Dietary Protein Level Research Articles

The Effects of Dietary Resveratrol and β-Hydroxy-β-Methylbutyric Acid Supplementation at Two Protein Levels on the Ruminal Microbiome and Metabolome of Tibetan Sheep

Resveratrol (RES) and β-hydroxy-β-methylbutyric acid (HMB) have antioxidant, anti-inflammatory, and other beneficial properties. Here, we hypothesize that supplementation with RES and HMB could affect the rumen function in Tibetan sheep. This study aims to explore the effects of RES and HMB supplementation at different protein levels on the rumen microbial and metabolite compositions of Tibetan sheep. Four treatments (n = 30) were prepared according to a 2 × 2 factorial arrangement, with two dietary protein levels (12% and 14%) and two feed additives (RES 1.50 g/day and HMB 1.25 g/day). The experimental treatments were fed diets with 12% CP level non-supplemented (L), 12% protein with RES and HMB (L-RES-HMB), 14% CP level non-supplemented (H), and 14% protein with RES and HMB (H-RES-HMB), respectively. Our results indicated that the trypsin, chymotrypsin, and lipase were significantly increased in the H-RES-HMB group (p < 0.05), while the lipopolysaccharide (LPS) concentration was significantly reduced (p < 0.05). The alpha diversity analysis found that the ACE indices of the L-RES-HMB, and H-RES-HMB groups was significantly higher than that of the L group (p < 0.05). Additionally, compared with the L, L-RES-HMB, and H groups, it was found that the abundance of Euryarchaeota, Spirochaeota, and Metanobrevibacter was significantly increased in the H-RES-HMB group, while the abundance of Proteobacteria was significantly decreased (p < 0.05). A total of 745 significantly different metabolites were identified, of which 14 metabolites were common among the three comparative groups. Differential metabolites were mainly enriched in pathways including the pyrimidine metabolism, the glycine, serine, and threonine metabolisms, and ABC transporters. Overall, CP level and RES/HMB exhibited positively interaction effect on digestive enzyme activity and antioxidant capacity. Dietary RES and HMB supplementation on 14% CP level improved the ruminal digestive enzyme activity and antioxidant capacity through modulating the microbial community and regulating the metabolism.

Energy and protein levels in dairy cow diets to recover milk ethanol stability

The objective of this study was to evaluate the effect of energy and protein in the diet on the recovery of milk ethanol stability (MES) induced by feed restriction. Twelve Holstein and Holstein x Jersey crossbred cows with an average of 146 ± 50 d in milk, 575.4 ± 70 kg of body weight, and 18.93 ± 5.46 kg/d of milk yield were distributed in a 3x3 Latin square design with 3 treatments and 3 experimental periods. Each experimental period lasted 24 d, comprising 3 phases: a 13-d adaptation phase (100E+100P), a 4-d induction phase for milk ethanol instability (50E+50P), and a 7-d recovery phase for MES (3 treatments). The 3 treatments during the recovery phase consisted of 3 diets aiming to meet the requirements of energy and protein (100E+100P), only energy (100E+50P), or only protein (50E+100P). The diet during the adaptation and induction phases was common for all cows. The energy and protein levels to meet each cow's requirements were based on the group average. Restriction of energy and protein reduced dry matter, crude protein, and total digestive nutrient intake for cows fed 100E+50P and 50E+100P. The lowest body weight was observed for cows fed 50E+100P, with no difference for body condition score. During the induction phase, MES "was" reduced by 9 percentage units. Cows fed 100E+100P recovered MES in the first days of the recovery phase, while 100E+50P slightly improved MES, and 50E+100P had a constant decrease in MES. Cows fed 100E+50P and 50E+100P produced, respectively, 3.6 and 5.9 kg less milk than those fed 100E+100P. The 50E+100P treatment exhibited the highest milk fat content and somatic cell score, along with the lowest milk lactose content. Protein content was higher in the 100E+100P treatment. Cows fed 50E+100P showed higher serum albumin levels compared with those on the 100E+100P treatment, not differing from the 100E+50P treatment. We concluded that the complete recovery of MES in cows with feed restrictions is possible only by supplying both the energy and protein requirements in the cows' diet. However, restricting energy intake poses a greater limitation on MES recovery compared with restricting protein.

Effects of Dietary Protein Level and Rumen-Protected Methionine and Lysine on Growth Performance, Rumen Fermentation and Serum Indexes for 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.

Effect of supplementing lysins and methionine to low-protein diets on growth performance, hepatic antioxidant capacity, immune status, and glycolytic activity of tibetan sheep

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.

Nutritional synergy: optimizing growth in Siruvidai chicken via diverse dietary energy and protein strategies and gene expression analysis - brooder phase.

Nutrient supply regulates overall body growth directly or indirectly through its influence on regulatory factors optimizing nutrient requirements becomes crucial before embarking on genetic improvements. Hence this study addresses this gap by evaluating the effect of feeding varying energy and crude protein levels on growth performance and gene expression related to the growth of indigenous Siruvidai chicken from 0 to 12 weeks. A 360-day-old straight-run Siruvidai chick were randomly distributed into six experimental groups with three replicates of each 20 chicks. The birds were fed corn-soy-based diets formulated with two levels of energy (2500 and 2700kcal ME/kg) each with three levels of crude protein (16, 18, and 20%) during the brooder stage (0-12 weeks) in 2 × 3 factorial design. Results revealed that there was no significant effect on the energy and protein interaction levels on average feed intake, body weight gain and feed conversion ratio in Siruvidai chicken at 12 weeks. The results showed significantly (P < 0.05) lower feed intake in 18% protein fed groups and significantly (P < 0.01) lower feed intake in higher energy 2700kcal ME/kg fed groups. A better feed conversion ratio (4.06 and 4.21) was observed on the effect of protein levels in bird diets with 18% and 20% protein fed groups. The Growth Hormone (GH) and Myostatin (MSTN) gene expression were significantly (P < 0.01) higher in 16% CP and 2500kcal ME/kg in hepatic tissue. The high protein and low energy diet up-regulated the Insulin-like Growth Factor-1 (IGF-1) gene expression in hepatic tissue. The study concluded that Siruvidai chicken fed with 18% crude protein and 2500kcal ME/kg is optimum for 0-12 weeks of age.

Effect of dietary protein levels and age on growth performance, total excreta and nitrogen balance of laying hens during the growing phase

Effect of dietary protein levels and age on growth performance, total excreta and nitrogen balance of laying hens during the growing phase

Exploring the Nutritional and Sensorial Enhancement of Traditional Indian Laddu through Flaxseed Fortification

Abstract: The purpose of the current study was to cultivate laddu by adding different amounts of flaxseed. to evaluate laddu, including its microbiological, tactile, and textural qualities, as well as its chemical and fatty acid composition and antioxidant activity. The primary objective of this research endeavor was to explore the potential enhancement of laddu, a traditional Indian sweet, through the incorporation of varied proportions of flaxseed. This exploration encompassed a multifaceted evaluation, including microbiological scrutiny, tactile discernment, textural analysis, chemical profiling, fatty acid characterization, and assessment of antioxidant potency. The procedural standardization entailed the utilization of sesame seeds, jaggery, and whole flaxseed in the formulation of Nutra Laddu. Distinct formulations denoted as T1, T2, T3, T4 were devised, featuring incremental adjustments in the proportion of whole flaxseed, ranging from 0% to 50%. Subsequent to the preparation process, the laddu specimens underwent meticulous evaluation of their organoleptic attributes, encompassing considerations such as color and visual appeal, flavor profile, textural attributes, taste perception, and overall palatability. This comprehensive assessment was facilitated through the application of a 9-point hedonic scale, enabling nuanced appraisal. Furthermore, it emerged from the analysis that Nutra Laddu fortified with flaxseed presents a notable nutritional profile, characterized by heightened levels of dietary fiber and protein. This underscores the potential of flaxseed as a valuable adjunct in laddu formulation, given its recognized nutritional and therapeutic attributes.

High protein requirements of juvenile Atlantic wolffish, Anarhichas lupus: Effects of dietary protein levels on growth, health, and welfare.

The objective of the present study was to investigate the optimal dietary protein requirement and the effect of varying protein levels on the growth and health of juvenile, wild-caught Atlantic wolffish, Anarhichas lupus, a promising candidate for cold-water aquaculture diversification. Six iso-energetic (ca. 18.3 MJ kg-1), fish meal-based experimental diets were formulated with crude protein levels ranging from 35% to 60%, with graded increments of 5% in a 12-week feeding trial in a recirculating aquaculture system (RAS). Weight gain, specific growth rate (SGR), and condition factor (K) were evaluated in response to dietary protein levels. Liver, muscle, and blood parameters were assessed for possible changes in protein and lipid metabolism and welfare. Overall growth was highly variable throughout the experiment on all diets, as expected for a wild population. The feed with highest in protein (60%) inclusion resulted in the highest growth rates, with an average weight gain of 37.4% ± 33.8% and an SGR of 0.31% ± 0.2% day-1. This was closely followed by feeds with 55% and 50% protein inclusion with an average weight gain of 22.9% ± 34.8% and 28.5% ± 38.3%, respectively, and an SGR of 0.18% ± 0.3% day-1 and 0.22% ± 0.3% day-1, respectively. Fish fed the high protein diets generally had increased hepatic lipid deposition (17%-18%) and reduced free fatty acid levels (3.1-6.8 μmol L-1) in the plasma relative to fish that were fed the lower protein diets (35%-45%). No effects of diet were found on plasma protein levels or muscle protein content. Furthermore, stress parameters such as plasma cortisol and glucose levels were unaffected by diet, as were plasma ghrelin levels. Overall, these results suggest that a high protein inclusion in the diet for Atlantic wolffish is required to sustain growth with a minimum protein level of 50%.

Impact of dietary protein and energy levels on fatty acid profile, gut microbiome and cecal metabolome in native growing chickens

The present study investigated the optimal concentration of dietary ME and CP for the fatty acid profile of meat, gut microbiome, and cecal metabolome in Danzhou chickens from 120 to 150 d of age. A total of seven hundred and twenty 120-d-old Danzhou female chickens, with a similar BW, were randomly allocated into 6 treatments with 6 replicates and each of 20 birds. The chickens were fed 2 levels of dietary ME (11.70 MJ/kg, 12.50 MJ/kg), and 3 levels of dietary CP (13%, 14%, and 15%). The results showed that dietary ME and CP levels didn't affect final BW, ADG, ADFI, and feed gain ratio (g: g) (P > 0.05). The serum concentrations of triglyceride, insulin, and glucose in the 12.50 MJ/kg group were the highest (P < 0.05). Dietary ME, CP levels, and their interactions affected (P < 0.05) the fatty acid content in the breast muscle, thigh muscle, and liver. The levels of C18:0, C20:0, C22:0, C22:1, C18:2, C18:3, C22:6, and SFA of the liver in the high ME group were higher than those in the low ME group (P < 0.05). The levels of C16:0, C14:1, C18:1, C22:5, SFA, MUFA and USFA in the low CP group were higher than the corresponding values in the other groups (P < 0.05). Dietary ME and CP levels altered the composition and relative abundance of microbiota in the cecum of chickens at various taxonomic levels to different extents. Significant effects of interactions were found between dietary ME and CP on the relative abundance of 10 species (P < 0.05), and among these species, 6 species belonged to the genus Bacteroides. Notably, the relative abundance of 2 probiotic species including Lactobacillus crispatus and Lactobacillus salivarius was significantly increased (P < 0.05) with increasing dietary ME level. There were 6 differential metabolites in the cecum, comprising thromboxane A2, 5,6-DHET, prostaglandin D2, 20-hydroxyeicosatetraenoic acid, 12(S)-HPETE and prostaglandin I2 significantly reduced (P < 0.05) with increasing the dietary ME level; all of them are involved in arachidonic acid metabolism. In conclusion, the present study suggested that the dietary levels of 12.50 MJ/kg ME and 14% CP enhanced meat quality in terms of fatty acid composition, and showed benefits for maintaining intestinal health via positive regulation of cecal microbiota in native growing Danzhou chickens.

Efficacy of maize differing in particle size in low-density protein diets fed to broilers from day 1 to 21 of age

ABSTRACT 1. This study evaluated the efficacy of maize differing in particle size in low-density protein diets on performance, the digestive tract and litter characteristics in broilers. Four dietary treatments; control commercial diet with a typical crude protein content 22.50% (CON); CON + 20% maize with particle size 350 µm (M350), crude protein 19.90%; CON + 20% maize with particle size 2600 µm (M2600), crude protein 19.90%; CON + 20% whole maize (WM), crude protein 19.90%, were fed ad libitum to broiler chicks up to 21 d of age. 2. No differences in body weight gain, feed intake and FCR were found between the WM and CON. WM increased body weight gain compared to M350 and M2600. M350, M2600 and WM increased (p = 0.004) gizzard relative weight compared with CON on day 14. Both WM and M2600 reduced (p = 0.001) gastric isthmus diameter on d 14 and 21 compared with CON and M350. 3. No differences were seen in mucosa for the Lamina propria and the extent of Tunica muscularis of gizzard on d 21 and ileum mucosal depth on d 14 between WM and CON diets. However, WM reduced villus-to-crypt ratio compared with CON on d 21. The M350 reduced (p < 0.05) gizzard digesta particle size compared with CON, M2600 and WM on d 14. 4. Both WM and M350 decreased (p < 0.05) nitrogen excretion compared to birds fed CON. Feeding WM increased nitrogen efficiency compared with M350 and M2600 diets, but was similar to birds fed CON. Feeding M350, M2600 or WM decreased (p < 0.05) litter moisture and footpad dermatitis (FPD) scores compared with results from birds fed CON. 5. Overall, diluting the protein level in broiler diets with whole maize appeared better than fine or coarse maize in terms of growth performance, digestive tract development, nitrogen excretion and litter parameters. This may lead to economic benefits by reducing grinding costs and dependence on rich protein resources contributing to sustainable meat production and food security.

#2106 Higher daily protein intake can reduce the risk of infections in kidney transplant recipients during the early post-transplant period

Abstract Background and Aims Kidney transplantation (KT) is considered the most effective treatment for end-stage renal disease (ESRD), and it significantly contributes to enhancing the quality of life and extending the survival of patients with ESRD. After kidney transplantation, the early and heavy use of immunosuppressants and glucocorticoids can affect the recipients' immune status to varying degrees, increasing the risk of postoperative infections caused by a wide range of pathogens. Thus, the prevention and management of infectious diseases are major factors contributing to improved outcomes in kidney transplantation. Protein-energy wasting (PEW) is commonly observed in uremic patients, and it may persist even after they have undergone kidney transplantation (KT). And PEW is a significant factor in the progression of chronic kidney disease (CKD). Providing appropriate dietary guidance and intervention is essential for enhancing the immune status of recipients, promoting a positive nitrogen balance in the body, minimizing infections, and safeguarding graft function. This study aimed to investigate the relationship between daily protein intake (DPI) and postoperative infections at 3 months post-transplant, which may establish a foundation for the early postoperative protein intake regimen, reducing the incidence of postoperative infections, and improving the early prognosis of kidney transplantation. Method This is a retrospective observational study. 176 kidney transplant recipients (KTRs) who underwent kidney transplant in West China Hospital from December 2021 to June 2022 were included and followed up regularly. 24-hour urine urea data were collected at months 1 and 3 post-transplant to calculate their DPI. These KTRs were further divided into two groups according to the recommended DPI for KTRs by the 2021 Practice Guidelines for the Nutritional Management of Chronic Kidney Disease, namely high intake group (Group 1, with DPI ≥ 1.4 g/kg·d, n = 66) and low intake group (Group 2, with DPI &amp;lt; 1.4 g/kg·d, n = 110). Occurrence of hospitalization and postoperative infections within 3 months were recorded. Multiple logistic regression was utilized to analyze the association between DPI and early postoperative infections at 3 months post-transplant. Results Mean DPI levels at month 1 post-transplant were 1.58 ± 0.22 g/kg·d in Group 1 and 1.02 ± 0.31 g/kg·d in Group 2, respectively (P &amp;lt; 0.05), this huge difference in DPI between the two groups continued to month 3. There was no significant difference in age, gender, pre-transplant body mass index (BMI), dialysis type and time, donor type, or the ratio of delayed graft function (DGF) between the two groups. There was a statistically significant difference in the percentage of hospitalization between the two groups during the postoperative period of 3 months (P = 0.027). Pneumonia was the most common reason of hospitalization after transplantation, followed by urinary tract infection. The results of multiple logistic regression analysis showed that higher DPI in the early post-transplant period was a protective factor for infection after kidney transplantation. Conclusion In the early post-transplant period, consuming higher levels of dietary protein may reduce the risk of infections and complications, and help preserve the function of the transplanted kidney.

#2736 Higher daily protein intake can reduce the risk of infections in kidney transplant recipients during the early post-transplant period

Abstract Background and Aims Kidney transplantation (KT) is considered the most effective treatment for end-stage renal disease (ESRD), and it significantly contributes to enhancing the quality of life and extending the survival of patients with ESRD. After kidney transplantation, the early and heavy use of immunosuppressants and glucocorticoids can affect the recipients' immune status to varying degrees, increasing the risk of postoperative infections caused by a wide range of pathogens. Thus, the prevention and management of infectious diseases are major factors contributing to improved outcomes in kidney transplantation. Protein-energy wasting (PEW) is commonly observed in uremic patients, and it may persist even after they have undergone kidney transplantation (KT). And PEW is a significant factor in the progression of chronic kidney disease (CKD). Providing appropriate dietary guidance and intervention is essential for enhancing the immune status of recipients, promoting a positive nitrogen balance in the body, minimizing infections, and safeguarding graft function. This study aimed to investigate the relationship between daily protein intake (DPI) and postoperative infections at 3 months post-transplant, which may establish a foundation for the early postoperative protein intake regimen, reducing the incidence of postoperative infections, and improving the early prognosis of kidney transplantation. Method This is a retrospective observational study. 176 kidney transplant recipients (KTRs) who underwent kidney transplant in West China Hospital from December 2021 to June 2022 were included and followed up regularly. 24-hour urine urea data were collected at month 3 post-transplant to calculate their DPI. These KTRs were further divided into two groups according to the recommended DPI for KTRs by the 2021 Practice Guidelines for the Nutritional Management of Chronic Kidney Disease, namely high intake group (Group 1, with DPI ≥ 1.4 g/kg·d, n = 66) and low intake group (Group 2, with DPI &amp;lt; 1.4 g/kg·d, n = 110). Occurrence of postoperative infections events within 3 months were recorded. Multiple logistic regression was utilized to analyze the association between DPI and early postoperative infections at 3 months post-transplant. Results Mean DPI levels at month 3 post-transplant were 1.75 ± 0.56 g/kg·d in Group 1 and 0.98 ± 0.24 g/kg·d in Group 2, respectively. There was no significant difference in age, gender, pre-transplant body mass index (BMI), dialysis type and time, donor type, or the ratio of delayed graft function (DGF) between the two groups. There was a statistically significant difference in the percentage of hospitalization for infections between the two groups during the postoperative period of 3 months (P = 0.027). Pneumonia was the most common reason of rehospitalization after transplantation, followed by urinary tract infection. The results of multiple logistic regression analysis showed that higher DPI in the early post-transplant period was a protective factor for infection after kidney transplantation. Conclusion In the early post-transplant period, consuming higher levels of dietary protein can reduce the risk of infections and complications, and help preserve the function of the transplanted kidney.

Intestinal health of squab pigeons responded to parental dietary protein levels during breeding period

The objective of this study was to determine the effects of dietary crude protein (CP) levels on intestinal antioxidant status, tight junction proteins expression, and amino acids transporters levels in squabs. A total of 180 pairs of White King parent pigeons approximately 10 mo old were randomly assigned to 5 groups with 6 replications of 6 pairs of parental pigeons each, and were fed with 14, 15, 16, 17, and 18% CP diets for 46 d, respectively. Dietary increasing CP levels increased final body weight (linear and quadratic, P < 0.05), serum urea nitrogen (linear, P<0.05) and triglyceride levels (quadratic, P < 0.05), and reduced kidney relative weight (quadratic, P < 0.05) in squabs. Final body weight of squabs in the 18% CP diet group was higher than that of the 14, 15, and 16% CP diet groups (P < 0.05) but was similar to that of the 17% CP diet group (P > 0.05). Increasing dietary CP levels reduced intestinal malondialdehyde contents (linear and quadratic, P < 0.05) and jejunal total superoxide dismutase (T-SOD) activity (linear, P < 0.05), and enhanced (linear and quadratic, P<0.05) ileal catalase and T-SOD activities in squabs, and these effects were more prominent in the 17% CP diet group. Graded CP levels up-regulated the mRNA expression of intestinal zonula occludens 1 (linear, P < 0.05), solute carrier family 7 members 9 (linear, P < 0.05) and claudin 1 (CLDN1, linear and quadratic, P < 0.05), ileal CLDN3 and solute carrier family 6 members 14 (linear, P < 0.05) but lowered jejunal solute carrier family 6 member 14 (quadratic, P<0.05) mRNA expression in squabs. The effects of dietary CP levels on intestinal tight junction proteins expression were more apparent when its supplemental levels were 18%. These results suggested that increasing parental dietary CP levels ranged from 14 to 18% during breeding period improved growth and intestinal function of squabs, with its recommended level being 17%.

Use of a mixture design to optimize dietary macronutrients for large turbot (Scophthalmus maximus Linnaeus, 1758)

Aim of study: Studies on the dietary needs of turbot fish (Scophthalmus maximus Linnaeus, 1758) have largely focused on the juvenile stage; however, there are not many on the larger (300–500 g) species. The purpose of this experiment was to determine the ideal dietary levels of protein, fat, and carbohydrate for large turbot. Area of study: Demre, Antalya, Türkiye. Material and methods: A three-component mixture design model was created to adjust the quantities of dietary protein between 45.6% and 63.4%, carbohydrates between 4.9% and 30.5%, and fat between 5.6% and 17.7%. The components of the model were fish meal (FM), fish oil (FO), and wheat flour (W). Fish initially weighing 301.6±0.1 g on average were fed 14 different diets for 10 weeks. The ideal dietary macronutrient levels were estimated by examining the prediction profiler at the highest desirability based on the variables that were selected to maximize final weight, daily growth coefficient, protein efficiency ratio, nitrogen and energy retentions, and minimize feed conversion ratio, nitrogen and carbon losses. Main results: The optimal diet formulation yielded the highest desirability of 0.87 for all selected responses and resulted in dietary inclusion levels of FM, W and FO as 63.6%, 20.8%, and 9.4%, respectively. The proposed optimal nutrient concentrations for large turbot (growing from 300 to 500 g) are 54% protein, approximately 17% lipid, and 15.8% carbohydrate on dry matter basis. Research highlights: The mixture design successfully allowed us to estimate the optimum levels of dietary protein, lipid and carbohydrate for large turbot.

Unleashing the potential of millets: a comprehensive review of its nutritional, therapeutic, and genomic attributes

Millets are cereal grains whose farming dates back thousands of years and have been farmed and consumed by a wide variety of cultures around the world. In recent times, there has been a growing interest in millets due to their medicinal characteristics and nutritional advantages. Millets have a substantial nutritional content and can provide a wide range of beneficial health effects. These foods have a relatively low glycemic index in addition to their high levels of dietary fiber, proteins, vitamins, and minerals. In this review, the most recent information regarding the potential effects of millets on the management of diabetes, the health of the heart, antioxidant activity, anti-cancer capacities, and other therapeutic benefits is investigated. In addition, the report provides an in-depth analysis of the current genome resources that are associated with millets, as well as a summary of the key genetic discoveries that have been made. The report also emphasizes the need for further research to maximize the potential of millets through the utilization of genetic resources and breeding techniques to develop high-nutrient-rich and climate-resilient varieties.

Dietary Protein Optimization for Growth and Immune Enhancement in Juvenile Hybrid Sturgeon (Acipenser baerii × A. schrenckii): Balancing Growth Performance, Serum Biochemistry, and Expression of Immune-Related Genes.

This study aimed to evaluate the effects of dietary protein levels on growth performance, serum indices, body amino acid composition, and intestinal gene expression in juvenile hybrid sturgeon (Acipenser baerii × A. schrenckii). Hybrid sturgeons (initial weight 29.21 ± 2.04 g) were fed isolipidic diets containing 30%, 33%, 36%, 39%, 42% or 45% crude protein for 12 weeks (n = 18 tanks, 30 fish/tank). Results showed significant differences between treatments, where weight gain and protein efficiency ratio peaked optimally between 35.9% and 38.3% dietary protein. Serum parameters such as glucose, alanine aminotransferase, aspartate aminotransferase, superoxide dismutase, and lipid peroxidation levels varied significantly with changes in dietary protein levels. Specifically, the highest enzymatic activities and growth parameters were observed in groups fed with 33% to 39% protein, enhancing whole-body concentrations of lysine, leucine, phenylalanine, proline, and glutamic acid. Immune parameters such as immunoglobulin M and lysozyme activity also showed peak levels at higher protein concentrations, particularly notable at 42% for lysozyme and 36% for both component 3 and immunoglobulin M. Gene expression related to immune and growth pathways, including MyD88, TLR1, IL-8, IL-6, NF-κB, and IL1β, was significantly upregulated at protein levels of 33% to 36%, with a noted peak in expression at 39% for TLR1, IL-10, and TOR signaling genes, before diminishing at higher protein levels. Overall, the dietary protein requirement for juvenile hybrid sturgeon ranges from 35.9% to 38.3% crude protein.

PSVI-18 Low and high feed efficiency grower-finisher pigs fed three different levels of dietary crude protein showed no immediate difference in blood metabolomics profile

Abstract Improving feed efficiency (FE) of grower-finisher pigs is of great importance considering its impact on production economy, nutrient excretions as well as carbon-footprint. The biological background describing variation in FE between pen mates, is difficult to establish as feed intake (FI) and FE are not estimated on an individual level. In this study advanced feeding stations were used to estimate FI and further calculate feed conversion ratio (FCR) on individual level. The study aimed to investigate the possible difference in the blood metabolic profile between low and high FE grower-finisher pigs fed three different levels of dietary crude protein (CP). The study included 60 newly weaned gilts divided in two series, housed as 10 pigs/pen. The 30 pigs per series were distributed between three pens (10 pigs/pen) and were balanced by body weight and litter. Throughout the entire weaner period all pigs had ad libitum access to the same diet. Pigs were redistributed among the grower-finisher pens to balance FCR levels between dietary treatments (CP levels) and to reduce any carry over effect from the weaner to the grower-finisher pens. From 30-115 kg body weight (BW), pigs were fed either a low (L; 14.8% CP), standard (15.2% CP) or high (H; 15.8% CP) CP diet equal in energy, where BW, average weekly gain (AWG), and FCR were determined on weekly basis, while FI was estimated on daily basis. Three low FE (20% least) and three high FE (20% greatest) pigs were selected based on the final 4 wk of growth within station and CP level. On the final day of the experimental period all low-FE and high-FE pigs within each dietary treatment were euthanized and blood plasma was sampled and subjected to a nontargeted LC-MS metabolomics analysis. Growth performance and metabolite data were, respectively, analyzed in R and MetaboAnalyst 5.0 with FE and CP as fixed effects. High-FE and H-CP pigs continuously displayed numerically greater BW, while AWG and FCR were, respectively, numerically greater, and less in L-CP than H-CP group during last 2 wk of the experimental period. Principal Component Analysis (PCA) showed no grouping (P &amp;gt; 0.05) of metabolites and no specific pattern of the metabolic profile from either the two FE categories or the three dietary CP levels. Furthermore, no correlation (P &amp;gt;0.05) of metabolites to any other observation was found, and only little variation, measured by distance to model showing deviation of each pig to overall model, was observed. In conclusion, at first glance the metabolomics profile did not appear to present any specific pattern between low and high feed efficiency grower-finisher pigs or between pigs exposed to different levels of dietary CP in the grower finisher period.

PSVI-19 No apparent association between the microbiome in the distal part of the small intestine and feed efficiency in grower-finisher pigs fed three different levels of dietary crude protein

Abstract Improving feed efficiency (FE) of grower-finisher pigs is important considering its production, environmental and climate impact. The biological background describing variation in FE between pen mates, is difficult to establish as feed intake (FI) and FE is not estimated on an individual level. In this study advanced feeding stations were used to estimate FI and further calculate feed conversion ratio (FCR) on individual level. The study aimed to investigate the possible association between FCR and microbiome (alpha and beta diversity; observed features and Shannon index, and Bray-Curtis dissimilarity and Jaccard Distance) in the distal part of the small intestine (SI) in grower-finisher pigs fed three different levels of dietary crude protein (CP). The study included 60 newly weaned gilts divided in two series, housed as 10 pigs/pen. The 30 pigs per series were distributed between three pens (10 pigs/pen) and were balanced by body weight (BW) and litter with ad libitum access to the same diet. Pigs were redistributed among the grower-finisher pens to balance FCR levels between dietary treatments (CP levels) and to reduce any carry over effect from the weaner to the grower-finisher pens. From 30-115 kg BW, pigs were fed either a low (L; 14.8% CP), standard (Std; 15.2% CP) or high (H; 15.8% CP) CP diet equal in energy, where BW, average weekly gain (AWG), and FCR were determined on weekly basis, while FI was estimated on daily basis. Three low FE (20% least) and three high FE (20% greatest) pigs were selected based on the final 4 wk of growth within station and CP level. All low-FE and high-FE pigs within each dietary treatment were euthanized around 115 kg BW and content and mucosa scrabe from the distal part of the SI was sampled and subjected to 16S rRNA gene amplicon sequencing. Data were analyzed in R using a generalized linear mixed-effects model with FE, CP, and their interaction as explanatory variables, start BW of weaner and grower phase as covariables, and series as random effect. High-FE and H-CP pigs continuously displayed numerically greater BW, while AWG and FCR were, respectively, numerically greater, and less in L-CP than H-CP group during last 2 wk of the experimental period. While FE and CP individually had no significant impact [Pr(&amp;gt; Chisq] &amp;gt; 0.05), their interaction could be important in explaining the variation (Chisq = 6.42, Df = 2, Pr(&amp;gt;Chisq) = 0.04) as expressed by observed features. But a pairwise comparison with a Benjamini–Hochberg correction showed no difference between groups. Concerning the Shannon index, no significance was found between groups, and no difference with respect to beta diversity was observed. In conclusion, the microbiome as expressed by alpha and beta diversity did not explain the variation between low and high FE in grower-finisher pigs.

176 Impact of dietary crude protein level and water-based arginine on piglet growth and scouring with an Enterotoxigenic Escherichia coli F18 challenge

Abstract The objective of this experiment was to evaluate the impact of dietary crude protein (CP) level and water-based arginine (Arg) on the growth performance and scouring of piglets post wean and following an enterotoxigenic Escherichia coli F18 infection (ETEC). A total of 240 pigs (PIC 337 x 1050, Genus, Henderson, TN) were randomly assigned to 40 mixed-sex pens (6 pigs/pen) for a 6-wk experiment. At arrival, all pigs were genotyped for fructosyltransferase (FUT1). Pens were assigned to one of four treatments in a 2 x 2 factorial, with two crude protein levels (standard: 23% vs. low: 19.5%, for period 1) and two water treatments (absence or presence (8, 6, and 4% stock dosed through 1:128 proportioner for wk 1, 2, and 3, respectively) of Arg in water. Pig body weight (BW), feed disappearance (average daily feed intake; ADFI), and feed conversion (gain to feed ratio; G:F) were evaluated for four periods: d 0-7, 7-14, 14-21, and 21-42. Scour scores were recorded daily for the first 28 d to calculate weekly percentage of days scouring (scouring percentage). On d 21, water and dietary treatments ceased, and pigs received a common diet. All pigs were orally inoculated with a field strain of ETEC for two consecutive days on d 15 and 16 of the experiment. One pig per pen had blood collected (8mL via jugular) and was euthanized on d 14 before ETEC. Blood was collected via a jugular vein from another pig confirmed to be susceptible to ETEC on d 15, 17, and 22. The same pig was euthanized for tissue collection on d 22. Fecal swabs from 1 susceptible pig per pen were collected on d 15, 17, 19, and 22 for measurement of ETEC shedding. Blood samples were analyzed for inflammatory markers, and villi: crypt within the ileum were measured. Data were analyzed using mixed model methods (SAS 9.4, Cary, NC) with pen as the experimental unit. Growth performance and scouring percentage included the fixed effects of CP level, water treatment, experimental period, and their interactions. Reducing the CP of diets reduced the overall G:F of pigs (P &amp;lt; 0.01, standard: 0.73, low: 0.71). The percentage of days scouring tended to be influenced by the interaction between water and period (P = 0.06); specifically, when arginine (Arg) was present in the water, there was a numerically greater scouring percentage for all periods, except for the final period (d 21-28). Confirming the success of the ETEC challenge, period significantly impacted scouring percentage (P &amp;lt; 0.01), where piglets experienced the greatest scouring percentage (59%) during the week following ETEC inoculation, compared with the least in the week preceding inoculation (22%). In conclusion, low CP diets reduced overall G:F, but neither CP or Arg showed benefit in terms of scouring.

PSV-12 Microbial community structure of dairy cattle is stable through oscillating crude protein inclusion

Abstract Diet has an important role in shaping the structure of rumen microbial communities. However, little is known about the interaction between dietary crude protein (CP) level and CP feeding pattern on the rumen microbiome of dairy cows. Here, the objective was to evaluate the influence of CP level (low protein [LP], 13.8%; high protein [HP], 15.5% of dry matter [DM] basis) and CP feeding pattern (OF = oscillating, SF = static) on the composition and diversity of the rumen microbiome of lactating dairy cows using 16S rRNA gene amplicon sequencing. Rumen-cannulated Holstein cows (n = 8) in mid- to late-lactation were assigned to a 2 x 2 factorial experiment consisting of 4 experimental periods of 28 d. Each experimental period had an adaptation phase to the diet (24 d) and a sampling phase (d 25 to 28). The treatments with oscillating feeding alternated diets every 48 h to vary CP above and below the mean CP level (OF-LP = 13.8 ± 1.8%; OF-HP = 15.5 ± 1.8% CP of DM) whereas diets were constant in the static feeding (SF-LP = 13.8%; SF-HP = 15.5% CP of DM). According to the NASEM (2021) model predictions the LP diet supplied 94% of the microbial protein requirement while the HP diet exceeded (104%) requirement. Rumen samples were collected 4 h after feeding through a rumen cannula and amplicon libraries were generated targeting the V4 region of the 16S rRNA gene. The amplicon sequences were analyzed in qiime2. Sequences where trimmed based on their quality and then grouped in ASVs using DADA2. The ASVs were used to analyze the composition and diversity of the rumen microbiome in each treatment. Alpha diversity of the rumen microbiome did not change across treatments (Kruskal Wallis, P &amp;gt; 0.05), but Pielou’s evenness increased by 0.01 units (Kruskal Wallis, P = 0.04). These results support the hypothesis that the rumen microbiome is stable to oscillating CP feeding patterns and compensates for the changes in crude protein content in the diet. Further research is required to understand the dynamics of this compensation and what other metabolic processes in the ruminant contribute to maintaining production under an oscillating diet.