Effect of Rumen-Protected Methionine on Metabolic Profile of Liver, Muscle and Blood Serum Samples of Growing German Simmental Bulls Fed Protein-Reduced Diets.

This study aimed to determine the metabolic response of growing German Simmental bulls fed rations low in crude protein (CP) supplemented with rumen-protected methionine (RPMET). In total, 69 bulls (on average 238 ± 11 days of age at start and 367 ± 25 kg of bodyweight) were assigned to three dietary treatments (n = 23/group): Positive control (CON; 13.7% CP; 2.11 g methionine/kg DM), negative control deficient in CP (RED; 9.04% CP; 1.56 g methionine/kg DM) and crude protein-deficient ration supplemented with RPMET (RED+RPMET; 9.04% CP; 2.54 g methionine/kg DM). At slaughter, samples of liver, muscle and blood serum were taken and underwent subsequent metabolomics profiling using a UHPLC-QTOF-MS system. A total of 6540 features could be detected. Twenty metabolites in the liver, five metabolites in muscle and thirty metabolites in blood serum were affected (p < 0.05) due to dietary treatments. In total, six metabolites could be reliably annotated and were thus subjected to subsequent univariate analysis. Reduction in dietary CP had minimal effect on metabolite abundance in target tissues of both RED and RED+RPMET bulls as compared to CON bulls. The addition of RPMET altered the hepatic anti-oxidant status in RED+RPMET bulls compared to both RED and CON bulls. Results exemplify nutrient partitioning in growing German Simmental bulls: bulls set maintenance as the prevailing metabolic priority (homeostasis) and nutrient trafficking as the second priority, which was directed toward special metabolic functions, such as anti-oxidant pathways.

Indicators of thermal comfort and nitrogen digestibility as a function of digestible arginine: lysine ratios in the diet of laying Japanese quails raised in hot weather.

The objective with this study was to determine the influence of the digestible arginine: lysine ratio in the diet of laying Japanese quails raised in hot weather on the physiological variables of thermoregulation, time in tonic immobility, behavior and nitrogen utilization. A total of 240 laying quails (Coturnix coturnix japonica) with 40 weeks of age were used in a completely randomized design with five treatments and six replications containing eight quails per experimental unit. The studied digestible arginine: lysine ratios were 110%; 120%, 130%, 140% and 150%, for 63 days divided into three periods of 21 days each. There was a quadratic effect (p < 0.05) for the variables average surface temperature, average body temperature, core to surface thermal gradient, ambient to surface temperature gradient observed in the morning. In the afternoon, a quadratic effect (p < 0.05) of the arginine: lysine ratio was observed for variables average surface temperature, average body temperature, core to surface thermal gradient, ambient to surface thermal gradient, back temperature, head temperature and respiratory frequency. There was no significant effect (p > 0.05) of arginine: lysine ratios on the frequency of behaviors, except drinking and panting (p < 0.05), for which 130% ratio provided the lowest frequencies of these behaviors. There was a quadratic effect (p < 0.05) for the parameters of nitrogen retention, nitrogen excreted and nitrogen retention efficiency. Nitrogen intake and excreta moisture were not influenced by the different relationships studied (p > 0.05). The 130% arginine: lysine ratio corresponding to 0.131 g/kg/feed of arginine improves physiological responses related to thermoregulation and decreases the expression of behaviors correlated to heat stress, also meeting the best estimated ratio for nitrogen retention in the diet of quails laying Japanese raised in hot weather.

Effects of Feeding Low Protein Diets with Different Energy-to-Protein Ratios on Performance, Carcass Characteristics, and Nitrogen Excretion of Broilers.

This study shows the effects of feeding low protein (LP) diets with different energy-to-protein ratios were evaluated on the production parameters, carcass composition, meat quality, nitrogen retention, and excreta composition of broilers. A total of 576-day-old Ross 308 broilers were fed a control diet (C) and three LP diets containing 1.5% less crude protein than diet C for 41 days. The LP1 treatment was isocaloric with diet C, while the dietary apparent metabolizable energy corrected by nitrogen (AMEn) levels in the case of the LP2 and LP3 treatments were reduced by 1.5% and 3%, respectively. The LP diets were supplemented with six crystalline essential amino acids (AA) to meet the standardized ileal digestible AA requirements of broilers. The LP1 treatment did not affect the performance parameters of broilers and increased the breast meat yield, the nitrogen retention and decreased drip loss of breast meat and the total-N and uric acid-N nitrogen excretion of birds in comparison with the C group. Although the energy-reduced LP2 and LP3 diets resulted in lower final body weight, they did not affect the carcass composition, breast meat quality, nitrogen retention, and excreta composition of birds compared with the control treatment.

Growth performance, caecal microbiome profile, short-chain fatty acids, and litter characteristics in response to placement on reused litter and combined threonine, arginine and glutamine supplementation to juvenile male broiler chickens.

BACKGROUND: Exposure of broilers to litter microbiome may increase specific amino acid (AA) requirements towards activated immune responses. This may challenge the generality of the ideal protein (IP) concept, in which dietary essential AA to lysine ratios aimed to mimic presumably constant AA to lysine ratios in whole bird requirements. Therefore, we tested the effect of threonine, arginine and glutamine (TAG) supplementation to IP-based control diets (C) on performance, caecal microbiome composition, short-chain fatty acids and litter characteristics of broiler chickens placed on reused litter. RESULTS: Thirty-two pens with ten male broiler chickens each were used in a 2 × 2 factorial arrangement of two diet treatments (with or without TAG supplementation) and two litter treatments (placement on clean or reused litter) for 21 days (n = 8). Caecal contents were analysed for microbiome profile using percent guanine + cytosine (%G + C profile) method and short chain fatty acids. TAG-supplemented birds underperformed compared to C birds (P = 0.002), whereas birds placed on reused litter outperformed those on clean litter (P = 0.047). Diet, reused litter and their interaction impacted the %G + C profile at different ranges. Whilst TAG supplementation reduced bacterial abundance at %G + C 51-56 (P < 0.05), reused litter placement tended to reduce %G + C 23-31 and increase %G + C 56-59 (P < 0.10). However, TAG supplementation reduced bacterial abundance at %G + C 47-51 (P < 0.05) and increased caecal branched chain fatty acids on clean litter only (P = 0.025). Greater levels of propionic acid were observed for C birds placed on reused litter only (P = 0.008). Litter pH was greater for reused litter pens than clean litter pens at day 21 (P < 0.001). In addition, litter moisture content was less for TAG birds and reused litter pens compared to C birds (P = 0.041) and clean litter pens (P < 0.001), respectively. CONCLUSIONS: These data support the view that irrespective of performance benefits arising from bird placement on reused litter, TAG supplementation to IP-formulated baseline rations impaired growth, supported by the lowered abundance of caecal bacteria known to dominate in well-performing birds and greater levels of caecal branched chain fatty acids.

Urea Nitrogen Metabolite Can Contribute to Implementing the Ideal Protein Concept in Monogastric Animals.

The ideal protein concept refers to dietary protein with an amino acid profile that exactly meets an animal's requirement. Low-quality protein levels in the diet have negative implications for productive and reproductive traits, and a protein oversupply is energetically costly and leads to an excessive N excretion, with potentially negative environmental impact. Urea Nitrogen (UN), which corresponds to the amount of nitrogen in the form of urea circulating in the bloodstream, is a metabolite that has been widely used to detect amino acid imbalances and deficiencies and protein requirements. This review aims to critically analyse how UN can contribute to accurately implementing the ideal protein concept in monogastric animals, particularly in pig, poultry, and rabbit nutrition (14,000 animals from 76 published trials). About 59, 37, and 4% of trials have been conducted in pigs, poultry, and rabbits, respectively. UN level was negatively correlated to main performance traits (Pearson Correlation Coefficient [PCC] of -0.98 and -0.76, for average daily gain and feed conversion ratio, respectively), and lower UN level was related to higher milk yield and concentration. High level of UN was positively correlated to N excretion (PCC = 0.99) and negatively correlated to protein retention (PCC = -0.99). Therefore, UN in blood seems to be a proper indicator of amino acid imbalance in monogastric animals. Great variability in the use of UN was observed in the literature, including uses as determination medium (blood, plasma, or serum), units, and feeding system used (ad libitum or restricted), among others. A standardization of the methods in each of the species, with the aim to harmonize comparison among works, is suggested. After review, UN measurement in plasma and, whenever possible, the utilization of the same nutritional methodology (ad libitum conditions or restriction with blood sampling after refeeding at standardised time) are recommended. More studies are necessary to know the potential of UN and other bioindicators for amino acid deficiencies evaluation to get closer to the ideal protein concept.

Biomarkers and De Novo Protein Design Can Improve Precise Amino Acid Nutrition in Broilers.

Precision nutrition in broilers requires tools capable of identifying amino acid imbalances individually or in groups, as well as knowledge on how more digestible proteins can be designed for innovative feeding programs adjusted to animals' dynamic requirements. This work proposes two potential tools, combining traditional nutrition with biotechnological, metabolomic, computational and protein engineering knowledge, which can contribute to improving the precise amino acid nutrition of broilers in the future: (i) the use of serum uric nitrogen content as a rapid biomarker of amino acid imbalances, and (ii) the design and modeling of de novo proteins that are fully digestible and fit exactly to the animal's requirements. Each application is illustrated with a case study. Case study 1 demonstrates that serum uric nitrogen can be a useful rapid indicator of individual or group amino acid deficiencies or imbalances when reducing dietary protein and adjusting the valine and arginine to lysine ratios in broilers. Case study 2 describes a stepwise approach to design an ideal protein, resulting in a potential amino acid sequence and structure prototype that is ideally adjusted to the requirements of the targeted animal, and is theoretically completely digestible. Both tools can open up new opportunities to form an integrated framework for precise amino acid nutrition in broilers, helping us to achieve more efficient, resilient, and sustainable production. This information can help to determine the exact ratio of amino acids that will improve the efficiency of the use of nitrogen by poultry.

Effects of amino acid levels during rearing on Cobb 500 slow-feathering broiler breeders: 1. Growth and development.

Adequate pullet nutrition is essential to reach BW and suitable body composition for reproduction. An experiment was conducted to determine the effects of 4 dietary amino acid (AA) levels on BW, flock uniformity, body conformation, organ, leg, and feathering development of broiler breeder pullets during the rearing phase from 5 to 24 wk. A total of 1,360 Cobb-500 slow-feathering (SF) pullets were randomly placed in 16-floor pens with 85 females per pen. Diets with corn, soybean meal, and wheat-midds were formulated without protein restriction maintaining minimum ratios between essential AA and Lys on a digestible (dig) ideal basis. Treatments consisted of 4 dietary AA levels with 80% (low-AA), 90% (moderate-AA), 100% (standard-AA), and 110% (high-AA) of the Cobb-Vantress recommendations guided by dig Lys using balanced protein. Up to 4 wk, all pullets were fed a common starter crumble diet. Grower and developer mash diets were fed to pullets from 5 to 15 wk and from 16 to 24 wk, respectively. Pullets fed standard-AA and high-AA diets were heavier (P < 0.001) than those fed low-AA diets at 10, 15, and 20 wk of age. High-AA diets resulted in better (P = 0.040) flock uniformity at 10 wk. Pullets fed a high-AA diet had the highest (P = 0.041) relative breast weight at 20 wk of age and the lowest (P = 0.044) deposits of abdominal fat at 15 wk of age. Fleshing increased (P < 0.05) as AA content rise in the diet, while the relative shank length (P < 0.001) and the number of wing juvenile feathers (P = 0.004) decreased. Pullets fed the lowest dietary AA level had the longest (P = 0.007) small intestine relative to BW at 10 wk of age, but a smaller (P = 0.001) liver than those fed moderate and standard-AA diets at 20 wk of age. Dietary AA levels have important effects on pullet BW, fleshing, and organ development during rearing with potential reproductive performance impacts.

How Does Protein Nutrition Affect the Epigenetic Changes in Pig? A Review.

Epigenetic changes regulate gene expression and depend of external factors, such as environment and nutrition. In pigs, several studies on protein nutrition have been performed to improve productive and reproductive traits. Indeed, these studies aimed not only to determine broad protein requirements but also pigs' essential amino acids requirements. Moreover, recent studies tried to determine these nutritional requirements for each individual, which is known as protein precision nutrition. However, nutritional changes could affect different epigenetic mechanisms, modifying metabolic pathways both in a given individual and its offspring. Modifications in protein nutrition, such as change in the amino acid profile, increase or decrease in protein levels, or the addition of metabolites that condition protein requirements, could affect the regulation of some genes, such as myostatin, insulin growth factor, or genes controlling cholesterol and glucose metabolism pathways. This review summarizes the impact of most common protein nutritional strategies on epigenetic changes and describes their effects on regulation of gene expression in pigs. In a context where animal nutrition is shifting towards precision protein nutrition (PPN), further studies evaluating the effects of PPN on animal epigenetic are necessary.

Efeito dos níveis de lisina/proteína ideal sobre desempenho, características de carcaça, digestibilidade e parâmetros sanguíneos de suínos machos, castrados, da raça Duroc, de 30kg a 50kg / [Effects of lysine/ideal protein level on performance, carcass characteristics, digestibility and blood parameters of Duroc barrows from 30 to 50kg]

Objetivou-se avaliar níveis de proteína e aminoácidos, mantendo-se as relações entre os aminoácidos para suínos machos, castrados, de30kg a 50kg. Foram utilizados 50 suínos machos, castrados, com peso inicial de 30,35±1,96kg, distribuídos em delineamento experimental inteiramente ao acaso, com cinco tratamentos e cinco repetições com dois animais por unidade experimental. Os tratamentos consistiram em níveis de lisina digestível, mantendo-se a relação com os demais aminoácidos digestíveis: 0,73%; 0,83%; 0,93%; 1,03% e 1,13% na dieta. Avaliou-se desempenho, avaliação de carcaça, parâmetros sanguíneos e digestibilidade das dietas. Houve efeito quadrático para ganho de peso, conversão alimentar e níveis de creatinina em função dos níveis de lisina, com níveis ótimos estimados em 0,92%, 0,93% e 0,93%, respectivamente. As características de carcaça não foram influenciadas significativamente pelos tratamentos. Constatou-se efeito linear positivo para digestibilidade aparente da proteína bruta, da proteína total e da ureia sérica. Conclui-se que os níveis de proteína e lisina digestível recomendados para dietas de suínos machos, castrados, da raça Duroc, na fase de crescimento I, são de 16,70% e 0,93%, respectivamente, pois esses níveis proporcionaram melhorias no ganho de peso, na conversão alimentar e na creatinina sérica.(AU)

The objective of this study was to evaluate digestible lysine levels, keeping the relation among amino acids for Duroc barrows from 30 to 50kg. Fifty Duroc barrows (30.35±1.96kg live weight) were allotted in a completely randomized experimental design, divided in five treatments with five replicates and two animals in each experimental unit. The treatments consisted of digestible lysine levels (0.73%; 0.83%; 0.93%; 1.03% and 1.13%), keeping the relation with other essential amino acids. Performance, carcass characteristics, blood parameters and digestibility of the diets were evaluated. There was a quadratic response on weight gain, feed conversion and creatinine serum concentration as a function of the digestible lysine levels, with the greater levels obtained at 0.92%, 0.93% and 0.93%, respectively. The carcass characteristics were not influenced by the treatments. There was a linear increase of apparent digestibility of crude protein, total serum protein and urea. Results suggest that the requirement of protein and digestible lysine was 16.70% and 0.93%, respectively, providing improvements on weight gain, feed conversion and creatinine serum concentration of Duroc barrows in the growth phase.(AU)

Exigência de lisina digestível de frangos de corte machos de 22 a 42 dias de idade / Digestible lysine levels of male broilers from 22 to 42 days of age

O objetivo deste estudo foi determinar a exigência de lisina digestível para frangos de corte machos sob as características de desempenho, composição corporal e rendimento de carcaça dos animais, de 22 a 42 dias de idade. As dietas diferiram quanto aos níveis de lisina digestível, mantendo-se a relação dos demais aminoácidos com a lisina. Foram utilizados seis níveis de lisina digestível: 0,88%; 0,96%; 1,05%; 1,13%; 1,22%; e 1,30%. Distribuídos em 36 unidades experimentais de 36 aves cada, 1296 animais da linhagem Cobb - 500® tiveram as seguintes características de desempenho avaliadas: consumo de ração (CR), peso corporal (PC), ganho de peso (GP), conversão alimentar (CA), viabilidade criatória (VC) e índice de eficiência produtiva (IEP). Aos 42 dias de idade, foram selecionadas ao acaso cinco aves para avaliação do rendimento de carcaça, e duas para avaliação da composição corporal. A CA, o IEP e o rendimento de peito foram influenciados, sendo sua exigência de 1,30%, sugerindo que níveis maiores de lisina digestível que as recomendações utilizadas como base neste estudo (1,13%) trouxeram benefícios aos animais sobre essas características.(AU)

The objective of the present study was to evaluate the optimal levels of digestible lysine in the diet of male broilers, evaluating performance characteristics, body composition, and carcass yield of the animals in the final phase (22 to 42 days old). The diets differed in digestible lysine content, maintaining the relation among the other amino acids and lysine in accordance with the ideal protein concept. The six levels of digestible lysine in the diet were: 0.88%; 0.96%; 1.05%; 1.13%; 1.22%, and 1.30%. A total of 1296 animals were employed, distributed in 36 experimental units of 36 birds each. The determined performance characteristics corresponded to feed intake (FI), body weight (BW), weight gain (WG), feed conversion (FC), viability (VB), and productive efficiency index (PEI). At 42 days of age seven birds per experimental unit were selected at random, five for the estimation of yield and total carcass and commercial cut weight, and two for the evaluation of body composition. FC, animal breast yield and PEI weres influenced with requirements of 1.30%. With respect to nationally known recommendations regarding digestible lysine (1.13%), higher levels of the amino acid in the diet have brought benefits regarding the characteristics above.(AU)

Ketogenic, Hypocaloric Diet Improves Nonalcoholic Steatohepatitis.

BACKGROUND AND OBJECTIVES: Nonalcoholic steatohepatitis (NASH) is strongly associated with obesity. A weight loss of ≥10% is necessary to improve NASH severity, but this goal has rarely been achieved in published studies using different diet protocols. The effect of a ketogenic, hypocaloric, commercial diet ("Ideal Protein," IP) on body weight, metabolic markers, and liver tests in a group of NASH patients is evaluated in this study. Daily calorie intake was tailored to achieve a weight loss of ≥10%. METHODS: We analyzed 38 patients with NASH who were placed on the IP diet between 2014 and 2018 and compared their outcomes with 6 control patients who declined the diet. All patients were evaluated by a trained health coach in weekly intervals throughout the study period. Clinical and laboratory data obtained before and at 6.5 months after intervention were compared using paired t-testing. RESULTS: The patients on the IP diet experienced a significant weight reduction (217 ± 8 lb vs. 194 ± 7 lb; mean ± S.E.M.), corresponding to an average weight loss of 9.7% ± 1.6%. Significant changes in systolic blood pressure (133 ± 3 mmHg vs. 123 ± 3 mmHg), triglycerides (200 ± 21 mmol/L vs. 132 ± 11 mmol/L), hemoglobin A1c (6.71% ± 0.29% vs. 5.74% ± 0.19%), SGPT (97.3 ± 11.1 IU/L vs. 44.2 ± 5.9 IU/L), SGOT (82.4 ± 10.5 IU/L vs. 32.8 ± 5.2 IU/L), and Fib-4 scores (2.25 ± 0.23 vs. 1.40 ± 0.13) were also observed (P<0.05 in all cases). In the IP group, 50.5% of patients lost ≥10% body weight. In contrast, no significant changes were observed in the control group. The IP diet was well tolerated, and no safety signals were noticed. CONCLUSIONS: A ketogenic, hypocaloric resulted in striking weight loss and significant improvements in metabolic parameters and liver tests, suggesting that this approach carries promise for the dietary management of patients with NASH.

Reducción de la proteína bruta en la dieta de pollos criollos de engorde en un sistema semi-intensivo / Reduction of the crude protein in the diet of creole broilers in a semi-intensive system

RESUMEN Objetivo. Evaluar la reducción de los niveles de proteína bruta sin alterar la relación de aminoácidos esenciales en pollos de engorde criollos de uno a 42 días de edad. Materiales y métodos. Se realizaron dos ensayos que comprendieron la fase inicial (un a 21 días) y crecimiento (22 a 42 días). Se utilizaron 630 pollos de la línea Redbro de un día de edad, distribuidos en un diseño completamente al azar, con cinco tratamientos y seis repeticiones de 21 aves cada una, totalizando 30 unidades experimentales distribuidas en corrales con abrigo. Los niveles reducidos de la proteína bruta para la fase inicial fueron: 21.5; 21.0; 20.5; 20.0 y 19.5% y para la fase de crecimiento: 19.0; 18.5; 18.0; 17.5 y 17.0%. En todos los tratamientos se mantuvo la proporción mínima entre aminoácidos esenciales y lisina. Las características de desempeño evaluadas fueron: ganancia de peso, consumo de ración y conversión alimenticia. Resultados. No hubo diferencia (p>0.05) en la reducción de proteína bruta para ninguna de las variables en todas las fases, excepto para conversión alimenticia (p<0.05) en la fase de crecimiento que mejoró con 18.2% de proteína bruta. Conclusiones. Los niveles de proteína bruta para pollos criollos de engorde de la línea Redbro, pueden ser reducidos a 19.5 y 18.2% para la fases inicial y de crecimiento, respectivamente, siempre cuando se mantengan las relaciones adecuadas de aminoácidos con lisina digestible y se atiendan las exigencias de los aminoácidos limitantes.

ABSTRACT Objective . To evaluate the reduction of crude protein levels, without altering the ratio of essential amino acids, of free-range chickens, of one at 42 days old. Materials and methods. Two trials were performed comprising the initial phase (one to 21 days) and growth (22 to 42 days). A total of 630 chicks of the Redbro line of one day old, were distributed in a completely randomized design with five treatments and six replicates of 21 birds each, totaling 30 experimental units consisting of a shelter area and corrals. The levels reduced of crude protein for the initial phase were: 21.5, 21.0, 20.5, 20.0 and 19.5% and for the growth phase: 19.0, 18.5, 18.0, 17.5 and 17.0%. In all the treatments were maintained the minimum ratio between essential amino acids and lysine. The performance characteristics evaluated were: weight gain, feed intake and feed conversion. Results. There was no effect (p>0.05) of the crude protein reduction for any of the variables in all phases, except for feed conversion (p<0.05) that improved with 18.20% in the growth phase. Conclusions. Crude protein levels for chickens of the Redbro line, can be reduced to 19.5% and 18.2% for the initial and growth phases, respectively, provided that the ideal amino acid ratios are maintained with digestible lysine and meet the requirements of limiting amino acids.

Pigs receiving daily tailored diets using precision-feeding techniques have different threonine requirements than pigs fed in conventional phase-feeding systems.

BACKGROUND: There is large variation in amino acids requirements among pigs, hence feeding pigs individually with daily tailored diets or in groups with a single feed may require different levels of nutrients. Thus, the response to different threonine levels (70%, 85%, 100%, 115%, and 130% of the ideal threonine:lysine protein ratio of 0.65) was studied in growing pigs raised in a conventional group phase-feeding (GPF) system or fed individually using individual precision-feeding (IPF) techniques. In a 21-day trial, 110 barrows (25 ± 0.80 kg body weight) were housed in the same room and fed using electronic feeders. Five pigs per treatment were slaughtered at the end of the trial. RESULTS: Threonine intake increased linearly for the IPF and GPF pigs (P < 0.05). Lysine intake was similar across the treatments. Average daily gain, gain:feed ratio, and protein deposition were affected linearly by threonine level (P < 0.05) in both feeding systems. Protein deposition in the GPF pigs was maximized at 150 g/d and a 0.65 threonine:lysine ratio, whereas protein deposition increased linearly in the IPF pigs. Plasma Met and serine levels were 11 and 7% higher, respectively, in the IPF pigs than in the GPF pigs (P < 0.05). Dietary threonine increased (P < 0.05) threonine concentration in the longissimus dorsi in a quadratic manner in the IPF pigs, whereas there was no effect in the GPF pigs. Longissimus dorsi collagen decreased as dietary threonine increased in the IPF and GPF pigs (P < 0.10). Carcass muscle crude protein was 2% higher in the GPF pigs than in the IPF pigs (P < 0.05). CONCLUSIONS: Individual pigs are able to modulate growth and the composition of growth according to threonine intake. The average amino acid ratio value that is currently used for GPF cannot be used for IPF.

Digestible methionine + cysteine: lysine ratios for growing meat-type quails / Relações de metionina + cisteína: lisina digestíveis para codornas de corte em crescimento

ABSTRACT: The objective was to estimate the most appropriate digestible methionine + cysteine:lysine ratios for growing meat-type quails (Coturnix coturnix) from 1 to 21 days of age. Quails were fed with a basal ration deficient in digestible methionine + cysteine, with five levels of DL-methionine, in substitution of glutamic acid and starch, resulting in digestible methionine + cysteine:lysine ratios of 0.61, 0.66, 0.71, 0.76 and 0.81. Feed and methionine + cysteine intake, body weight gain, feed conversion and uniformity were assessed. From 1 to 7 days, an increasing linear effect was observed for feed and methionine + cysteine intake, body weight gain, and uniformity, and a linear decrease for feed conversion. From 8 to 14 days, the 0.70 methionine + cysteine: lysine ratio was the best for feed intake and body weight gain, and for uniformity, the 0.75 methionine + cysteine:lysine ratio was the most appropriate. For methionine + cysteine intake and feed conversion, an increasing and decreasing linear adjustment was observed, respectively. From 15 to 21 days, an increasing linear effect was observed for feed and methionine + cysteine intake and body weight gain; a decreasing linear effect was observed for feed conversion. The 0.81 ratio was the most efficient for feed conversion during all evaluated experimental periods. In conclusion, the 0.81 dietary methionine + cysteine:lysine ratio is the most appropriate for meat-type quails during the first 21 days of age.

RESUMO: O objetivo foi estimar as relações metionina + cisteína: lisina digestíveis mais apropriadas para a criação de codornas de corte (Coturnix coturnix) de 1 a 21 dias de idade. As codornas foram alimentadas com uma ração basal deficiente em metionina + cisteína digestível, com cinco níveis de DL-metionina, em substituição ao ácido glutâmico e ao amido, resultando nas relações metionina + cisteína: lisina digestíveis de 0,61; 0,66; 0,71; 0,76 e 0,81. O consumo de ração, a ingestão de metionina + cisteína, o ganho de peso corporal, a conversão alimentar e a uniformidade foram avaliados. De 1 a 7 dias, um efeito linear crescente foi observado para consumo de ração e de metionina + cisteína, ganho de peso corporal e uniformidade, e redução linear para conversão alimentar. De 8 a 14 dias, a relação metionina + cisteína: lisina de 0,70 foi melhor para consumo de ração e ganho de peso corporal, e para uniformidade, a relação metionina + cisteína: lisina de 0,75 foi a mais apropriada. Para consumo de metionina + cisteína e conversão alimentar, um ajuste linear crescente e decrescente foi observado, respectivamente. De 15 a 21 dias, um efeito linear crescente foi observado para consumo de ração e de metionina + cisteína e ganho de peso corporal; um efeito linear decrescente foi observado para conversão alimentar. A relação de 0,81 foi mais eficiente para a conversão alimentar durante todos os períodos experimentais avaliados. Conclui-se que a relação metionina + cisteína: lisina de 0,81 é mais apropriada para codornas de corte durante os primeiros 21 dias de idade.

Effects of amino acid composition in pig diet on odorous compounds and microbial characteristics of swine excreta.

BACKGROUND: Major amino acids in pig diets are Lys, Met, Thr, and Trp, but little is known about the requirements for the other essential amino acids, especially on odorous compounds and microbial characteristics in feces of growing-finishing pigs. To this end, different levels of amino acid composition added to diets to investigate the effects of amino acid composition on microbial characteristics and odorous compounds concentration. METHODS: A total eight (n = 8) barrows (Landrace × Yorkshire × Duroc) with an average bodyweight of 89.38 ± 3.3 kg were individually fed diets formulated by Korean Feeding Standards 2007 (old version) or 2012 (updated with ideal protein concept) in metabolism crates with two replication. After 15-day adaptation period, fresh faecal samples were collected directly from pigs every week for 4 weeks and analysed for total volatile fatty acids (VFA), phenols and indoles by using gas chromatography. The nitrogen was determined by Kjeldahl method. Bacterial communities were detected by using a 454 FLX titanium pyrosequencing system. RESULTS: Level of VFA tended to be greater in 2012 than 2007 group. Among VFAs, 2012 group had greater (p < 0.05) level of short chain fatty acids (SCFA) than control.Concentration of odorous compounds in feces was also affected by amino acid composition in pig diet. Levels of ammonium and indoles tended to be higher in 2012 group when compared with 2007 group.Concentration of phenols, p-cresol, biochemical oxygen demand, and total Kjeldahl nitrogen, however, were lower (P < 0.05) in 2012 treatment group compare to 2007. The proportion of Firmicute phylum were decreased, while the Bacteriodetes phylum proportion increased and bacterial genera includingCoprococcus, Bacillus, and Bacteroides increased (p < 0.05) in 2012 compare to 2007 group. CONCLUSION: Results from our current study indicates that well balanced amino acid composition reduces odor by modulating the gut microbial community. Administration of pig diet formulated with the ideal protein concept may help improve gut fermentation as well as reduce the odor causing compounds in pig manure.

Lisina digestível na ração de frangos de corte tipo caipira na fase de crescimento / Dietary digestible lysine in free-range broiler chickens during the growth phase

O presente experimento foi conduzido para determinar as exigências de lisina digestível para frangos de corte (linhagem Redbro), machos e fêmeas, durante o período de crescimento. Foram utilizados 630 frangos, alojados em 30 boxes com acesso à área de pastejo. O delineamento experimental utilizado foi o inteiramente ao acaso, em esquema fatorial 5x2 (lisina e sexo), e três repetições com 21 aves cada. Os níveis de lisina digestível avaliados foram: 7,07; 8,07; 9,07; 10,07 e 11,07g/kg. Avaliou-se o consumo de lisina, o consumo de ração, o ganho de peso e a conversão alimentar. Observou-se efeito de interação (P<0,05) entre os níveis de lisina e sexo para o ganho de peso. Houve efeito (P<0,01) dos níveis de lisina sobre o consumo de lisina, o ganho de peso e a conversão alimentar. Verificou-se que todas as variáveis foram influenciadas (P<0,05) pelo sexo dos frangos. Recomendam-se 10,08 e 9,49g de lisina digestível/kg de ração, correspondendo ao consumo estimado de 21 e 20g de lisina, para machos e fêmeas, respectivamente, para melhor ganho de peso das aves. Para melhor conversão alimentar, recomendam-se 9,61g de lisina digestível/kg, para frangos de ambos os sexos, correspondendo ao consumo estimado de 20g de lisina.(AU)

This experiment was conducted to determine the requirements of digestible lysine in male and female free-range broiler chickens (Redbro lineage) during the growth phase. Six hundred and thirty broiler chickens were allocated in 30 pens with access to the pasture area. The experimental design was completely randomized in a 5x2 (lysine and gender) factorial arrangement with 3 repetitions with 21 chickens each. The levels of digestible lysine evaluated were: 7.07, 8.07, 9.07, 10.07 and 11.07g/kg. The performance traits evaluated were lysine intake, feed intake, weight gain and feed conversion ratio. An interaction effect (P<0.05) was observed between dietary lysine level and gender for body weight gain. There was an effect (P<0.01) of the levels of lysine on lysine intake, body weight gain and feed conversion ratio. It was found that all the variables were affected (P<0.05) for the gender of chickens. We recommended 10.08 and 9.49 g of digestible lysine/kg diet, corresponding to the estimated intake of 21 and 20g of lysine, for males and females, respectively, for better body weight gain of chickens. For better feed conversion ratio, the recommendation is of 9.61 g of lysine/kg of diets, for chickens of both genders, corresponding to the estimated intake of 20g of lysine.(AU)

Ideal ratio of digestible methionine plus cystine to digestible lysine for growing Japanese quails / Proporción ideal de metionina más cistina digestibles a lisina digestible para codornices japonesas en crecimiento / Relação ideal de metionina mais cistina digestível e lisina digestível na dieta de codornas japonesas na fase de crescimento

Background: methionine is considered essential for maintenance, growth, and feather development. Methionine supply during the growth phase can influence the weight at sexual maturity and egg size. Objective: to evaluate the effects of several digestible methionine + cystine/digestible lysine ratios for growing Japanese quails (1 to 40 days of age) with repercussions on the early stage of production (41 to 110 days of age). Methods: a total of 1,000 one-day-old Japanese quails were randomly distributed to five digestible (methionine + cystine)/digestible lysine ratios, with 10 replicates and 20 birds per experimental unit. A basal diet formulated to meet all nutrient requirements was added with graded levels of DL-methionine replacing glutamic acid. Results: weight of the birds at 40 days, weight gain until 40 days, feed intake, carcass weight, fat, and body protein deposition, methionine + cystine intake and birds viability in the growing phase presented a linear trend. A quadratic effect was observed for feed conversion and uniformity at 40 days of age, and percentage of feathers did not vary. A linear increase occurred in the laying phase for feed intake and weight gain of the birds. No effects of the assessed ratios were observed on the other variables. Conclusion: a 0.73 ratio of digestible (methionine + cystine) to digestible lysine in the growing phase provided uniform growth and satisfying performance of Japanese quails during the laying phase.

Antecedentes: la metionina es esencial para el mantenimiento, crecimiento y desarrollo de las plumas. El suministro de metionina durante la fase de crecimiento puede influir en factores tales como el peso corporal a la madurez sexual y el tamaño del huevo. Objetivo: evaluar los efectos de varias proporciones de metionina + cistina digestibles y lisina digestible en la dieta de codornices japonesas en fase de crecimiento (1 a 40 días de edad) y su efecto en la producción inicial de huevos (41 a 110 días de edad). Métodos: se utilizaron 1.000 codornices japonesas de un día de edad, en un diseño aleatorizado con cinco proporciones de (metionina + cistina) digestible/lisina digestible, con 10 replicaciones y 20 aves por unidad experimental. La dieta basal formulada se complementó con cinco niveles de DL-metionina en sustitución del ácido glutámico. Resultados: el peso de los animales al día 40, la ganancia de peso hasta el día 40, la ingesta de alimento, el peso de la carcasa, la deposición de grasa y proteína corporal, la ingesta de metionina + cistina y la viabilidad de las aves en la fase de crecimiento apresentaram uma tendência linear. Se observó un efecto cuadrático para conversión de alimento y uniformidad a los 40 días de edad y el porcentaje de plumas no varió. Durante el período de producción de huevos hubo un aumento lineal para consumo de alimento y ganancia de peso de las aves. Não foram observados outros efeitos proporções em relação a outras variáveis. Conclusión: una proporción de 0,73 entre metionina + cistina digestible/lisina digestible en la fase de crecimiento provee un desarrollo uniforme y un rendimiento satisfactorio en la producción de huevos de la codorniz japonesa.

Antecedentes: a metionina é considerada essencial para manutenção, crescimento e desenvolvimento das penas nas codornas. O fornecimento nutricional de metionina durante a fase de crescimento pode influenciar fatores como peso corporal para maturidade sexual e tamanho do ovo. Objetivo: avaliar os efeitos entre metionina + cistina digestível e lisina digestível na dieta para codornas japonesas na fase de crescimento (1 a 40 dias de idade) com repercussão na fase inicial de postura (41 a 110 dias de idade). Métodos: foram utilizadas 1.000 codornas japonesas com 1 dia de idade, distribuídas em delineamento inteiramente casualizado com 5 relações entre (metionina mais cistina) digestível/lisina digestível, 10 repetições e 20 aves por unidade experimental. Foi formulada uma ração basal suplementada com cinco níveis de DL-metionina em substituição ao ácido glutâmico. Resultados: o peso corporal das aves até os 40 dias, ganho de peso até os 40 dias, consumo de ração, peso de carcaça, deposição de gordura e de proteína corporal, consumo de metionina + cistina e viabilidade das aves na fase de crescimento houve aumento linear para. Efeito quadrático foi observado para conversão alimentar e uniformidade aos 40 dias e a porcentagem de penas não variou. Na fase de postura, ocorreu aumento linear para consumo de ração e ganho de peso das aves. Conclusão: a relação metionina + cistina e lisina digestível de 0,73 na dieta de recria proporcionou crescimento uniforme e desempenho satisfatório de codornas japonesas na fase de postura.

Desempenho e rendimento de carcaça em frangos de corte de um a 46 dias alimentados com dietas contendo diferentes níveis de valina e reduzido teor proteico / Performance and carcass yield of broilers from 1 to 46 days fed diets containing different levels of valine and reduced protein content

Este estudo teve como objetivo avaliar as relações de valina:lisina digestíveis em dietas com teor reduzido de proteína bruta (PB) e os efeitos dessa redução sobre desempenho e rendimento de carcaça em frangos de corte. Foram utilizados 1200 pintos machos seguindo modelo inteiramente ao acaso, com seis tratamentos de seis repetições (exceto controle, com 10 repetições), compostos por 30 aves cada. O tratamento controle (T1) foi formulado conforme os níveis de proteína bruta e aminoácidos (AAs) recomendados por Rostagno et al . (2011), e os demais tratamentos (T2 a T6) tiveram seus níveis de PB reduzidos (4% em relação ao controle) e variaram em função da relação valina:lisina digestíveis, com cinco níveis equidistantes em intervalos de 0,07:1, variando de 0,63:1 e 0,91:1 (dietas até 21 dias) e de 0,64:1 e 0,92:1 (dietas após 21 dias). As seguintes características de desempenho foram avaliadas: ganho de peso, consumo de ração, conversão alimentar, viabilidade criatória e índice de eficiência produtiva. Aos 46 dias de idade, seis animais por repetição foram abatidos para determinação de rendimento de carcaça e de cortes comerciais. As diferentes relações valina:lisina digestíveis não influenciaram o desempenho dos animais (P>0,05) para nenhuma característica avaliada. A redução proteica piorou a conversão alimentar dos animais (P≤0,05) até os 21 dias. Os resultados sugerem que os níveis de valina utilizados não afetam o desempenho dos animais, apenas o rendimento de peito e que, portanto, a redução proteica não é recomendada durante as três primeiras semanas de criação.

This study aimed to evaluate valine:lysine ratios in diets with reduced content of crude protein and the effects of this reduction on the performance of broiler chickens. 1200 male chicks were used following a complete randomized design with six replicates of six treatments (except control, with 10 replicates), each one with 30 chicks. The control treatment (T1) was formulated following levels of crude protein (CP) and the amino acids (AAs) recommended by Rostagno et al. (2011), and the other treatments (T2 to T6) had reduced levels of CP (4 % compared to control) and varied in proportion valine:lysine, with 5 levels at equidistant intervals 0.07:1 ranging from 0.63:1 to 0.91:1 (up to 21 days) and from 0.64:1 to 0.92:1 (after 21 days). The performance characteristics measured were: weight gain, feed intake, feed conversion, viability and productive efficiency index. At 46 days six animals per replicate were slaughtered for evaluation of carcass and commercial cuts. The different valine:lysine ratios did not affect animal performance (P>0.05). Reducing protein impaired feed conversion (P≤.05) up to 21 days. The results suggest that levels of valine used did not affect the broilers' performance, however, breast meat yield and reduced protein are not recommended during the first three weeks.

Control over overall shape and size in de novo designed proteins.

We recently described general principles for designing ideal protein structures stabilized by completely consistent local and nonlocal interactions. The principles relate secondary structure patterns to tertiary packing motifs and enable design of different protein topologies. To achieve fine control over protein shape and size within a particular topology, we have extended the design rules by systematically analyzing the codependencies between the lengths and packing geometry of successive secondary structure elements and the backbone torsion angles of the loop linking them. We demonstrate the control afforded by the resulting extended rule set by designing a series of proteins with the same fold but considerable variation in secondary structure length, loop geometry, ß-strand registry, and overall shape. Solution NMR structures of four designed proteins for two different folds show that protein shape and size can be precisely controlled within a given protein fold. These extended design principles provide the foundation for custom design of protein structures performing desired functions.

Exigência nutricional de lisina digestível para galinhas poedeiras leves em produção / Nutritional requirement of digestible lysine for white-egg laying hens in production

O objetivo com este trabalho foi determinar a exigência nutricional de lisina digestível para galinhas poedeiras leves em idade avançada. Foram utilizadas 288 galinhas poedeiras Hy Line W-36 com 60 semanas de idade, distribuídas em delineamento inteiramente casualizado, com seis níveis de lisina digestível (6,0; 6,6; 7,2; 7,8; 8,4 e 9,0g kg-1), oito repetições e seis aves por unidade experimental. Os níveis de lisina digestível na ração influenciaram de forma linear o consumo de lisina e a eficiência de utilização da lisina. Para a produção e massa de ovos, os platôs ocorreram a partir dos níveis de 6,57g kg-1 e de 7,10g kg-1 de lisina digestível, respectivamente. Houve efeito quadrático dos níveis de lisina sobre o peso de gema, com o nível estimado em 7,6g kg-1 de lisina digestível. A exigência de lisina digestível de galinhas poedeiras leves no período de 60 a 76 semanas de idade é de 7,10g kg-1 de ração, correspondendo ao consumo diário de 690mg ave-1 de lisina digestível.

The objective of this research was to determine the nutritional requirement of digestible lysine for white laying hens in old age. Two hundred eighty-eight Hy Line W-36 laying hens at 60 weeks of age were distributed in a completely randomized design, with six levels of digestible lysine (6.0; 6.6; 7.2; 7.8; 8.4 and 9.0g kg-1) and eight replications with six birds per experimental unit. There was linear effect of lysine levels on lysine intake and efficiency of utilization of lysine. For the production and egg mass, the levels of digestible lysine in the diet from which the plateaus occurred were of 6.57g kg-1 and 7.10g kg-1, respectively. There was quadratic effect of lysine levels on yolk weight, with the estimated level of 7.6g kg-1 of digestible lysine. The digestible lysine requirement of white laying hens from 60 to 76 weeks of age is 7.10g kg-1 in diet, corresponding to daily intake of 690mg bird-1 of digestible lysine.