (165% Leu : Lys). Using a curvilinear-plateau model, the average SID Val : Lys requirement was 72%. However, low Val supply (60% SID Val : Lys) reduced performance by 13% to 38%, which was much greater than what we observed in earlier studies. Experiment 4 was carried out to test the hypothesis that the Val requirement is not affected by low Ile supply (50% SID Ile : Lys). Performance was not improved for Val : Lys supplies greater than 65%, which may indicate that Ile (and not Lys) was second-limiting in this study. In conclusion, the first response of piglets to deficient Val supply appears to be a reduction in ADFI, rather than a reduction in ADG or nitrogen retention. A large supply of Leu may not affect the Val requirement per se, but may aggravate the consequences of Val deficiency.

International audience; Deterioration of the environment in which piglets are housed after weaning induces a moderate inflammatory response and modifies tryptophan (Trp) metabolism that can, in turn, decrease Trp availability for growth. We hypothesised that a Trp supply above the current recommendations may be required to preserve Trp availability and to maximise the growth of pigs suffering from moderate inflammation. The aim of this experiment was to compare growth performance and plasma concentrations of Trp and some of its metabolites in piglets, suffering or not from moderate inflammation, when they were fed diets containing graded levels of standardised ileal digestible (SID) Trp, obtained with the addition of crystalline L-Trp to the same basal diet (15%, 18%, 21% or 24%, relative to SID lysine). Differences in inflammatory status were obtained by housing the pigs under different sanitary conditions. Forty blocks of four littermate piglets each were selected and weaned at 4 weeks of age. The experimental design consisted of a split plot where the housing conditions (moderate inflammation v. control) were used as the main plot and dietary Trp content as the subplot. Body weight gain and feed intake were recorded 3, 5 and 7 weeks after weaning. Blood was sampled 13, 36 and 43 days after weaning to measure plasma concentrations of Trp, kynurenine and nicotinamide (i.e. two metabolites of Trp catabolism) and haptoglobin, a major acute phase protein in pigs. There was no interaction between dietary Trp and inflammatory status, irrespective of the response criterion. Compared with control pigs, pigs housed in poor housing conditions consumed less feed (P < 0.0001), had a lower growth rate (P < 0.001), higher plasma concentrations of haptoglobin (P < 0.05) and lower concentrations of plasma Trp irrespective of the Trp content in the diet. Increasing the Trp content in the diet improved feed intake (P < 0.05), growth rate and feed/gain (P < 0.05), but did not prevent the deterioration of performance induced by moderate inflammation because of poor housing conditions. The results of this study suggest that an inflammatory response caused by poor housing sanitary conditions altered Trp metabolism and growth performance, but this was not prevented by additional dietary crystalline L-Trp.

The use of crystalline amino acids allows reducing the CP in the diet without compromising performance. The extent to which the CP content in the diet can be reduced under practical conditions depends on accurate knowledge of the requirements of amino acids that may become limiting when pigs are offered low-CP diets. Valine is now considered the next-limiting amino acid after Lys, Met (+Cys), Thr, and Trp in cereal-soybean meal based diets. Nevertheless, experimental studies on the response of pigs to the Val supply are scarce. Our objective was to analyze studies for growing pigs fed diets with increasing levels of L-Val.

In poultry production, there is a constant need for updating birds' requirements especially protein and amino acids, because of economical purposes, genetic improvements and also because parameters of interest are changing from the classical ones i.e. body weight, feed conversion ratio, to more recent ones, i.e. meat yield and processing quality (Berri et al., 2008; Dozier et al., 2010). In chickens, these last characteristics are strongly influenced by the ultimate pH of the meat which depends on muscle glycogen content (Le Bihan-Duval et al., 2008). Recent observations suggest the possibility of modulating these characteristics by varying the lysine intake of broilers (Jlali et al., 2012). Our objective was to determine the digestible lysine requirements of male Ross broilers during the finishing period, taking into account birds growth, feed conversion, edible parts yields, adiposity and meat quality.

Improving the amino acid (AA) profile of the diet by using l-Lys, l-Thr, dl-Met, l-Trp and l-Val helps to reduce the dietary CP content, thereby reducing nitrogen excretion while maintaining the performance of pigs. Valine is the fifth limiting AA in cereal–soybean meal-based diets. The extent to which the CP content in the diet can be reduced further without compromising performance depends on the requirement of the next limiting AA. In cereal–soybean meal-based diets, Ile, His and Leu may be the limiting AAs after Val, although information on the requirements for these AAs is scarce. Six experiments were conducted to determine the effect of supplementing a low-CP diet with l-Ile, l-His and l-Leu on the performance of pigs weighing 10 to 20 kg. Experiment 1 was designed to determine the most limiting AA with respect to performance among Ile, His and Leu. A diet 10% deficient in Ile, Leu and His relative to the National Research Council (NRC, 1998) requirement estimates tended to decrease daily feed intake and daily gain by 6% and 8%, respectively. A 10% deficiency in His alone had no effect, whereas a 10% deficiency in Ile or Leu slightly reduced daily feed intake and gain. In the remaining experiments, the standardized ileal digestible (SID) Ile : Lys, His : Lys and Leu : Lys requirements were estimated. In Experiments 2, 3, 4, 5 and 6, 14 blocks of six pigs each were assigned to six levels of SID Ile : Lys (40%, 43%, 46%, 49%, 52% and 55%), His : Lys (20%, 24%, 28%, 32%, 36% and 40%), His : Lys (21%, 24%, 27%, 30%, 33% and 36%), Leu : Lys (70%, 78%, 86%, 94%, 102% and 110%) and Leu : Lys (80%, 90%, 100%, 110%, 120% and 130%), respectively. Across experiments, the estimated SID Ile : Lys, His : Lys and Leu : Lys requirements for maximizing daily gain were 49%, 32% and 102%, respectively, using a curvilinear plateau model. When Ile, His and Leu levels were 10% below the requirement estimate, daily gain was reduced by 9%, 3% and 3%, respectively. The results of this study indicate that the Ile requirement estimate is lower than the current NRC requirement estimate, whereas the Leu and His requirements correspond to those proposed by the NRC.

International audience; There is no consensus concerning the Trp requirement for piglets expressed relative to Lys on a standardized ileal digestible basis (SID Trp : Lys). A meta-analysis was performed to estimate the SID Trp : Lys ratio that maximizes performance of weaned piglets between 7 and 25 kg of BW. A database comprising 130 experiments on the Trp requirement in piglets was established. Thenutritional values of the diets were calculated from the composition of feed ingredients. Among all experiments, 37 experiments were selected to be used in the meta-analysis because they were designed to express the Trp requirement relative to Lys (e.g. Lys was the second-limiting amino acid in the diet) while testing at least three levels of Trp. The linear-plateau (LP), curvilinear-plateau (CLP) and asymptotic (ASY) models were tested to estimate the SID Trp : Lys requirement using average daily gain (ADG), average daily feed intake (ADFI) and gain-to-feed ratio (G : F) as response criteria. A multiplicative trial effect was included in the modelson the plateau value, assuming that the experimental conditions affected only this parameter and not the requirement or the shape of the response to Trp. Model choice appeared to have an important impact on the estimated requirement. Using ADG and ADFI as response criteria, the SID Trp : Lys requirement was estimated at 17% with the LP model, at 22% with the CLP modeland at 26% with the ASY model. Requirement estimates were slightly lower when G : F was used as response criterion. The Trp requirement was not affected by the composition of the diet (corn v. a mixture of cereals). The CLP model appeared to be the best-adapted model to describe the response curve of a population. This model predicted that increasing the SID Trp : Lys ratiofrom 17% to 22% resulted in an increase in ADG by 8%.

The efficiency of nitrogen utilization will be highest when the amino acid (AA) supply approaches the requirement of the animal. With the availability of different crystalline AA, it is theoretically possible to formulate low-protein diets for growing pigs in which seven AA are co-limiting for performance. In such a diet, the concentration of Lys, Met, Met + Cys, Thr, Trp and Val and a seventh AA would exactly match the requirement. To determine the extent to which low-protein diets can be used, it is important to have reliable information about the requirements for these AA. Isoleucine is often considered the seventh-limiting AA in diets for growing pigs; however, information about the Ile requirement is limited and sometimes conflicting. The purpose of this study was to carry out a meta-analysis of the available literature information to determine the Ile requirement in growing pigs. A total of 46 Ile dose-response experiments were identified that used at least four concentrations of Ile in the diet. Because of differences in experimental design, both the Ile concentration and the response criteria were standardized. In 13 dose-response experiments, there was no indication of a response to an increasing Ile concentration. For the other 33 experiments, a response to the increasing Ile concentration was observed and the Ile requirement estimates ranged from 53% to 114% of that of the National Research Council (1998). An Ile concentration below the requirement resulted in important reductions in both feed intake and growth. A 10% reduction in the Ile concentration (below the requirement) resulted in a 15% reduction in feed intake and a 21% reduction in daily gain. The use of blood products in the diet was the main factor determining whether a response to the Ile concentration was observed or not. Blood meal and blood cells are protein sources with a very low Ile concentration, but with high or very high concentrations of Leu, Val, Phe and His. Some of these AA compete with Ile for catabolic pathways or transport across the blood-brain barrier, thereby potentially increasing the requirement for Ile. In diets without blood products, the Ile requirement appears to be lower than the currently recommended requirement. On the basis of the outcome of this study, we recommend a Ile : Lys requirement ratio of at least 50% on a standardized ileal digestible basis.

International audience; Four experiments were conducted to measure total tract metabolizability of gross energy (GE), the AME, and AME(n) or AME content corrected for a standardized N retention (AME(s)) of 10 European wheat dried distillers grains with solubles (DDGS) in roosters, broilers (3 wk old), layers (25 wk old), and growing turkeys (10 wk old). The wheat DDGS were obtained from 7 European ethanol plants and selected to get a large variability in chemical composition. The AME, AME(n), or AME(s) of wheat DDGS was obtained according to the difference method. The highest AME(n): GE was obtained for roosters with an average (minimum-maximum) value of 49% (43-55), the lowest in turkeys (43%; 34-50), and intermediate values (47%; 41-57 and 46%; 36-50) in broilers and layers, respectively. Corresponding AME(n) values were 10.3 (9.0-11.3), 9.9 (8.5-11.7), 9.6 (7.8-10.5), and 9.6 (7.8-10.5) MJ/kg of DM for roosters, broilers, layers, and turkeys, respectively. The AME(s) for N retention equal to 50% of N intake was about 0.6 MJ higher than the corresponding AME(n) value. Our data indicate that the AME(n) content of wheat DDGS can be predicted from either their acid detergent fiber content (R(2) = 0.79) or the lightness score (L*; R(2) = 0.77) with a common slope but different intercepts for the 4 poultry categories. If dark and overheated samples (L* < 50; n = 3) with the lowest AME(n): GE ratio and AME(n) values are excluded, the average AME(n): GE ratio becomes 51, 49, 48, and 45% in roosters, broilers, layers, and turkeys, respectively, with corresponding AME(n) values of 10.7, 10.2, 10.0, and 9.5 MJ/kg of DM that are more representative of a well-controlled process for DDGS preparation. The negative effect of L* on energy value and energy metabolizability indicates that overheating while drying should be minimized to maximize the energy value of wheat DDGS for poultry. Finally, equations for predicting AME values in layers, broilers, or turkeys from the AME values in roosters are proposed.

International audience; In recent years, policies encouraging the production of ethanol from cereals have resulted in increased production of distillers dried grains with solubles (DD GS). Unlike corn, DDGS nutritional value and its variability for pigs is poorly described for wheat DDGS. Seventeen wheat DDGS samples were obtained from seven plants in Europe. Each sample was analysed for chemical composition and 10 representative samples were analysed for amino acids (AA) concentration and their standardized ileal digestibility (SID) in pigs. Luminance (L) of the DDGS was also measured. Results indicate a rather stable crude protein (CP; N x 6.25) concentration (326-389 g/kg DM; average: 361 g/kg DM) but the AA profile was variable among samples. Lysine (lys) concentration was the most variable with values ranging between 0.83 and 3.01 g/100g CP. Only 76% of total lys was available if measured by the fluor dinitro benzene procedure and 85% was available when measured by the furosine procedure. The SID of lys was also highly variable (0.09-0.83) with the lowest values observed for the three samples that had a low lys concentration in CP. These latter samples had also a high occurrence of Maillard reaction products and low L values (

In recent years, policies encouraging the production of ethanol from corn or wheat have stimulated an increased production of distillers dried grains with solubles (DDGS) whose nutritional value for pigs is little described. Seventeen wheat DDGS samples were obtained from 7 different plants in Europe from July to September 2007. Each sample was analyzed and 10 representative samples were measured for amino acids (AA) content and their standardized ileal digestibility (SID) in pigs. Lightness score (L) of each DDGS was also measured. Our results indicate a rather stable crude protein content (32.6 to 38.9% DM basis; average: 36.1% DM basis) whereas lysine was the most affected AA with contents ranging between 0.82 and 3.00% of crude protein (CP; N*6.25). In addition, lysine SID was also variable (9 to 82%) with the lowest values observed in DDGS with low lysine level in CP. In fact, samples with low lysine content in CP and low SID of lysine had low lightness values (L

The carry-over effect of a pre-starter diet (0 to 3 days of age) deficient in lysine on subsequent growth and body composition (3 to 10 days) was examined in two experiments on male broiler chicks raised in cages. In experiment 1, lysine deficiency was applied from 3 to 10 days after providing a balanced pre-starter control feed (Dþ, 1.40% lysine) or a lysine deficient feed (D2) during the first 3 days. Three levels of deficiency (A ¼ 0.63%, B ¼ 0.72%, C ¼ 0.82%) were tested. Growth and feed intake were higher in Dþ than in D2 chicks (P , 0.001). However, the feed conversion ratio from 3 to 10 days of age was higher in Dþ chicks (P , 0.001); pre-starter and starter feeds interacted (P , 0.04) with the feed conversion of treatment D2/A ¼ 2.07 being better than treatment Dþ/A ¼ 2.61 (P, 0.05). This suggests that chicks deficient from hatching exhibit a relatively lower sensitivity to lysine deficiency than chicks started on a control diet. In experiment 2, performance, slaughter parameters and body composition were analysed at 3 and 10 days of age, in chicks having received a lysine deficient feed (D0, 0.72% lysine), a control feed (Dþ, 1.40% lysine) or having been pair fed with control feed adjusted to D0 intake (PF) from 0 to 3 days of age, and then fed D0 ad libitum from 3 to 10 days of age. At 3 days, PF chicks had a higher body weight (P, 0.05) than D0, and thus a better feed conversion. Body composition in relative values was little or not affected by dietary treatments, but the breast muscle weight at 3 days was higher in Dþ and PF chicks compared with D0 (P , 0.05) and this effect was even accentuated at 10 days of age. The present work confirms that early nutrition can have subsequent consequences on the adjustment of fast growing broiler chicks to their nutritional conditions. It also suggests that breast muscle development is a more reactive parameter than whole body composition in this kind of experiments. (Resume d'auteur)