Protein Digestibility Research Articles

Comparative analysis of intestinal structure, enzyme activity, intestinal microbiota and gene expression in different segments of pufferfish (Takifugu Obscurus)

The structure of fish intestines does not have a clear regional division, while the function of the intestines may be related to their structure. Therefore, in this study, the delimitation of intestinal segments in pufferfish (Takifugu obscurus) was achieved by morphological analysis. Subsequently, enzyme activity, intestinal microbiota, and gene expression were examined to compare the differences among the pufferfish various segments. According to four morphological parameters: height of mucosa folds (HF), width of mucosa folds (WF), thickness of muscularis (TM), and cross-sectional area (CSA), the pufferfish's intestine was divided into anterior intestine (AI), middle intestine (MI), and posterior intestine (PI). The activity levels of amylase, lipase, and trypsin in the AI and MI were significantly higher than these in the PI. According to the analysis of 16S rDNA, the dominant microbiota at the phylum level in the different segments were Epsilonbacteraeota, Spirochaetes, and Proteobacteria. At the genus level, there were variations observed in the relative abundance of Brevinema, Mycobacterium, Bradyrhizobium, and Microvirga. α diversity analysis revealed that the richness indexes (Ace and Chao1) were the lowest in the MI, while β diversity analysis revealed significant difference in intestinal microbial community composition among the three intestinal segments. Furthermore, RNA-Seq was used to identify differential expression genes (DEGs) and biological pathways among the different intestinal segments. The DEGs between the AI and MI were enriched in pancreatic secretion and protein digestion and absorption, those between AI and PI were involved in ascorbate and aldarate metabolism and glutathione metabolism, and those between MI and PI were involved in steroid biosynthesis, fat digestion and absorption, vitamin digestion and absorption, and glycine, serine and threonine metabolism. In conclusion, the presented results compare and analyze the differences in various intestinal segments of pufferfish, which will be conductive to future exploration of the functions of these different segments.

Combined transcriptome and metabolome analysis reveals the mechanism of high nitrite tolerance in freshwater mussel Anodonta woodiana

Nitrite contamination and stress on aquatic organisms are increasingly emphasized in freshwater ecosystems. Freshwater bivalves exhibit high tolerance to nitrite; however, the underlying mechanism is unknown. Accordingly, this study investigated the tolerance mechanism of the globally occurring freshwater bivalve Anodonta woodiana. A. woodiana were exposed to nominal concentrations of 0, 250, 500, 1000, 2000, and 4000 mg/L nitrite for 96 h to calculate the 96-h median lethal concentration (96-h LC50). A combined transcriptome and metabolome analysis of the hemolymph (the most vital component of the bivalve immune system) was performed after exposing A. woodiana to 300 mg/L nitrite (approximately half the 96-h LC50) for 96 h. The 96-h LC50 of nitrite in A. woodiana was 618.7 mg/L. Transcriptome analysis identified 5600 differentially expressed genes (DEGs) primarily related to ribosomes, lysosomes, DNA replication, and nucleotide excision repair. Metabolome analysis identified 216 differentially expressed metabolites (DEMs) primarily involved in biosynthesis of amino acids, 2-oxocarboxylic acid metabolism, protein digestion and absorption, aminoacyl-tRNA biosynthesis, nucleotide metabolism, ABC transporters, and valine, leucine and isoleucine degradation. Combined transcriptome and metabolome analysis revealed that DEGs and DEMs were primarily associated with nucleotide (purine and pyrimidine) and amino acid metabolism (including aminoacyl-tRNA biosynthesis, cysteine and methionine metabolism, arginine and proline metabolism, and valine, leucine and isoleucine degradation) as well as the immune system (necroptosis and glutathione metabolism). This study is the first to describe the high tolerance of A. woodiana to nitrite and elucidate the molecular mechanisms underlying high nitrite tolerance in mussels.

Storage causes protein oxidation of soybean meal and affects antioxidant status, digestive performance and meat quality of broilers.

This study investigated the protein oxidation of soybean meal (SBM) stored in a warehouse and the effects of SBM on growth performance, antioxidant status, digestive performance, intestinal morphology, and breast muscle quality of broilers. In total, 160 one-day-old Arbor Acres Plus broilers (half male and half female) were randomly divided into two groups with ten replicates of eight birds each: The control group was served with a basal diet including SBM stored at -20°C (FSBM), and the experimental group was served with a basal diet including SBM stored in a warehouse at room temperature for 45 days (RSBM). Compared with FSBM, the protein carbonyl level in RSBM was increased, the free and total thiol levels and in vitro digestibility of protein were decreased. The RSBM decreased the serum glutathione (GSH) level and the hepatic total superoxide dismutase (T-SOD) activity at days 21 and 42 when compared with FSBM. Further, RSBM reduced the duodenal T-SOD activity, jejunal catalase (CAT), and T-SOD activities at day 21, and decreased the duodenal CAT and T-SOD activities, jejunal T-SOD activity, and ileal GSH level and T-SOD activity at days 21 and 42 when compared with FSBM. Besides, the trypsin activity and the ratio of villus height to crypt depth in small intestines of broilers at days 21 and 42 were reduced when fed with a RSBM-contained diet. Compared with FSBM, the 24-h drip loss, shear force, and 24- and 48-h cooking loss of breast muscle were increased of RSBM group, the opposite result was observed for muscle lightness at 48 h. Room temperature storage for 45 days led a protein oxidation and decreased in vitro digestibility in SBM, and fed RSBM impaired growth performance, antioxidant status, and meat quality, reduced trypsin activity, and affected the small intestine morphology in broilers.

Lactobacillus fermented chickpeas: Improving dough process quality and biscuit nutritional value

This study aimed to examine the impact of lactobacillus fermented chickpeas (LFC) on dough quality and assess their application potential in biscuits. The results of rheological properties showed that LFC significantly increased the storage modulus (G') and loss modulus (G'') of the dough, with a greater increase in G'. The textural analysis showed that the LFC significantly increased the hardness of the dough before and after fermentation. In the low-field NMR analysis, LFC enhanced the bound water content of the dough and reduced the mobility of the water molecules. Furthermore, the network structure of gluten proteins was weakened by LFC, resulting in more exposed starch. In vitro protein digestibility increased by 28.01% at the gastric end and 11.76% at the intestinal end of LFC-biscuits as compared to chickpea biscuits. It was associated with lactobacilli fermentation reducing phytic acid and trypsin inhibitor activity in chickpeas. Moreover, the protein content of the biscuits has been increased (33.26%) and their free amino acid composition has been optimized. The hardness, brittleness, and specific volume of biscuits were significantly enhanced by LFC, with well sensory acceptance. These findings will enrich the theory of lactobacilli fermentation of legumes and inspire its application in baked foods.

Enzymatic production and physicochemical and functional properties of sorghum protein isolates.

Grain sorghum has emerged as a promising source for producing alternative proteins, yet current extraction methods lack efficiency. In this study, a novel enzymatic approach using α-amylase and cellulase on sorghum materials was developed to address this challenge. Comparisons were made among the proteins isolated from dry-milled sorghum flours, wet-milled sorghum gluten meals, and sorghum dried distiller's grains (DDG). Remarkably, proteins obtained from sorghum gluten meals demonstrated the highest protein purity (83-85 %) and recovery rate (92-93 %), followed by those from sorghum flour (purity 75-76 %) and DDG (purity 45-50 %). Physicochemical properties and functionalities of the isolated sorghum proteins were analyzed and compared with common commercial plant proteins (e.g., soy protein isolate, pea protein isolate, and wheat gluten). Sorghum proteins exhibited higher levels of crude fat content, α-helix, and random coil structures, along with higher surface hydrophobicity and oil holding capacity (OHC) compared to the commercial plant protein isolates. Notably, proteins extracted from sorghum flours displayed slightly higher α-helix and random coil structures, total sulfhydryl content, water holding capacity (WHC), OHC, and protein digestibility compared to proteins isolated from sorghum gluten meals. Overall, this study demonstrates that enzymatic processing is feasible in producing sorghum proteins and provides insights into their basic properties and functionalities.

Pulsed Electric Field for Quick-Cooking Rice: Impacts on Cooking Quality, Physicochemical Properties, and In Vitro Digestion Kinetics

Pulsed electric field (PEF) is one of the emerging technologies that has been applied in many aspects of the food industry. This study examined the impacts of a PEF on the cooking quality, physicochemical properties, nutritional factors, and in vitro protein and starch digestion of two varieties of rice, including Jasmine 105 (white non-glutinous rice) and San Pa Tong 1 (white glutinous rice). Response surface methodology (RSM) and a three-level, three-factor Box–Behnken design were employed to assess the effects of the pulse number, electric field strength, and frequency on cooking time. The findings demonstrated that the number of pulses was a crucial factor influencing cooking time. Under optimal conditions (3347–4345 pulses, electric field strengths of 6–8 kV/cm, and frequencies ranging from 6 to 15 Hz), the rice cooking time was significantly reduced by 40–50% (p < 0.05) when compared to a conventional method. Moreover, PEF-treated rice showed a significant enhancement in in vitro protein and starch digestibility (p < 0.05), as well as retained a higher content of rapidly digestible starch. These results suggested that PEF treatment is a promising green technology for producing a novel quick-cooking rice with an improved eating quality.

Evaluation of the Aral Region Adolescent Nutrition with the FFQ_KZ Questionnaire

ABSTRACT The rapid drop in the Aral Sea’s level since the 1960s has resulted in an environmental disaster and major shifts in quality of life. The research aims to determine the eating habits of adolescents from 11 to 17 years old living in the Aral Sea Basin by using an FFQ questionnaire. The respondents’ diets were found to be unbalanced due to a shortage of proteins, polyunsaturated fatty acids, and complex carbohydrates, with a predominance of easily digestible carbohydrates and plant proteins. The study highlights the need for educational efforts to increase awareness of the consequences of poor nutrition.

Effect of Feeding Ginger (Zingiber officinale) Powder on Nutrient Digestibility of Konkan Kanyal Kids

The present study aimed to determine the Effect of feeding Ginger (Zingiber officinale) powder on nutrient digestibility of Konkan Kanyal kids. antibiotics were commonly used in animal diets to promote growth. However, due to the search for alternative additives and restrictions in many countries on using antibiotics to increase feed value, feed expenses now make up a significant part of the total cost of goat production. An experimental trial was conducted to evaluate the effect of feeding Ginger (Zingiber officinale) powder on body weight of Konkan Kanyal kids. Twenty Konkan Kanyal kids were selected and classified in five treatments by using Randomized Block Design (RBD). Each treatment was subdivided into four replications. All the animals were fed with complete feed having mulato grass, jowar kadabi and concentrate mixture. In treatment T1 no ginger powder was supplemented while in treatment T2 3.0 g ginger powder, in treatment T3 6.0 g ginger powder, in treatment T4 9.0 g ginger powder and in treatment T5 12.0 g ginger powder was supplemented. The duration of experimental trial was 90 days. The study showed that ginger inclusion in the diet improved digestibility thus12g ginger can be included in diet of konkankanyal kids for better performance. The crude protein (CP) digestibility indicated that the animals effectively utilized dietary protein. This could be attributed to certain phytochemicals in ginger, such as tannins and saponins, which help prevent protein degradation in the rumen, allowing for better digestion in the abomasum and small intestine.

Sugarcane, corn silage and concentrate levels in cattle diet

This study evaluated two roughage types (sugarcane and corn silage) and two concentrate feed levels (0 and 25% of the total dry matter) in the cattle diet, in a 2x2 factorial design, and compared passage rate measurements (indicator and rumen evacuation). Four Holstein-Zebu heifers cannulated in the rumen and ileum were evaluated, in a 4x4 Latin square design. Stool samples (8th - 10th day) and rumen fluid (8th day) were collected and the rumen was emptied (14th and 16th day). Treatments were compared by contrast, evaluating the effects of roughage, concentrate feed and interaction between these factors. Dry matter (DM) intake and neutral detergent fiber corrected for ash and protein (apNDF) were highest for animals fed corn silage, and DM and organic matter (OM) intake were highest when fed concentrate. There was no roughage effect on ruminal mass, but concentrate decreased ruminal NDF in the total digesta mass. The coefficients of total digestion of crude protein (CP), apNDF and non-fiber carbohydrates (NFC) were higher for sugarcane than corn silage. Concentrate feed improved the total digestibility of OM and NFC. Passage rates evaluated by the marker technique and rumen evacuation were similar. Corn silage or 25% concentrate in the cattle diet improved consumption, intake rate and nutrient digestibility. The particle passage rate can be estimated by rumen evacuation or by adjusting a nonlinear mathematical model.

Consideration of the role of protein quality in determining dietary protein recommendations

The quality of a dietary protein refers to its ability to provide the EAAs necessary to meet dietary requirements. There are 9 dietary amino acids that cannot be metabolically produced in the body and therefore must be consumed as part of the diet to avoid adverse metabolic consequences. These essential amino acids (EAAs) serve a variety of roles in the body. The amount and profile of the dietary EAAs relative to the individual EAA requirements and the digestibility of the dietary protein are the key factors that determine its quality. Currently the Digestible Indispensable Amino Acid Score (DIAAS) is the best available approach to quantifying protein quality. The most prominent metabolic role of dietary EAAs is to stimulate protein synthesis by serving as signals to activate molecular mechanisms responsible for the initiation of protein synthesis and, most importantly, to provide the necessary precursors for the synthesis of complete proteins. Current dietary recommendations generally do not consider protein quality. Accounting for protein quality in dietary patterns can be accomplished while staying within established ranges for dietary protein consumption. Poor protein quality can be compensated for to some extent by eating more low-quality protein, but to be effective (“complementary”) the limiting EAA must differ between the low-quality protein and the base diet to which it is being supplemented. Adding a high-quality protein to a dietary pattern based on low-quality protein is more effective in meeting EAA goals than increasing the amount of low-quality protein, even if the low-quality proteins are complementary. Further, reliance entirely on low-quality protein food sources, particularly in circumstances that may benefit from a level of dietary EAAs greater than minimal requirements, is likely to include excessive caloric consumption. While protein consumption in high-income nations is generally perceived to be adequate or even excessive, assessment of dietary patterns indicates that a significant percentage of individuals may fall short of meeting optimal levels of EAA consumption, especially in circumstances such as aging in which the optimal EAA consumption is greater than basal values for healthy young individuals. The case is made that protein quality is an important consideration in meeting EAA requirements.

Effect of feeding guava agroindustrial waste on nutrient utilization, lamb performance and economic analysis

Abstract. Our study sought to investigate the impact of incorporating guava agroindustrial waste (GAW) at varying concentrations on nutrient utilization, lamb performance and economic viability. Forty non-castrated, 4-month-old Santa Inês lambs with an initial mean weight of 21.3 ± 2.18 kg were utilized in a confined setting. These lambs were allocated randomly to five treatment groups, each consisting of eight replicates, and were subjected to diets containing increasing levels of GAW (0 %, 7.5 %, 15 %, 22.5 % and 30 % based on dry matter). The feed formulation also included Tifton hay, corn, soybean and mineral salt. Throughout the trial period, parameters such as dry matter intake (DMI), nutrient digestibility and economic metrics were meticulously evaluated. Notably, the performance metrics among the different GAW treatments did not exhibit statistically significant differences (p > 0.05), with an average daily gain of 328 g d−1 observed across all the groups. However, there was a discernible positive effect on the intake of ether extract (p > 0.05). Regarding nutrient digestibility, only the crude protein digestibility demonstrated no significant variance (p > 0.001) among the treatments. Consequently, our findings suggest that GAW can be effectively integrated into sheep diets at levels of up to 30 % without compromising lamb performance. Moreover, from an economic standpoint, this incorporation proves to be the most financially viable and cost-effective option among the evaluated treatments.

Genotype and grain pretreatment effects on digestibility of sorghum proteins in the Ethiopian fermented bread

AbstractBackground and ObjectivesSorghum is the principal food source for smallholder farmers in Sub‐Saharan Africa. Animal proteins are beyond economic reach, and only few food legumes are well‐adapted in major sorghum‐growing regions. Hence, sorghum serves as the primary source of protein and calories. However, the low digestibility of its proteins renders the communities vulnerable to protein malnutrition. Several factors, including genotypes and processing methods, have been shown to affect the digestibility of proteins in sorghum food products. The objective of this study was to investigate the impact of grain pretreatment on the protein digestibility of Ethiopian fermented flatbread.FindingsThe effect of four grain pretreatment processes: decortication, sprouting, parching, and untreated control was compared using four diverse sorghum genotypes milled to medium (2 mm) and fine (0.5 mm) particle sizes. The in‐vitro protein digestibility (IVPD) was significantly lower in the parched samples compared to the unprocessed control, while sprouting significantly increased IVPD. Decortication appears to have no impact on IVPD. Finer particle size tended to enhance IVPD in all genotypes and for all pretreatement methods. The treatments had no significant effect on protein content except the sprouting consistently but marginally increased total protein.ConclusionsSprouting sorghum grains can significantly improve the protein digestibility of fermented breads. Given that it involves little cost, the process can be readily adopted by the local community, provided that they are educated about the impact of protein deficiency on the health and productivity of the community.Significance and NoveltyLow‐cost grain pretreatment procedures such as sprouting can have a significant impact on the availability of nutrients, especially protein, the most limiting nutrient in smallholder communities. Combining the procedure with genetically enhanced varieties and improved cropping systems that integrate food legumes can significantly enhnace protein nutrition for smallholder farmers.

Abstract 4136861: Title: Protein interaction profiling of the Kv11.1 potassium channel reveals new therapeutic targets for Long QT Syndrome

Background: The voltage-gated potassium ion channel K V 11.1 plays a crucial role in cardiac repolarization. Genetic variants in K V 11.1 lead to Long QT Syndrome (LQTS), a condition associated with fatal arrhythmias. Approximately 90% of missense variants linked to LQTS cause intracellular protein transport (trafficking) dysfunction. Some K V 11.1 channel blockers act as chemical chaperones (e.g., E-4031) and increase K V 11.1 channel trafficking. However, these drugs cannot be used in LQTS patients. The underlying mechanisms, such as the protein networks involved in folding and quality control for K V 11.1 channel trafficking remain largely unexplored. Methods: We used affinity-purification (e.g., coimmunoprecipitation) coupled with mass spectrometry to quantify protein interaction changes in human embryonic kidney cells expressing wild-type K V 11.1 or two trafficking-deficient channel variants in the presence or absence of chemical chaperone E-4031. After co-immunoprecipitations and protein digestions, peptides were identified using multiplexed mass spectrometry. Results: We identified 572 protein interactions enriched in K V 11.1-expressing cells. We used bioinformatic analysis to make a cellular model showcasing likely K V 11.1 protein interactions localization from early biogenesis and transcription to plasma membrane expression (Figure 1). We revealed proteins responsible for protein folding, translation, proteasomal degradation, and others with most protein interactions significantly elevated in the genetic variants compared to wild-type (Figure 2). Upon 24-hour treatment with E-4031, some of these interactions were reduced towards wild-type and indicated potential molecular targets for therapeutic intervention (Figure 3). Conclusions: We report the discovery of novel K V 11.1 protein-protein interactions that could be therapeutically targeted to improve K V 11.1 trafficking and treat Long QT Syndrome.

Cecal Microbial Diversity and Metabolome Reveal a Reduction in Growth Due to Oxidative Stress Caused by a Low-Energy Diet in Donkeys

Dietary energy level plays an important role in animal growth and development. The present study investigated the effect of dietary energy on the growth performance, antioxidative state, and nutrient digestion of meat donkeys. It simultaneously explored the probable reason for cecal microbiota and metabolome. Twelve meat donkeys (male) aged 1 year with a similar weight (150 ± 25 kg) were divided into two treatment groups: low-energy group (E1) and high-energy group (E2). The experiment was divided into a 10-day pre-trial period and a 135-day trial period. Donkeys in the trial periods were fed diets with digestible energy values (in dry matter) of 12.08 and 13.38 MJ/kg (pre-fattening, 1–45 d), 13.01 and 14.07 MJ/kg (mid-fattening, 46–90 d), and 13.54 and 14.93 MJ/kg (late-fattening, 91–135 d). The results show that E1 decreases body weight, average daily gain (ADG), and the digestibility of crude protein, ether extract, neutral detergent fiber, and acid detergent fiber (p < 0.05), but increases cecal acetate and butyrate concentrations, non-esterified fatty acids (NEFAs) in serum, and the ratio of dry matter intake to ADG(F/G). E1 diminished the activities of catalase and glutathione peroxidase, while it increased the content of interleukin, tumor necrosis factor-alpha, and reactive oxygen species (ROS) (p < 0.05). Cecal microbiome showed that the abundance of Firmicutes and Actinobacteria in E1 was significantly lower than in E2 (p = 0.029, p = 0.002), whereas Bacteroidetes was higher (p = 0.005). E1 increased the genera Ruminococcaceae-UCG-004, Acinetobacter, and Rikenellaceae_RC9_gut_group. Meanwhile, cecal metabolome showed that formyl-5-hydroxykynurenamine, chorismate, 3-sulfinoalanine, and 3-isopropylmalate were upregulated in E1, while brassinolide was downregulated. The altered metabolites were mainly enriched in metabolic pathways related to energy metabolism and metabolism to mitigate oxidative stress in the meat donkeys, such as tryptophan metabolism, brassinosteroid biosynthesis metabolism, etc. In conclusion, low-energy diets resulted in a negative energy balance in meat donkeys, resulting in more nutrients being oxidized to provide energy, inducing oxidative stress, and thereby leading to decreasing growth. The reduction in meat donkey growth from low-energy diets was related to changes in cecum microbiota and metabolites.

A Biochemistry Teaching Experiment That Demonstrates the Digestion of Carbohydrates, Proteins, and Lipids in the Digestive Tract

A Biochemistry Teaching Experiment That Demonstrates the Digestion of Carbohydrates, Proteins, and Lipids in the Digestive Tract

Novel miRNA markers and their mechanism of esophageal squamous cell carcinoma (ESCC) based on TCGA

MicroRNAs(miRNAs) are promising biomarkers for early esophageal squamous cell carcinoma (ESCC) detection and prognostic prediction. This study aimed to explore the potential biomarkers and molecular pathogenesis in the early diagnosis of ESCC. Firstly, 48 differentially expressed miRNAs (DEMs) and 1319 differentially expressed genes (DEGs) were identified between 94 ESCC tissues and 13 normal esophageal tissues in TCGA. From miRNA–mRNA regulatory network, there are 6558 target genes of the 48 DEMs, where 400 target genes are also among 1319 DEGs. Then, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment indicate that the 400 DEGs significantly enriched in cell cycle, proteoglycans in cancer, p53 signaling pathway, protein digestion and absorption, transcriptional dysregulation in cancer, and oocyte meiosis. And there are 66 DEGs among these six biological pathways, which we called GO-DEGs. From miRNA–mRNA regulatory network, 32 DEMs regulated the 66 GO-DEGs, where 22 DEMs were verified by different types of experiments in ESCC tissues, cells, or serum from the literature. For the other novel 10 DEMs, single-factor Cox regression analysis show that only hsa-miR-34b-3p showed no significant correlation with the overall survival of ESCC patients. Finally, we obtained the novel 9 ESCC-related DEMs, where three are down-regulated, and six are up-regulated. We analyzed the expression trends of target genes for five miRNAs and identified three significantly different miRNAs (hsa-miR-205-3p, hsa-miR-452-3p, and hsa-miR-6499-3p) confirmed by qPCR. Moreover, the stage-specific miRNAs were also suggested. These three qPCR validated miRNAs are also specific to the early stages of ESCC: hsa-miR-452-3p is specific to Stage I, II and III; hsa-miR-205-3p is specific in Stage II and III; and hsa-miR-6499-3p is Stage II specific. They might be the potential biomarkers for ESCC stage diagnosis. This study identified three novel miRNA markers potentially related to the diagnosis of ESCC and participated in the occurrence and development of ESCC through cell cycle, proteoglycans in cancer, p53 signaling pathway, protein digestion and absorption, transcriptional dysregulation in cancer, and signaling pathway for oocyte meiosis.

Utilization of Purple Napier Grass Silage on Milk Quality and Blood Antioxidant Activity in Lactating Dairy Goats

In this study, our subjects were 18 female crossbred Saanen lactating goats; the goats weighed approximately 43.25 ± 2.35 kg and had been producing milk for 14 ± 2 days. They were assigned to three equally sized experimental groups based on the cycle of the lactation period. In accordance with the randomized complete block design (RCBD), six animals were randomly assigned to the treatments in each block. There were three treatments: (1) control = Napier Pakchong-1 grass silage (NPS); (2) = sweet grass silage (SGS); and (3) = purple Napier silage (PNS). Our findings show that the goats fed with purple Napier grass silage had a higher DM intake (1805.97 g/day) than those that underwent a different treatment (1312.76 and 1443.43 g/day). The goats fed with purple Napier grass silage had higher protein digestibility (79.85) than those fed with Napier Pakchong-1 and sweet grass silage. There were significant differences in the ruminal ammonia nitrogen and blood urea nitrogen. Nevertheless, purple Napier grass silage significantly increased butyric acid 2 and 4 h after feeding and increased the number of microorganisms. In the dairy goats fed purple Napier grass silage, we observed a reduction in protozoa and methanogen populations. The levels of antioxidants shown by the plasma indices differed in the goats fed with purple Napier grass silage and showed enhanced milk composition, higher levels of total antioxidants, superoxide dismutase and glutathione peroxidase in the plasma, reduced protozoa methanogen, and a decreased level of malondialdehyde in the plasma. This study highlights that purple Napier grass silage has the potential to be a beneficial source of roughage for lactating dairy goats.

Effect of protease supplementation on amino acid digestibility of soybean meal fed to growing-finishing pigs in two different ages.

This study was conducted to investigate the effect of protease inclusion level in two different ages on the apparent (AID) and standardized (SID) ileal digestibility of crude protein (CP) and amino acids (AA) in soybean meal (SBM) fed to growing-finishing pigs. Ten cannulated pigs (21kg ± 2kg) were assigned to experimental diets in a duplicate 5 × 5 Latin square design. In Phase I (23 to 30 kg-pigs, 90 ± 17 days of age), ileal digesta was collected in 5 periods of 7d (5d adaptation and 2d ileal digesta collection). In phase II, (50 to 65 kg-pigs, 140 ± 17 days of age), ileal digesta was collected in 5 more periods of 7 d. For both phases, a corn starch-based diet was formulated with SBM as the sole source of CP and AA and containing titanium as an indigestible marker. Protease was supplemented at 0, 15,000, 30,000, and 45,000 NFP/kg of feed (0, 25, 50, and 75g/ton of ProAct 360®). A nitrogen-free diet was used to estimate basal ileal endogenous AA losses. Pigs were fed at 4% of their body weight, which was adjusted at the end of each period. Orthogonal polynomial contrasts were used to determine the linear and quadratic effects of dietary protease supplementation in each phase. In phase I, increasing levels of protease resulted in a linear increase (P<0.10) in SID for the 7/11 indispensable AA (Except Arg, His, Met + Cys, and Trp) and the average of all dispensable AA. In phase II, the SID of Ile, Leu, Met, Met + Cys, Val, the average of all indispensable AA, and 4/7 dispensable AA were quadratically increased (P<0.10). In most cases, supplementation with 30,000 NFP/ kg of feed (50g/ton) resulted in the greatest increase in AA digestibility. However, the linear response in phase I for some AA suggests that diets for younger pigs could be supplemented with a greater level (45,000 NFP/kg or 75g/Ton of feed). Interestingly, younger pigs had consistently increased (P<0.10) SID of CP and 15/18 AA (Except Arg, Cys, and Ser), being ~5.6% greater for indispensable AA when compared to older pigs. In conclusion, dietary protease supplementation can increase the SID of AA in soybean meal in both growing and finishing periods. Pig age can potentially influence AA digestibility, possibly related to a greater ileal endogenous AA flow in younger pigs. However, this fact warrants further investigation.

Determination of Plasma Metabolites and Basal Ileal Endogenous Amino Acid Losses in Growing Pigs Fed a Nitrogen-Free or Casein Diet.

The nitrogen-free diet (NFD) method for determining basal ileal endogenous losses (BEL) of amino acids (AA) has been associated with different metabolic abnormalities that can affect the accurate determination of BEL. Consequently, the use of highly digestible proteins has been suggested. This study aimed to determine the metabolic status and BEL of AA in pigs fed either an NFD or a casein (CAS) diet. Eight cannulated, castrated male pigs (39.8 kg) were randomly assigned to a 2 × 2 crossover design. An NFD diet based on corn starch, dextrose, cellulose, oil, vitamins and minerals was used. The CAS diet was equivalent, but 18% of the corn starch was replaced with casein. Pigs were fed one of the diets for a 7-day period, and blood samples were collected at the beginning and end of each period to determine plasma metabolites. Ileal digesta samples were collected on Days 6 and 7 to estimate the BEL of the AA. Results indicated that plasma albumin was significantly higher (p < 0.05) in pigs fed the CAS diet, whereas creatinine and LDL levels were higher (p < 0.03) in pigs fed the NFD. No significant differences were observed in the levels of other plasma metabolites. The BEL of protein did not differ between diets. However, in pigs fed the CAS diet, the BEL of glutamic acid, aspartic acid, serine, glycine, histidine, threonine, alanine, tyrosine and valine significantly increased (p < 0.05), while isoleucine showed a tendency to increase (p = 0.06). In conclusion, NFD did not significantly affect energy and lipid metabolism in pigs. However, the decrease in albumin synthesis and increase in plasma creatinine levels indicate that pigs fed NFD have a negative protein balance, affecting the estimation of the BEL of AA. Therefore, it is essential to consider the metabolic state of animals when estimating the BEL of AA.

New fermented plant-based ingredients in sourdough breads enhanced nutritional value and impacted on gut microbiota

Two new recipes of baker's yeast bread fortified with fermented apple by-products and avocado or walnut were designed resulting in enhanced profiles of total free amino acids, in vitro protein digestibility (IVPD) and predicted glycemic index (pGI). Concurrently, pools of lactic acid bacteria and yeast were screened to select the most promising starters for sourdough preparation. The type II sourdough with Lactiplantibacillus plantarum CR1, Furfurilactobacillus rossiae CR5 and Saccharomyces cerevisiae E10 had the highest acidification and total free amino acids value, while resulting in bread with the highest IVPD and the lowest pGI.Sourdough breads were manufactured with the new recipes. They had improved protein digestibility and starch hydrolysis, and enhanced content of dietary fiber, phenolics and unsaturated free fatty acids. The impact of new fortified sourdough breads on colon microbial ecosystems was investigated by the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®). The intake promoted the short-chain fatty acids synthesis and expanded several bacterial taxa with potential to exert beneficial activities. The synergic combination of sourdough fermentation and fortification with fermented plant-based matrices (including by-products) was a suitable strategy to promote better nutritional and digestibility properties in breads, and to promisingly address the modulation of gut microbiota.