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Abstract: BACKGROUND: The effects of dietary levels of hop β‐acids on physical attributes, lipid oxidation and chemical composition of pork meat were evaluated. Thirty‐two castrated male pigs obtained from a complete block design feeding experiment (6.23 ± 0.42 kg initial body weight (BW) to 20.45 ± 0.95 kg final BW) and fed diets supplemented with 0, 120, 240 or 360 mg kg−1 hop β‐acids during 35 days were slaughtered to sample longissimus dorsi muscle for meat analysis. RESULTS: No effects (P > 0.05) of dietary hop β‐acids were observed on meat physical attributes. Quadratic effects (P < 0.05) of hop β‐acids were observed on lipid and protein contents and on thiobarbituric acid‐reactive substance (TBARS) values of meatballs, whose equations allowed the estimation of dietary hop β‐acid levels of 176, 169 and 181 mg kg−1 to provide up to 16.20% lipid reduction, 1.95% protein accretion and 23.31% TBARS reduction respectively. CONCLUSION: Dietary hop β‐acids fed to pigs might reduce lipid, increase protein and reduce lipid oxidation without affecting physical attributes of the pork meat. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Este experimento foi realizado para estimar a exigência de energia metabolizável (EM) para codornas de corte de 1 a 14 dias de idade. Foram utilizadas 1.140 aves com 1 dia de idade, distribuídas em delineamento inteiramente casualizado, com cinco tratamentos (2.750; 2.850; 2.950; 3.050 e 3.150 kcal de EM/kg de ração), seis repetições e 38 aves por unidade experimental. Observou-se redução linear dos níveis de energia no peso corporal, consumo de ração e ganho de peso das aves. A conversão alimentar foi influenciada de forma quadrática, com melhor estimativa obtida com 2.997 kcal de EM/kg de ração. Enquanto o teor de proteína bruta não sofreu diferença, o teor de água diminuiu e o de extrato etéreo aumentou de forma linear com os níveis crescentes de EM. Os níveis de EM tiveram efeito quadrático sobre a taxa de deposição de proteína e eficiência de deposição de proteína nos cortes. A exigência de EM de codornas de corte na fase inicial de crescimento é de 2.997 kcal de EM/kg, que corresponde à relação energia metabolizável:proteína bruta de 108,9.This experiment was carried out to estimate the metabolizable energy (ME) requirements for meat quails from 1 to 14 days of age. A total of 1,140 1-day old meat quails were distributed in a completely randomized design, with five treatments (2,750; 2,850; 2,950; 3,050 and 3,150 kcal of ME/kg), six replications and 38 quails per experimental unit. There was linear reduction of energy levels in body weight, feed intake and weight gain of birds. The feed conversion ratio showed a quadratic effect, with the best estimate obtained with 2,997 kcal of ME/kg. Whereas crude protein content did not differ, water content decreased and ether extract increased linearly with the increasing levels of ME. The ME levels showed a quadratic effect on daily protein accretion rate and daily protein accretion efficiency. The ME requirements for meat quail in the initial growing stage is 2,997 kcal/kg, corresponding to a metabolizable energy/crude protein relation of 108.9.

A feeding, digestibility, and balance trial was performed to determine the effect of the incorporation of increasing amounts of soybean protein concentrate (SPC) to a basal acorn diet at a fixed energy intake on the rate of growth, protein deposition (PD), and carcass traits of heavy Iberian (IB) pigs. Sixteen purebred IB barrows (103.9 ± 0.9 kg initial BW) were used. The pigs were individually confined and allocated to 4 groups of 4 pigs each. Whole acorns were provided with slight restriction to minimize acorn kernel (AK) remains. Water was freely available. The incorporation of SPC raised the available CP from 49.1 g/kg DM (1.91 g total Lys/kg DM) in AK up to 135 g/ kg DM (7.24 g total Lys/kg DM). After 72 d of trial, the pigs achieved 134.4 ± 1.3 kg BW and were then slaughtered. Average daily BW gain increased with increasing dietary CP (linear, P < 0.001; quadratic, P < 0.01), with a plateau at dietary CP concentrations (provided by AK and SPC) beyond 72.2 and 100 g/ kg DM, respectively, for which an ADG of 449 g was achieved. There was a linear and quadratic effect of dietary CP and Lys level on the apparent digestibility of CP (linear, P < 0.001; quadratic, P < 0.05) and on the efficiencies of utilization of total N (retained N/N intake; linear, P < 0.001; quadratic, P < 0.001) and N apparently absorbed (retained N/apparent digestible N; linear, P < 0.05; quadratic, P = 0.067). Protein deposition ranged between -4.59 g/d in pigs not provided with SPC to 61.4 g/d in pigs fed the greatest level of SPC inclusion. The lowest daily intake of total Lys resulting in maximum PD (69.5 g/d) at the fixed level of energy intake observed (2.36 × ME maintenance requirements) was 21.0 g. Hot carcass and cold carcass weights, but not carcass yield, increased when feeding the daily ration containing 100 g SPC and leveled off thereafter (linear, P < 0.01; quadratic, P < 0.01). An average increase of 8.3% and 8.7% was obtained, respectively. The provision of SPC had no effect on back fat thickness. Primal cuts, but not yield (except for loin), increased (sirloin: linear, P < 0.05; loin: linear, P < 0.001; quadratic, P < 0.05; ham: linear, P < 0.05) or showed a tendency to increase (butt lean: linear, P = 0.068; quadratic, P = 0.077; ribs: quadratic, P = 0.067; shoulder: quadratic, P = 0.064) with the provision of dietary protein. No effect of the level of incorporation of SPC to the diet was observed on CP, total fat, total ash, and energy contents or on relative fatty acid profile of loin and sirloin. [ABSTRACT FROM AUTHOR]

Enhanced production of high quality and healthy fry is a key target for a successful and competitive expansion of the aquaculture industry. Although large quantities of fish larvae are produced, survival rates are often low or highly variable and growth potential is in most cases not fully exploited, indicating significant gaps in our knowledge concerning optimal nutritional and culture conditions. Understanding the mechanisms that control early development and muscle growth are critical for the identification of time windows in development that introduce growth variation, and improve the viability and quality of juveniles. This literature review of the current state of knowledge aims to provide a framework for a better understanding of fish skeletal muscle ontogeny, and its impact on larval and juvenile quality as broadly defined. It focuses on fundamental biological knowledge relevant to larval phenotype and quality and, in particular, on the factors affecting the development of skeletal muscle. It also discusses the available methodologies to assess growth and larvae/juvenile quality, identifies gaps in knowledge and suggests future research directions. The focus is primarily on the major farmed non-salmonid fish species in Europe that include gilthead sea bream, European sea bass, turbot, Atlantic cod, Senegalese sole and Atlantic halibut. [ABSTRACT FROM AUTHOR]

Two experiments were conducted to assess the effects of porcine ST (pST) on the responses to a near-ideal blend of AA for pigs from 22 to 60 kg BW. Eighty Hampshire x Yorkshire gilts (40 gilts/experiment) were individually penned and assigned to a 4 x 2 factorial arrangement of treatments, consisting of 4 diets with and without pST injection. A fortified corn-soybean meal basal diet was formulated to contain 1.50% total Lys and Thr, Met, and Tip were added to obtain a near-ideal blend of these AA relative to Lys. In 3 additional diets, Lys was reduced to 1.25%, 1.00%, or 0.75% by diluting the basal diet with cornstarch, cellulose, and sand, such that the diets also contained the same ratios of AA. Pigs that received pST were administered a daily intramuscular injection of 2 mg of pST Data from the 2 experiments were pooled. Administration of pST increased ADG (P < 0.01), G:F (P < 0.01), and LM area (P < 0.01), and decreased ADFI (P < 0.03), last rib backfat (P < 0.01), and 10th rib backfat (P < 0.01). Also, estimated carcass muscle and calculated lean gain increased (P < 0.01) in pST-treated pigs. Administration of pST also increased (P < 0.01) the percentage, total gain and accretion rate of water, protein, and ash in the carcass, and decreased (P< 0.01) the percentage, total gain, and accretion rate of carcass fat. Growth rate, G:F, and carcass traits improved (P < 0.01), percentage of carcass proteinand water increased (P < 0.01 ), and carcass fat percentage decreased (P < 0.01) with increasing dietary Lys. The percentage, total gain, and accretion rate of carcass protein increased to a greater extent in pST-treated pigs than in untreated pigs, resulting in a pST x Lys interaction (P < 0.05). The results indicated that pST improves performance, leanness, and protein accretion in pigs from 22 to 60 kg BW, and that these responses to dietary Lys and a near-ideal blend of AA is greater in growing pigs treated with pST than untreated pigs. [ABSTRACT FROM AUTHOR]

Nine experimental feeds were prepared, having two different digestible energy levels (DE, 19.5 and 21.5 MJ kg−1) and three different amino acid levels (90%, 100% and 110%), and formulated with two alternative strategies (protein and fat vary freely or only protein varies freely). The design was not balanced and thus the 110% amino acid profile was only studied at 19.5 MJ kg−1 DE. Atlantic salmon ( Salmo salar) with a mean body weight of 449±19 g were distributed in 24 tanks and were fed each of the experimental diets for a period of 90 days. The fish were fed three times daily and uneaten feed was collected. Increasing the dietary DE energy from 19.5 to 21.5 MJ kg−1 and the amino acid level from 90% to 100% of the requirement increased the feed intake and growth performance in Atlantic salmon. Increasing the amino acid level from 90% to 100% had a positive effect on the feed intake, growth and protein accretion. Also, the mRNA levels of insulin-like growth factor I in muscle tissues pointed to this positive effect when the amino acid level increased. High probabilities were associated with a negative effect on the feed intake of reducing the amino acid level regardless of the DE level. It is recommended that the balanced amino acid level should not be adjusted by the same percentage rate as dietary energy, and possibly should not be reduced at all in order to maintain optimum performance and profitability. [ABSTRACT FROM AUTHOR]

Abstract: A growth trial was conducted with the aim of developing a practical, environmentally sustainable and cost-effective plant-protein-based diet for Senegalese sole juveniles without compromising growth or protein deposition. A reference diet contained fish meal as the main protein source (F45, containing 37% fish meal and 45% of the dietary protein being from marine sources) and four plant-protein diets either containing 5% (F15) or no fishmeal (F5). The F15 diet also contained 5% hydrolysed protein (CPSP) and 5% squid meal while the F5 contained 2% CPSP and 3% squid meal. The rest of the protein derived from a blend of soybean meal, corn and wheat gluten. Thus, the plant-protein fraction in these test diets ranged from 70–80%. The plant-based diets were supplemented either with a mixture of all indispensable amino acids (IAA) (F15+IAA, F5+IAA) or only with lysine (F15+Lys, F5+Lys). Triplicate groups of 18 fish of 9.5g were fed by automatic feeders that distributed 8 meals over 24h, for a period of 12weeks. At the end of the experiment mean body weight more than tripled in all treatments (32.8 to 42.7g). Sole fed with either F15+Lys (33.3g) or F5+Lys (32.8g) grew significantly less than all the other treatments. Protein productive value (PPV) was significantly lower in sole fed with F5+Lys (0.30) than in all other treatments (0.34 to 0.37) while F5+Lys (0.23) energy productive value (EPV) just differed significantly from fish fed with F45 (0.38). Moreover, protein gain (P gain) was significantly higher in sole fed with diet supplemented with all IAA (F15+IAA and F5+IAA) than those fed with diet with only lysine added (F15+Lys and F5+Lys) and a strong positive correlation between P gain and methionine (Met) intake was found (P =0.00002). Dietary fish meal protein can be totally replaced by a mixture of plant-protein sources without any adverse effects on growth, feed or protein utilization provided the dietary amino acids are balanced. The test diet F5+IAA seems a good alternative to use in Senegalese sole production when the main objective is to substitute an increasingly scarce ingredient – fish meal – without compromising fish performance. Moreover, for large-scale production feeds the F15+Lys putatively supplemented with Met, Thr and Arg would be recommended. [Copyright &y& Elsevier]

We investigated the effect of resistance exercise and feeding on the activation of signaling proteins involved in translation initiation. Nine young men (23.7 ± 0.41 yr; BMI = 25.5 ± 1.0 kg/m² means ± SE) were tested twice after they performed a strenuous bout of unilateral resistance exercise, such that their contralateral leg acted as a nonexercised comparator, in either the fasted and fed [1,000 kJ, each 90 min (3 doses): 10 g protein, 41 g carbohydrate, 4 g fat] states. Muscle biopsies were obtained 6 h postexercise from both legs, resulting in four experimental conditions: rest-fasted, rest-fed, exercise-fasted, and exercise-fed. Feeding increased PKB/Akt (Ser473) phosphorylation (P < 0.05), while exercise increased the phosphorylation of Akt and the downstream 70 kDa S6 protein kinase (p70S6K1, Thr389) and ribosomal protein S6 (rpS6, Ser235/236, Ser240/244; all P < 0.05). The combination of resistance exercise and feeding increased the phosphorylation of p70S6K1 (Thr389) and rpS6 (Ser240/244) above exercise alone (P < 0.05). Exercise also reduced phosphorylation of the catalytic epsilon subunit of eukaryotic initiation factor 2B (eIF2Bε, Ser540; P < 0.05). Mammalian target of rapamycin (rnTOR, Ser2448), glycogen synthase kinase-3β (GSK-3β, Ser9), and focal adhesion kinase (FAK, Tyr576/577) phosphorylation were unaffected by either feeding or resistance exercise (all P > 0.14). In summary, feeding resulted in phosphorylation of Akt, while resistance exercise stimulated phosphorylation of Akt, p70S6K1, rpS6, and dephosphorylation elF2Bε with a synergistic effect of feeding and exercise on p70S6K1 and its downstream target rpS6. We conclude that resistance exercise potentiates the effect of feeding on the phosphorylation and presumably activation of critical proteins involved in the regulation of muscle protein synthesis in young men. [ABSTRACT FROM AUTHOR]

Abstract: Nutritional factors influence regulation of the growth hormone (GH) and the insulin-like growth factor (IGF) system in fish, but so far there are no published studies describing how single indispensable amino acids influence these systems. Therefore, the present study aimed to test whether lysine (Lys) intake at low (LL=2.85g/16gN), medium (ML=4.91g/16gN) and high levels (HL=9.19g/16gN) affected the expression of genes related to the GH–IGF system (i.e. GH receptor, GH-R, IGF-I, IGF-II, IGF binding protein 1, IGFBP-1, IGF-I receptor IGF-IR) in Atlantic salmon during seawater growth phase. Salmon fed the HL diet significantly up-regulated hepatic IGF-I mRNA level by a factor of 2.2 as compared to those with medium Lys intake. In addition a significant up-regulation of 2.7-fold in muscle IGF-II mRNA was present. Low Lys intake decreased the nitrogen deposition and muscle protein accretion in fish and significantly down-regulated hepatic IGFBP-1 as well as muscle GH-R and IGF-II, as compared to those fed the ML diet. mRNA of IGF-IR on the other hand was not affected by Lys intake. High Lys intake resulted in a 7-fold up-regulation of muscle IGF-II mRNA level as compared to low Lys intake, and thus might be an important local anabolic regulator in fast muscle tissue. The single indispensable amino acid Lys indeed affected signalling through the genes of IGF-I, IGFBP-1 in hepatic tissue and GH-R, IGF-II in fast muscle in Atlantic salmon. Concomitantly the higher Lys intake increased nitrogen deposition to a certain level. [Copyright &y& Elsevier]

Abstract: Two trials (I and II) were conducted to finally determine the Lys requirement in the Atlantic salmon during the fast growing period in seawater. First three test diets with well balanced AA''s as well as a IAA:DAA ratio close to 1, but differing in amount and source of an attractant, were developed allowing for both a reduction of dietary Lys and a reasonable performance when supplementing Lys. The diets were based on our previous study in which all fish meal was replaced by plant proteins, of which resulted in both inferior body weight gain and lipid deposition ([Espe, M., Lemme, A., Petri, A., El-Mowafi, A. 2006. Can Atlantic salmon grow on diets devoid of fish meal? Aquaculture 255, 255–262]). Basically, the amino acid profiles of all test diets did not differ (p >0.05) from the control fish meal based diet although 90% of the fish meal was replaced by plant proteins. The diets were fed to Atlantic salmon of BW 327 g for a period of 85 days. The test diet supporting both growth and deposition of protein and lipid not differing (p >0.05) from the fish meal control finally consisted of plant proteins supplemented with 5% fish meal, 5% fish soluble and 3% squid hydrolysate. This diet then was used in a dose response experiment aiming to determine Lys requirement in the fast growing salmon. Atlantic salmon with BW of 642 g were fed graded amounts of Lys (2.85 to 9.19 g Lys/16 g N) for a period of 85 days. Dietary Lys did not affect growth (p >0.05), but the protein accretion suggested an optimum dietary Lys supply of 5.04 g /16 g N (corresponding to 0.12 g Lys/fish/day). This response was accompanied with reduced fat accretion. To obtain weight gain to the level present in the fish meal control diet 3.17 g Lys/16 g N was sufficient. Thus lean growth rather than body weight gain should be the response parameter to determine Lys requirement in salmon. [Copyright &y& Elsevier]

Abstract: The present experiment tested whether Atlantic salmon accept, grow and utilise diets devoid of fish meal. Four diets were prepared, one reference diet in which 49% of the diet was fish meal and three diets not containing any fish meal. The amino acid composition in the test diets not containing fish meal was made similar to the reference diet by balancing with crystalline amino acids. All plant protein diets also contained 5% fish protein hydrolysate and, additionally, two diets were added with either stick water or squid hydrolysate in order to improve the palatability and thus feed acceptance. The experimental diets were fed to Atlantic salmon of 300 g body weight for a period of 3 months during which period no fish died. Fish fed the plant protein diets showed reduced feed intake as compared to fish fed the reference fish meal diet resulting in lower growth in the former. Feed conversion did not differ between treatments. Although the fish fed the fish meal diet showed higher growth than those fed the alternative three diets, protein accretion was not significantly different. In contrast, fat retention was significantly higher in the fishmeal treatment suggesting both a higher retention of dietary fat which was higher in the fish meal diet and a better utilisation of the dietary energy by salmon fed the vegetable diets due to a highly balanced dietary amino acid profile. The use of up to 10% crystalline amino acids in the diet increased the amino acid digestibility in the plant protein diets but utilisation of the dietary protein was not affected. The latter indicate that crystalline amino acids are utilised as well as protein bound amino acids at the level of 10% addition. Taking all together, particularly the diet containing squid hydrolysate might be an alternative to the fish meal diet in order to produce salmon. [Copyright &y& Elsevier]

Chronic respiratory infections reduce growth in pigs but protein accretion (PA) during an ongoing multifactorial respiratory infection has not been determined, and the mechanisms underlying growth inhibition are largely unknown. The objectives of this study were to determine whether viral and bacterial pneumonia in young pigs decrease PA, increase serum IL-1beta and IL-6, and increase myostatin (MSTN) mRNA in biceps femoris and triceps muscles. Mycoplasma hyopneumoniae (Mh) or medium was given intratracheally at 4 wk of age, Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) or medium was given intranasally at 6 wk of age, and pigs were killed 7 or 14 d after PRRSV inoculation for body composition analysis. PRRSV but not Mh induced a marked increase (P < 0.01) in IL-1beta, IL-6, and MSTN mRNA and a decrease (P < 0.01) in food intake, daily weight gain, PA, and lipid accretion. PRRSV also reduced (P < 0.01) myofiber area in the biceps femoris. Food intake, weight gain, PA, and weight of biceps femoris and triceps muscles were negatively correlated (r = -0.4 to -0.8, P < 0.05) with serum IL-1beta and IL-6 and with MSTN mRNA in muscle. These results suggest that the magnitude of increases in inflammatory cytokines during a respiratory infection may be predictive of decreases in PA and growth. They further suggest that during infection growth of skeletal muscle is limited in part by myostatin. [ABSTRACT FROM AUTHOR]

Juvenile gilthead sea bream were fed to visual satiety with isonitrogenous diets based on fish meal and different plant ingredients (33–35% replacement) supplemented with free amino acids to meet the desired indispensable amino acid (IAA) profile and dispensable amino acid (DAA) content. In diets M and WB, IAA profile and DAA content resemble that of the muscle or whole body, respectively. In diets MGlu and WBGlu, DAA content was increased by adding l-glutamic acid (Glu) and thus the IAA/DAA ratio varied from 1.13 (diet M) to 0.80 (diet WBGlu). Growth rates were not significantly different among experimental groups, but feed conversion ratio and nitrogen retention were impaired by the decrease of dietary IAA/DAA ratio. Postprandial ammonia excretion increased with the increase of dietary DAA content irrespective of IAA profile. Conversely, hepatic activity of glutamate dehydrogenase (GDH) was lower in fish fed diet WBGlu than in fish fed diet M. Hepatic growth hormone (GH) binding was not significantly affected by the dietary treatment, but circulating levels of insulin-like growth factor-I (IGF-I) and GH were, respectively, down- and up-regulated in fish fed diet WBGlu, which suggests some defect in the transmission of GH receptor signal. Fat retention and hepatic activities of lipogenic enzymes (glucose-6-phosphate dehydrogenase, G6PD; malic enzyme, ME) were decreased in fish fed diet MGlu. Key metabolic enzymes of hepatic glycolysis (glucokinase, GK) and gluconeogenesis (phosphoenolpyruvate carboxykinase, PEPCK) were also altered in this group of fish. Since soybean meal concentration was highest in diet MGlu, results on lipid and carbohydrate metabolism can be primarily attributed to this component of the diet. In contrast, data on growth performance, ammonia excretion and GH axis mainly reflect changes in the dietary amino acid profile, which reveals that a muscle IAA profile and a high IAA/DAA ratio are important in feeds for gilthead sea bream. [Copyright &y& Elsevier]

The article focuses on the study to evaluate a method for predicting daily protein accretion rates of various genotypes of pigs reared indifferent environmental conditions using easily obtained mean daily fat-free growth rates. Data were obtained for seven genotype-environment groups of gilts and nine groups of barrows. Daily empty body protein accretion rates were estimated at 1.0-kgintervals between 20 and 120 kg live weight. The estimates were fitted to a generalized exponential.

The article evaluates determine the association of energy intake and protein and lipid accretion and body composition between 20 and 45 kg growing gilts.