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Simple Summary: In contrast to a conventional layer diet with the same nutrient content during the day, morning and afternoon feeds with different compositions are fed in a split feeding system. This system is based on the sequential need for energy, amino acids, and calcium during egg formation and might be suitable to decrease the intake and emission of nitrogen and develop a more sustainable nutrition plan for laying hens. Therefore, our study investigated the reduced or low crude protein and adjusted amino acid supply of laying hens in a split feeding system. The investigated split system resulted in a similar egg production with reduced protein intake, a more favorable feed conversion ratio, increased eggshell thickness, better digestibility of some amino acids, and a decreased nitrogen emission compared to conventional feeding. The decrease in the crude protein content of both morning and afternoon diets by 2% while maintaining important essential amino acid levels constantly led to a decreased protein intake, higher laying rate, lower egg weight, and similar nitrogen emissions of laying hens. Two model experiments were conducted to investigate the different protein and amino acid supply of laying hens fed split feeding (SF) diets. In Experiment 1, one conventional (C) and one SF dietary treatment were established, and the diets were implemented for 12 weeks. The concentrations of crude protein, SID Lys, Met, Met + Cys Arg, Val, Thr, Leu, Ile, and Trp of the SF morning diet were the same as in the C diet. The crude protein content of the SF afternoon diet was lower (92%), while the SID values of Lys, Met, Met + Cys were identical compared to the C diet (100%). The SF treatment resulted in a reduced protein/N intake, better feed conversion ratio, higher eggshell thickness and apparent ileal digestibility of Asp, Leu, Lys, Gly, and Ser, and lower concentration of N forms (total, fecal, NH4+, uric acid, urinary) in the excreta compared to the C treatment. In Experiment 2, a control and a low protein (−2% crude protein but the same SID values of Lys, Met, Met + Cys, Thr, Val) SF treatment were compared for 6 weeks. The low protein SF treatment led to a decreased protein/N intake, higher laying rate, lower egg weight, higher ileal digestibility of Ala, Asp, Leu, and Ile, and similar N emission compared to the control SF treatment. [ABSTRACT FROM AUTHOR]

This study aimed to assess the effects of varying dietary energy and protein levels on growthrelated gene expression and intestinal morphology in Hubbard broilers. A total of 234 one-day-old chicks were used and divided into six groups, with 39 chicks per group. Group I: Received a basal diet containing standard energy and protein. Group II: Received a diet with standard protein and 10% reduced energy. Group III: Received a diet with standard protein and 20% reduced energy. Group IV: Received a diet with standard energy and 10% reduced protein. Group V: Received a diet with standard energy and 20% reduced protein. Group VI: Received a diet with 20% reduced energy and 10% reduced protein. Gene expression of IGF1, Myostatin, and Ghrelin was measured. Histological and morphometric analyses of the intestines were also conducted. The results revealed that IGF1 gene expression was downregulated in all groups, except for group IV, which showed no significant change compared to the control group. Group III and group VI exhibited the lowest IGF1 expression. For Myostatin, the highest expression levels were observed in group III and group VI, while group IV showed no significant difference (p<0.05) compared to the control group. Ghrelin gene expression was significantly upregulated in all groups, with the highest upregulation seen in group III and group VI. Regarding intestinal histomorphology, all groups showed a significant decrease in villi length compared to the control group. The jejunal crypt depth was significantly reduced (p<0.05) in the group III and group VI. In conclusion, low energy had a more pronounced effect on the expression of growth-related genes and intestinal indices than low protein. [ABSTRACT FROM AUTHOR]

Reducing the dietary crude protein (CP) could effectively reduce pressure on protein ingredient supplies. However, few data have been reported about the extent to which CP can be reduced and whether limiting the use of soybean meal leads to electrolyte imbalance. In this experiment, using the low protein (LP) diet [2% lower than NRC (2012)], seventy‐two piglets (35 days old) were randomly divided into 2 groups with 6 replicates of 6 piglets each: CON group (CP = 18.5%) and LP group (CP = 16.5%), to investigate the effect of the LP diet on electrolyte balance, acid‐base balance, intestinal structure and amino acid transport in piglets. The results revealed that the LP diet decreased the average daily gain and dietary CP digestibility, and damaged the villi structure of the small intestine. Compared with the CON diet, the potassium content decreased and the chlorine content increased in the LP diet, and similar trends were shown in piglet serum. The arterial pH, pCO2, HCO3−, and base excess of piglets in the LP group were lower than those in the CON group, while pO2 was higher than those in the CON group. Interestingly, the LP diet significantly increased the lysine content in piglet serum and significantly decreased the levels of arginine, leucine, and glutamic acid. Furthermore, the LP diet significantly affected the expression of some amino acid transport vectors (B0AT1, EAAC1, and y+LAT1). In summary, these findings suggested that the LP diet leads to acid‐base imbalance, amino acid transport disorder and amino acids imbalance in piglets, and the dietary electrolyte may be a key factor in the impact of the LP diet on piglet growth performance and intestinal health. [ABSTRACT FROM AUTHOR]

The increasing cost of milk production, in association with tighter manure N application regulations and challenges associated with ammonia emissions in many countries, has increased interest in feeding lower crude protein (CP) diets based on legume silages. Most studies have focused on alfalfa silage, and little information is available on low-CP diets based on red clover silage. Our objectives were to examine the effects of dietary CP content and supplementing a low-CP diet with dietary starch or rumen-protected Met (RPMet) on the performance, metabolism, and nitrogen use efficiency (NUE; milk N output/N intake) in dairy cows fed a red clover and grass silage-based diet. A total of 56 Holstein-Friesian dairy cows were blocked and randomly allocated to 1 of 4 diets over a 14-wk feeding period. Diets were based on red clover and grass silages at a ratio of 50:50 on a dry matter (DM) basis and were fed as a total mixed ration, with a 53:47 ratio of forage to concentrate (DM basis). The diets were formulated to supply a similar metabolizable protein (MP) content, and had a CP concentration of either 175 g/kg DM (control [CON]) or 150 g/kg DM (low-protein [LP]), or LP supplemented with either additional barley as a source of starch (LPSt; +64 g/kg DM) or RPMet (LPM; +0.3 g/100 g MP). At the end of the 14-wk feeding period, 20 cows (5 per treatment) continued to be fed the same diets for a further 6 d, and total urine output and fecal samples were collected. We observed that dietary treatment did not affect DM intake, with a mean of 21.5 kg/d; however, we also observed an interaction between diet and week with intake being highest in cows fed LPSt in wk 4 and CON in wk 9 and 14. Mean milk yield, 4% fat-corrected milk, and energy-corrected milk were not altered by treatment. Similarly, we found no effect of dietary treatment on milk fat, protein, or lactose content. In contrast, milk and plasma urea concentrations were highest in cows fed CON. The concentration of blood plasma β-hydroxybutyrate was highest in cows receiving LPM and lowest in LPSt. Apparent NUE was 28.6% in cows fed CON and was higher in cows fed any of the low-protein diets (LP, LPSt, or LPM), with a mean value of 34.2%. The sum of milk fatty acids with a chain length below C16:0 was also highest in cows fed CON. We observed that dietary treatment did not affect the apparent whole-tract nutrient digestibility of organic matter, N, neutral detergent fiber, and acid detergent fiber, with mean values of 0.785, 0.659, 0.660, and 0.651 kg/kg respectively, but urinary N excretion was approximately 60 g/d lower in cows fed the low-CP diets compared with CON. We conclude that reducing the CP content of red clover and grass silage-based diets from 175 to 150 g/kg DM while maintaining MP supply did not affect performance, but reduced the urinary N excretion and improved NUE, and that supplementing additional starch or RPMet had little further effect. [Display omitted] [ABSTRACT FROM AUTHOR]

ABSTRACT: The present study investigated the effects of low protein diets with different starch sources and starch to protein ratio on growth, digestibility, intestinal health, caecal short chain fatty acids (SCFAs), serum cholesterol and triglycerides in broiler chickens. Eight hundred one-day-old male broiler chicks (Ross 308) were randomly allotted to one of 4 dietary treatments with 10 repeats and 20 birds in each repeat. The dietary treatments included 1) a standard protein corn-SBM based diet (SP), 2) a low protein corn-SBM based diet (LPI) without reduced starch: protein ratio, 3) a low protein corn-SBM based diet (LPII) with reduced starch: protein ratio, and 4) a low protein corn-SBM-peas based diet (LPP) and reduced starch: protein ratio. Soy hulls were added in the LPII and LPP diets to reduce starch: protein ratio. During the experiment period from 11 to 24 d, FI was not affected by the dietary treatments (P > 0.05). The BWG was significantly reduced in the LPI diet compared to the SP diet (P < 0.05). Likewise, FCR deteriorated in LPI and LPII but was better in the SP diet followed by the LPP diet (P < 0.05). The apparent total tract digestibility (ATTD) of dry matter (DM) varied significantly among the dietary treatments (P < 0.01). While ATTD of starch was similar for all the diets except the LPP diet wherein the ATTD of starch was significantly lower (P < 0.001). Ether extract digestibility was also significantly different between the SP and LPII dietary treatments (P < 0.01). The AME and AMEn values were significantly lower in the LPP diet compared with other dietary treatments (P < 0.001). Nitrogen retention (%) was increased in all the LP diets compared with the SP diet (P < 0.001), but it was significantly better in both LPII and LPP diets compared to the LPI diet. The data showed that cecal SCFAs production was increased in the LPII and LPP compared to the SP and LPI diets (P < 0.001). Further, the production of acetic, butyric, and propionic acids was substantially higher in the LPP diet (P < 0.001). There was no significant difference in gene expression of Claudin-1 and ZO-1 (P > 0.05). However, MUC-2 and GLUT-1 gene expression were significantly downregulated in the LPI diet (P < 0.05). The concentration of cholesterol and triglycerides was significantly increased in the LPI diet (P < 0.001). In conclusion, the addition of peas as a slowly digestible starch source combined with soy hulls in low protein diet helped to partly recover the growth performance and improved cecal SCFAs production compared to other low protein diets with and without reduced starch: protein ratio in broiler chickens.

1. This study evaluated the effect of wheat dilution increasing in particle size in low crude protein diets on growth performance, digestive tract, nitrogen efficiency and litter quality in broiler chickens. 2. Ross 308 male broiler chicks (n = 336) were allocated to one of four dietary treatments (each with 7 pens, 12 chicks per pen); Control (CON; commercial pellet diet with standard crude protein, CP: 22.50%), W578 (CON +20% wheat of geometric mean diameter (GMD) of 578 µm; CP: 20.25%), W1326 (CON +20% wheat of GMD 1326 µm; CP: 20.25%) and WW (CON +20% whole wheat, CP: 20.25%), from d 0 to 21 of age. 3. Body weight gain was increased (P < 0.05) for birds fed CON compared to the low crude protein diets. However, WW increased (P < 0.05) body weight gain compared to W578 and W1326, while feed intake and feed conversion ratio on CON and WW were similar (P > 0.05). Birds fed W1326 showed the poorest (P < 0.05) FCR compared to CON, W578 and WW. 4. Gizzard relative weight (g/kg body weight) was increased (P < 0.05) on WW compared to CON on d 14 and 21, whereas gastric isthmus diameter was significantly reduced on W1326 and WW compared with CON and W578. 5. There were no differences (P > 0.05) in the depth of gizzard mucosa of lamina propria between CON and WW at d 14 and 21. Birds fed WW increased (P < 0.05) gizzard tensile strength compared to W578 and W1326, whereas no difference was observed between WW and CON on d 14. 6. No significant differences were seen for ileum villus height and mucosal layer between CON and WW on d 21, however, feeding CON increased the extent of the mucosal layer compared to W578 and W1326. 7. Nitrogen excretion (g/kg BWG) was significantly lower (P > 0.05) on W1326 and WW compared with CON and W578. Litter nitrogen, moisture, and footpad scores significantly decreased (P < 0.05) for birds fed WW compared with CON. 8. Diluting dietary protein content from 22.50 to 20.25% resulted in lower body weight gain in broilers. However, dilution with whole wheat resulted in comparable FCR, reduced nitrogen excretion, litter moisture and footpad dermatitis compared with a standard protein diet. [ABSTRACT FROM AUTHOR]

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Two model experiments were conducted to investigate the different protein and amino acid supply of laying hens fed split feeding (SF) diets. In Experiment 1, one conventional (C) and one SF dietary treatment were established, and the diets were implemented for 12 weeks. The concentrations of crude protein, SID Lys, Met, Met + Cys Arg, Val, Thr, Leu, Ile, and Trp of the SF morning diet were the same as in the C diet. The crude protein content of the SF afternoon diet was lower (92%), while the SID values of Lys, Met, Met + Cys were identical compared to the C diet (100%). The SF treatment resulted in a reduced protein/N intake, better feed conversion ratio, higher eggshell thickness and apparent ileal digestibility of Asp, Leu, Lys, Gly, and Ser, and lower concentration of N forms (total, fecal, NH4+, uric acid, urinary) in the excreta compared to the C treatment. In Experiment 2, a control and a low protein (−2% crude protein but the same SID values of Lys, Met, Met + Cys, Thr, Val) SF treatment were compared for 6 weeks. The low protein SF treatment led to a decreased protein/N intake, higher laying rate, lower egg weight, higher ileal digestibility of Ala, Asp, Leu, and Ile, and similar N emission compared to the control SF treatment.

Copyright of Journal of Hydrobiology is the property of Editorial Department of Journal of Hydrobiology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Understanding the order of limiting amino acids (AA) in reduced-protein (RP) diets for laying hens will facilitate precise feed formulation and ensure that AA requirements are met cost-effectively. The order of the first three limiting AAs—lysine (Lys), methionine (Met), and threonine (Thr)—has been well established in RP laying hen diets. This study aimed to determine the priority order of eight additional limiting AAs (critically important AAs) when formulating wheat–sorghum-based RP diets for laying hens: tryptophan (Trp), valine (Val), isoleucine (Ile), arginine (Arg), leucine (Leu), histidine (His), phenylalanine (Phe), and glycineequivalent (Gly). A total of 330 Hy-Line Brown laying hens were randomly assigned to 11 dietary treatments (30 replicates of individual birds per treatment) from 20 to 39 weeks of age (WOA). Treatments were a standard-protein (17.24% CP) diet as the control (SP); a reduced-protein (15.00% CP) diet with sufficient levels of Lys, Met, and Thr but insufficient levels of the eight experimental essential AA (RP); a reduced-protein diet with sufficient levels of all essential AAs (RP-EAA); and eight subsequent dietary treatments of the RP-EAA diet with one of the experimental essential AAs removed: Trp (RP-EAA-Trp), Val (RP-EAA-Val), Ile (RP-EAA-Ile), Arg (RP-EAA-Arg), Leu (RP-EAA-Leu), His (RP-EAA-His), Phe (RP-EAA-Phe), and Gly (RP-EAA-Gly). Eggs were collected and weighed daily, and feed intake and feed conversion ratio (FCR) were calculated weekly. External and internal egg quality was measured at 29 and 39 WOA. Nutrient digestibility, serum uric acid concentration, caecal microbiota composition, and tibia parameters were measured at 40 WOA. Overall, hens fed the RP-EAA-Val, RP-EAA-Ile, and RP diets presented significantly lower egg mass compared to hens fed the SP, RP-EAA-His, and RP-EAA-Gly diets (p < 0.001). Hens fed the RP diet and RP-EAA-Val diet had a higher FCR compared to those offered the RP-EAA, RP-EAA-Leu, RP-EAA-Phe, and RP-EAA-Gly diets (p = 0.046). Lower protein intake and excretion were observed in hens offered the RP diets compared to hens fed the SP diet (p = 0.001 and 0.018, respectively). Based on the egg mass, Ile may be considered the fourth and Val the fifth limiting AA, after Lys, Met, and Thr, in laying hens fed wheat–sorghum-based RP diets during peak lay. However, if ranked based on FCR, Val may be considered the fourth limiting AA, followed by Trp, Ile, Arg, and His as the co-fifth limiting AAs. Leu, Phe, and Gly may be considered as non-essential AAs for laying hens fed RP diets. [ABSTRACT FROM AUTHOR]

The alterations in feed ingredients and the nutrient matrix to produce reduced-protein diets may affect bone morphology and mineralization in laying hens. This study was implemented to determine the effects of L-arginine (Arg), guanidinoacetic acid (GAA), and L-citrulline (Cit) supplementation to Arg-deficient reduced-protein diets on bone morphology, strength, and mineralization status of laying hens. Individually housed Hy-Line Brown laying hens were evenly distributed to five dietary treatments with 25 replicates per treatment from 20 to 40 wk of age. Treatments consisted of a standard protein diet (17% crude protein, SP), a reduced-protein diet deficient in Arg (13% crude protein, RP), and RP supplemented with Arg (0.35% Arg, RP-Arg), GAA (0.46% GAA equivalent to 0.35% Arg, RP-GAA), or Cit (0.35% Cit equivalent to 0.35% Arg, RP-Cit) to reach the Arg level of SP diets. Birds fed the SP diet had similar bone weight, ash, length, width, Seedor index, breaking strength, and serum mineral concentration, but higher toe B level (P

The experiment was conducted at the poultry house of the Department of Animal Production - College of Agriculture - Tikrit University for the period between 18/9 and 25 /10/2021. The purpose of this research was to find solutions in order to strengthen low-protein diets with some essential amino acids and to detect their effect on the productive performance and some physiological characteristics of broilers. In this experiment (300) birds of ROSS 308 strain birds were used, with an average initial weight of 39.7 gm. The birds were divided into five treatments with three replications for each treatment (20 birds for each replicate). The treatments were randomly distributed as follows: the first treatment (T1) of the control diet contains crude protein according to ROSS 308 breeding guide, the other four treatments T2, T3, T4, and T5 treatments were subjected to a reduction in the crude protein by 5, 10, 15, 20% respectively and supported by the amino acids (lysine, methionine and threonine). The results showed that there were no significant differences between the treatments with amino acids and the control treatments regarding body weight at the age of 38 days and the total weight gain except for the third treatment (T3) in which the protein was reduced by 10%. No significant effect was recorded on the average feed intake when reducing the feed protein by 5% (T2) and the control treatment (T1). The differences between the control treatment and other treatments concerning the feed conversion index were no significant. The percentage of the litter decreased whenever the protein was reduced. The ratio of the length of the villi to the depth of the crypts was significantly increased for the treatments in which the crude protein was reduced compared to the control treatment. [ABSTRACT FROM AUTHOR]

The objective of this experiment was to determine the effect of low crude protein (CP) diets containing increasing amounts of enzymolytic soybean meal (ESBM) on growth performance, economic benefit and organ development and the role of cecal fermentation and microbiota in broilers. A total of 360 one-day-old Arbor Acres chicks were randomly allocated into 6 groups with 6 replicates and 10 chicks each. The six dietary treatments consisted of a standard high-CP diet (PC), a low-CP diet (NC), and an NC diet with 0.5, 1.0, 1.5%, or 2.0% ESBM. The experiment lasted for 42 days. Compared to PC, NC showed decreased (p 0.05), while the cecal abundances of Bacteroides, Faecalibacterium and Clostridium IV increased (p

This study was conducted to investigate the effects of Pinus pinaster extract (PPE) and encapsulated Pinus pinaster extract (EPPE) supplementation in normal and low protein broiler diets on performance, some blood and antioxidant parameters, and intestinal histomorphology. In the present study, PPE was covered with alginate in order to obtain EPPE. The present research was conducted during 41-days with 288 one-day-old male broiler chicks. Chicks were classified into two groups that had different protein levels, one of with normal, the other one with 10% low protein. Also, normal and low protein level groups were divided into one control and two trial groups. The amount of 100 mg/kg PPE was added to each trial group diet; and the same amount of EPPE was added to other trial group diets. Consequently, compared to PPE and EPPE groups with control, statistically significant differences were observed for body weight and body weight gain in terms of protein on 41-day results (P<0.05). For feed conversation ratio, better results were detected in PPE groups at 41 days (P<0.05). Besides that, statistically significant differences were found in breast meat thiobarbituric acid reactive substances (TBARS) values and intestinal histomorphology in PPE and EPPE groups compared to the control groups (P<0.05). In this study, the findings suggest that 100 mg/kg PPE and EPPE can be supplemented in normal and low protein broiler diets without any adverse effects and considered alternative aromatic substances for broiler rations. [ABSTRACT FROM AUTHOR]

Objective The objective of this study was to investigate the effects of decreasing dietary crude protein content on rumen fermentation, mictobiota, and metabolites in goats. Methods In an 84-day feeding trial, a total of twelve male Anhui white goat kids with initial body weight 15.9±1.13 kg were selected and randomly classified into two groups, feeding a normal crude protein diet (14.8% CP, NCP) or a low crude protein diet (12.0% CP, LCP). At the end of the experimental trial (on day 84), six animals were randomly selected from each group and were slaughtered to collect rumen fluid samples for the analysis of rumen fermentation parameters, microbiome, and metabolome. Results The concentrations of ammonia-nitrogen, total volatile fatty acid, acetate, and propionate were decreased (p

Understanding the order of limiting amino acids (AA) in reduced-protein (RP) diets for laying hens will facilitate precise feed formulation and ensure that AA requirements are met cost-effectively. The order of the first three limiting AAs—lysine (Lys), methionine (Met), and threonine (Thr)—has been well established in RP laying hen diets. This study aimed to determine the priority order of eight additional limiting AAs (critically important AAs) when formulating wheat–sorghum-based RP diets for laying hens: tryptophan (Trp), valine (Val), isoleucine (Ile), arginine (Arg), leucine (Leu), histidine (His), phenylalanine (Phe), and glycineequivalent (Gly). A total of 330 Hy-Line Brown laying hens were randomly assigned to 11 dietary treatments (30 replicates of individual birds per treatment) from 20 to 39 weeks of age (WOA). Treatments were a standard-protein (17.24% CP) diet as the control (SP); a reduced-protein (15.00% CP) diet with sufficient levels of Lys, Met, and Thr but insufficient levels of the eight experimental essential AA (RP); a reduced-protein diet with sufficient levels of all essential AAs (RP-EAA); and eight subsequent dietary treatments of the RP-EAA diet with one of the experimental essential AAs removed: Trp (RP-EAA-Trp), Val (RP-EAA-Val), Ile (RP-EAA-Ile), Arg (RP-EAA-Arg), Leu (RP-EAA-Leu), His (RP-EAA-His), Phe (RP-EAA-Phe), and Gly (RP-EAA-Gly). Eggs were collected and weighed daily, and feed intake and feed conversion ratio (FCR) were calculated weekly. External and internal egg quality was measured at 29 and 39 WOA. Nutrient digestibility, serum uric acid concentration, caecal microbiota composition, and tibia parameters were measured at 40 WOA. Overall, hens fed the RP-EAA-Val, RP-EAA-Ile, and RP diets presented significantly lower egg mass compared to hens fed the SP, RP-EAA-His, and RP-EAA-Gly diets (p < 0.001). Hens fed the RP diet and RP-EAA-Val diet had a higher FCR compared to those offered the RP-EAA, RP-EAA-Leu, RP-EAA-Phe, and RP-EAA-Gly diets (p = 0.046). Lower protein intake and excretion were observed in hens offered the RP diets compared to hens fed the SP diet (p = 0.001 and 0.018, respectively). Based on the egg mass, Ile may be considered the fourth and Val the fifth limiting AA, after Lys, Met, and Thr, in laying hens fed wheat–sorghum-based RP diets during peak lay. However, if ranked based on FCR, Val may be considered the fourth limiting AA, followed by Trp, Ile, Arg, and His as the co-fifth limiting AAs. Leu, Phe, and Gly may be considered as non-essential AAs for laying hens fed RP diets.

Patients with phenylketonuria (PKU) have to restrict the intake of phenylalanine (Phe) or its structural analogues for life because of the genetic defect that prevents them from metabolizing Phe normally. Therefore, the research and development of food for special medical purpose for PKU is important to protect the health of patients and improve their quality of life. This paper reviews the dietary regimen for patients with PKU, focusing on special low-protein foods, low-Phe foods, and food for special medical purpose based on glycomacropeptides, and details the sources or preparation techniques and functional properties of these foods, and look into future research directions and research priorities to address the current problems of single product form and poor palatability in this field, with a view to providing a better understanding of the development of food for special medical purpose for PKU. The research direction and focus of future research are also presented to provide reference for the research and development of food for special medical purpose for PKU.

Protein intake is higher in formula-fed than in breast-fed infants during infancy, which may lead to an increased risk of being overweight. Applying alpha-lactalbumin (α-lac)-enriched whey or casein glycomacropeptide (CGMP)-reduced whey to infant formula may enable further reduction of formula protein by improving the amino acid profile. Growth, nutrient intake, and protein metabolites were evaluated in a randomized, prospective, double-blinded intervention trial where term infants received standard formula (SF:2.2 g protein/100 kcal; n = 83) or low-protein formulas with α-lac-enriched whey (α-lac-EW;1.75 g protein/100 kcal; n = 82) or CGMP-reduced whey (CGMP-RW;1.76 g protein/100 kcal; n = 80) from 2 to 6 months. Breast-fed infants (BF; n = 83) served as reference. Except between 4 and 6 months, when weight gain did not differ between α-lac-EW and BF (p = 0.16), weight gain was higher in all formula groups compared to BF. Blood urea nitrogen did not differ between low-protein formula groups and BF during intervention, but was lower than in SF. Essential amino acids were similar or higher in α-lac-EW and CGMP-RW compared to BF. Conclusion: Low-protein formulas enriched with α-lac-enriched or CGMP-reduced whey supports adequate growth, with more similar weight gain in α-lac-enriched formula group and BF, and with metabolic profiles closer to that of BF infants. [ABSTRACT FROM AUTHOR]

Proteinuria is a broad term used to describe the pathological presence of proteins, including albumin, globulin, Bence-Jones protein, and mucoprotein in the urine. When persistent, proteinuria is a marker of kidney damage and represents a reliable predictor of the risk of progression of renal failure. Medical nutrition therapy is imperative for patients with proteinuria because it may slow the progression of renal disease. The aim of this review is to explore different nutritional approaches in the management of proteinuria and their influence on pathophysiological processes. As such, protein restriction is the main dietary intervention. Indeed, other management approaches are frequently used to reduce it regarding micro and macronutrients, but also the dietary style. Among these, the nutritional approach represents one of the most used and controversial interventions and the studies rarely take the form of randomized and controlled trials. With this work we aspire to analyze current clinical knowledge of how nutrition could influence proteinuria, potentially representing a useful tool in the management of proteinuric nephropathy. [ABSTRACT FROM AUTHOR]

In a protein reduction feeding trial (Study 1) on a commercial broiler farm in northern Germany, it was attempted to be shown that research results from station tests on protein reduction can be transferred to agricultural practice. In a second study, the limits of the N reduction were tested in a research facility. In Study 1, commercial standard feeds were fed to the control group (variant 1:210,000 animals; n = 5 barns). In the test group (variant 2:210,000 animals; n = 5 barns), the weighted mean crude protein (CP) content was moderately reduced by 0.3%. The nitrogen reduction in the feed did not affect performance (feed intake (FA), daily gain (DG), feed conversion (FCR)), but nitrogen conversion rate increased from approx. 61% to approx. 63%. The solid litter weight was reduced by 12% and nitrogen excretion by 9% (p < 0.05). Significantly healthier footpads were due to lower water intake (−4%; p < 0.05) and a numerically drier bedding. In Study 2, responses of treatments (1250 broiler per variant; n = 5) showed that sharper N-lowering (−1.5% CP; weighted average) did not impair performance either, but N-conversion improved and N-excretions decreased significantly. Converted to a protein reduction of one percentage point, the N excretions were able to be reduced by 22% in Study 1 and 18% in Study 2. Feeding trials in the commercial sector, such as the present Study 1, should convince feed mills and farmers to allow the latest scientific results to be used directly and comprehensively in commercial ration design. [ABSTRACT FROM AUTHOR]

A 42-day study was conducted to consider the effect of composite enzyme (Natuzyme®) supplementation on production parameters, intestinal segment measurements, and nutrient digestibility of broiler chickens fed low energy and protein (LEP) diets. Two hundred male Ross 308 broiler chicks consisting of 4 groups were divided into five pens (10 chicks/pen). The first group (control) received a standard diet without composite enzyme (CE) supplementation, whereas the LEP0, LEP0.25, and LEP0.50 groups received LEP supplemented with CE at 0, 0.25, and 0.50 g/kg feed, respectively. Compared to birds in the control group, supplementation of 0.50 g/kg CE to LEP diet offset (P < 0.05) the poor feed intake (FI), body weight gain (BWG), feed conversion ratio (FCR), and cost/kg gain observed among LEP0 and LEP0.25 groups on days 0–21, 22–42, and 0–42. Birds in the LEP0, followed by the LEP0.25 group, had decreased (P < 0.05) ileum weight, villi height, villus height, and crypt depth ratio (VH/CD), and deeper crypt depth of duodenum and ileum compared to birds in the control group. However, the aforementioned parameters were improved in the LEP0.50 group. Likewise, supplementation of CE at 0.50 g/kg to broiler diet having LEP improved (P < 0.05) digestibility of energy, fiber, and protein on day 42. In conclusion, CE supplemented at 0.50 g/kg diet ameliorated the negative effect caused by feeding LEP diets on production parameters, ileum weight, villi height, VH/CD, and deeper crypt depth of duodenum and ileum as well as energy, fiber, and protein digestibility of broiler chickens. [ABSTRACT FROM AUTHOR]

The present study investigated the effects of low protein diets with different starch sources and starch to protein ratio on growth, digestibility, intestinal health, caecal short chain fatty acids (SCFAs), serum cholesterol and triglycerides in broiler chickens. Eight hundred one-day-old male broiler chicks (Ross 308) were randomly allotted to one of 4 dietary treatments with 10 repeats and 20 birds in each repeat. The dietary treatments included 1) a standard protein corn-SBM based diet (SP), 2) a low protein corn-SBM based diet (LPI) without reduced starch: protein ratio, 3) a low protein corn-SBM based diet (LPII) with reduced starch: protein ratio, and 4) a low protein corn-SBM-peas based diet (LPP) and reduced starch: protein ratio. Soy hulls were added in the LPII and LPP diets to reduce starch: protein ratio. During the experiment period from 11 to 24 d, FI was not affected by the dietary treatments (P > 0.05). The BWG was significantly reduced in the LPI diet compared to the SP diet (P < 0.05). Likewise, FCR deteriorated in LPI and LPII but was better in the SP diet followed by the LPP diet (P < 0.05). The apparent total tract digestibility (ATTD) of dry matter (DM) varied significantly among the dietary treatments (P < 0.01). While ATTD of starch was similar for all the diets except the LPP diet wherein the ATTD of starch was significantly lower (P < 0.001). Ether extract digestibility was also significantly different between the SP and LPII dietary treatments (P < 0.01). The AME and AME n values were significantly lower in the LPP diet compared with other dietary treatments (P < 0.001). Nitrogen retention (%) was increased in all the LP diets compared with the SP diet (P < 0.001), but it was significantly better in both LPII and LPP diets compared to the LPI diet. The data showed that cecal SCFAs production was increased in the LPII and LPP compared to the SP and LPI diets (P < 0.001). Further, the production of acetic, butyric, and propionic acids was substantially higher in the LPP diet (P < 0.001). There was no significant difference in gene expression of Claudin-1 and ZO-1 (P > 0.05). However, MUC-2 and GLUT-1 gene expression were significantly downregulated in the LPI diet (P < 0.05). The concentration of cholesterol and triglycerides was significantly increased in the LPI diet (P < 0.001). In conclusion, the addition of peas as a slowly digestible starch source combined with soy hulls in low protein diet helped to partly recover the growth performance and improved cecal SCFAs production compared to other low protein diets with and without reduced starch: protein ratio in broiler chickens. [ABSTRACT FROM AUTHOR]

Early life nutritional imbalances are risk factors for metabolic dysfunctions in adulthood, but the long term effects of perinatal exposure to high versus low protein diets are not completely understood. We exposed C57BL/6J offspring to a high protein/low carbohydrate (HP/LC) or low protein/high carbohydrate (LP/HC) diet during gestation and lactation, and measured metabolic phenotypes between birth and 10 months of age in male offspring. Perinatal HP/LC and LP/HC exposures resulted in a decreased ability to clear glucose in the offspring, with reduced baseline insulin and glucose concentrations in the LP/HC group and a reduced insulin response post-glucose challenge in the HP/LC group. The LP/HC diet group also showed reduced birth and weanling weights, whereas the HP/LC offspring displayed increased weanling weight with increased adiposity beyond 5 months of age. Gene expression profiling of hypothalamus and liver revealed alterations in diverse molecular pathways by both diets. Specifically, hypothalamic transcriptome and pathway analyses demonstrated perturbations of MAPK and hedgehog signaling, processes associated with neural restructuring and transmission, and phosphate metabolism by perinatal protein imbalances. Liver transcriptomics revealed changes in purine and phosphate metabolism, hedgehog signaling, and circadian rhythm pathways. Our results indicate maternal protein imbalances perturbing molecular pathways in central and peripheral metabolic tissues, thereby predisposing the male offspring to metabolic dysfunctions.

Heat stress causes significant economic losses in the broiler industry. Dietary supplementation of arginine (Arg) and citrulline (Cit) might increase the performance of broilers raised under warm temperature due to vasodilation effects. This study investigated the effects of L-Arg or L-Cit supplementation in broilers fed a reduced protein wheat-based diet deficient in Arg under thermoneutral (NT) and cyclic warm temperature (WT). Ross 308 cockerels (n = 720) were randomly allocated to 4 dietary treatments with 12 replicates of 15 birds per pen from d 7 to 21. The 4 treatments were: normal protein (NP), i.e., 22.3% and 20.9% crude protein in grower and finisher, respectively; reduced protein (RP), i.e., 2.5% lower protein and deficient in Arg; and RP supplemented with 0.28% Arg (RP-Arg) or 0.28% Cit (RP-Cit). A factorial arrangement of treatments was applied during the finisher phase (21 to 35 d). Factors were: diet (4 diets above); and temperature, NT (24 °C) or cyclic WT (33 ± 1 °C for 6 h per day) with 6 replicate pens per treatment. During 7 to 35 d and 21 to 35 d, the birds fed the RP diet had lower body weight gain (BWG) and higher FCR compared to the NP diet (P 0.05) compared to birds exposed to NT. Diet by temperature interactions were not observed for performance parameters during the period of WT (P > 0.05). On d 35, the RP-fed birds had a lower yield of thigh and drumstick, higher fat pad, lower femur ash, and breaking strength but similar serum uric acid level and higher nitrogen digestibility on d 21 compared to those offered NP (P

The aimed of this study evaluate the ability of tyrosine, tryptophan, citric acid (CA), sodium sulphate (SS) or their mixture to improve the utilization of broiler low protein diets (LP diet). A total number of 270 Cobb broiler 10 day old were randomly distributed into nine groups received basal diet (control), diet containing 2 percentage points lower protein (LP diet), LP +0.3 % citric acid (CA), LP +0.3% Anhydrous sodium sulphate (SS), LP+0.3 % CA + 0.3 % SS, LP+ 0.05% tyrosine, LP +0.05% tyrosine + 0.3 % CA +0.3 % SS, LP+0.05% tryptophan and LP+0.05% tryptophan +0.3 % CA + 0.3 % SS. At 21 day, using LP diet significantly decreased broiler body weight compared to control diet while all feed additives improved weight gain and feed conversion compared to LP diet. The birds fed mixture of tyrosine +CA+SS recorded the highest value of body weight and the best feed conversion. At 35 day, The birds fed mixture of tyrosine +CA+SS recorded significantly higher body weight value and better feed conversion by 8.63 and 8.53 %, respectively, compared to those fed control diet . Compared to other treatments, birds fed mixture of tyrosine +CA+SS recorded the highest values of total protein, albumin and total cholesterol in plasma. It can be concluded that addition of tyrosine, tryptophan, CA or SS to LP diet improved the broiler performance to be like those fed control diet while the mixture of tyrosine +CA+SS surpassed the control. [ABSTRACT FROM AUTHOR]

Context: Necrotic enteritis (NE) has been considered a major threat to broiler gut health and growth performance. Aims: This study aimed at investigating the effects of l-arginine (Arg) or l-citrulline (Cit) supplementation on intestinal morphology, short-chain fatty acid (SCFA), microbiota count, gut permeability, and pH in broilers fed reduced-protein diets during subclinical NE challenge. Methods: Ross 308 cockerels (n = 720) were randomly assigned to six experimental treatments with eight replicates of 15 birds per pen. The treatments were standard protein without NE challenge (SP−), or with NE challenge (SP+); reduced protein (two percentage points lower crude protein) without NE challenge (RP−), or with NE challenge (RP+); RP+ plus added Arg (103% of Ross 308 requirement, RPA+) and RPC+ where supplemental Arg in RPA+ was replaced with Cit. A 2 × 2 factorial arrangement was employed for the first four treatments. Factors were NE (− or +) and protein concentration (SP or RP). Treatments SP+, RP+, RPA+, and RPC+ were analysed by one-way ANOVA. Key results: Necrotic enteritis × protein interactions were detected for serum fluorescein isothiocyanate dextran (FITC-d) level, C. perfringens (P < 0.05) count in the caeca (P < 0.01), and acetic acid (P < 0.01) and total SCFA concentrations in the ileum on Day 16 (P < 0.001). Feeding the RP diet reduced serum FITC-d concentration, number of C. perfringens in the caeca, and increased acetic acid and total SCFA concentrations in the ileum compared with the SP group only in birds challenged with NE. Birds in the RPC+ treatment had greater jejunal villus height (P < 0.001), and lower caecal C. perfringens and Enterobacteriaceae count than did those in the SP+ treatment (P ≤ 0.001). Conclusions: The results indicated a benefit to gut health of broilers during NE challenge when replacing crystalline Arg with Cit in RP diets. Implications: In part, replacement of Arg by Cit in the RP diets is of great potential to increase gut health, reduce growth loss, thus, minimising negative effects of NE in broilers. Necrotic enteritis has been considered a major threat in broiler chicken production. The results of this study showed that feeding reduced protein diets supported gut health of necrotic enteritis-challenged birds by reducing Clostridium perfringens in the caeca, and increasing total short-chain fatty acid concentrations in the ileum compared with standard protein diets. Also, in-part replacement of arginine by citrulline in reduced protein diets had beneficial effects on gut health during necrotic enteritis challenge. [ABSTRACT FROM AUTHOR]

Context: Improving immune status through nutritional adjustments may be part of an effective strategy to reduce reliance on antibiotic growth promoters for controlling necrotic enteritis (NE) in broiler chickens. Aims: This study examined the effect of dietary protein level and the replacement of crystalline l-arginine (Arg) with l-citrulline (Cit) in the reduced-protein diet on the performance of broilers challenged with subclinical NE. Methods: Ross 308 cockerels (n = 720) were randomly allocated to six dietary treatments, with eight replicates of 15 birds per pen, during a 35-day feeding experiment. The treatments were as follows: standard protein without NE challenge (SP−); standard protein with NE challenge (SP+); reduced protein (two percentage points lower crude protein) without NE challenge (RP−); reduced protein with NE challenge (RP+); RP+ plus added Arg (103% of RP, RPA+) and RPC+ where supplemental Arg in RPA+ was replaced with Cit. The first four treatments were considered as a 2 × 2 factorial arrangement, with factors being NE (− or +) and protein level (SP or RP). Treatments SP+, RP+, RPA+, and RPC+ were analysed by one-way ANOVA. Key results: Subclinical NE challenge reduced feed intake (FI), reduced body weight gain (BWG) and increased feed to gain ratio (FCR) from Day 0 to Day 35, increased intestinal lesion scores on Day 16, and reduced relative breast yield on Day 35 (P < 0.05). Feeding RP diets increased FI (P < 0.001), increased BWG (P < 0.01) and reduced FCR (P < 0.01) during the grower phase compared with SP diets when birds were challenged with NE. Birds in the RPC+ treatment had a lower overall FCR than did those in the SP+ treatment (P < 0.001). Birds in the RPA+ treatment had similar FI, BWG and FCR to those in the RP+ treatment (P > 0.05). Conclusions: Collectively, the results showed protective effects of replacing the supplemental Arg with Cit against NE in RP diets, as indicated by higher performance during and after the challenge. Implications: Feeding the RP diets supplemented with Cit may be part of an effective strategy to reduce reliance on antibiotic growth promoters for controlling NE in broiler chickens. Economic losses from necrotic enteritis have increased in the broiler industry with the removal of in-feed antibiotic growth promoters. The results of this study showed that feeding reduced-protein diets supplemented with citrulline was beneficial in promoting gut health and recovery from the necrotic enteritis challenge. This information may help control and/or mitigate the effects of necrotic enteritis in antibiotic growth promoter-free poultry production. [ABSTRACT FROM AUTHOR]

Context: The impact of necrotic enteritis (NE) on acute-phase proteins, interleukins, blood mineral profiles, and gene expression have not been well documented. Aims: This study aimed to determine the effects of l-arginine (Arg) or l-citrulline (Cit) supplementation on serum immunological parameters, serum mineral composition and gene expression in broilers fed reduced-protein diets (RP) during subclinical NE challenge. Methods: Ross 308 cockerels (n = 720) were randomly assigned to six experimental treatments, with eight replicates of 15 birds per pen. The treatments were standard protein without and with NE challenge (SP−, SP+); reduced protein (2% points lower crude protein) without and with NE challenge (RP−, RP+), RP plus added Arg (103% of Ross 308 requirement) with NE challenge (RPA+) and RPC+ where supplemental Arg in RPA+ was replaced with Cit. A 2 × 2 factorial arrangement was employed for the first four treatments. Additionally, treatments SP+, RP+, RPA+, and RPC+ were analysed by one-way ANOVA. Key results: The NE × protein interactions indicated that serum calcium concentration decreased in birds fed the RP diets only when challenged with NE (P < 0.05). The NE × protein interactions showed that the NE challenge downregulated the mRNA expression of jejunal y+ L amino acid transporter-2, and mucin 2 only in birds fed the RP diets (P < 0.05). Feeding the RP decreased expression of catenin alpha 1, but increased expression of claudin 5 and tight junction protein genes compared with the SP (P < 0.05). Birds in the RPC+ treatment had increased gene expression of tight junction protein and claudin 5 compared with the SP+ treatment (P < 0.05). Conclusions: Dietary protein level and infection with NE both have an impact on immune response and expression of genes involved in immunity and nutrient digestibility. In part replacement of Arg with Cit in the RPC diet may have beneficial effects on gene expression in NE-challenged birds. Implications: Feeding RP diets may alleviate a decline in growth during subclinical NE by increasing gene expression of tight junction proteins compared with the SP diets. Necrotic enteritis has been estimated to cause losses of US$6 billion annually to the global broiler industry. Feeding reduced protein diets may alleviate a decline in growth during subclinical necrotic enteritis by increasing gene expression of tight junction proteins compared with the standard protein diets. However, if birds are infected with a more severe form of the disease, additional supplementations of minerals and crystalline amino acids to the reduced protein diets are necessary to support the host immune response. [ABSTRACT FROM AUTHOR]

Different levels of valine in low protein diets have a significant effect on the immune system of broiler chickens. This experiment was performed to evaluate the effect of different levels of valine in low protein diets on the immune response of broiler chickens. This study was conducted using 200 one-day old male broilers of Ross 308 strain in a completely randomized design with 5 replicates and 10 birds per replicate. Experimental treatments were adjusted based on the Brazilian tables and included: control diet with recommended levels of valine, 10% higher than the recommended level of valine and 20% higher than the recommended level of valine diluted in a diet containing 2% protein. The results showed that different levels of valine had no significant effect on the weight of liver, spleen, fabricius bursa and leukocytes (p

The aim of the study was to test the interaction between Thr and Gly in low crude protein (CP) diets in 7 to 28 d broilers on production performance and plasma metabolites. A total of 2,040 broilers were allocated to 17 treatments. A positive control (PC) diet (20.5% CP) was formulated to be adequate in dietary Thr and Gly. A negative control (NC) diet (18.5% CP, deficient in Thr and Gly) was supplemented with crystalline l-Thr and Gly to obtain a 4 Thr × 4 Gly design. Dietary Thr was tested at an apparent faecal digestibility (AFD) Thr-to-Lys ratio, which was 55%, 58%, 61% or 64%, and dietary Gly was tested at an AFD (Gly + Ser)-to-Lys ratio, which was 135%, 142%, 149% or 156%. Plasma samples were collected at 28 d. The low CP diet, formulated at 64% Thr and 156% Gly, resulted in a higher body weight gain (BWG) (P

Abstract There is growing interest among nutritionists in feeding reduced protein diets to broiler chickens. Although nearly a century of research has been conducted providing biochemical insights on the impact of reduced protein diets for broilers, practical limitation still exists. The present review was written to provide insights on further reducing dietary protein in broilers. To construct this review, eighty-nine peer reviewed manuscripts in the area of amino acid nutrition in poultry were critiqued. Hence, nutritional research areas of low protein diets, threonine, glycine, valine, isoleucine, leucine, phenylalanine, histidine, and glutamine have been assessed and combined in this text, thus providing concepts into reduced protein diets for broilers. In addition, linkages between the cited work and least cost formation ingredient and nutrient matrix considerations are provided. In conclusion, practical applications in feeding reduced protein diets to broilers are advancing, but more work is warranted.

Developing a low-protein feed is important for the sustainable advancement of aquaculture. The aim of this study was to investigate the effects of essential amino acid (EAA) supplementation in a low-protein diet on the growth, intestinal health, and microbiota of the juvenile blotched snakehead, Channa maculata in an 8-week trial conducted in a recirculating aquaculture system. Three isoenergetic diets were formulated to include a control group (48.66 % crude protein (CP), HP), a low protein group (42.54 % CP, LP), and a low protein supplementation EAA group (44.44 % CP, LP-AA). The results showed that significantly lower weight gain (WG), specific growth rate (SGR), protein efficiency ratio (PER), and feed efficiency ratio (FER) were observed in fish that were fed LP than in the HP and LP-AA groups (P < 0.05). The HP and LP-AA groups exhibited a significant increase in intestinal villus length, villus width, and muscular thickness compared to the LP group (P < 0.05). Additionally, the HP and LP-AA groups demonstrated significantly higher levels of intestinal total antioxidant capacity (T-AOC), catalase (CAT), and superoxide dismutase (SOD) and lower levels of malondialdehyde (MDA) compared to the LP group (P < 0.05). The apoptosis rate of intestinal cells in the LP group was significantly higher than those in the LP and HP groups (P < 0.05). The mRNA expression levels of superoxide dismutase (sod), nuclear factor kappa B p65 subunit (nfκb-p65), heat shock protein 70 (hsp70), and inhibitor of NF-κBα (iκba) in the intestine were significantly higher in the LP group than those in the HP and LP-AA groups (P < 0.05). The 16s RNA analysis indicated that EAA supplementation significantly increased the growth of Desulfovibrio and altered the intestinal microflora. The relative abundances of Firmicutes and Cyanobacteria were positively correlated with antioxidant parameters (CAT and T-AOC), whereas Desulfobacterota was negatively correlated with sod and T-AOC. The genera Bacillus , Bacteroides , and Rothia were associated with the favorable maintenance of gut health. In conclusion, dietary supplementation with EAAs to achieve a balanced amino acid profile could potentially reduce the dietary protein levels from 48.66 % to 44.44 % without adversely affecting the growth and intestinal health of juvenile blotched snakeheads. • Supplementation of EAA to a low-protein diet can improve the growth and feed utilization of juvenile blotched snakehead. • The addition of EAAs to a low-protein diet influences intestinal mucosa morphology and the abundance of gut microbes. • Supplementing EAAs with low-protein diets exerts its anti-inflammatory and antioxidant effects by altering gut microbes. • EAAs can alleviate intestinal oxidative stress and inflammatory response induced by low protein intake. [ABSTRACT FROM AUTHOR]

The aim of this experiment is the study of the effect of protease supplementation enzyme to reduced protein diets, on production performance of broiler chickens. Two hundred seventy unsexed one-day-old chicks were randomly distributed into six groups receiving different treatments. By each treatment were performed three replications, with 15 chicks/replication. The treatments were as follows: T1 - control, T2 - control + protease 400 g/t, T2 control + protease 400 g / t, T3 - crude protein reduced by 2%, T4- crude protein reduced by 2% + protease 400 g/t, T5 - crude protein reduced by 2% + protease 800 g/t, T6 - crude protein reduced by 2% + protease 1200 g/t. The results showed no significant differences between T1, T5 and T6 groups concerning live body weight and body weight gain. T1, T2 and T6 recorded significant decrease in feed intake, and also significant improvement in feed conversion ratio. [ABSTRACT FROM AUTHOR]

Context: Mineralisation of the bone matrix is a pivotal factor affecting bone strength in broilers. Reduced bone strength might cause fracture during catching and transportation to slaughterhouses, leading to economic loss. Aims: This study was conducted to investigate the effects of l-arginine (Arg), guanidinoacetic acid (GAA), and l-citrulline (Cit) supplementation to Arg-deficient reduced-protein diets on bone mineral composition and mineral digestibility of broiler chickens. Methods: Day-old Ross 308 males were allocated to one of eight dietary treatments with six replicates of 16 birds per treatment. The treatments were standard protein (SP), reduced protein deficient in Arg (RP), and RP with two levels of either Arg (0.238% and 0.476%), GAA (0.309% and 0.618%) or Cit (0.238% and 0.476%). The difference in crude protein content between RP and SP was five percentage points. Key results: Birds fed the RP diet had higher ileal digestibility of P, Na, Mg, S, Al, Fe, Cu and Zn than did those fed the SP on Day 23 (P < 0.01). Supplementation of both Arg, GAA and Cit to the RP reduced Mg digestibility on Day 23 (P < 0.001). The tibia and femur Ca and P concentrations were not different among the dietary treatments on either Day 23 or Day 35 (P > 0.05). Birds fed the RP had lower tibia and femur B concentrations and higher tibia and femur Zn concentrations on Day 23 and Day 35 and higher tibia and femur Mn concentrations on Day 35 than did those fed the SP (P < 0.01). Supplementation of Arg at the high level and Cit at both levels to the RP increased tibia S concentration on Day 23 (P < 0.001). Supplementation of Arg, Cit and GAA to the RP decreased femur Zn concentration on Day 35 (P < 0.001). Supplementation of GAA at the high level decreased concentrations of the tibia and femur B and Fe on Day 23, but increased tibia and femur Mn concentrations on Day 23 and Day 35 (P < 0.01). Conclusions: The findings indicated an increased mineral digestibility but relatively similar bone mineral concentrations in broilers fed the RP diets when compared with the SP diets. Implications: The results of the current study may provide useful information on the bird bone mineralisation and help expand the adoption of reduced-protein diets in the poultry industry. Mineralisation of the bone matrix is a pivotal factor affecting bone strength in broilers. The findings of the current study showed that feeding reduced-protein diets increased ileal mineral digestibility but mineral concentrations in the tibia and femur of birds fed these diets were not different from those of birds fed the standard-protein diets. This information may help expand the adoption of reduced-protein diets in the poultry industry. [ABSTRACT FROM AUTHOR]

Valine (Val) alone or in combination with isoleucine (Ile) improves the growth under severe protein restriction; however, the underlying mechanisms remain unknown. In this study, we assessed whether Val/Ile-induced growth in protein-restricted pigs is associated with changes in gut development, hepatic insulin-like growth factor 1 (IGF-1) production, and blood metabolomics. Forty piglets were assigned to five dietary groups: positive control (PC) with standard protein content; low protein (LP) with very low protein content; and LP supplemented with Val (LPV), Ile (LPI), and Val and Ile (LPVI). LPVI reversed the negative effects of VLP diets on growth and gut morphology. Both LPV and LPVI restored the reduced transcript of IGF-1 while decreasing the transcript of insulin-like growth factor binding protein 1 (IGFBP1) in the liver. LPV and LPVI recovered the reduced plasma Val, glycine, and leucine concentrations, which were positively correlated with improved gut morphology and the hepatic IGF-1 gene expression and negatively correlated with hepatic IGFBP1 mRNA abundance. In conclusion, supplementation with a combination of Val and Ile into the VLP diets restored the decreased growth performance of pigs fed with these diets likely through improved gut development, hepatic IGF-1 expression and bioavailability, and plasma metabolomics profile. [ABSTRACT FROM AUTHOR]

The effect of different types of low protein diets based on digestible amino acids on laying performance, egg quality, apparent nutrient digestibility and serum biochemical indexes were studied. 648 chickens were randomly divided into nine groups, with six replicates in each group and 12 chickens in each replicate, and 3 x 3 two factor design was adopted. The diet types were corn-soybean meal, corn-soybean meal-cotton meal and corn-soybean-peanut meal diets, and the protein levels were 16.4%, 14.4% and 12.4%. The results showed that reducing dietary protein level had no significant effect on production performance, egg quality, apparent nutrient digestibility, serum total protein, urea nitrogen and uric acid content (P>0.05). Corn-soybean-cotton meal and corn-soybean-peanut meal diets had no significant effect on production performance, egg quality, apparent digestibility and serum biochemical indexes (P>0.05). The interaction of diet type and protein level had no significant effect on egg quality and apparent digestibility of nutrients (P>0.05). Except for group 4 and group 5, the economic benefits of each experimental group were higher than those of the control group. The experiment indicates that the adaptive group are corn-soybean meal + protein level of 12.4%, corn-soybean mealcotton meal + protein level of 16.4%, corn-soybean meal-peanut meal + protein level of 14.4%. [ABSTRACT FROM AUTHOR]

Chronic kidney disease (CKD) is a global health problem, affecting approximately 10% of the adult population. It has a significant impact on patient quality of life and mortality rates, and increases costs for healthcare systems. Nutrition plays an important role in disease prevention, as it can help prevent hypertension and Type 2 diabetes mellitus, the two major underlying causes in CKD development. Medical nutrition therapy with protein reduction is an important pillar in the conservative management of patients with chronic renal failure and may improve overall patient outcomes. Its effects on uraemia, proteinuria, and metabolic acidosis have been demonstrated in numerous studies. Hence, the 2020 update to the Kidney Disease Outcomes Quality Initiative (KDOQI) Clinical Practice Guideline for Nutrition in CKD has taken this into account, and recommends, with the highest level of evidence (1A), a diet with reduced protein intake in metabolically stable, nondialysis-dependent patients with CKD Stages 3–5. In practice, low-protein diets are often not particularly used for several reasons, such as concerns about the potentially increased risk for protein-energy wasting and poor adherence expectations. However, there is further evidence to show that a low-protein diet with adequate energy intake and high biological value protein supply, regularly followed by a trained dietitian, is safe and patient adherence increases with a personalised dietary approach, tailored to individual patient needs and considerations for dietary habits. Also, medical foods can help to facilitate reaching nutritional targets and preventing malnutrition, as they are a good source of almost nitrogen-free energy, providing only little amounts of protein, sodium, phosphorus, and potassium.

This study was aimed to probe broiler responses to the maintenance of adequate level of glycine plus serine in low crude protein (CP) diets by glycine (Gly) addition from 8 to 42 days of age. A total of 1152 7-d-old birds were divided into 8 groups and fed with one of the following diets: (I) normal CP diet; (II, III vIV V) diets with 1.5%, 3%, 4.5% and 6% points less CP than normal diet, respectively; (VI, VII, VIII) diets with 3%, 4.5% and 6% points reduced CP than the normal CP diet, respectively, and added with Gly to achieve 2.32% total Gly + Ser. Each treatment was replicated with 12 cages. Results showed that dietary CP reduction by 3% or higher compromised (p .05) abdominal fat percentage of birds fed the diet containing 4.5% points less CP as compared with birds fed the normal-CP diet. Comparatively, Gly fortification in the diet with a 6% CP reduction resulted in breast muscle yield, serum UN content on d 21 and albumin content on d 42 comparable to (p > .05) those in normal-CP group. Collectively, the absence of Gly addition allowed dietary CP reduction by no more than 3% to obtain normal performance and carcase traits of broilers. Gly fortification in the diet with a 3% CP reduction induced no improvements in growth performance and carcase traits of broilers. However, maintain a level of 2.32% total Gly + Ser via Gly fortification enabled a reduction of dietary CP by 4.5% without deteriorating the accumulative growth performance and carcase traits of broilers.Highlights Gly addition that provides 2.32% total Gly + Ser allows dietary CP reduction of 4.5% without compromising the accumulative growth performance and carcase traits of broilers. Maintaining 2.32% total Gly + Ser via Gly fortification could not completely overcome the depression of growth performance in broilers fed the diet with a 6% CP reduction.

Necrotic enteritis (NE) is an infection of the gastrointestinal tract and is estimated to cost the global poultry industry billions of dollars annually. A study was conducted to examine whether reducing the crude protein might offset the severity of NE in broilers experimentally challenged with Eimeria spp. on day 9 and Clostridium perfringens on days 14 and 15. Furthermore, increasing the dietary amino acid (AA) density of the diet was also examined owing to identified benefits of improving performance compromised from low protein (LP) diets or NE. A 2 × 2 × 3 factorial arrangement of treatments at 6 replicates per treatment was used with 972 Ross 308 cockerels fed wheat-sorghum-soy-based diets to 35 D. Factors were NE challenge: no or yes; protein: standard (SP) or LP; and AA density: 100% AA, 115% with only essential AA (115% EAA) increased, and 115% AA with both essential and nonessential AA (115% AA) increased. The performance was measured in grower (days 7–21), finisher (days 21–35), and overall (day 7–35) periods. In addition, on day 16, intestinal lesion score and cecal short-chain fatty acids were measured. Only in nonchallenged birds fed LP diets, 115% AA increased grower feed intake (P

The present study investigated the effects of supplementing a low protein (LP) diet supplemented with key essential amino acids (AA) to broilers on growth performance, intestinal tract function, blood metabolites, and nitrogen excretion when the animals were maintained under various sanitary conditions for 35 D after hatching. Three hundred eighty-four one-day-old male broilers (Ross 308) were randomly allotted to groups that received one of 6 dietary treatments in a 2 × 3 factorial arrangement (i.e., 2 environmental conditions and 3 dietary treatments) to give 8 replicates per treatment. Broilers were challenged with 2 environmental conditions (sanitary vs. poor sanitary). The dietary treatments were (1) high protein (HP) diet, (2) LP diet, and (3) LP diet with synthetic key essential AA (LPA): the LP diet was supplemented with synthetic AA up to the required levels for broilers. On day 14, birds consumed the LP diet impaired growth performance compared with those fed the HP diet, while the average daily weight gain-to-feed conversion ratio of birds fed the LPA diet improved to the level of birds fed the HP diet under poor sanitary conditions (P < 0.05). Broilers raised under poor sanitary conditions and fed the LP diet displayed higher (P < 0.05) zonula occludens (ZO-1) expression on day 14 than broilers fed either the HP or LPA diet. Under sanitary conditions, birds fed HP and LPA diets showed higher villus height and crypt depth compared with those of broilers fed the LP diet on day 35. Moreover, broilers raised in the poor sanitary environment had higher (P < 0.05) serum endotoxins than those raised in the sanitary environment. Broilers fed the LPA diet showed reduced (P < 0.05) nitrogen excretion on days 14 and 35 compared with those fed the LP and HP diets independent of the environment. In conclusion, the LPA diet did not impair growth performance under poor sanitary conditions for 14 D after hatch while resulting in lower nitrogen excretion in any environment conditions throughout the experiment.

In a protein reduction feeding trial (Study 1) on a commercial broiler farm in northern Germany, it was attempted to be shown that research results from station tests on protein reduction can be transferred to agricultural practice. In a second study, the limits of the N reduction were tested in a research facility. In Study 1, commercial standard feeds were fed to the control group (variant 1:210,000 animals; n = 5 barns). In the test group (variant 2:210,000 animals; n = 5 barns), the weighted mean crude protein (CP) content was moderately reduced by 0.3%. The nitrogen reduction in the feed did not affect performance (feed intake (FA), daily gain (DG), feed conversion (FCR)), but nitrogen conversion rate increased from approx. 61% to approx. 63%. The solid litter weight was reduced by 12% and nitrogen excretion by 9% (p < 0.05). Significantly healthier footpads were due to lower water intake (−4%; p < 0.05) and a numerically drier bedding. In Study 2, responses of treatments (1250 broiler per variant; n = 5) showed that sharper N-lowering (−1.5% CP; weighted average) did not impair performance either, but N-conversion improved and N-excretions decreased significantly. Converted to a protein reduction of one percentage point, the N excretions were able to be reduced by 22% in Study 1 and 18% in Study 2. Feeding trials in the commercial sector, such as the present Study 1, should convince feed mills and farmers to allow the latest scientific results to be used directly and comprehensively in commercial ration design.

Proteinuria is a broad term used to describe the pathological presence of proteins, including albumin, globulin, Bence-Jones protein, and mucoprotein in the urine. When persistent, proteinuria is a marker of kidney damage and represents a reliable predictor of the risk of progression of renal failure. Medical nutrition therapy is imperative for patients with proteinuria because it may slow the progression of renal disease. The aim of this review is to explore different nutritional approaches in the management of proteinuria and their influence on pathophysiological processes. As such, protein restriction is the main dietary intervention. Indeed, other management approaches are frequently used to reduce it regarding micro and macronutrients, but also the dietary style. Among these, the nutritional approach represents one of the most used and controversial interventions and the studies rarely take the form of randomized and controlled trials. With this work we aspire to analyze current clinical knowledge of how nutrition could influence proteinuria, potentially representing a useful tool in the management of proteinuric nephropathy.

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Dietary protein restriction is one of the effective ways to reduce post-weaning diarrhoea and intestinal fermentation in piglets, but it may also reduce growth performance. The compensatory growth induced by subsequent protein realimentation may solve the issue. However, little research has been done on the impact of protein realimentation on the gut. In this study, the effects of protein restriction and realimentation on ileal morphology, ileal microbial composition and metabolites in weaned piglets were investigated. Thirty-six 28-day-old weaned piglets with an average body weight of 6.47 ± 0.04 kg were randomly divided into a control group and a treatment group. The CP level in the diet of the control group was 18.83% for the entire experimental period. The piglets in the treatment group were fed 13.05% CP between days 0 and 14 and restored to a diet of 18.83% CP for days 14 to 28. On day 14 and 28, six pigs from each group were sacrificed and sampled. It was found that the abundance of Lactobacillus and Salmonella in the ileal digesta was significantly lower in the treatment group than the control group on day 14, whereas the abundance of Clostridium sensu stricto 1, Streptococcus, Halomonas and Pseudomonas significantly increased in the ileal digesta of the treatment group on day 14 compared with the control group. In addition, reduced concentrations of lactic acid, total short-chain fatty acids (total SCFAs), total branched chain fatty acids, ammonia and impaired ileal morphology and mucosal barrier were observed in the treatment group on day 14. However, diarrhoea levels decreased in the treatment group throughout the experiment. During the succedent protein realimentation stage, the treatment group demonstrated compensatory growth. Compared with the control group, the treatment group showed increased abundance of Lactobacillus and reduced abundance of Salmonella, Halomonas and Pseudomonas in the ileum on day 28. The concentrations of lactic acid and total SCFAs increased significantly, whereas the concentration of ammonia remained at a lower level in the treatment group on day 28 compared with the control group. Overall, protein realimentation could improve ileal morphology and barrier functions and promote ileal digestive and absorptive functions. In conclusion, ileal microbial composition and metabolites could change according to dietary protein restriction and realimentation and eventually influence ileal morphology and barrier functions.

Introduction: Proteins are the essential part of all organism cells. Nutrition plays the most important role in the structure and function of the brain. CA1 region belongs to hippocampus and plays a vital role in converting short-term to long-term memory. This study was designed to assess the effects of low-protein diet on hippocampal region CA1 and learning deficit in rats. Materials and Methods: In this study, 30 male rats were randomly assigned to two groups: control group and low-protein diet group (8% protein). Animals in a low-protein diet group have eaten food with low protein daily for 10 months. Body weight was measured. Transcardiac perfusion method was applied to tissue fixation. Passive avoidance learning of animals was examined by the shuttle-box apparatus technique. The number of dendritic spines was investigated by the Golgi staining technique. Furthermore, Cresyl violet staining method was used to determine the number of neurons in the hippocampal region CA1. Results: The passive avoidance learning of the low-protein diet rats was reduced significantly compared to the control ones (P < 0.001). Low-protein diet decreased the body weight, number of neuronal dendritic spines and neurons compared to the control group (P < 0.001). Conclusion: It seems that administration of low-protein diet had harmful effects of structure and function of hippocampal region CA1 in rats.

The effects of feeding low dietary crude protein (CP) and/or metabolisable energy (ME) with or without supplemental protease on growth performance, carcase characteristics and physiological responses in broiler chickens were investigated under cyclic heat stress condition. A total of 350 day-old male broiler chicks were fed with one of the following seven experimental diets: (1) recommended-CP and recommended-ME (RPE, served as control); (2) recommended-CP and low-ME (RPLE); (3) recommended-CP and low-ME with protease (RPLEP); (4) low-CP and recommended-ME (LPRE); (5) low-CP and recommended-ME with protease (LPREP); (6) low-CP and low-ME (LPE) and (7) low-CP and low-ME with protease (LPEP). From 22 to 42 d of age, half of the chickens from each dietary group were exposed to 34 ± 1 °C for 7 h daily (heat stress), whereas the other half were raised at constant 23 ± 2 °C (normal temperature). Supplementation of protease to RPLE, LPRE and LPE diets had no significant effects on feed intake (FI), weight gain (WG) or feed conversion ratio (FCR). Diet had no effect on serum glucose, total protein, certain acute phase proteins (APPs), corticosterone or breast yield. Regardless of protease supplementation, heat stressed birds had significantly lower FI, WG and breast yield, and higher FCR, APPs and corticosterone compared to birds raised in normal temperature. In conclusion, dietary supplementation of protease to low CP and/or ME diets showed negligible effects on growth performance, carcase characteristic and physiological responses in broiler chickens under heat stress condition. The inclusion of microbial protease in broiler diets could be considered by poultry industry as an effective nutritional tool for reducing ME or CP, in order to decrease abdominal fat deposition, improve feed efficiency and increase the profit margin. HighlightsProtease supplementation has no specific help for broilers under heat stress. Feeding low CP and/or ME diet is not stressful for broiler chickens.