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Background: Research on low-protein-level diets has indicated that even though the profiles of essential amino acids (EAAs) follow the recommendation for a normal-protein-level diet, broilers fed low-protein diets failed to achieve productive performance compared to those fed normal diets. Therefore, it is imperative to reassess the optimum profile of EAAs in low-protein diets and establish a new ideal pattern for amino acid balance. Furthermore, identifying novel sensitive biomarkers for assessing amino acid balance will greatly facilitate the development of amino acid nutrition and application technology. In this study, 12 dietary treatments [Con(+), Con(-), L&A(-), L&A(+), M&C(-), M&C(+), BCAA (-), BCAA(+), Thr(-), Thr(+), Trp(-) and Trp(+)] were established by combining different EAAs including lysine and arginine, methionine and cysteine, branched-chain amino acid (BCAA), threonine, and tryptophan to observe the growth and development of the broiler chickens fed with low-protein-level diets. Based on the biochemical parameters and untargeted metabolomic analysis of animals subjected to different treatments, biomarkers associated with optimal and suboptimal amino acid balance were identified. Results: Growth performance, carcass characteristics, hepatic enzyme activity, serum biochemical parameters, and breast muscle mRNA expression differed significantly between male and female broilers under different dietary amino acid patterns. Male broilers exhibited higher sensitivity to the adjustment of amino acid patterns than female broilers. For the low-protein diet, the dietary concentrations of lysine, arginine, and tryptophan, but not of methionine, cystine, or threonine, needed to be increased. Therefore, further research on individual BCAA is required. For untargeted metabolomic analysis, Con(+) was selected as a normal diet (NP) while Con(-) represented a low-protein diet (LP). L&A(+) denotes a low-protein amino acid balanced diet (LPAB) and Thr(+) represents a low-protein amino acid imbalance diet (LPAI). The metabolites oxypurinol, pantothenic acid, and D-octopine in birds were significantly influenced by different dietary amino acid patterns. Conclusion: Adjusting the amino acid profile of low-protein diets is required to achieve normal growth performance in broiler chickens fed normal-protein diets. Oxypurinol, pantothenic acid, and D-octopine have been identified as potentially sensitive biomarkers for assessing amino acid balance. [ABSTRACT FROM AUTHOR]

Although low-protein diets can improve the nitrogen utilization efficiency and alleviate economic pressures in ruminants, they may also negatively impact dairy performance. Rumen-protected lysine (RPL) supplementation can improve the health status and growth performance of ruminants without compromising nitrogen utilization efficiency and feed intake. In this study, a total of thirty-three multiparous dairy goats in the late-lactation period were randomly divided into three groups that were separately fed the control diet (namely the protein-adequacy group), the low-protein diet (namely the protein-deficient group), and the RPL-supplemented protein-deficient diet (namely RPL-supplementation group) for five weeks. Here, we investigated the molecular mechanisms regarding how low-protein diets with RPL supplementation compromise lactation phenotypes in dairy goats through cross-tissue transcriptomic analyses. Dietary protein deficiency caused an imbalance in amino acid (AA) intake, disrupted hepatic function, and impaired milk synthesis. Transcriptomic analyses further showed that RPL supplementation exhibited some beneficial effects, like mitigating abnormal lipid and energy metabolism in the liver, elevating hepatic resistance to oxidative stress, improving the mammary absorption of AAs, as well as activating mammary lipid and protein anabolism primarily through peroxisome proliferator-activated receptor (PPAR) and janus kinase-signal transducer (JAK)—signal transducer and activator of transcription (STAT) signaling, respectively. RPL supplementation of a low-protein diet contributes to maintaining late lactation in dairy goats primarily through mitigating hepatic energy disturbances and activating both lipid and protein metabolism in the mammary glands. Since RPL supplementation initiated a series of comprised events on mammary protein and lipid metabolism as well as the hepatic function and energy generation in dairy goats under protein deficiency during late lactation, these findings thus provide some insights into how RPL supplementation helps maintain milk production and health in dairy mammals especially at late lactation. [ABSTRACT FROM AUTHOR]

Background A low-protein diet (LPD) is recommended to patients with advanced chronic kidney disease (CKD), whereas geriatric guidelines recommend a higher amount of protein. The aim of this study was to evaluate the safety of LPD treatment in older adults with advanced CKD. Methods The EQUAL study is a prospective, observational study including patients ≥65 years of age with an incident estimated glomerular filtration rate <20 ml/min/1.73 m2 in six European countries with follow-up through 6 years. Nutritional status was assessed by a 7-point subjective global assessment (SGA) every 3–6 months. Prescribed diet (g protein/kg of bodyweight) was recorded on every study visit; measured protein intake was available in three countries. Time to death and decline in nutritional status (SGA decrease of ≥2 points) were analysed using marginal structural models with dynamic inverse probability of treatment and censoring weights. Results Of 1738 adults (631 prescribed LPD at any point during follow-up), there were 1319 with repeated SGA measurements, of which 267 (20%) decreased in SGA ≥2 points and 565 (32.5%) who died. There was no difference in survival or decrease in nutritional status for patients prescribed a LPD ≤0.8 g/kg ideal bodyweight {odds ratio [OR] for mortality 1.15 [95% confidence interval (CI) 0.86–1.55)] and OR for decrease in SGA 1.11 [95% CI 0.74–1.66]} in the adjusted models. In patients prescribed a LPD <0.6 g/kg ideal bodyweight, the results were similar. There was a significant interaction with LPD and older age >75 years, lower SGA and higher comorbidity burden for both mortality and nutritional status decline. Conclusions In older adults with CKD approaching end-stage kidney disease, a traditional LPD prescribed and monitored according to routine clinical practice in Europe appears to be safe. [ABSTRACT FROM AUTHOR]

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Background: Parental malnutrition, particularly a low-protein diet (LPD), causes oligonephropathy at birth and predisposes offspring to hypertension and chronic kidney disease later in life. The onset of adult kidney disease varies based on genetics and environmental factors, often with subclinical alterations in kidney function being overlooked. This study aimed to examine changes in kidney morphology before significant kidney function decline in the offspring of mice fed a low-protein diet. Methods: Using a combination of histological analysis, kidney metabolic and hemodynamic panel assessments, and advanced statistical techniques such as Linear Discriminant Analysis (LDA) and Principal Component Analysis (PCA), we investigated the initial impact of a maternal low-protein diet (LPD) on kidney development and function. Our study utilized 12-week-old F1 mice from F0 parents fed either a low-protein diet (LPD) or a normal-protein diet (NPD) before the onset of hypertension. Results: The offspring (F1 generation) of parents (F0 generation) fed an LPD show reduced body weight from birth to P20. The kidney weight was also reduced compared to F1 offspring from parents fed an NPD. At 12 weeks of age, body weight normalized, but kidney weight remained low. Offspring of parents fed an LPD displayed abnormal kidney morphology, including dilated tubules, oligonephropathy, and fluid-filled cysts which had worsened with age. A kidney metabolic panel analysis at 12 weeks revealed a slight but consistent increase in urine albumin, plasma creatinine, mean urea, and BUN concentrations. Although no significant changes in hemodynamic variables were observed, 2/12 mice, both males, showed alterations in systolic blood pressure, suggesting sex-specific effects when comparing F1 mice from F0 fed either diet. Overall, kidney metabolic changes were strongly correlated to parental LPD. Conclusion: Our findings indicate that significant kidney damage must accumulate in the F1 generation from parents fed an LPD before any detectable changes in blood pressure occur. Our study suggests that small variations in kidney metabolic function may point to early kidney damage and should not be overlooked in the offspring of these malnourished mice and likely humans. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. The study investigated the effects of dietary protein level and the inclusion of hydroponic barley sprouts (HB) on lactation performance, blood biochemistry and N use efficiency in mid-lactation dairy cows. Treatments were arranged in a 2 × 2 factorial design with 2 CP levels (16.8% and 15.5% of DM), with HB (4.8% of DM, replacing 4.3% of alfalfa hay and 0.5% of distillers dried grains with solubles [DDGS]) or without HB. Forty-eight multiparous Holstein dairy cows (146 ± 15 DIM, 40 ± 5 kg/d of milk) were randomly allocated to 1 of 4 diets: high-protein diet (16.8% CP, HP), HP diet with HB (HP+HB), low-protein diet (15.5% CP, LP), or LP diet with HB (LP+HB). An interaction between CP × HB on DMI was detected, with DMI being unaffected by HB inclusion in cows fed the high-protein diets, but was lower in cows fed HB when the low-protein diet was fed. A CP × HB interaction was also observed on milk and milk protein yield, which was higher in cows fed HB with HP, but not LP. Inclusion of HB also tended to reduce milk fat content, and feeding HP resulted in a higher milk protein and MUN content, but lower milk lactose content. Feed efficiency was increased by feeding HP or HB diets, whereas N use efficiency was higher for cows fed LP or HB diets. There was an interaction on the apparent total-tract digestibility of DM and CP, which was higher when HB was fed along with HP, but reduced when fed with LP, whereas the digestibility of ADF was increased by feeding low-protein diets. In conclusion, feeding a low-protein diet had no adverse effect on cow performance, while feeding HB improved milk and milk component yield, and N efficiency when fed with a high-CP diet, but compromised cow performance with a low-CP diet. [ABSTRACT FROM AUTHOR]

A ketogenic diet (KD) is a high-fat, low-carbohydrate, and low-protein diet that exerts antiepileptic effects by attenuating spontaneous recurrent seizures, ameliorating learning and memory impairments, and modulating the gut microbiota composition. However, the role of the gut microbiome in the antiepileptic effects of a KD on temporal lobe epilepsy (TLE) induced by lithium-pilocarpine in adult rats is still unknown. Our study provides evidence demonstrating that a KD effectively mitigates seizure behavior and reduces acute-phase epileptic brain activity and that KD treatment alleviates hippocampal neuronal damage and improves cognitive impairment induced by TLE. We also observed that the beneficial effects of a KD are compromised when the gut microbiota is disrupted through antibiotic administration. Analysis of gut microbiota components via 16S rRNA gene sequencing in fecal samples collected from TLE rats fed either a KD or a normal diet. The Chao1 and ACE indices showed decreased species variety in KD-fed rats compared to TLE rats fed a normal diet. A KD increased the levels of Actinobacteriota, Verrucomicrobiota and Proteobacteria and decreased the level of Bacteroidetes. Interestingly, the abundances of Actinobacteriota and Verrucomicrobiota were positively correlated with learning and memory ability, and the abundance of Proteobacteria was positively correlated with seizure susceptibility. In conclusion, our study revealed the significant antiepileptic and neuroprotective effects of a KD on pilocarpine-induced epilepsy in rats, primarily mediated through the modulation of the gut microbiota. However, whether the gut microbiota mediates the antiseizure effects of a KD still needs to be better elucidated. [ABSTRACT FROM AUTHOR]

Western diets are the underlying cause of metabolic and liver diseases. Recent trend to limit the consumption of protein-rich animal products has become more prominent. This dietary change entails decreased protein consumption; however, it is still unknown how this affects innate immunity. Here, we studied the influence of a low protein diet (LPD) on the liver response to bacterial infection in mice. We found that LPD protects from Salmonella enterica serovar Typhimurium (S. Typhimurium)-induced liver damage. Bulk and single-cell RNA sequencing of murine liver cells showed reduced inflammation and upregulation of autophagy-related genes in myeloid cells in mice fed with LPD after S. Typhimurium infection. Mechanistically, we found reduced activation of the mammalian target of rapamycin (mTOR) pathway, whilst increased phagocytosis and activation of autophagy in LPD-programmed macrophages. We confirmed these observations in phagocytosis and mTOR activation in metabolically programmed human peripheral blood monocyte-derived macrophages. Together, our results support the causal role of dietary components on the fitness of the immune system. Low protein diet protects against Salmonella Typhimurium-mediated liver injury in mice corresponding to reduced mTOR activation and increased autophagy in macrophages. mTOR pathway activation with amino acid supplementation reverses this protection. [ABSTRACT FROM AUTHOR]

As part of the Anson Street African Burial Ground Project, we characterized the oral microbiomes of twelve 18th century African-descended individuals (Ancestors) from Charleston, South Carolina, USA, to study their oral health and diet. We found that their oral microbiome composition resembled that of other historic (18th-19th century) dental calculus samples but differed from that of modern samples, and was not influenced by indicators of oral health and wear observed in the dentition. Phylogenetic analysis of the oral bacteria, Tannerella forsythia and Pseudoramibacter alactolyticus, revealed varied patterns of lineage diversity and replacement in the Americas, with the Ancestors carrying strains similar to historic period Europeans and Africans. Functional profiling of metabolic pathways suggested that the Ancestors consumed a diet low in animal protein. Overall, our study reveals important insights into the oral microbial histories of African-descended individuals, particularly oral health and diet in colonial North American enslavement contexts. Oral microbiomes from dental calculus of 18th century African-descended individuals in Charleston, South Carolina (USA), yield insights into their health and diet through metagenomic sequencing, phylogenetic analysis and functional profiling. [ABSTRACT FROM AUTHOR]

Background: The importance of parental diet in relation to eventual offspring health is increasing in prominence due to the increased frequency of parents of reproductive age consuming poor diets. Whilst maternal health and offspring outcome have been studied in some detail, the paternal impacts are not as well understood. A father's poor nutritional status has been shown to have negative consequences on foetal growth and development and ultimately impact the long-term adult health of the offspring. In this study, we examined sperm- and seminal vesicle fluid-mediated mechanisms of preimplantation embryo development alterations in response to sub-optimal paternal diets. Results: Male mice were fed a diet to model either under (low-protein diet (LPD)) or over (high-fat/sugar 'Western' diet (WD)) nutrition, LPD or WD supplemented with methyl donors or a control diet (CD) before mating with age-matched females. Male metabolic health was influenced by WD and MD-WD, with significant changes in multiple serum lipid classes and hepatic 1-carbon metabolites. Sperm RNA sequencing revealed significant changes to mRNA profiles in all groups when compared to CD (LPD: 32, MD-LPD: 17, WD: 53, MD-WD: 35 transcripts). Separate analysis of the seminal vesicle fluid proteome revealed a significant number of differentially expressed proteins in all groups (LPD: 13, MD-LPD: 27, WD: 24, MD-WD: 19) when compared to control. Following mating, in vitro time-lapse imaging of preimplantation embryos revealed a significant increase in the timing of development in all experimental groups when compared to CD embryos. Finally, qPCR analysis of uterine tissue at the time of implantation identified perturbed expression of Cd14 and Ptgs1 following mating with WD-fed males. Conclusions: Our current study shows that paternal nutritional status has the potential to influence male metabolic and reproductive health, impacting on embryonic development and the maternal reproductive tract. This study highlights potential direct (sperm-mediated) and indirect (seminal vesicle fluid-mediated) pathways in which a father's poor diet could shape the long-term health of his offspring. [ABSTRACT FROM AUTHOR]

Chronic kidney disease (CKD) has a high prevalence worldwide, with increasing incidence in low- and middle-income countries, and is associated with high morbidity and mortality, particularly from cardiovascular disease. Protein-restricted diets are one of the most widely used non-pharmacological approaches to slow the progression of CKD and prevent associated metabolic abnormalities. However, some concerns have been raised about the long-term safety of these diets, particularly with regard to patients' nutritional status and bone and mineral disorders. Therefore, the aim of this article is to review the most recent scientific evidence on the relevance of using protein-restricted diets (with or without keto-analogue supplementation) and, in particular, their relationships with malnutrition and mineral and bone disorders in people with CKD without kidney replacement therapies. Although protein-restricted diets, especially when supplemented with keto-analogues and highly personalized and monitored, do not appear to be associated with malnutrition, research on their effects on bone and mineral disorders is scarce, deserving further investigation. [ABSTRACT FROM AUTHOR]

Background and Aim: Rice straw, a widely available agricultural byproduct globally, has significant potential as a basal diet for livestock. The major challenge lies in obtaining high-protein foliage that can be easily extracted using natural water rather than chemical solvents. This study aimed to assess the ability of distilled water to extract protein concentrate from Indigofera leaves (Indigofera zollingeriana Miq.) and to evaluate its effectiveness in enhancing rumen feed fermentation and digestibility in low-quality rice straw basal diets. Materials and Methods: The study was conducted in two experimental series. Experiment 1 was designed to explore the ability of distilled water to extract protein concentrate from fresh and dry Indigofera leaves by comparing it with the 0.1 N NaOH standard solvent. Experiment 2 focused on the in vitro digestibility of protein concentrates extracted from fresh Indigofera leaves based on optimal findings from experiment 1. Five treatments consisting of 0.5% and 1.0% protein concentrate and two extractants (distilled water and 0.1 N NaOH) were used to extract protein from Indigofera leaves. These extracts were then added to rice straw-based diets. Rice straw without supplements was used as a control. The treatments were arranged using a randomized complete design with five replicates. Results: The results of experiment 1 showed that distilled water was superior to 0.1 N NaOH for extracting protein concentrate from fresh Indigofera leaves, as revealed by higher dry matter, protein yield, total amino acids (AA), and total essential AA (EAA) production. For in vitro experiment 2, supplementation with distilled water-extracted protein concentrates successfully increased rumen fermentation and digestibility in rice straw basal diets, as indicated by higher gas production, total volatile fatty acid, and microbial protein levels compared with 0.1 N NaOH. Conclusion: Findings from this study confirm that Indigofera leaf protein concentrate offers a new alternative for enhancing rumen feed fermentation and the digestibility of low-quality rice straw diets. This study implies that it is an easy, costeffective, and environmentally friendly approach, particularly beneficial for smallholders, to extract protein concentrate from fresh Indigofera leaves using distilled water and use it to enhance the quality of rice straw for ruminant feed. The limitation of this study is that the Indigofera supplement was established using in vitro digestibility under controlled laboratory conditions, which does not reflect real rumen conditions. Therefore, further studies using in vivo digestibility in ruminant animals are required to confirm the ability of the protein extracted from indigofera to enhance rumen feed fermentation in low-protein basal diets. [ABSTRACT FROM AUTHOR]

Abstract Background Research on low-protein-level diets has indicated that even though the profiles of essential amino acids (EAAs) follow the recommendation for a normal-protein-level diet, broilers fed low-protein diets failed to achieve productive performance compared to those fed normal diets. Therefore, it is imperative to reassess the optimum profile of EAAs in low-protein diets and establish a new ideal pattern for amino acid balance. Furthermore, identifying novel sensitive biomarkers for assessing amino acid balance will greatly facilitate the development of amino acid nutrition and application technology. In this study, 12 dietary treatments [Con(+), Con(-), L&A(-), L&A(+), M&C(-), M&C(+), BCAA (-), BCAA(+), Thr(-), Thr(+), Trp(-) and Trp(+)] were established by combining different EAAs including lysine and arginine, methionine and cysteine, branched-chain amino acid (BCAA), threonine, and tryptophan to observe the growth and development of the broiler chickens fed with low-protein-level diets. Based on the biochemical parameters and untargeted metabolomic analysis of animals subjected to different treatments, biomarkers associated with optimal and suboptimal amino acid balance were identified. Results Growth performance, carcass characteristics, hepatic enzyme activity, serum biochemical parameters, and breast muscle mRNA expression differed significantly between male and female broilers under different dietary amino acid patterns. Male broilers exhibited higher sensitivity to the adjustment of amino acid patterns than female broilers. For the low-protein diet, the dietary concentrations of lysine, arginine, and tryptophan, but not of methionine, cystine, or threonine, needed to be increased. Therefore, further research on individual BCAA is required. For untargeted metabolomic analysis, Con(+) was selected as a normal diet (NP) while Con(-) represented a low-protein diet (LP). L&A(+) denotes a low-protein amino acid balanced diet (LPAB) and Thr(+) represents a low-protein amino acid imbalance diet (LPAI). The metabolites oxypurinol, pantothenic acid, and D-octopine in birds were significantly influenced by different dietary amino acid patterns. Conclusion Adjusting the amino acid profile of low-protein diets is required to achieve normal growth performance in broiler chickens fed normal-protein diets. Oxypurinol, pantothenic acid, and D-octopine have been identified as potentially sensitive biomarkers for assessing amino acid balance.

Dietary nutrient manipulation (e.g. protein fractions) could lower the environmental footprints of ruminants, especially reactive nitrogen (N). This study investigated the impacts of dietary soluble protein (SP) levels with decreased crude protein (CP) on intestinal N absorption, hindgut N metabolism, fecal microbiota and metabolites, and their linkage with N metabolism phenotype. Thirty-two male Hu sheep, with an age of six months and an initial BW of 40.37 ± 1.18 kg, were randomly assigned to four dietary groups. The control diet (CON), aligning with NRC standards, maintained a CP content of 16.7% on a dry matter basis. Conversely, the experimental diets (LPA, LPB, and LPC) featured a 10% reduction in CP compared with CON, accompanied by SP adjustments to 21.2%, 25.9%, and 29.4% of CP, respectively. Our results showed that low-protein diets led to significant reductions in the concentrations of plasma creatinine, ammonia, urea N, and fecal total short-chain fatty acids (SCFA) (P

The purpose of the present study was to assess the nutritional value of yeast culture (YC) and to explore the effect of YC on growth performance and health of piglets fed low-protein diets. In Exp. 1, 12 growing barrows were allocated into control diet and YC diet treatments to determine the available energy of YC. Results showed that the digestible energy and metabolizable energy of YC are 12.12 and 11.66 MJ/kg dry matter (DM), respectively. In Exp. 2, 12 growing barrows were surgically equipped with a T-cannula near the distal ileum and were assigned to 2 dietary treatments (nitrogen-free diet and YC diet), and the amino acid digestibility of YC was determined. In Exp. 3, a total of 96 weaned piglets were randomly divided into 4 treatments, including low-protein basal diet (Basal), Basal + 0.5% YC (0.5%YC), Basal + 1.0% YC (1.0%YC), and Basal + 1.5% YC (1.5%YC). The results were as follows: YC supplementation linearly improved the weight gain and feed intake ratio (P

This study aimed to evaluate the effects of adding chromium-methionine (Cr-meth) chelate in extruded diets containing reduced protein content on growth performance, carcass composition, nutrient retention, and hematobiochemical responses in Nile tilapia juveniles. The fish were fed with two control diets (no Cr-meth): positive control (311 g kg−1 of crude protein, estimated 258 g kg−1 of digestible protein) and negative control (255 g kg−1 of crude protein, estimated 207 g kg−1 of digestible protein). Another five experimental diets (mean 251 g kg−1 of crude protein, mean estimated 204 g kg−1 of digestible protein) were supplemented with 0.2, 0.4, 0.6, 0.8, and 1.0 mg Cr-meth kg diet−1. Juveniles (34.31 g) were organized in a randomized design (seven treatments in triplicate) in 21 tanks (250 L) and fed until apparent satiety. The experiment lasted 9 weeks. Fish fed 0.8 and 1.0 mg Cr-meth kg diet−1 showed zootechnical variables similar to the positive control. The reduced protein diets showed lower costs, and supplementation with 0.91 mg kg−1 of chromium matched the profitability observed in the positive control diet. Carcass gross energy and energy retention, plasma cholesterol (total and LDL), and triglycerides values were higher in fish fed 0.6 mg Cr-meth kg diet−1 than in the positive control. Treatments with dietary Cr-meth (mainly between 0.4 and 0.8 mg kg−1) decreased carcass Cr, selenium, and copper retention and increased carcass nitrogen retention and muscle glycogen levels compared to the positive control. This treatment (positive control) also had lower values for total leukocytes and monocytes, respectively, than fish fed 0.2 and 0.4 mg Cr-meth kg diet−1 and for eosinophils and lymphocytes than fish fed 0.8 mg Cr-meth kg diet−1. In conclusion, we recommend supplementation with 0.8 mg Cr-meth kg diet−1 for diets with low protein content, as it produces a dietary protein-sparing effect, reducing costs, improving immune defense, muscle glycogen, and nitrogen retention without compromising growth performance, physiology, and fish metabolism. [ABSTRACT FROM AUTHOR]

Low protein intake (LPI) has been suggested as a treatment for chronic kidney disease (CKD). However, protein intake is essential for bone health. We studied the database of the National Health and Nutrition Examination Survey, 2005–2010. Basic variables, metabolic diseases, and bone density of different femoral areas were stratified into four subgroups according to different protein intake (DPI) (that is, <0.8, 0.8–1.0, 1.0–1.2, and >1.2 g/kg/day). Significant differences were found among all lumbar area bone mineral density (BMD) and T-scores (p < 0.0001). There was an apparent trend between a decreasing BMD in the CKD groups with increasing DPI in all single lumbar spines (L1, L2, L3, and L4) and all L spines (L1-L4). Compared with DPI (0.8–1.0 g/day/kg), higher risks of osteoporosis were noticed in the subgroup of >1.2 g/day/kg over L2 (relative risk (RR)=1.326, 95% confidence interval (CI)=1.062–1.656), subgroup >1.2 g/day/kg over L3 (RR = 1.31, 95%CI = 1.057–1.622), subgroup <0.8 g/day/kg over L4 (RR = 1.276, 95%CI = 1.015–1.605), subgroup <0.8 g/day/kg over all L spines (RR = 11.275, 95%CI = 1.051–1.548), and subgroup >1.2 g/day/kg over all L spines (RR = 0.333, 95%CI = 1.098–1.618). However, a higher risk of osteoporosis was observed only in the non-CKD group. There was an apparent trend of higher DPI coexisting with lower BMD and T scores in patients with CKD. For osteoporosis (reference:0.8–1.0 g/day/kg), lower (<0.8 g/day/kg) or higher DPI (>1.2 g/day/kg) was associated with higher risks in the non-CKD group, but not in the CKD group. In the CKD group, LPI for renal protection was safe without threatening L spine bone density and without causing a higher risk of osteoporosis. A low-protein diet should be encouraged in patients with CKD, but protein is essential for bone health. In this study, we showed that a low-protein diet did not affect lumbar bone density. Therefore, in the care of CKD, a low-protein diet is beneficial for renal function and without harm to lumbar bone health. [ABSTRACT FROM AUTHOR]

Abstract Maternal malnutrition has been associated with neurodevelopmental deficits and long-term implications on the offspring’s health and behavior. Here, we investigated the effects of maternal low-protein diet (LPD) or obesity-inducing maternal high-fat diet (HFD) on dyadic social interactions, group organization and autism-related behaviors in mice. We found that maternal HFD induced an autism-related behavioral phenotype in the male offspring, including a robust decrease in sociability, increased aggression, cognitive rigidity and repetitive behaviors. Maternal LPD led to a milder yet significant effect on autism-related symptoms, with no effects on olfactory-mediated social behavior. Under naturalistic conditions in a group setting, this manifested in altered behavioral repertoires, increased magnitude in dominance relations, and reduced interactions with novel social stimuli in the HFD male offspring, but not in the LPD offspring. Finally, we found HFD-induced transcriptomic changes in the olfactory bulbs of the male offspring. Together, our findings show that maternal malnutrition induces long-lasting effects on aggression and autism-related behaviors in male offspring, and potential impairments in brain regions processing chemosensory signals.

Abstract Background The energy/protein imbalance in a low-protein diet induces lipid metabolism disorders in late-phase laying hens. Reducing energy levels in the low-protein diet to adjust the energy-to-protein ratio may improve fat deposition, but this also decreases the laying performance of hens. This study investigated the mechanism by which different energy levels in the low-protein diet influences liver lipid metabolism in late-phase laying hens through the enterohepatic axis to guide feed optimization and nutrition strategies. A total of 288 laying hens were randomly allocated to the normal-energy and normal-protein diet group (positive control: CK) or 1 of 3 groups: low-energy and low-protein diet (LL), normal-energy and low-protein diet (NL), and high-energy and low-protein diet (HL) groups. The energy-to-protein ratios of the CK, LL, NL, and HL diets were 0.67, 0.74, 0.77, and 0.80, respectively. Results Compared with the CK group, egg quality deteriorated with increasing energy intake in late-phase laying hens fed low-protein diet. Hens fed LL, NL, and HL diets had significantly higher triglyceride, total cholesterol, acetyl-CoA carboxylase, and fatty acid synthase levels, but significantly lower hepatic lipase levels compared with the CK group. Liver transcriptome sequencing revealed that genes involved in fatty acid beta-oxidation (ACOX1, HADHA, EHHADH, and ACAA1) were downregulated, whereas genes related to fatty acid synthesis (SCD, FASN, and ACACA) were upregulated in LL group compared with the CK group. Comparison of the cecal microbiome showed that in hens fed an LL diet, Lactobacillus and Desulfovibrio were enriched, whereas riboflavin metabolism was suppressed. Cecal metabolites that were most significantly affected by the LL diet included several vitamins, such as riboflavin (vitamin B2), pantethine (vitamin B5 derivative), pyridoxine (vitamin B6), and 4-pyridoxic acid. Conclusion A lipid metabolism disorder due to deficiencies of vitamin B2 and pantethine originating from the metabolism of the cecal microbiome may be the underlying reason for fat accumulation in the liver of late-phase laying hens fed an LL diet. Based on the present study, we propose that targeting vitamin B2 and pantethine (vitamin B5 derivative) might be an effective strategy for improving lipid metabolism in late-phase laying hens fed a low-protein diet.

ABSTRACT: Lowering dietary protein content is a promising strategy to reduce N excretions in cattle but it requires improved N utilization by the animal. Feed enzymes (e.g., exogenous α-amylase) and plant extracts (e.g., essential oils [EO]) are 2 additives that may enhance rumen function and possibly also microbial protein yield. This may increase fat- and protein-corrected milk yield (MY) and milk nitrogen efficiency and thus lower N losses from dairy cows. Both types of additives were studied in an experiment including 39 Holstein cows that had (average ± SD) 40.7 ± 7.95 kg/d MY, 89 ± 43 DIM, 2.7 ± 1.5 lactations, and 677 ± 68.6 kg of BW, consisting of a covariate (4 wk) and treatment period (5 wk). During the whole experiment cows were fed a typical Benelux diet (CTRL), supplemented with concentrates to meet individual requirements for energy and MP, which were fulfilled for 100% and 101%, respectively. The total diet was low in CP (15.5%) and relatively high in starch (22.6% and 6.6% rumen bypass starch). Cows were balanced for parity, DIM, MY, and roughage intake and randomly assigned to one of 3 groups, which received the following treatments in the treatment period: (1) CTRL (n = 13); (2) CTRL + 14 g/cow per day Ronozyme RumiStar α-amylase enzyme (AMEZ, n = 13; DSM); and (3) CTRL + 2.5 g/cow per day Crina Protect, a blend of EO components (ESOL, n = 13; DSM). Animal performance, ruminal pH, and enteric gas emissions were monitored throughout the experiment. During the last week of the covariate and treatment periods, nitrogen balances were conducted, total-tract nutrient digestibility was determined, and urinary allantoin and uric acid were determined as indicators for microbial N production. The statistical model applied to these variables contained group and DIM during treatment period as fixed effects and the values from the covariate period as covariate. Post hoc Dunnet-corrected comparisons between each treatment group and the control group were explored. The α-amylase enzyme tended to increase apparent total-tract starch digestibility and increased milk lactose concentration. The EO blend tended to increase MY and increased milk N output, milk nitrogen efficiency, and feed efficiency. Therefore, when feeding reduced dietary protein levels, EO have potential to improve the N-use efficiency in cattle, whereas the α-amylase enzyme might increase starch digestibility and milk lactose. However, additional research is necessary to substantiate our findings.

The reduced nutrient digestibility of low-protein (LP) diets has been shown to be caused by the weakened fermentative capacity of the post-gut flora. The dynamic regulation of dietary protein contents on post-gut microbial population and fermentative metabolism is unclear. Twelve growing barrows (19.9 ± 0.8 kg) fitted with a T-cannula at the blind end of the cecum were randomly administered a high-protein (HP, 21.5% crude protein [CP]) diet or an LP (15.5% CP) diet for 28 d. The cecal content and feces were collected at d 1, 14, and 28 of the experiment for microflora structures and metabolite concentrations analysis. The nutrient digestibility coefficient and plasma biochemical parameters were also determined. Compared with the HP treatment, the LP treatment showed decreased plasma urea nitrogen concentration and apparent total tract digestibility of dry matter, gross energy, and CP (P

Background: Carbamoyl phosphate synthetase 1 (CPS1) deficiency (OMIM 237300), an autosomal recessive rare and severe urea cycle disorder, is associated with hyperammonemia and high mortality. Methods: Herein we present 12 genetic variants identified in seven clinically well-characterized Chinese patients with CPS1 deficiency who were admitted to the Children's Medical Center of Peking University First Hospital from September 2014 to August 2023. Results: Seven patients (two male and five female patients including two sisters) experienced symptoms onset between 2 days and 13 years of age, and they were diagnosed with CPS1 deficiency between 2 months and 20 years. Peak blood ammonia levels ranged from 160 to 1,000 µmol/L. Three patients showed early-onset CPS1 deficiency, with only one surviving after treatment with sodium phenylbutyrate, N-carbamoyl-L-glutamate, and liver transplantation at 4 months, showing a favorable outcome. The remaining four patients had late-onset CPS1 deficiency, presenting with mental retardation, psychiatric symptoms, and self-selected low-protein diets. Among the 12 CPS1 variants identified in these patients, 10 were novel, with all patients exhibiting compound heterozygosity for CPS1 mutant alleles. Seven variants (c.149T > C, c.616 A > T, c.1145 C > T, c.1294G > A, c.3029 C > T, c.3503 A > T, and c.3793 C > T) resulted in single amino acid substitutions. Three frameshift variations (c.2493del, c.3067dup, and c.3241del) were identified, leading to enzyme truncation. One mutation (c.3506_3508del) caused an in-frame single amino acid deletion, while another (c.2895 + 2T > C) resulted in aberrant splicing. Conclusions: Except for two known variants, all other variants were identified as novel. No hotspot variants were observed among the patients. Our data contribute to expanding the mutation spectrum of CPS1. [ABSTRACT FROM AUTHOR]

Introduction: T-sheep and H-sheep exhibit different environmental adaptability and production performance. The rumen microbiome has co-evolved with hosts and plays a vital role in nutrient digestion and energy metabolism. In our previous study, we found that T-sheep have a higher efficiency in energy metabolism than H-sheep, but the rumen microbial community remains unclear. Methods: In this study, we determined the rumen bacterial profile and rumen fermentation parameters to reveal the bacterial profiles and predictive functions among breeds and diets with four different energy levels, as well as the correlation between bacterial profiles and rumen fermentation characteristics. Results: The results showed that the rumen total volatile fatty acids (VFAs), acetate, butyrate, total branched-chain VFAs, iso-butyrate, and iso-valerate were higher in T-sheep than H-sheep. The alpha diversity of ruminal bacteria is not affected by dietary energy, but it shows a distinction between the sheep breeds. Specifically, T-sheep rumen bacteria exhibit higher alpha diversity than H-sheep. The beta diversity of ruminal bacteria is not influenced by dietary energy or sheep breeds, indicating similar communities of ruminal bacteria between different diets and sheep breeds. The phyla of Bacteroidetes and Firmicutes predominate in the rumen, with a higher relative abundance of Firmicutes observed in T-sheep than H-sheep. The two most abundant genera in the rumen were Prevotella 1 and Rikenellaceae RC9 gut group. Prevotella 1 is the predominant bacterial genus in the rumen of H-sheep, while the Rikenellaceae RC9 gut group dominates in the rumen of T-sheep. Microbial co-occurrence network analysis reveals that variations in rumen fermentation characteristics result from differences in module abundance, with a higher abundance of VFA-producing modules observed in the rumen of T-sheep. Microbial function prediction analysis showed that dietary energy rarely alters the functional composition of rumen bacteria. However, there were differences in the functions of rumen bacteria between sheep breeds, with T-sheep showing a greater emphasis on energy metabolism-related functions, while H-sheep showed a greater emphasis on protein metabolism-related functions. Discussion: These findings provide evidence of the special rumen microbial community that helps T-sheep efficiently obtain energy from low-protein and low-energy diets, enabling them to survive in the extreme environment of the Qinghai–Tibet Plateau. [ABSTRACT FROM AUTHOR]

With the three major advantages of reducing feed costs and protein feed usage, improving feed utilization efficiency, and reducing environmental pollution, low-protein diet technology has a very broad application prospect. The application of low-protein diets in the production of laying hens has become a research hotspot, but the research results are not consistent. This article reviews the effects of low-protein diets on the production performance, egg quality, and nitrogen excretion of laying hens, as well as the key factors affecting the application effect of low-protein diets, providing a reference for the promotion and application of low-protein diet technology in the production of laying hens. [ABSTRACT FROM AUTHOR]

Simple Summary: An experiment was conducted to test the hypothesis that pigs fed a low-protein diet containing 6% spray-dried plasma during phase 1 have improved growth performance and intestinal health if fed a low-protein diet during phase 2 containing spray-dried plasma. Low-protein phase 1 diets contained 0 or 6% spray-dried plasma, whereas low-protein, as well as normal-protein, phase-2 diets contained 0 or 2.5% spray-dried plasma. Including spray-dried plasma in low-protein diets improved growth performance during the initial 14 d post-weaning, but not during the combined phase 1 and phase 2 periods. Pigs fed a low-protein diet with spray-dried plasma in phase 1 and then a normal protein diet with spray-dried plasma in phase 2 had an improved growth performance compared with pigs fed a diet without spray-dried plasma, and the villus-height-to-crypt-depth ratio in the jejunum was reduced. Diarrhea and pro-inflammatory cytokines were lower in pigs fed diets with spray-dried plasma or diets low in protein compared with pigs fed diets without spray-dried plasma and with normal protein, indicating less intestinal inflammation. The hypothesis that pigs fed a low crude protein (CP) diet with 6% spray-dried plasma (SDP) in phase 1 will have improved growth and intestinal health if the phase-2 diet contains 2.5% SDP was tested. Three hundred weaned pigs were used. Growth performance, feces, blood, and intestinal tissue were evaluated. Pigs fed 6% SDP in phase 1 had improved average daily gain (ADG) and final body weight (BW), but had reduced villus-height-to-crypt-depth ratio in phase 2 if 2.5% SDP was included in the normal-CP diet (p < 0.05), but not in the low-CP diet. Diarrhea incidence was less (p < 0.05) with 2.5% SDP in the phase 2 diet and for the low-CP diet. Ileal mucosa interleukin-1α (IL-1α) and IL-1β decreased (p < 0.05) for pigs fed the phase-1 diet with 6% SDP compared with pigs fed the diet without SDP. Addition of 2.5% SDP in phase 2 reduced (p < 0.05) IL-1β compared with the diet without SDP. Although the combination of SDP and low CP did not affect intestinal health in phase 2, diarrhea incidence and pro-inflammatory cytokines were reduced in pigs fed SDP in phase 1 or phase 2 or if a low-CP diet was fed. [ABSTRACT FROM AUTHOR]

Objective: An increasing number of studies shown that inadequate energy intake causes an increase in adverse incidents in chronic kidney disease (CKD) patients on low-protein diets (LPD). The study aimed to investigate the relationship between energy intake and cardiovascular mortality in CKD patients on a LPD. Methods: This was a cross-sectional study, a total of 4264 CKD patients were enrolled from the NHANES database between 2009 and 2018. Restricted cubic spline plots and Cox regression analysis were used to analyze the association between energy intake and cardiovascular mortality in CKD patients on a LPD. Additionally, a nomogram was constructed to estimate cardiovascular survival in CKD patients on a LPD. Results: Among CKD patients on a LPD in the United States, 90.05% had an energy intake of less than 25 kcal/kg/day, compared to 36.94% in CKD patients on a non-LPD. Energy intake and cardiovascular mortality showed a linear relationship in CKD patients on a LPD, while a 'U-shaped' relationship was observed in CKD patients on a non-LPD. Multifactorial Cox regression models revealed that for Per-standard deviation (Per-SD) decrement in energy intake, the risk of cardiovascular mortality increased by 41% (HR: 1.41, 95% CI: 1.12, 1.77; P = 0.004) in CKD patients on a LPD. The concordance index of the nomogram was 0.79 (95% CI, 0.75, 0.83). Conclusion: CKD patients, especially those on a LPD, have significantly inadequate energy intake. Lower energy intake is associated with higher cardiovascular mortality in CKD patients on a LPD. [ABSTRACT FROM AUTHOR]

Low-protein diets (LPDs) seem to improve metabolic complications of advanced CKD, thus postponing kidney replacement therapy (KRT) initiation. However, the nutritional safety of LPDs remains debatable in patients with diabetic kidney disease (DKD), especially in the elderly. This is a sub-analysis of a prospective unicentric interventional study which assessed the effects of LPD in patients with advanced DKD, focusing on the feasibility and safety of LPD in elderly patients. Ninety-two patients with DKD and stable CKD stage 4+, proteinuria >3 g/g creatininuria, good nutritional status, with confirmed compliance to protein restriction, were enrolled and received LPD (0.6 g mixed proteins/kg-day) supplemented with ketoanalogues of essential amino acids for 12 months. Of the total group, 42% were elderly with a median eGFR 12.6 mL/min and a median proteinuria 5.14 g/g creatininuria. In elderly patients, proteinuria decreased by 70% compared to baseline. The rate of kidney function decline was 0.1 versus 0.5 mL/min-month before enrolment. Vascular events occurred in 15% of cases, not related to nutritional intervention, but to the severity of CKD and higher MAP. LPDs seem to be safe and effective in postponing KRT in elderly patients with advanced DKD while preserving the nutritional status. [ABSTRACT FROM AUTHOR]

Background: The energy/protein imbalance in a low-protein diet induces lipid metabolism disorders in late-phase laying hens. Reducing energy levels in the low-protein diet to adjust the energy-to-protein ratio may improve fat deposition, but this also decreases the laying performance of hens. This study investigated the mechanism by which different energy levels in the low-protein diet influences liver lipid metabolism in late-phase laying hens through the enterohepatic axis to guide feed optimization and nutrition strategies. A total of 288 laying hens were randomly allocated to the normal-energy and normal-protein diet group (positive control: CK) or 1 of 3 groups: low-energy and low-protein diet (LL), normal-energy and low-protein diet (NL), and high-energy and low-protein diet (HL) groups. The energy-to-protein ratios of the CK, LL, NL, and HL diets were 0.67, 0.74, 0.77, and 0.80, respectively. Results: Compared with the CK group, egg quality deteriorated with increasing energy intake in late-phase laying hens fed low-protein diet. Hens fed LL, NL, and HL diets had significantly higher triglyceride, total cholesterol, acetyl-CoA carboxylase, and fatty acid synthase levels, but significantly lower hepatic lipase levels compared with the CK group. Liver transcriptome sequencing revealed that genes involved in fatty acid beta-oxidation (ACOX1, HADHA, EHHADH, and ACAA1) were downregulated, whereas genes related to fatty acid synthesis (SCD, FASN, and ACACA) were upregulated in LL group compared with the CK group. Comparison of the cecal microbiome showed that in hens fed an LL diet, Lactobacillus and Desulfovibrio were enriched, whereas riboflavin metabolism was suppressed. Cecal metabolites that were most significantly affected by the LL diet included several vitamins, such as riboflavin (vitamin B2), pantethine (vitamin B5 derivative), pyridoxine (vitamin B6), and 4-pyridoxic acid. Conclusion: A lipid metabolism disorder due to deficiencies of vitamin B2 and pantethine originating from the metabolism of the cecal microbiome may be the underlying reason for fat accumulation in the liver of late-phase laying hens fed an LL diet. Based on the present study, we propose that targeting vitamin B2 and pantethine (vitamin B5 derivative) might be an effective strategy for improving lipid metabolism in late-phase laying hens fed a low-protein diet. [ABSTRACT FROM AUTHOR]

Developmental plasticity allows organisms to increase the fit between their phenotype and their early-life environment. The extent to which such plasticity also enhances adult fitness is not well understood, however, particularly when early-life and adult environments differ substantially. Using a cross-factorial design that manipulated diet at two life stages, we examined predictions of major hypotheses—silver spoon, environmental matching, and thrifty phenotype—concerning the joint impacts of early-life and adult diets on adult morphology/display traits, survival, and reproductive allocation. Overall, results aligned with the silver spoon hypothesis, which makes several predictions based on the premise that development in poor-quality environments constrains adult performance. Males reared and bred on a low-protein diet had lower adult survivorship than other male treatment groups; females' survivorship was higher than males' and not impacted by early diet. Measures of allocation to reproduction primarily reflected breeding diet, but where natal diet impacted reproduction, results supported the silver spoon. Both sexes showed reduced expression of display traits when reared on a low-protein diet. Results accord with other studies in supporting the relevance of the silver spoon hypothesis to birds and point to significant ramifications of sex differences in early-life viability selection on the applicability/strength of silver spoon effects. [ABSTRACT FROM AUTHOR]

Lowering dietary protein content is a promising strategy to reduce N excretions in cattle but it requires improved N utilization by the animal. Feed enzymes (e.g., exogenous α-amylase) and plant extracts (e.g., essential oils [EO]) are 2 additives that may enhance rumen function and possibly also microbial protein yield. This may increase fat- and protein-corrected milk yield (MY) and milk nitrogen efficiency and thus lower N losses from dairy cows. Both types of additives were studied in an experiment including 39 Holstein cows that had (average ± SD) 40.7 ± 7.95 kg/d MY, 89 ± 43 DIM, 2.7 ± 1.5 lactations, and 677 ± 68.6 kg of BW, consisting of a covariate (4 wk) and treatment period (5 wk). During the whole experiment cows were fed a typical Benelux diet (CTRL), supplemented with concentrates to meet individual requirements for energy and MP, which were fulfilled for 100% and 101%, respectively. The total diet was low in CP (15.5%) and relatively high in starch (22.6% and 6.6% rumen bypass starch). Cows were balanced for parity, DIM, MY, and roughage intake and randomly assigned to one of 3 groups, which received the following treatments in the treatment period: (1) CTRL (n = 13); (2) CTRL + 14 g/cow per day Ronozyme RumiStar α-amylase enzyme (AMEZ, n = 13; DSM); and (3) CTRL + 2.5 g/cow per day Crina Protect, a blend of EO components (ESOL, n = 13; DSM). Animal performance, ruminal pH, and enteric gas emissions were monitored throughout the experiment. During the last week of the covariate and treatment periods, nitrogen balances were conducted, total-tract nutrient digestibility was determined, and urinary allantoin and uric acid were determined as indicators for microbial N production. The statistical model applied to these variables contained group and DIM during treatment period as fixed effects and the values from the covariate period as covariate. Post hoc Dunnet-corrected comparisons between each treatment group and the control group were explored. The α-amylase enzyme tended to increase apparent total-tract starch digestibility and increased milk lactose concentration. The EO blend tended to increase MY and increased milk N output, milk nitrogen efficiency, and feed efficiency. Therefore, when feeding reduced dietary protein levels, EO have potential to improve the N-use efficiency in cattle, whereas the α-amylase enzyme might increase starch digestibility and milk lactose. However, additional research is necessary to substantiate our findings. [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 serious shortage of protein feed resources and greenhouse gases emissions from livestock production system have become two major bottlenecks restricting the high-quality and sustainable devel‐ opment of animal husbandry in China. Low-protein diet technology is based on the precise nutrient re‐ quirement of animals to achieve stable or improved production performance by lowering the feed cost. Methane is an inevitable product of ruminant physiological metabolism, representing not only an impor‐ tant energy loss, but also a critical source of greenhouse gas emissions. In recent years, the research on the effect of low-protein diet on production performance, enteric methane emissions of ruminants have increasingly become an important area. Therefore, this paper briefly summarized the definition and characteristics of low-protein diet used for ruminants in recent years, and reviewed the impact of low-protein diet on growth performance, milk pro‐ duction, and enteric methane emissions, and explored the possible mechanism of action behind the low-protein diet to provide theoretical reference for the research and application of this technology in ruminant production regimes [ABSTRACT FROM AUTHOR]

Simple Summary: Tryptophan plays an important role in the pig industry but has the potential to improve performance in the poultry industry. However, the effects of tryptophan in a diet of different protein levels remain poorly understood. This study assessed the effect of tryptophan supplementation in diets with different protein levels on the growth performance and serum glycolipid metabolism-related parameters of broilers. A medium-protein diet with more tryptophan can improve male broiler performance; a low-protein diet with more tryptophan may temporarily reduce the feed intake of female broilers in the early stage of the experiment. Tryptophan plays an important role in the pig industry but has the potential to improve performance in the poultry industry. The purpose of this study was to examine the effects of tryptophan supplementation in diets with different protein levels on the feed intake, average daily gain (ADG), and feed conversion ratio (F/G) of broilers. A total of 180 twenty-one-day-old broilers (half male and half female) were weighed and randomly allocated to twelve groups, with six male and six female groups. Each group consisted of 15 broilers. The broilers were fed low- (17.2%), medium- (19.2%), or high- (21.2%) protein diets with or without extra tryptophan (up to 0.25%) during the 28-day experiment. Food intake and body weight were measured weekly during the trial period. Male broilers fed a medium-protein diet containing more tryptophan showed a lower F/G. In the low-protein diet groups, additional tryptophan caused a significant reduction in the feed intake of female broilers during the first two weeks. Moreover, the serum GLP-1, cholesterol, and bile acid levels, as well as the expression of FXR mRNA in the ileum, were significantly increased. Additionally, the FXR mRNA in the hypothalamus and the GCG and GLP-1R mRNAs in the ileum tended to increase in these broilers. In summary, the tryptophan concentration in the diet can influence the feed intake and metabolism of broilers. Under a standard diet, an appropriate amount of tryptophan is beneficial to the F/G of male broilers, while under a low-protein diet, tryptophan supplementation may cause a short-term reduction in the feed intake of female broilers by increasing serum GLP-1 and bile acid signals. [ABSTRACT FROM AUTHOR]

The regulation of the circadian clock plays an important role in influencing physiological conditions. While it is reported that the timing and quantity of energy intake impact circadian regulation, the underlying mechanisms remain unclear. This study investigated the impact of dietary protein intake on peripheral clocks. Firstly, transcriptomic analysis was conducted to investigate molecular targets of low-protein intake. Secondly, mPer2::Luc knock-in mice, fed with either a low-protein, normal, or high-protein diet for 6 weeks, were analyzed for the oscillation of PER2 expression in peripheral tissues and for the expression profiles of circadian and metabolic genes. Lastly, the candidate pathway identified by the in vivo analysis was validated using AML12 cells. As a result, using transcriptomic analysis, we found that the low-protein diet hardly altered the circadian rhythm in the central clock. In animal experiments, expression levels and period lengths of PER2 were different in peripheral tissues depending on dietary protein intake; moreover, mRNA levels of clock-controlled genes and endoplasmic reticulum (ER) stress genes were affected by dietary protein intake. Induction of ER stress in AML12 cells caused an increased amplitude of Clock and Bmal1 and an advanced peak phase of Per2. This result shows that the intake of different dietary protein ratios causes an alteration of the circadian rhythm, especially in the peripheral clock of mice. Dietary protein intake modifies the oscillation of ER stress genes, which may play key roles in the regulation of the circadian clock. [ABSTRACT FROM AUTHOR]

Background: In the poultry industry, additives are used to stimulate growth, improve production performance, and improve the health of the flock. On the other hand, reducing the quality of food items and their protein level, as well as the high level of anti-nutritional substances, disturbs the balance of the microbial ecosystem of the digestive system of birds and health and ultimately reduces their performance. The health and nutritional status of poultry is largely dependent on the microbial flora of the digestive system, which directly and indirectly affects the morphology of the digestive system, nutrition, and immune system. The microbial flora of the intestine is relatively unstable and is easily affected by various nutritional factors. Therefore, this research aimed to investigate the effect of the simultaneous use of organic acids and prebiotics in diets containing low-quality soybean meal on the performance of laying hens. Methods: This experiment was conducted using a completely randomized design in a 2 x 2 factorial arrangement using two levels of mixed organic acids and prebiotics and two types of soybean meal in the diet of laying hens. Chickens were distributed among pens based on weight and production rates for 2 weeks. Then, 192 laying hens of the LSL strain at the end of 73 weeks of age, after weighing and entering the wing number, were placed in 48 experimental cages, including four treatments with 12 replications, and fed for 12 weeks. Experimental treatments were treatment I (without the combination of organic acids and probiotics and containing 42% protein soy), treatment II (without the combination of organic acids and probiotics and containing 38% protein soy), treatment III (the combination of organic acids and probiotics and containing 42% protein soy), and treatment IV (a combination of organic acids and probiotics with 38% protein soy). To add the combination of organic acids and prebiotics, organic acid was used at a level of 1 kg per ton. The composition of the product included 30% propionic acid, 10% butyric acid, and 15% acetate plus 20% prebiotic with the origin of the Saccharomyces cerevisiae yeast cell wall. Performance traits, including production percentage and egg weight, egg mass weight, and feed conversion ratio (FCR) were measured at the end of the experiment (age 85 weeks) when all the birds were killed using the cervical vertebrae displacement method. The abdominal fat response of the immune system, histomorphology of the small intestine, and microbial population of the cecum were the investigated parameters. Results: Except for the first week of the experiment, the addition of the combination of organic acids and probiotics and the use of high-quality soybean meal in the diet significantly increased the egg-laying percentage during the rest of the experiment (p < 0.01). In the first 4 weeks of the experiment (weeks 75-78), the percentage of egg production was under the significant influence of the interaction effects of the experimental factors. The treatment with organic acids plus prebiotics and high-quality soybean meal (treatment 3) presented the highest egg production rate (p< 0.05). From the second week to the end of the experiment, the consumption of diets containing the combination of organic acids and probiotics and high-quality soybean meal significantly increased the weight of the produced eggs (p< 0.05). The interaction effects of experimental treatments during the experimental period did not show a constant trend in the weight of produced eggs (p≥ 0.05). Adding the combination of organic acids and probiotics to the diet elevated egg mass in the entire experimental period, the difference of which was significant (p< 0.05). The use of soybean meal with low-protein soybean meal in the diet during the experimental period decreased the weight of the egg mass compared to the group consuming the diet containing high- quality soybean meal (p< 0.05). Adding the combination of organic acids and probiotics and the use of high-quality soybean meal in the diet of the studied laying hens improved the FCR during the test period (p< 0.05). The FCR in the first 5 weeks of the experiment was under the interaction effects of the experimental factors (p < 0.05). Abdominal fat at the beginning (age 73 weeks) and the end of the experiment (age 85 weeks) did not show significant differences between different treatments (p≥ 0.05). Cellular immune response to DNCB injection significantly increased using the organic acids and prebiotic mixture and decreased with the presence of low-protein soybean meal in the diet (p < 0.05). The microbial population of the cecum changed significantly under the influence of the interaction effects of the mixture of organic acids and prebiotics and the quality of the feed soup (p < 0.05). The use of a mixture of organic acids and prebiotics caused a significant increase in the height of the duodenal villi (p< 0.05). The presence of low-protein soybean meal in the diet significantly elevated the depth of crypts (p< 0.05). The ratio of villus height to crypt depth changed under the significant influence of the interaction effects of the experimental factors. The highest ratio was recorded in the treatment with a mixture of organic acids and prebiotics and high-quality soybeans in the diet while the lowest ratio was measured in the treatment without a mixture of organic acids and prebiotics and low-protein soybeans in the diet (p< 0.05). The width of the duodenal villi did not change under the influence of experimental factors, with no significant differences (p≥ 0.05). Conclusion: In general, the results showed that using a combination of organic acids and probiotics in the diet of laying hens improved their productive performance and the health of their digestive system, as well as the performance of chickens fed with low-protein soybean meal. [ABSTRACT FROM AUTHOR]

The intensive raising model for meat duck production has widely adopted cascading cages. However, investigations on low-protein diets for Pekin ducks under this model are scarce. Thus, a 3 × 6 factorial experiment was conducted using six dietary crude protein (CP) levels (17.61%, 16.25%, 15.34%, 14.55%, 13.38%, and 12.64%, analyzed) and three cage layers (lower, middle, and upper). The study aimed to examine the effects of dietary CP reduction with crystalline amino acid supplementation on growth performance, carcass traits, and apparent nutrient digestibility in growing Pekin ducks from 21 to 42 days of age housed at different cage layers. A total of 1620 21-day-old Pekin ducks were randomly divided into 18 groups, each with six replicates of 15 ducks per replicate. Ducks were distributed across different cage layers and were fed one of six experimental diets, respectively, each varying in dietary CP levels but maintaining similar dietary energy and amino acid profiles. The results showed that the reduction in dietary CP levels affected growth performance (p < 0.05), while weight gain, feed intake, and feed/gain of Pekin ducks had no difference among 17.61%, 16.25%, and 15.34% CP groups (p > 0.05). As dietary CP decreased, abdominal fat yield increased (p < 0.05), but breast and leg meat yields were unaffected (p > 0.05). CP intake, nitrogen intake, and nitrogen excretion decreased linearly (p < 0.05) with decreasing dietary CP levels, while apparent nutrient digestibility in Pekin ducks increased proportionally (p < 0.05). Additionally, body weight, weight gain, feed intake, CP intake, nitrogen intake, and nitrogen excretion of Pekin ducks decreased (p < 0.05) due to different cage layers, while carcass characteristics remained unaffected by cage layer (p > 0.05). In summary, it is feasible to reduce the dietary CP level with crystalline amino acid supplementation in growing Pekin ducks from 21 to 42 days of age housed in cascading cages, while the cage layers affected growth performance of ducks. Based on broken-line models, it was determined that the optimal dietary CP requirement for achieving maximum weight gain and feed efficiency in growing Pekin ducks is approximately 15%. [ABSTRACT FROM AUTHOR]

ObjectivesMethodsResultsDiscussionThe present study aims to evaluate the impact of early exposure to brain injury and malnutrition on episodic memory and behavior.For this, a systematic review was carried out in the Medline/Pubmed, Web of Science, Scopus, and LILACS databases with no year or language restrictions.Initially, 1759 studies were detected. After screening, 53 studies remained to be read in full. The meta-analysis demonstrated that exposure to double insults worsens episodic recognition memory but does not affect spatial memory. Early exposure to low-protein diets has been demonstrated to aggravate locomotor and masticatory sequelae. Furthermore, it reduces the weight of the soleus muscle and the muscle fibers of the masseter and digastric muscles. Early exposure to high-fat diets promotes an increase in oxidative stress and inflammation in the brain, increasing anxiety- and depression-like behavior and reducing locomotion.Epigenetic modifications were noted in the hippocampus, hypothalamus, and prefrontal cortex depending on the type of dietetic exposure in early life. These findings demonstrate the impact of the double insult on regions involved in cognitive and behavioral processes. Additional studies are essential to understand the real impact of the double insults in the critical period. [ABSTRACT FROM AUTHOR]

Dietary protein is a critical regulator of metabolic health and aging. Low protein diets are associated with healthy aging in humans, and dietary protein restriction extends the lifespan and healthspan of mice. In this study, we examined the effect of protein restriction (PR) on metabolic health and the development and progression of Alzheimer's disease (AD) in the 3xTg mouse model of AD. Here, we show that PR promotes leanness and glycemic control in 3xTg mice, specifically rescuing the glucose intolerance of 3xTg females. PR induces sex-specific alterations in circulating and brain metabolites, downregulating sphingolipid subclasses in 3xTg females. PR also reduces AD pathology and mTORC1 activity, increases autophagy, and improves the cognition of 3xTg mice. Finally, PR improves the survival of 3xTg mice. Our results suggest that PR or pharmaceutical interventions that mimic the effects of this diet may hold promise as a treatment for AD. There is growing need for ways to slow or prevent Alzheimer's disease (AD). Here, the authors demonstrate that a low protein diet can protect against metabolic dysfunction, slow AD progression, and preserve cognitive function in a mouse model of AD. [ABSTRACT FROM AUTHOR]

Low-protein diet was an important direction for the development of livestock and poultry nutrition. The feed formula for broilers based on the standard ileal amino acid digestibility (SIAAD) calculation can more accurately and reasonably reflect the digestion ability of poultry to feed protein and reduce nitrogen excretion. Therefore, using standard ileal amino acid digestibility to design a dietary formula is a prerequisite for low protein nutrition. The article reviews the recently research and the existing problems on determination of standard ileal amino acid digestibility in poultry, in order to provide a reference for establishing a database of standard ileal amino acid digestibility parameters for feed ingredients. [ABSTRACT FROM AUTHOR]

Simple Summary: The yak (Bos grunniens) is a multi-tasking grazing ruminant species playing vital roles for Tibetan nomads living in the Hindu Kush-Himalayan region and the Qinghai-Tibetan Plateau. Yaks are subjected to undernutrition in traditional pasture management systems during long winters due to inadequate forage intakes. This results in animals losing 25.7~30.2% of their live weight. Large ruminant animals have high intakes of feed and water. The utilization of dietary nitrogen efficiency of yaks is only about 25.9%, and a large amount of nitrogen is excreted in their feces and urine. Changes in nutritional measurement could improve the utilization of dietary nutrients and regulate the synthesis of proteins in yaks. Methionine and lysine are the first two limiting amino acids in a corn–soybean-meal-based diet for ruminants; therefore, we added rumen-protected methionine and lysine to low- and high-protein diets and found that the low-protein diet supplemented with rumen-protected methionine and lysine is beneficial for rumen and body health, physiological response, and metabolic status in yaks. This study investigated the effects of the dietary protein level and rumen-protected methionine and lysine (RPML) on the growth performance, rumen fermentation, and serum indexes of yaks. Thirty-six male yaks were randomly assigned to a two by three factorial experiment with two protein levels, 15.05% and 16.51%, and three RPML levels: 0% RPML; 0.05% RPMet and 0.15% RPLys; and 0.1% RPMet and 0.3% RPLys. The trial lasted for sixty days. The results showed that the low-protein diet increased the DMI and feed conversion ratio of yaks. The diet supplemented with RPML increased the activities of IGF1 and INS and nutrient digestibility. The high-protein diet decreased the rumen butyrate concentration and increased the rumen isovalerate concentration. The low-protein diet supplemented with RPML increased the rumen pH and the concentrations of total volatile fatty acids, butyrate and NH3-N; the high-protein diet supplemented with a high level of RPML decreased the rumen pH and the concentrations of isobutyrate, isovalerate, propionate and NH3-N. The low-protein diet supplemented with RPML increased the total antioxidant capacity and glutathione peroxidase activity, along with the concentrations of malondialdehyde and amino acids such as aspartic acid, lysine, cysteine, etc. In conclusion, a low-protein diet supplemented with RPML is beneficial for rumen and body health, physiological response, and metabolic status in yaks. [ABSTRACT FROM AUTHOR]

Simple Summary: Organic pig production aims to ensure high animal health and welfare standards. Despite this, diseases such as post-weaning diarrhoea may affect piglets after weaning. Given that the use of drugs is limited on organic farms, other prevention strategies, like nutritional interventions, have become a promising approach to preventing post-weaning diarrhoea. In this study, we fed the animals with three diets: high crude protein feed, low crude protein feed, and low crude protein feed supplemented with liquid whey. These diets were given to the piglets four weeks after they were weaned, and their diarrhoea incidence, health, behaviour, and intestinal microbiota composition were assessed. The results of this study showed that the diet did not affect diarrhoea incidence. However, the piglets receiving the diet supplemented with liquid whey showed increased growth as well as changes in their behavioural patterns, such as a lower percentage of negative social behaviours and drinking. In addition, there was an increase in beneficial bacteria in the intestinal microbiota of piglets fed liquid whey. These results altogether indicate that liquid whey could be a valuable supplement for pigs in organic farming, showing positive effects on some behaviour patterns, microbiota composition, and performance efficiency. Organic livestock farming is committed to high environmental and animal welfare standards, although pathologies such as post-weaning diarrhoea (PWD) may appear. The main objective of this study was to assess nutritional strategies to prevent PWD in organic piglets. A total of 134 weaned piglets were fed one of three diets: high crude protein (17.8%, HCP), low crude protein (16.8%, LCP), and low crude protein supplemented with liquid whey (LCP+W). Piglets were assessed weekly for four weeks on the following parameters: diarrhoea incidence, additional health parameters, average daily gain, and behaviour. Faecal samples were taken to analyse the intestinal microbiota composition. Data were analysed using LMM and GLMM models and Shannon and Whittaker indexes. No significant effect of diet on diarrhoea incidence was found, but the LCP+W diet increased average daily gain. Pigs fed the LCP+W diet presented a lower percentage of drinking and negative social behaviour compared with the HCP diet, and LCP pigs presented higher exploration compared with HCP. In addition, LCP+W piglets showed a higher abundance of the beneficial genus Frisingicoccus. Although liquid whey did not reduce diarrhoea incidence, the benefits found in growth, microbiota composition, and reduced negative social behaviour indicate that it could be an optimal supplement to organic diets. [ABSTRACT FROM AUTHOR]

Reducing the levels of dietary protein is an effective nutritional approach in lowering feed cost and nitrogen emissions in ruminants. The purpose of this study was to evaluate the effects of dietary Lys/Met ratio in a low protein diet (10%, dry matter basis) on the growth performance and hepatic function (antioxidant capacity, immune status, and glycolytic activity) in Tibetan lambs. Ninety two-month-old rams with an average weight of 15.37 ± 0.92 kg were randomly assigned to LP-L (dietary Lys/Met = 1:1), LP-M (dietary Lys/Met = 2:1) and LP-H (dietary Lys/Met = 3:1) treatments. The trial was conducted over 100 d, including 10 d of adaption to the diets. Hepatic phenotypes, antioxidant capacity, immune status, glycolytic activity and gene expression profiling was detected after the conclusion of the feeding trials. The results showed that the body weight was higher in the LP-L group when compared to those on the LP-M group (P < 0.05). In addition, the activities of the catalase (CAT) and glutathione peroxidase (GSH-Px) in the LP-L group were significantly increased compared with the LP-M group (P < 0.05), while the malondialdehyde (MDA) levels in LP-H group were significantly decreased (P < 0.05). Compared with LP-H group, both hepatic glycogen (P < 0.01) and lactate dehydrogenase (LDH) (P < 0.05) were significantly elevated in LP-L group. For the LP-L group, the hepatocytes were arranged radially with the central vein in the center, and hepatic plates exhibited tight arrangement. Transcriptome analysis identified 29, 179, and 129 differentially expressed genes (DEGs) between the LP-M vs. LP-L, LP-H vs. LP-M, and LP-H vs. LP-L groups, respectively (Q-values < 0.05 and |log2Fold Change| > 1). Gene Ontology (GO) and correlation analyses showed that in the LP-L group, core genes (C1QA and JUNB) enriched in oxidoreductase activity were positively correlated with antioxidant indicators, while the MYO9A core gene enriched in the immune response was positively associated with immune indicators, and core genes enriched in molecular function (PDK3 and PDP2) were positively correlated with glycolysis indicators. In summary, low-protein diet with a low Lys/Met ratio (1:1) could reduce the hepatic oxidative stress and improve the glycolytic activity by regulating the expression of related genes of Tibetan sheep. [ABSTRACT FROM AUTHOR]

Objective: This study aims to investigate the interactive effect of a glycine equivalent (Glyequi) and standardized ileal digestible threonine (SID Thr) levels in low crude protein diets on performance, blood biochemistry, pectoral muscular creatine content and oxidative stability of meat in broiler chickens from 21 to 42 days. Methods: A total of 1,500, twenty-one-day-old Cobb-Vantress male broiler chickens were distributed in a completely randomized 5×3 factorial arrangement of Glyequi×SID Thr with five replicates of 20 birds each. Fifteen dietary treatments of 16.5% CP were formulated to contain five levels of total Glyequi (1.16%, 1.26%, 1.36%, 1.46%, and 1.56%) and three levels of SID Thr (0.58%; 0.68% and 0.78%). Results: Interaction effects (p<0.05) of Glyequi and SID Thr levels were observed for weight gain, carcass yield, pectoral muscular creatine content and serum uric acid. Higher levels of Glyequi increased (p = 0.040) weight gain in 0.58% and 0.68% SID Thr diets compare to the 0.78% SID Thr diet. The SID Thr level at 0.68% improved (p = 0.040) feed conversion compared to other SID Thr diets. Levels of Glyequi equal to or above 1.26% in diets with 0.78% SID Thr resulted in birds with higher (p = 0.033) pectoral muscular creatine content. The breast meat yield observed in the 0.68% SID Thr diet was higher (p = 0.05) compared to the 0.58% SID Thr diet. There was a quadratic effect of Glyequi levels for pectoral pectoral muscular creatine content (p = 0.008), breast meat yield (p = 0.030), and serum total protein concentrations (p = 0.040), and the optimal levels were estimated to be 1.47%, 1.35%, and 1.40% Glyequi, respectively. The lowest (p = 0.050) concentration of malondialdehyde in the breast meat was found in 0.68% SID Thr diets at 1.36% Glyequi. Conclusion: The minimum dietary level of Glyequi needed to improve performance in low crude protein diets is 1.26% with adequate SID Thr levels for broiler chickens. [ABSTRACT FROM AUTHOR]

Objective To investigate how a low-protein diet during pregnancy and lactation affects the islet function in the female offspring mice, and to explore the potential mechanisms using transcriptome sequencing technology. Methods Thirty-three female C57BL/6J mice were randomly divided into two groups according to a random number table method on the day of conception and given a control diet (22% protein) (13 mice) and a low-protein diet (9% protein) (20 mice) throughout pregnancy and lactation, respectively. After weaning, all offspring were given a standard diet. The female offspring were divided into the control diet group (CD group, 20 mice) and the low protein diet group (LPD group, 20 mice) based on their maternal diet. Body weight and fasting plasma glucose (FPG) data of the female offspring were collected. Intraperitoneal glucose tolerance test (IPGTT), simultaneous serum insulin release test (IRT) and intraperitoneal insulin tolerance test (IPITT) were performed to assess the function of the offspring islets and their insulin sensitivity. Long non-cody RNA (LncRNA) from the offspring primary islets were extracted for transcriptome sequencing. The bioinformatics analysis applied between the targeted genes and the differentially expressed messenger RNA (mRNA). Experimental verification of biosignature analysis was performed using quantitative real-time PCR (qRT-PCR) and Western blotting. To verify the expression of (lactate dehydrogenase A) Ldha, a common differential gene of mRNA and LncRNA predicted target genes, we performed immunofluorescence staining on paraffin sections of pancreatic tissue. Thereafter, LncRNA Gm38850 knockdown Min6 cell model was constructed to study the effect of Gm38850 on islet function and its regulatory relationship with Ldha. Group comparisons were conducted using either independent samples t-test or corrected t-test. Results The LPD group showed impaired glucose tolerance (P<0.05) and reduced insulin release (P<0.05) at week 17 of age compared to the CD group. However, no significant differences were observed in FPG and blood glucose area under curve of IPITT. Whole transcriptome sequencing screened a total of 55 differentially expressed mRNAs (42 up-regulated and 13 down-regulated) and 4 differentially expressed LncRNA (all down-regulated) in islet cells between the two groups. The pathway enrichment analysis suggested that these differentially expressed RNAs were mainly involved in the biological functions of the pyruvate metabolism, interleukin-17 (IL-17) signaling pathway, glucagon pathway, advanced glycation end-products-receptor for advanced glycation end-products (AGE-RAGE) signaling pathway and hypoxia-inducible factor 1 (HIF-1) signaling pathway. The experimental validation results of pancreatic tissues were consistent with the trend of the biosignature analysis results. Among them, immunofluorescence staining showed that Ldha expression was up-regulated in the pancreatic islets of mice in the LPD group, and that cellular Ldha expression was up-regulated after knockdown of the LncRNA Gm38850 in Min6 cells. We also observed a significant reduction in glucose-stimulated insulin secretion in the Gm38850 knock-down cells. Conclusion A low-protein diet during pregnancy and lactation may impair islet function in the offspring female mice, possibly due to epigenetic changes in the islets. [ABSTRACT FROM AUTHOR]

Simple Summary: The first and second limiting amino acids in ruminants 66 are methionine and lysine, respectively, and an appropriate lysine-to-methionine ratio is necessary for amino acid balance in a low-protein diet. A Lys/Met ratio of 1:1 increased the antioxidant capacity and the activities of digestive enzymes and reduced the production of ammonia nitrogen in Tibetan sheep. In addition, 16S rDNA sequencing revealed that a Lys/Met ratio of 1:1 significantly increased the Ace and Chao1 indices, and non-target metabolomics analysis revealed that cis-jasmone and Val-Asp-Arg could be involved in mediating the antioxidant capacity and increasing the activity of digestive enzyme activities in Tibetan sheep rumen. Phosphoric acid, one of the metabolic products, increased cellulase activity by regulating the abundance of Succiniclasticum through the oxidative phosphorylation pathway. In ruminants, supplementing appropriate amounts of amino acids improves growth, feed utilization efficiency, and productivity. This study aimed to assess the effects of different Lys/Met ratios on the ruminal microbial community and the metabolic profiling in Tibetan sheep using 16S rDNA sequencing and non-target metabolomics. Ninety-two-month-old Tibetan rams (initial weight = 15.37 ± 0.92 kg) were divided into three groups and fed lysine/methionine (Lys/Met) of 1:1 (LP-L), 2:1 (LP-M), and 3:1 (LP-H) in low-protein diet, respectively. Results: The T-AOC, GSH-Px, and SOD were significantly higher in the LP-L group than in LP-H and LP-M groups (p < 0.05). Cellulase activity was significantly higher in the LP-L group than in the LP-H group (p < 0.05). In the fermentation parameters, acetic acid concentration was significantly higher in the LP-L group than in the LP-H group (p < 0.05). Microbial sequencing analysis showed that Ace and Chao1 indicators were significantly higher in LP-L than in LP-H and LP-M (p < 0.05). At the genus level, the abundance of Rikenellaceae RC9 gut group flora and Succiniclasticum were significantly higher in LP-L than in LP-M group (p < 0.05). Non-target metabolomics analyses revealed that the levels of phosphoric acid, pyrocatechol, hydrocinnamic acid, banzamide, l-gulono-1,4-lactone, cis-jasmone, Val-Asp-Arg, and tropinone content were higher in LP-L. However, l-citrulline and purine levels were lower in the LP-L group than in the LP-M and LP-H groups. Banzamide, cis-jasmone, and Val-Asp-Arg contents were positively correlated with the phenotypic contents, including T-AOC, SOD, and cellulase. Phosphoric acid content was positively correlated with cellulase and lipase activities. In conclusion, the Met/Lys ratio of 1:1 in low-protein diets showed superior antioxidant status and cellulase activity in the rumen by modulating the microbiota and metabolism of Tibetan sheep. [ABSTRACT FROM AUTHOR]

A long-term intake of a high-fat and high-fructose diet (HFFD), even a high-fat, high-fructose but low-protein diet (HFFD + LP), could cause obesity associated with cognitive impairments. In the present study, rats were subjected to a normal diet (ND), an HFFD diet, an HFFD + LP diet, and an HFFD with kidney bean protein (KP) diet for 8 weeks to evaluate the effect of KP on HFFD- or HFFD + LP-induced obesity and cognitive impairment. The results demonstrated that compared with the HFFD diet, KP administration significantly decreased the body weight by 7.7% and the serum Angiotensin-Converting Enzyme 2 (ACE-2) and Insulin-like Growth Factor 1 (IGF-1) levels by 14.4% and 46.8%, respectively (p < 0.05). In addition, KP suppressed HFFD-induced cognitive impairment, which was evidenced by 8.7% less time required to pass the water maze test. The 16s RNA analysis of the colonic contents showed that the relative abundance of Bifidobacterium, Butyricimonas, and Alloprevotella was increased by KP by 5.9, 44.2, and 79.2 times. Additionally, KP supplementation primarily affected the choline metabolic pathway in the liver, and the synthesis and functional pathway of neurotransmitters in the brain, thereby improving obesity and cognitive function in rats. [ABSTRACT FROM AUTHOR]

ABSTRACT: Low crude protein (CP) diets might be fed to dairy cows without affecting productivity if the balance of absorbed AA were improved, which would decrease the environmental effect of dairy farms. The aim of this study was to investigate the effects of supplementing ruminally protected Lys (RPL) and Met (RPM) at 2 levels of dietary CP on nutrient intake, milk production, milk composition, milk N efficiency (MNE), and plasma concentrations of AA in lactating Holstein cows and to evaluate these effects against the predictions of the new NASEM (2021) model. Fifteen multiparous cows were used in a replicated 3 × 3 Latin square design with 21-d periods. The 3 treatments were (1) a high-protein (HP) basal diet containing 16.4% CP (metabolizable protein [MP] balance of −130 g/d; 95% of target values), (2) a medium-protein diet containing 15% CP plus RPL (60 g/cow per day) and RPM (25 g/cow per day; MPLM; MP balance of −314 g/d; 87% of target values), and (3) a low-protein diet containing 13.6% CP plus RPL (60 g/cow per day) and RPM (25 g/cow per day; LPLM; MP balance of −479 g/d; 80% of target values). Dry matter intake was less for cows fed MPLM and LPLM diets compared with those fed the HP diet. Compared with the HP diet, the intake of CP, neutral detergent fiber, acid detergent fiber, and organic matter, but not starch, was lower for cows fed MPLM and LPLM diets. Milk production and composition were not affected by MPLM or LPLM diets relative to the HP diet. Milk urea N concentrations were reduced for the MPLM and LPLM diets compared with the HP diet, indicating that providing a low-protein diet supplemented with rumen-protected AA led to greater N efficiency. There was no significant effect of treatment on plasma AA concentrations except for proline, which significantly increased for the MPLM treatment compared with the other 2 treatments. Overall, the results supported the concept that milk performance might be maintained when feeding lactating dairy cows with low CP diets if the absorbed AA balance is maintained through RPL and RPM feeding. Further investigations are needed to evaluate responses over a longer time period with consideration of all AA rather than on the more aggregated MP and the ratio between Lys and Met.