Total Acid Research Articles

Effects of different trophic conditions on total fatty acids, amino acids, pigment and gene expression profiles in Euglena gracilis.

Euglena gracilis is a unique microalga that lacks a cell wall and is able to grow under different trophic culture conditions. In this study, cell growth, biomass production, and changes in the ultrastructure of E. gracilis cells cultivated photoautotrophically, mixotrophically, and under sequential-heterotrophy-photoinduction (SHP) were assessed. Mixotrophy induced the highest cell growth and biomass productivity (6.27 ± 0.59mg/L/d) in E. gracilis, while the highest content of fatty acids, 2.69 ± 0.04% of dry cell weight (DCW) and amino acids, 38.16 ± 0.08% of DCW was obtained under SHP condition. E. gracilis also accumulated significantly higher saturated fatty acids and lower unsaturated fatty acids when cultivated under SHP condition. Transcriptomic analysis showed that the expression of photosynthetic genes (PsbA, PsbC, F-type ATPase alpha and beta) was lower, carbohydrate and protein synthetic genes (glnA, alg14 and fba) were expressed higher in SHP-culture cells when compared to other groups. Different trophic conditions also induced changes in the cell ultrastructure, where paramylon and starch granules were more abundant in SHP-cultured cells. The findings generated in this study illustrated that aerobic SHP cultivation of E. gracilis possesses great potential in human and animal feed applications.

Estimation of Heterosis and Combining Ability for Quality Traits in Bottle Gourd [Lagenaria siceraria (Mol.) Standl.

An experiment was conducted at the Vegetable Research Farm, Maharajpur, Department of Horticulture, JNKVV, Jabalpur in kharif season of 2022 and 2023. The current study evaluated the performance of 23 bottle gourd genotypes, including 6 parental lines, their 15 diallel crosses, and 2 checks, focusing on their quality traits. Over two years of pooled data, genotype, JBG-4×JBG-5 was found to possess maximum TSS (3.93 °Brix), followed by JBG-2×JBG-4 (3.77 °Brix). JBG-4×JBG-5 was found to have maximum ascorbic acid content (14.48 mg 100-1 g) followed by JBG-4 (14.01 mg 100-1 g). Rind thickness was found maximum in JBG-2×JBG-4 (3.36 mm) followed by JBG-2×JBG-3 (3.28 mam). This study found a substantial association between the total soluble solids (TSS) and ascorbic acid content with the yield of bottle gourd genotypes. Among the genotypes, JBG-4×JBG-5 demonstrated the highest yield per plant, along with the highest total soluble solids (TSS) and ascorbic acid content. Regarding heterosis, JBG-4×JBG-5 has found the highest heterosis for total soluble solids and ascorbic acid content. JBG-4 and JBG-2 are the best general combiners for TSS, ascorbic acid content, and rind thickness. JBG-4×JBG-5 has found the best specific combiner for TSS and ascorbic acid content.

Rootstock Influences Growth, Yield, Berry Physiochemical and Quality Wine Produced from Cabernet Sauvignon Grown in the Pune Region

The experiment was conducted to study the effect of rootstock on growth, yield, quality, and sensory evaluation of wine made from ‘Cabernet Sauvignon’ grapes. Among the rootstock’s, pruning weight was significantly higher in vines grafted on 110R rootstock. Days for buds sprout and days to veraison was early in Gravasec grafted rootstocks, while early days to harvest in Gravasec and SO4 rootstocks. Cabernet Sauvignon vines grafted on 110R rootstock recorded significantly higher fruit yield than other rootstocks studied. Wine composition like volatile acid, total acids and ethanol was higher in vines grafted on 140RU; malic acids in 1103P and colour intensity in SO4 grafted vines. The wine sensory attributes were also positively influenced using different rootstocks, wine prepared from Cabernet Sauvignon grapes grafted on 1103P recorded the highest overall wine quality which was followed by Fercal rootstock.

Average daily gain in lambs grazing mixed annual forage species compared with single species and relationship to feed on offer

Context Annual forage crops provide high-quality fodder for livestock during typical autumn and winter feed-gaps in the south-east of Australia and benefits through rotations in cropping systems. While benefits from intercropping with cereals and pasture or mixing canola and peas have been studied in Australia, the potential animal-production benefits of grazing mixed annual species forage crops have not been examined. Aims To determine average daily gain (ADG) and rumen fluid parameters when sheep graze mixtures of annual fodder crops compared with a single species. Methods Ninety six Dorset × Border Leicester × Merino lambs (mean = 44.3 ± 0.55 kg) were allocated to one of the following four treatment groups (n = 24/treatment) on the basis of sex and liveweight; a single species brassica control (canola) (Br) or annual forage species mixes containing brassica (canola, turnip, radish) and cereal (wheat, cereal rye) (B + C), brassica and legume (vetch, arrowleaf clove) (B + L) or brassica, cereal and legume (B + C + L). Liveweight and rumen fluid parameters were assessed prior to grazing and again 21 and 35 days after the commencement of grazing. Key results Mean ADG from Day 0 to Day 21 was lower for female, but not male, lambs grazing the Br control (231 ± 23 g head−1 day−1) than for those grazing any forage mix (B + C = 292 ± 23 g head−1 day−1, B + L = 296 ± 23 g head−1 day−1, B + C + L = 310 ± 22 g head−1 day−1). Liveweight change over 35 days of grazing was not different between any forage mixtures. Rumen fluid pH was higher (P < 0.001) for sheep grazing forages containing cereals (B + C = 6.97 ± 0.06, B + C + L = 6.86 ± 0.06) than for those grazing brassica or legume (Br = 6.59 ± 0.06, B + L = 6.68 ± 0.06). Total volatile fatty acid concentration was lower and rumen pH was higher when sheep grazed B + C than when they grazed any other forage mix. Conclusions The higher ADG in females grazing mixtures than in those grazing the Br was related to higher dry matter on offer. Further research should determine whether the lower pH observed when sheep grazed brassica and legume than when grazing mixes containing cereals is associated with subacute rumen acidosis and reduced fibre degradation and forage energy utilisation. Implications Mixed forage species can provide higher DM on offer and ADG. Improved rumen efficiency could be related to improved growth.

The Role of Camellia Shell Substrates in Modulating the Nutritional Characteristics of Pleurotus pulmonarius

Camellia shells are the main by-product of camellia seed processing and are usually incinerated or disposed of as agricultural waste. In this study, camellia shells were employed in the Pleurotus pulmonarius cultivation process using five distinct formulae substituting for cottonseed shells. Our results show that as the substitution rate of camellia shells increased from 0% to 35%, the protein content in P. pulmonarius significantly increased from 34.05% to 53.35%. The polysaccharide content reached a peak value of 5.62% at 30% substitution of camellia shells. The DPPH free radical scavenging rate reached its maximum of 82.70% at 20% substitution of camellia shells. Furthermore, increases in the total amino acid contents in P. pulmonarius were positively correlated with the substitution rate of camellia shells. Considering the yield characteristics, the formula of 20% camellia shell substitution tested in this study appears to be optimal for P. pulmonarius cultivation. These findings not only provide a substrate to enhance the nutritional quality of P. pulmonarius but also demonstrate a novel approach for the ecological utilization of camellia shells.

De Novo Synthesis of Perdeuterated Phosphoinositide by Installing a Non-native Phospholipid Biopathway in E. coli.

Phosphatidylinositol (PI) and its phosphorylated derivatives are of paramount importance in cellular functions and diseases. Understanding their diverse roles is, however, challenged by difficulties in synthesis and labeling techniques. In this proof-of-concept study, we demonstrate that PI can be straightforwardly de novo-synthesized and deuterium (2H)-labeled in Escherichia coli by genomic insertion of PI synthase from Trypanosoma brucei under constitutive synthetic promoter proD. Insertion into loci atpi-gidB and ybb revealed PI accumulation of 41% and 34% (mol/mol), respectively, when cultivated with glycerol as the sole carbon source. Growth of the atpi-gidB-PIS strain in deuterium-labeled (2H) substrates D2O, D8-glycerol, and D6-myo-inositol achieved PI deuteration of 90%, PE deuteration of 95%, and total fatty acids|fatty acid (FA) deuteration of 97%. This study offers an alternative convenient route to chemical and enzymatic labeling synthesis of PI; more excitingly, this work also, in principle, opens a door for tailoring the FA profile of deuterated PI/PE for task-specific application by repurposing FA biosynthesis pathways.

Hemp Seed Protein Hydrolysate Enriched with γ-Aminobutyric Acid and Peptides by Microbial Bioconversion

Hemp seed protein (HSP), a by-product of hemp oil processing, was converted into a functional protein ingredient enriched with γ-aminobutyric acid (GABA) and peptides through a two-step microbial fermentation process. To enhance peptide and free amino acid production from HSP, it was hydrolyzed using alkaline protease produced by Bacillus subtilis HA. The HSP was hydrolyzed at a degree of 40% at 55 °C for 24 h, yielding a pH of 6.55, an acidity of 1.22%, and 205.45 mg% tyrosine equivalents. This process resulted in the production of low molecular-weight peptides. (<5000 Da) The total amino acid content and branched-chain amino acids (leucine, isoleucine, and valine) were 6.78 mg/g and 1.47 mg/g. Subsequently, the production of γ-aminobutyric acid (GABA) in the HSP hydrolysate was optimized through co-fermentation with lactic acid bacteria in the presence of 5% MSG at 30 °C for 5 days. The serial co-fermented HSP hydrolysate exhibited a GABA content of 33.98 mg/g and a viable bacterial count of 9.51 log CFU/mL for Lb. plantarum KS2020. This serial co-fermentation process, combining proteolysis and lactic acid fermentation, not only increased the peptide content but also promoted GABA accumulation, positioning HSP hydrolysate as a promising candidate for functional foods with potential health benefits.

Amino acid requirements of the infant: the amino acid composition of human breast milk

The recommended amino acid requirements of the infant are based on the amino acid composition of mature human breast milk. The amino acid composition of breast milk is usually determined following either acid or alkaline (for tryptophan) hydrolysis. For accuracy, however, the known effect of hydrolysis time on amino acid composition should be accounted for. Also, ideally the amino acid composition of breast milk should be given in units of digested (assumed to be absorbed) amino acids. A review of the literature is presented which gives mean total amino acid concentrations in mature human milk (n = 26 studies), mean hydrolysis correction factors (n = 3 studies) and mean true ileal amino acid digestibility coefficients (n = 3 studies, suckling piglet). There were differences between the estimates of amino acid concentration corrected for hydrolysis time and digestibility, and current FAO (2013) recommendations that were not corrected for these factors. The values based on the published literature up until 2023 (mg/g true protein) corrected for hydrolysis time and digestibility gave higher values (more than 16% higher) for leucine, lysine and threonine, and considerably higher values (greater than 30%) for histidine and tryptophan. Current recommendations may need revision.

Investigating the availability of omega-3 fatty acid from different sources and its effect on table eggs

The impact of three different commercial omega-3 fortifying agents on the growth performance, egg weight, egg production, and omega-3 fatty acid enrichment of white table eggs in layers was investigated. The experiment involved 12,000-layer birds randomly divided into four groups, with each group replicated three times and consisting of 1000 birds per replicate. The three groups, namely LP, AG, and DD, were supplemented with omega-3 fortifying agents LinPro, All-G-Rich, and DHA-gold, respectively, while the fourth group NC served as a negative control without omega-3 fortifying agent supplementation. The experiment commenced after the 25th week of age and lasted for a period of four weeks in a completely randomized design. Egg weight and egg production were recorded weekly, while the omega-3 fatty acid content of the white eggs was determined at the end of the 30-day trial after the 25th week of age. The supplementation of different omega-3 fortifying agents significantly impacted feed intake, with notable differences observed among weekly and overall means. Birds supplemented with LinPro consumed less feed during the 2nd and 4th week of the trial compared to the control, resulting in an overall reduction of 1.1 g/chick in feed intake. However, supplementation did not significantly affect the body weight of layers throughout the trial, nor did it impact egg weight or production. Nevertheless, the omega-3 fortifying agents had a significant effect on the omega-3 fatty acid content of the white table eggs in layers. LinPro supplementation notably increased α-linolenic acid (18:3; ALA) and eicosapentaenoic acid (20:5; EPA) levels, while DHA-Gold resulted in the highest docosahexaenoic acid (22:6; DHA) content. Total fatty acid content was highest in eggs from layers supplemented with LinPro, followed by DHA-Gold and All-G-Rich, with the lowest levels observed in the control group. These findings suggest that dietary supplementation of LinPro in layer diets post the 25th week of age could effectively enhance the omega-3 fatty acid content of white table eggs without compromising feed intake, body weight, egg weight, or egg production.

PSLBI-17 Total sulfur amino acid requirements across the canine life cycle in Labrador Retrievers using the indicator amino acid oxidation (IAAO) technique

Abstract Methionine and cysteine are the principal sulfur-containing amino acids that are incorporated into proteins, although homocysteine and taurine also have important physiological roles in canines. As limited studies have been conducted for total sulfur-containing amino acids (TSAA) requirements across the canine life cycle, our objective was to determine the minimum requirements (MR) for TSAA at 4 life stages using the indicator amino acid oxidation (IAAO) technique. Labrador Retrievers (n = 24) were used in feeding studies to evaluate the changing requirements of TSAA as dogs mature: 6 puppies aged 10 to 14 wk, 6 puppies >14 wk to 9 mos, 6 adults 2 to 5 yr (yr), and 6 seniors > 8yr. Following a 2-d adaptation to a TSAA-adequate basal diet (TSAA = 1.12% dry matter), dogs underwent individual IAAO studies. In brief, all dogs were randomly fed one of six test diets with varying levels of TSAA ranging from deficient to sufficient (final TSAA content in experimental diets were 0.41, 0.46, 0.51, 0.98, 1.05, and 1.12% dry matter, with indispensable amino acids formulated at 1.6x NRC values). The test diet was divided into 13 equal meals; at the 5th meal, a tracer amino acid was included (a bolus L-[1-13C] phenylalanine based on body weight was first given, followed by [1-13C] Phe doses every 30 spanning 4 h). Breath samples were collected via a respiration mask every 30 min. Total CO2 production was determined via indirect calorimetry and production of 13CO2 at each dose was measured by enrichment of 13C in breath samples via isotope ratio mass spectrometry (IRMS). Results for IRMS data were converted to atom percent excess (APE) and analyzed using segmented linear regression. The Four Rivers mean and population requirements for TSAA were estimated to be 1.55 ± 0.069 g/1,000 kcal (mean ± 2 SD) for puppies 10 to 14 wk, 1.53 ± 0.21 g/1,000 kcal (mean ± 2 SD) for puppies 14 wk to 9 mo, 1.4 ± 0.30 g/1000 kcal (mean ± 2 SD) for adults 2 to 5 yr, and 1.27 ± 0.23 g/1,000 kcal (mean ± 2 SD) for seniors. These results may contribute to the formulation of diets that meet the age-appropriate requirements of TSAA for large-breed dogs at all life stages.

PSIII-10 Flaxseed oil-based supplement alters water consumption and plasma fatty acid profile of beef heifers

Abstract The objective of this study was to determine the effects of a flaxseed oil-based supplement (FlaxLic, New Generations, SD) on reproductive parameters, feeding behavior, and lipid profile in beef heifers. Crossbred Angus heifers [n = 60 body weight (BW) = 397kg ± 5.2 kg) were blocked by BW and antral follicle count and randomly assigned to two supplementation treatments: free-choice commercial lose mineral supplement (CON; n = 30) or free-choice flaxseed oil-based supplement (FLAX; n = 30) for 7 wk. Heifers were individually fed via the Insentec feeding system (Insentec RIC, Hokofarm, Marknesse, Netherlands), where basal diet (TMR) and supplements were provided in separate feeders to measure supplement intake and feeding behavior. Further, water intake and behavior were measured via Insentec water system. Individual intake was compiled over 24 h for each animal. Body weight, transrectal ultrasonography, and blood samples were collected weekly. On wk 5, heifers were enrolled in a fixed-time artificial insemination (FTAI) commercial protocol. Largest follicle diameter (LF) and corpus luteum (CL) presence were recorded weekly and on d of the FTAI protocol (d 0, d 7, and d 0). Pregnancy diagnosis was performed 30 d and 60 d following AI. Blood samples were analyzed for progesterone (P4) by radioimmunoassay (RIA) to determine puberty attainment before wk 5, and fatty acid profile was determined via gas chromatography-flame ionization detection. Heifers with a CL or P4 ≤ 1.0 ng/mL were considered pubertal. Data were analyzed using SAS 9.4. ADG was similar between groups (P = 0.90) but was affected by week (P < 0.01). TMR intake was similar in duration and quantity (P > 0.18) between groups. Supplement intake was greater (P < 0.01) for FLAX (0.73 ± 0.03 kg/d) compared with CON (0.18 ± 0.02 kg/d) and from wk 2 to wk 8 (P = 0.01). Time spent consuming the supplements was greater for FLAX compared with CON heifers (62.65 ± 2.11 vs 0.10 ± 0.11 min/d, respectively) over the entire trial (P < 0.01). Further, FLAX heifers consumed less water than CON heifers (32.2 ± 0.39 vs 33.93 ± 0.35 kg/d, respectively; P = 0.03) and from wk 2 to wk 7 (P = 0.03). LF was not different between groups on any of the days of the protocol (d 0, d 7, d 0; P > 0.20). Additionally, P4 (P ≤ 0.20), puberty attainment by wk 5 (P = 0.24), and pregnancy rates (P > 0.48) were similar between groups. Concentrations of arachidonic acid (3.00 ± 0.24 vs 2.32 ± 0.19 mg/mL; P = 0.04), linoleic (60.11 ± 4.34 vs 40.35 ± 4.04 mg/mL; P = 0.002), αLinolenic (16.73 ± 0.26 vs 15.86 ± 0.23 mg/mL; P = 0.02), and total polyunsaturated fatty acids (PUFA; 130.52 ± 5.97 vs 111.19 ± 5.56 mg/mL; P = 0.02) were greater on wk 8 for FLAX compared with CON heifers. Collectively, these findings did not show evidence that the flaxseed oil-based supplement affects variables that impact reproductive performance. However, it altered the plasma lipid profile, increasing omega-3, arachidonic, and linoleic fatty acids, as well as total PUFA.

307 Use of defatted black soldier fly larvae meal (BSFLM) as an alternative and functional ingredient in canine nutrition

Abstract Black soldier fly (Hermetia illucens) larvae meal (BSFLM) is an alternative, sustainable, and nutrient-rich ingredient for pet foods. However, limited information is available on optimal inclusion levels and its functional properties. The objective of the study was to evaluate the effects of incremental levels of BSFLM (15% or 30%) as a partial or full substitute for chicken by-product meal (CM) in extruded diets. Three complete and balanced diets were formulated and extruded: Control, 15% BSFLM, and 30% BSFLM. The effects of the diets on nutrient digestibility, fecal metabolites and microbiota, and serum oxidative stress and inflammatory biomarkers in adult dogs were examined. A complete randomized design was used with adult Beagles (n = 10/treatment). The experimental period lasted 70 d, consisting of a 14-d adaptation to the control diet followed by 56-d test period. Data were analyzed using SAS Proc Mixed 9.4 with P ≤ 0.05 significance. All diets were well-accepted by the dogs; food intake and fecal output were not affected (P > 0.05) by treatment. Apparent total tract digestibility (ATTD) of dry matter, crude protein, and fat did not differ among treatments, whereas ATTD of organic matter (81.2%) and total dietary fiber (18.9%) was less (P < 0.05) for dogs fed 30% BSFLM in contrast with the Control group (83.2% and 30.3%, respectively). Fecal concentrations of total short-chain fatty acids and total phenols were less (P < 0.05) for dogs fed 30% BSFLM relative to dogs fed Control. No treatment effect was observed for serum biomarkers of oxidative stress and inflammation. Fecal microbial diversity differed between Control and 30% BSFLM groups. Overall, extruded diets containing 15% or 30% were well-digested by dogs as demonstrated by similar ATTD coefficients compared with Control. Intrinsic presence of chitin in BSFLM, and other insect-derived ingredients, can behave like insoluble dietary fiber in a food matrix, which would explain the decreased ATTD for organic matter and total dietary fiber, as well as less fecal concentration of total short-chain fatty acids. The inclusion of 30% BSFLM may have decreased protein hindgut fermentation due to less fecal concentration of total phenols. Altogether, the inclusion of 15% BSFLM resulted in similar physiological responses in comparison with dogs fed the Control diet. Greater inclusion levels of BSFLM may impact ATTD, however, it also has the potential to modulate fecal metabolites and microbiota, without negatively affecting fecal microbial richness.

Molecular profiling of triacylglycerols in bovine and goat milk powders via ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry

Triacylglycerols (TAG) play several nutritional, technological, and functional roles in the dairy industry, representing approximately 98 % of milk fat. In the present study, the total fatty acid composition and the sn-2 fatty acid positional distribution of bovine and goat milk powders fat were analyzed by using the gas chromatography-flame ionization detector. Furthermore, the identification of TAG molecular species from milk powders was conducted using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). The separation of milk TAG was accomplished by using isopropanol/acetonitrile (90:10, v/v) as mobile phase A, and water/acetonitrile (60:40, v/v) as mobile phase B. Myristic, palmitic, stearic, and oleic acids were identified as the most abundant fatty acids making up 11.55 and 10.71 %, 33.23 and 30.64 %, 10.86 and 12.52 %, and 26.74 and 21.80 % in the bovine and goat milk powders, respectively. In bovine milk, 221 molecular species of TAG were identified, with the predominant molecular species (LaCyO, CaLaPa, CyPaM, OCaCa, CaGCy, GLaCo) detected at a retention time of 6.362 min, with a relative abundance of 8.28 %. In goat milk, 202 molecular species were identified, with the major molecular species (CaLaM, CaPCa, CaCyS, CaCoAra, CaBuBe, LaPCy, LaCoS, LaBuAra, MPCo, MCyM, MBuS, PBuP, CyCoBe) detected at a retention time of 6.106 min, making up 8.14 % of the total TAG detected. These results provide valuable insights into milk fat composition for the dairy sector, aiding in the development of specialized dairy products.

94 Associative effects of two potent anti-methanogenic Moringa oleifera accessions mixed at various proportions on in vitro rumen fermentation and methane inhibition

Abstract Moringa is an important anti-methanogenic plant with a potential to develop as multipurpose feed additives. Previous studies identified two potent accessions (accession 07633 designated as A3 and accession collected from Pretoria designated as A11) with high methane (CH4) inhibition characteristics. Two metabolite ion features (MIFs) 4.44_609.1462 and MIF 4.53_433.1112 were identified as bioactive MIFs associated with greater methane inhibition in Moringa accession A3 and A11, respectively. Two separate studies were conducted with an aim to name the MIF associated with methane inhibition and evaluate the benefit of mixing plant extract from A3 and A11 in different proportions to exploit their additive or synergistic effect in inhibiting CH4 emission. In study 1, software and online tools such as MS-DIAl, MS-FINDER, and the mass bank database were used to identify the MIF 4.44_609.1462 and MIF 4.53_433.1112, and the two MIFs were tentatively named as Hesperidin and Isovitexin, respectively (Figure 1). In study 2, the Moringa plant extracts from A3 and A11 were mixed in the following proportion A3100:A110, A380:A1120, A360:A1140, A350:A1150, A340:A1160, A320:A1180, and A30:A11100 proportions (A3:A11), and applied at a rate 50 mg/kg DM of Eragrostis curvula hay incubated in an Incoshake incubator to determine their effect on in vitro gas production and CH4, and in vitro organic matter digestibility (IVOMD) of the hay. In each incubation run, the sole or a mixture of the Moringa plant extract treatments were added to the test feed and incubated in 125 mL serum bottles with four replications per treatment, and the incubation was repeated for three runs. A Chi–square (☐2) test were used to determine the presence of an associative effect for mixtures combined at different proportion. Generally, the mixture resulted in less (P < 0.05) CH4 volume, slightly improved or no effect on IVOMD, propionate concentration decreased acetate while increasing propionate concentration, with higher CH4 inhibition, and % CH4 inhibition was significantly greater when the two accessions were mixed in 50% proportion (Figure 2). Specifically, associative effects were recorded when the two accessions are mixed in 50% proportion in terms of greater CH4 inhibition, propionic acid concentration and total volatile fatty acid production (TVFA), as well as reduction in CH4 per unit TVFA and C2:C3 ratio (Table 1). Therefore a 50% binary cocktail of M. oleifera accession A3 and A11 (A350:A1150) plant extracts can be used as feed additive for CH4 inhibition without affecting the feed fermentation adversely when compared with the sole accession leaf extracts or other proportions of binary cocktails. Detailed mechanisms of action, however, need to be confirmed.

383 Performance of piglets in response to graded dietary supplementation of sulfur amino acids using either hydroxy-methionine or DL-Methionine during the post-weaning period

Abstract Providing piglets with their precise nutritional need is critical during the stressful post-weaning period. Methionine (Met), a sulfur-containing amino acid, has a crucial role in piglet growth and health. Stressful conditions may increase Met demand due to its involvement in maintaining redox balance via downstream metabolites such as glutathione. There are different sources of supplementary Met for pigs such as DL-methionine (DL-Met) and hydroxy-methionine. The latter comes mostly as an acidic liquid form (OH-Met) and to a lesser degree as a powder calcium-salt (OH-Met-Ca). This study investigates the effect of graded levels of dietary total sulfur amino acids (TSAA) by supplementing different sources of Met on the performance and capacity of post-weaning piglets to respond to stress. Two experiments were performed. In experiment 1, post-weaning piglets [n = 90; 28 d of age; body weight (BW) = 9.13 ± 0.65 kg] were fed with either DL-Met or OH-Met-Ca to provide 80%, 100%, and 125% TSAA recommendations of NRC and performance parameters were measured for 41 d. Treatments were replicated nine times, and blocking was done according to initial BW. For experiment 2, 720 post-weaning piglets (n = 720; 28 d of age; BW = 6.84 ± 1.07 kg) from three consecutive breeding batches were fed with either DL-Met, OH-Met, or OH-Met-Ca at or above (100% or 125%) TSAA requirements of FEDNA. Performance parameters and oxidative status through various plasma indicators were measured. Treatments were replicated 12 times. Data from both experiments were analyzed separately using a mixed effect model with Met source and level as fixed effects (and their interaction in experiment 2) and blocks and batch as random effects for experiments 1 and 2, respectively. In experiment 1, piglets fed 80% of TSAA requirement showed the least average daily weight gain, while those fed OH-Met-Ca at 100% or DL-Met at 125% requirement had the greatest BW gain among the treatments (P < 0.01). Feed conversion ratio was best for piglets fed with OH-Met-Ca at 100% requirement, while animals fed with 80% requirement were the least efficient (P = 0.04). Contrasts showed no differences between Met sources (P ≥ 0.51) and level of TSAA (P ≥ 0.56) for any of the parameters. Meanwhile in experiment 2, there were no interactions between Met source and TSAA level (P > 0.10). The Met source did not affect any parameter (P ≥ 0.14). However, there was a significant decrease in daily feed intake when piglets were fed above requirements (P = 0.02), and a significant increase in the concentration of plasma glutathione peroxidase when piglets were fed at TSAA requirements (P < 0.05). These results suggest that post-weaning piglet performance and oxidative status can be sustained regardless of the Met source tested. Feeding healthy and unchallenged piglets with excess dietary Met may not bring extra benefits.

191 Awardee Talk: Characterizing biological processes influencing the efficiency of nutrient utilization in growing cattle

Abstract 2Abstract: Residual feed intake (RFI), a metric of feed efficiency, is moderately heritable and minimally associated with body size and productivity, making it an ideal trait for investigation as a selection criterion to improve feed efficiency of growing cattle. The objective of this research was to characterize the inter-animal variation in biological processes of growing cattle selected to be divergent in RFI. Holstein heifers [n = 55; body weight (BW) = 351 ± 64 kg) with low- (n = 29) or high- (n = 26) genomically enhanced RFI (RFIg) were selected from a contemporary group of 453 heifers. Heifers were assigned to 1 of 2 pens, equipped with electronic feed bunks and a GreenFeed gaseous-exchange measurement system. Individual dry matter intake (DMI) and feeding behavior data were collected for 84-d. Body weight was measured weekly, and spot fecal samples collected at weighing. Phenotypic RFI (RFIp) was calculated as the residual from regression of DMI on ADG and mid-test BW0.75. On d 70 of the study a rumen fluid sample was collected via esophageal tubing. Blood samples were collected and analyzed for complete blood count (CBC). A mixed model including the fixed effect of RFIg classification and random effect of pen was used to evaluate the effect of RFIg classification on response variables. There were no differences (P > 0.05) in BW and ADG for heifers with divergent RFIg; however, low RFIg heifers consumed 7.5% less (P < 0.05) feed per day. Consequently, low RFIg heifers exhibited a more favorable (P < 0.05) RFIp (-0.188 vs 0.211 kg/d, respectively). Low RFIg heifers exhibited more favorable feeding behavior, with 8.7% fewer (P < 0.05) bunk visit events per day and an 11.2% slower (P ≤ 0.05) eating rate. Low RFIg heifers had 12.5% greater (P < 0.05) total rumen volatile fatty acid concentrations than high RFIg heifers, indicating potentially enhanced microbial fermentation and improved efficiency of feed utilization. Low RFIg heifers had 8.2% less (P < 0.05) methane emissions (g/d), 6.3% less (P < 0.05) carbon dioxide production (g/d), and 6.1% less (P < 0.05) heat production (Mcal/d) calculated according to Brouwer (1965) than high RFIg heifers. Dry matter digestibility did not differ (P > 0.05) between heifers with divergent RFIg. Overall, heifers selected to be more feed efficient exhibited more favorable energy efficiencies and feed efficiency phenotypes. To quantify the variation in RFIg explained by feeding behavior, gas flux, digestibility and rumen fermentation, and CBC partial least squares regression models were developed. Feeding behavior accounted for the largest proportion of variation in RFIg (28.8%). Upon sequential addition of gas flux, digestibility and rumen fermentation, and CBC to feeding behavior, 56.3% of the variation in RFIg was accounted for. Identifying the magnitude at which metabolic processes influence inter-animal variation in efficiency of nutrient utilization provides opportunities to discover valuable candidate biomarkers for selection of more feed efficient cattle.

516 Effects of increasing hybrid rye silage as a replacement for barley silage for growing beef heifers

Abstract The objective of these studies was to evaluate effects of increasing hybrid rye silage (HRS; harvested at boot stage in Study 1 and soft-dough in Study 2) inclusion as a replacement for barley silage (BS; harvested at soft-dough stage) on dry matter intake (DMI), ruminal fermentation, and growth performance of growing beef cattle. In Study 1, ruminally cannulated Hereford × Simmental heifers (n = 8) with an initial body weight (BW) of 519 ± 25.8 kg were used in a replicated 4 × 4 Latin square design with 28-d periods including 21 d of dietary adaptation and 7 d of data and sample collection to assess DMI and ruminal fermentation. Treatments included a control diet (DM basis) that contained 59.62% BS, 38.60% barley grain, and 1.78% of a vitamin and mineral supplement. Hybrid rye silage replaced 33, 67, and 100% of the BS on a DM basis. In Study 2, steers (n = 384; BW = 343 ± 20.2 kg) were stratified by BW and allocated to 32 pens in a randomized complete block design over 2 yr (4 pens/treatment/yr) to evaluate DMI, growth, and gain:feed (G:F). Steers were fed similar diets as Study 1 for 84 d in both years. In Study 1, increasing HRS linearly (P < 0.01) decreased DMI from 12.0 to 9.2 kg/d, and linearly increased (P = 0.02) water intake from 18.6 to 22.5 L/d. Increasing HRS linearly increased mean (P < 0.01) and minimum ruminal pH (P < 0.01). There was no effect of HRS inclusion on total short-chain fatty acid concentration (P = 0.46) in ruminal fluid, but the molar proportion of acetate linearly (P < 0.01) increased while propionate and butyrate linearly decreased (P < 0.01, and < 0.01, respectively) with increasing HRS inclusion. Moreover, increasing HRS inclusion linearly increased the molar proportions of isobutyrate and valerate (P = 0.06, and < 0.01, respectively) while caproate decreased linearly (P = 0.02). The ammonia-N concentration linearly increased with increasing HRS inclusion. In Study 2, DMI was 9.23, 9.10, 8.82, 8.08 kg/d (quadratic, P = 0.02) for diets containing 0, 33, 67, and 100% HRS, respectively. Likewise, ADG decreased (1.45, 1.36, 1.30, 1.08 kg/d; quadratic P < 0.01) as HRS inclusion increased and G:F ratio decreased linearly (P < 0.01) from 0.158 with 0% HRS to 0.134 g/kg when diets contained 100% HRS. Final BW was 462, 456, 450, and 432 kg when HRS was included at 0, 33, 67, and 100% of the silage, respectively (quadratic, P = 0.04). In conclusion, replacing BS with increasing proportions of HRS reduced DMI resulting in greater ruminal pH, altered molar proportions of individual SCFA, and reduced growth performance and G:F during the growing phase.

157 Microbial inoculant effects on limpograss silage

Abstract Warm-season perennial grasses are the main forage sources preserved as silage or haylage by livestock producers in subtropical and tropical regions; however, the nutritive value and silage fermentation parameters are often less than desirable. Microbial inoculants have been used to improve grass silage nutritive value and fermentation characteristics with inconsistent results. The objective of this study was to investigate the effects of a microbial inoculant on nutritive value and fermentation parameters of ‘Gibtuck’ limpograss (Hemarthria altissima) silage. Treatments were silage treated with SiloSolve FC (68.1 billion CFU/g, Lactobacillus lactis and Lactobacillus buchneri) or control (no microbial inoculant) distributed in a complete randomized design with 10 replicates. The inoculant level used was 0.5 g/Mg of forage. The experiment was conducted in Ona, FL in May 2023. Twenty 4 × 4 m plots of established limpograss were harvested at 15-cm stubble height with 58-d regrowth interval. The forage was chopped to a particle size ranging from 10 to 18 mm, placed into mini-silos (PVC pipes with rubber), and sealed immediately. The inoculant was applied with a hand sprayer before ensiling. The silos were opened after 60 d for analysis. There was no difference (P > 0.05) between the inoculant and control treatments on DM concentration (25%), DM recovery (96%), NDF (67%), and NFC concentrations (14%); however, silage treated with inoculant had greater CP (8.5 vs. 8.0%; P = 0.03), IVTD (56 vs. 54%; P = 0.01), and NDFD (53 vs. 51%, P = 0.02) and lesser ADF concentrations (38 vs. 40%; P = 0.02) than control. The inoculant did not affect (P > 0.05) silage pH (4.2) and lactic acid concentrations (1.5%) but resulted in greater acetic acid (2.5 vs. 2.0%; P = 0.01), propionic acid (1.6 vs. 1.0%, P < 0.01), and total acid concentrations (5.6 vs. 5.0%; P = 0.04), and decreased butyric acid (0 vs. 0.2%; P < 0.01), isobutyric acid (0.1 vs. 0.4%; P < 0.01), and NH3-N concentrations (4.4 vs. 5.3% N; P < 0.01). Aerobic stability (140 h), mold (1.1 log cfu/g) and yeast (2.2 log cfu/g) count were not affected (P > 0.05) by the inoculant treatment. At the genus level, there was no difference (P > 0.05) in relative abundance of Lactobacillus (85%), Enterobacter (4.0%), Enterococcus (1.8%), and Weissella (0.2%) between inoculant and control, but silage treated with inoculant had less Clostridium (1.0 vs. 2.3%, P = 0.04), Pediococcus (0.2 vs. 0.3%, P = 0.03) and greater relative abundance of Lactococcus (2.8 vs. 0.5%, P < 0.01) and Bacillus (0.2 vs. 0.1%, P = 0.01). At the species level, the inoculant was effective to increase the relative abundance of Lactococcus lactis (from 0.02 to 0.48, P = 0.002) and Lactobacillus buchneri (from 1.4 to 1.9, P = 0.03). SiloSolve FC is a promising microbial inoculant to be used in warm-season grass silage in subtropical and tropical regions.

Elevated total bile acid levels as an independent predictor of mortality in pediatric sepsis.

The close relationship between bile acid (BA) metabolism and sepsis has been investigated in recent years, as knowledge of the role of the gut microbiome and metabolomics in sepsis has grown and become more comprehensive. Patients with sepsis who were admitted to the PICU of the Children's Hospital, Zhejiang University School of Medicine from January 2016 to December 2021 were enrolled in this study. Preoperative non-infectious pediatric patients undergoing elective surgeries in our hospital's department of surgery were recruited as controls during the same period. Clinical data were collected and analyzed. 702 children were enrolled, comprising 538 sepsis survivors, 164 sepsis fatalities, and 269 non-infected controls. Statistical analysis revealed that total BA (TBA) increased in both the early and severe stages of pediatric sepsis. In the severe stage, TBA (OR = 2.898, 95% CI 1.946-4.315, p < 0.05) was identified as a risk factor for sepsis. A clinical model identified TBA (the cut-off value is >17.95 µmol/L) as an independent predictor of sepsis mortality with an AUC of 0.842 (95% CI 0.800-0.883), sensitivity of 54.9%, specificity of 96.6%, and HR = 7.658 (95% CI 5.575-10.520). The study showed that elevated TBA was associated with a heightened risk of mortality in pediatric sepsis. Many clinical indicators show differences between children with sepsis and the control group, among which the difference in serum total bile acid levels is the most significant. During the hospitalization of the patients, the overall bile acid levels in the sepsis death group were higher and exhibited greater fluctuations compared to the survival group, with significant differences. Serum total bile acid levels can serve as effective biomarker for predicting the prognosis of children with sepsis.

Be prepared: how does discontinuous hydration in Tabebuia heterophylla seeds induce stress tolerance in seedlings?

Discontinuous hydration and dehydration (HD) cycles refer to controlled imbibition followed by dehydration before seed germination. Here, we investigated whether the level of imbibition before HD cycles affects the physiology of Tabebuia heterophylla seeds and seedlings. Seeds were imbibed for 10 h (T1; phase I of imbibition) or 35 h (T2; phase II), dehydrated, and progressively rehydrated one to four times (HD cycles). Germination and biochemical parameters (membrane integrity; total soluble, reducing, and nonreducing (NRS) sugars; proteins, amino acids, proline, H2O2, catalase, ascorbate peroxidase, and glutathione reductase activity) were quantified at the last rehydration step of each cycle. Biometric and biochemical parameters (including pigments) were analysed in seedlings 60 days after germination. HD cycles at T1 led to reduced seed germination and greater plasma membrane damage, higher enzyme activity (catalase and glutathione reductase) and accumulation of NRS, total amino acids, and proline compared to the controls and T2 treatment. Cellular damage became more severe with more HD cycles. HD cycles at T2 synchronized germination regardless of the number of cycles and also had a priming effect. T2 seeds had less NRS, total amino acids, and proline content than T1. HD cycles at T1 produced seedlings with higher carotenoid and total chlorophyll content than controls and T2, while seedlings from HD cycles at T2 had higher amounts of osmoprotectants. HD cycles at T2 benefited seeds and seedlings more than at T1. This suggests that the physiological and biochemical effects of HD cycles in seeds modulate seedling plasticity, depending on water availability, potentially promoting increased tolerance to recurrent droughts that will be intensified with ongoing climate changes.