Dietary Starch Research Articles

Growth performance, nutrient digestibility, antioxidant status and metabolic enzyme activity in pearlspot (Etroplus suratensis), fed carbohydrates of different complexities

Carbohydrate utilization by fish is influenced by many factors and structural complexity is one among them. A 60-days feeding study was conducted to assess the capacity of pearlspot, Etroplus suratensis to utilize different complexity of carbohydrate in growth performance, nutrient digestibility, antioxidant status, metabolic and digestive enzyme activity and histology of liver. Five isonitrogenous (35%) and isolipidic (7%) diets were formulated to contain 35% of glucose (GLU-feed), sucrose (SUC-feed), dextrin (DEX-feed), starch (STA-feed) and cellulose (CEL-feed), respectively. The survival and condition factor were not affected (p > 0.05) by the diets. Fish fed with the STA-feed showed significantly (p < 0.05) higher weight gain and specific growth rate. The feed efficiency ratio and protein efficiency ratio were significantly higher (p < 0.05) and alike in STA-feed and Dex-feed groups. Except for protein, the other whole-body composition was affected significantly (p < 0.05) by the different carbohydrate sources. The activities of antioxidant enzymes were significantly (p < 0.05) higher in groups fed on complex carbohydrate diets. Simillar trend was observed in the protease enzyme activity. Significantly (p < 0.05) higher dry matter digestibility was recorded in starch fed group. STA-feed group increased the specific activity of malate dehydrogenase and hexokinase.The glucose 6 phosphate dehydrogenase (G6PDH) activity was significantly (p < 0.05) higher in the GLU-feed group, and gradually decreased with increase in the complexity of carbohydrates.The DEX-feed and CEL-feed groups showed heavy fatty change with numerous large lipid droplets as compared to other groups. Overall, these results indicate that dietary starch was more efficiently utilized than other carbohydrate sources by pearlspot.

Acarbose impairs gut Bacteroides growth by targeting intracellular glucosidases.

Acarbose is a type 2 diabetes medication that works primarily by stopping starch breakdown into glucose in the small intestine. This is accomplished by the inhibition of host enzymes, leading to better blood sugar control via reduced ability to derive glucose from dietary starches. The drug and undigested starch travel to the large intestine where acarbose interferes with the ability of some bacteria to grow on starch. However, little is known about how gut bacteria interact with acarbose, including microbes that can use starch as a carbon source. Here, we show that two gut species, Bacteroides ovatus (Bo) and Bacteroides thetaiotaomicron (Bt), respond differently to acarbose: Bt growth is inhibited by acarbose, while Bo growth is less affected. We reveal a complex set of mechanisms involving differences in starch import and sensing behind the different Bo and Bt responses. This indicates the gut microbiome may be a source of variable response to acarbose treatment for diabetes via complex mechanisms in common gut microbes.

Different starch sources and amino acid levels on growth performance, starch and amino acids digestion, absorption and metabolism of 0- to 3-week-old broilers fed low protein diet

The synchronized absorption of amino acids and glucose in the gut is essential for amino acid utilization and protein synthesis in the body. The study aimed to investigate how the starch digestion rate and amino acid levels impact the growth and intestinal starch and amino acid digestion, transport, and metabolism in juvenile broilers. The experiment was conducted with 702 Arbor Acres Plus broilers at 1 d old, which were randomly divided into 9 treatments with 6 replicates of 13 chickens each. The treatments included 3 different starch sources (corn, waxy corn, and tapioca) with 3 different apparent ileal digestible lysine (AID Lys) levels (1.08%, 1.20%, and 1.32%). A notable interaction was noted for dietary starch sources and AID Lys levels in the feed-to-gain ratio (F/G) and distal ileal starch digestibility (P < 0.01). The tapioca starch and waxy corn starch diets with 1.32% of AID Lys significantly decreased F/G compared with corn starch (P < 0.01). There was no significant difference in F/G of broilers among waxy corn starch diet with 1.08% AID Lys level, tapioca starch diet with 1.20% AID Lys level, and corn starch diet with 1.32% AID Lys level (P > 0.05). The 1.32% AID Lys level and the waxy corn starch both improved the body weight (BW) of broilers from 0 to 3 weeks of age, intestinal starch digestibility, and intestinal villi height or the ratio of villi height to crypt depth (P < 0.05). Compared with the corn starch diet, waxy corn starch and tapioca starch diets significantly elevated the AID of Met, Glu, Lys, Arg, Asp, His, Ile, Tyr, Gly, and Val levels (P < 0.05). The carbon metabolomics results revealed that the waxy corn starch diet significantly reduced malic acid and cis-aconitic acid levels (P < 0.05) in the tricarboxylic acid cycle compared to the corn starch diet. It was concluded that a waxy corn starch diet improves the growth performance of broilers by improving intestinal morphology, increasing the absorption and transport of amino acids, reducing the amino acid oxidation for energy supply in the intestinal mucosa, and promoting protein synthesis in muscles, which not only reduces the need for dietary AID Lys but also saves on production costs.

Effects of dose, dietary nutrient composition, and supplementation period on the efficacy of methane mitigation strategies in dairy cows: A meta-analysis

The objective of this meta-analysis was to quantify the potential of CH4-mitigating strategies in dairy cattle when accounting for the effects of treatment dose, dietary nutrient composition, and supplementation period. Data from 218 studies with dairy cattle published between 1963 to 2022 were reviewed. Individual CH4 mitigation strategies selected for the analysis were algae (Asparagopsis spp.), 3-nitrooxypropanol, nitrate, lipids, plant secondary compounds, and direct-fed microbials (DFM). Response variables evaluated were daily CH4 emission (g/d), CH4 yield (g CH4/kg DMI), and CH4 intensity (g CH4/kg milk yield [MY] and ECM). Relative mean difference between treatment and control means reported in the studies were calculated and used in the statistical analysis. Robust variance estimation method was used to analyze the effects of CH4 mitigation strategies. Dose, forage-to-concentrate ratio (F:C), dietary concentrations of CP, ether extract (EE), NDF, ADF, and starch, and supplementation period were used as continuous explanatory variables. Data for algae supplementation were limited and responses to studied species were contrasting but, overall, Asparagopsis spp. effectively decreased daily CH4 emission, CH4 yield, and CH4 intensities by 29.8 ± 4.6%, 23.0 ± 5.3%, 34.0 ± 4.3%, and 22.6 ± 7.3%, respectively. Supplementation of 3-nitrooxypropanol decreased daily CH4 emission, yield, and intensity (per kg MY and ECM) by 28.2 ± 3.6%, 28.7 ± 2.8%, 29.2 ± 3.1%, and 31.8 ± 2.8%, respectively, compared with control. Decreasing dietary fiber (i.e., F:C, NDF, and ADF), whereas increasing dietary starch concentration increased the efficacy of 3-nitrooxypropanol at mitigating enteric CH4 emission. Nitrate supplementation decreased CH4 emission, yield, and intensity (per kg ECM) by 18.5% ± 1.9%, 17.6 ± 1.6%, and 13.0 ± 0.2%, respectively, compared with control. Efficacy of nitrate at mitigating enteric CH4 yield and CH4 intensity was positively associated with dose, and efficacy of nitrate at mitigating CH4 yield was positively associated with dietary starch concentration. Lipid supplementation decreased CH4 emission, yield, and intensities by up to 14.8 ± 2.3%, respectively, compared with control. Efficacy of lipids supplementation was positively associated with dietary EE, starch, and supplementation period, but negatively associated with dietary ADF concentration. Free oil supplementation tended to increase lipid efficacy by 31% at decreasing CH4 emission, compared with control. Condensed tannins and plant-derived bioactive compounds decreased CH4 yield by 11.3 ± 2.9% and 5.7 ± 2.5%, respectively, but oregano did not affect enteric CH4 emission metrics in the current meta-analysis. Direct-fed microbials were not effective in mitigating enteric CH4 emission variables. Data were limited to determine the effects of dietary nutrients and duration of supplementation on efficacy of Asparagopsis spp., plant secondary compounds and DFM. Overall, supplementation of the diet with Asparagopsis spp., 3-nitrooxypropanol, nitrate, and lipids were the most effective strategies for decreasing enteric CH4 emission in dairy cattle. Variability in the efficacy of most CH4 mitigation strategies can be partially explained by differences in treatment dose, dietary nutrient composition, and supplementation period.

Improvement of gastric disease and ridden horse pain ethogram scores with diet adaptation in sport horses.

Gastric disease is highly prevalent in sport horses and may lead to poor performance, cause behavioral changes and impact welfare. Assess whether diet affects gastric disease and pain expression during riding, and whether it has an impact on physiological and locomotor variables during an exercise test, including jumps. Nine healthy show-jumping Warmbloods trained at the same stable. Prospective observational cohort study. The horses receiving a pelleted diet, high in sugar and starch (>30%), were examined at T0 and after 12 weeks (T12) of changing to a cooked, muesli-type low-starch (11%) diet. Each time, the horses underwent a standardized exercise test (SET) and a ridden pain score (Ridden Horse Pain Ethogram [RHpE]) was calculated by 2 blinded observers. The next day, horses underwent gastroscopy and gastric lesions were scored blindly. Results were analyzed using Wilcoxon and Spearman tests. After 12 weeks of a low starch diet, the Equine Gastric Disease (EGD; 4 [3-5] at T0 vs 1 [0-1] at T12, P < .01) and RHpE scores (6 [3-13] at T0 vs 3 [0-6] at T12, P < .01) improved significantly. Squamous, glandular, and EGD scores were positively correlated with RHpE scores (respectively, r = .747, P < .01; r = .743, P < .01 and r = .867, P < .01). Gastric disease and pain scores correlated positively in ridden horses. A low starch diet significantly decreases the severity of gastric disease and associated pain score during riding in horses. Gastric ulcers may be mitigated and the comfort of equines athletes improved by dietary adjustments.

Impact of feeding age on cognitive impairment in mice with Disrupted-In-Schizophrenia 1 (Disc1) mutation under a high sucrose diet

A combination of genetic predisposition and environmental factors contributes to the development of psychiatric disorders such as schizophrenia, bipolar disorder and major depressive disorder. Previous studies using mouse models suggested that prolonged high sucrose intake during puberty can serve as an environmental risk factor for the onset of psychiatric disorders. However, the impact of both the duration and timing of high sucrose consumption during different developmental stages on pathogenesis remains poorly defined. We therefore investigated the effects of a long-term high sucrose diet on cognitive deficit, a core symptom of psychiatric disorders, using Disrupted-in-Schizophrenia 1 locus-impairment heterozygous mutant (Disc1het) mice as a model for genetic predisposition. First, Disc1het mice and their littermate control (WT) were fed either a high sucrose diet or a control starch diet for nine weeks starting at weaning (postnatal day 24), and tested for cognitive performance in the object location test (OLT) and the novel object recognition test (NORT) (assessing spatial and recognition memory, respectively). Only Disc1het mice on a high sucrose diet displayed deficits in OLT (p < 0.0001), demonstrating impaired hippocampus-dependent spatial memory. This behavioral abnormality was accompanied by a decreased proportion of the high parvalbumin-expressing interneurons (High-PV neurons) in the ventral hippocampus, a cell type that regulates neural activity and a variety of learning and memory processes such as spatial and working memory. We further explored the critical developmental period for high sucrose intake to cause cognitive deficits in adulthood by comparing specific feeding periods during puberty (P24-P65) and post-puberty (P65-P90). Compared to those on a standard chow diet, high sucrose intake caused deficits in spatial memory in both WT and Disc1het mice, with more pronounced effects in Disc1het mice. In particular, Disc1het mice on a sucrose diet during adolescence showed more pronounced cognitive deficit than those fed after adolescence. Our results suggest that adolescence is particularly vulnerable to nutritional environmental risk factors, and that high sucrose consumption may cause hippocampus-dependent memory deficits via decreased High-PV interneuron function when combined with Disc1-related genetic predisposition.

High fat intake aggravates hyperlipidemia and suppresses fatty liver symptoms induced by a high-sucrose diet in rats.

Overconsumption of sucrose or fat is widely acknowledged as a prominent feature of unhealthy dietary patterns. Both factors commonly co-occur and are recognized as hallmarks of the Western diet, which is an important contributor to non-communicative diseases. In this study, we investigated the hazards of high sucrose or fat intake, either alone or in combination. Wistar rats were divided into four groups and fed a control starch diet, high-sucrose diet, high-fat diet, or high-sucrose/fat diet for 30 days. High fat intake increased body weight and visceral and subcutaneous adipose tissue weights. Both high-sucrose and -fat diets were associated with increased plasma triglyceride and glucose levels, and high sucrose also elevated plasma cholesterol levels. The combination of high sucrose and fat synergistically elevated plasma triglyceride levels. The high-sucrose diet increased liver weight and hepatic total lipid and triglyceride levels, whereas this increase was suppressed by the high-fat diet. The high sucrose increased the mRNA levels of hepatic genes involved in fatty acid synthesis and transport (ACLY, ACACA, FAS, ELOVL6, SCD1, SREBP1, and CD36), whereas the high fat suppressed the high sucrose-induced expression of these genes. We observed that high sucrose and fat contents differently exerted their effects on hyperlipidemia and fatty liver. Furthermore, high fat aggravated hyperlipidemia and suppressed fatty liver induced by high sucrose.

Liver proteomics identifies a disconnect between proteins associated with de novo lipogenesis and triglyceride storage

De novo lipogenesis (DNL) has been implicated in the development and progression of liver steatosis. Hepatic DNL is strongly influenced by dietary macronutrient composition with diets high in carbohydrate increasing DNL and while diets high in fat decrease DNL. The enzymes in the core DNL pathway have been well characterised, however less is known about other liver proteins that play accessory or regulatory roles. In the current study, we associate measured rates of hepatic DNL and fat content with liver proteomic analysis in mice to identify known and unknown proteins that may have a role in DNL. Male mice were fed either a standard chow diet, a semi-purified high starch or high fat diet. Both semi-purified diets resulted in increased body weight, fat mass and liver triglyceride content compared to chow controls and hepatic DNL was increased in the high starch and decreased in high fat fed mice. Proteomic analysis identified novel proteins associated with DNL that are involved in taurine metabolism, suggesting a link between these pathways. There was no relationship between proteins that associated with DNL and those associated with liver triglyceride content. Further analysis identified proteins that are differentially regulated when comparing a non-purified chow diet to either of the semi-purified diets which provide a set of proteins that are influenced by dietary complexity. Finally, we compared the liver proteome between 4- and 30-week diet-fed mice and found remarkable similarity suggesting metabolic remodelling of the liver occurs rapidly in response to differing dietary components.

Hydroponic fodders as alternative feeds for ruminants to reduce ruminal methane emissions: An in vitro study

Malate, a precursor in the ruminal propionate production pathway, competes with methanogenesis for metabolic hydrogen, offering a way to reduce ruminal methane (CH4) production in ruminants. However, cost considerations hinder widespread use of malate in ruminant diets. An alternative approach involves utilizing transient malate levels generated during seed germination via the glyoxylate cycle. This study investigated the methane-mitigating potential of malate-containing hydroponic fodder. Fodder samples with peak malate concentrations from alfalfa, forage pea, Italian ryegrass, rye, soybean, triticale, and wheat during germination were subjected to in vitro rumen fermentation using the Hohenheim gas test. The basal diet of in vitro fermentation comprised 40% grass silage, 40% maize silage, 15% hay, and 5% concentrate on a dry matter basis, with nutritional characteristics including 42.1% neutral detergent fiber (NDF), 25.0% acid detergent fiber, 14.0% starch, 12.7% crude protein, and 3.5% ether extract (EE), on a dry matter basis. Experimental treatments were fodder inclusion involved replacing 20% of the basal diet (20R), and additionally, 100% replacement of the silages with alfalfa d 10 and rye d 9 (SR), the 2 high-malate fodders. Reductions in CH4 production were observed with soybean (20R, 6.7% reduction), alfalfa (20R, 6.6% reduction), and increased with rye (20R, 6.3% increase). In the setup replacing silages with high-malate fodders (SR), alfalfa decreased CH4 production (17.7%) but increased ammonia (174%), while rye increased CH4 production (35.8%). Organic matter digestibility increased with SR rye (12.6%). Marginal effects of dietary variables were analyzed in a Generalized Additive Model. A negative relationship between dietary malate content and CH4 production was observed, whereas dietary NDF and starch content were positive correlated with CH4 production. In conclusion, malate within the hydroponic fodder could potentially reduce CH4 emissions in ruminants. However, achieving sufficient efficacy requires high malate content. Additionally, use of hydroponic fodder may increase the risk of nitrogen emissions. Animal studies are required for further investigation.

High-sucrose diet induces abnormalities in lipid metabolism through gut microbiome dysbiosis linked to five metronidazole-suppressed bacteria

Public attention to the correlation between excessive sucrose consumption and metabolic syndrome has facilitated research on its underlying mechanisms. Recent studies have newly identified the intestine, rather than the liver, as the predominant site of dietary fructose metabolism, which corrects the previous concepts and links the promotion of fatty liver and hyperlipidemia to gut microbiota dysbiosis, although the specific mode of action remains unclear. Here, we used microbiota suppression to identify the causative bacteria. Male Wistar rats were fed a starch or high-sucrose diet and orally administered two independent antibiotic treatments for four weeks. Metronidazole, neomycin, ampicillin, vancomycin, and their mixture were used to explore highly sucrose-responsive bacteria. Metronidazole and the mixture decreased or showed a tendency to decrease high-sucrose diet-induced increases in liver weight, plasma triglyceride levels, and fatty acid synthesis-related gene expression (ATP citrate lyase, fatty acid synthase, and malic enzyme). To further investigate the ability of metronidazole to ameliorate high-sucrose diet-induced abnormalities in lipid metabolism, three nitroimidazole antibiotics (metronidazole, tinidazole, and ornidazole) were used. Only metronidazole reduced the liver weight and decreased plasma triglyceride levels on a high-sucrose diet. Among the high-sucrose diet induction effects, five bacteria suppressed by metronidazole were screened, belonging to the family Rikenellaceae, genera Bacteroides, Blautia, and Dorea, and species Eubacterium dolichum. Overall, suppression of the gut microbiota by metronidazole-specific action, rather than the nitroreductase activity of tinidazole and ornidazole, was responsible for the amelioration of high-sucrose diet-induced fatty liver and hypertriglyceridemia. Five causative bacteria were identified in this study.

Amylase activity across black soldier fly larvae development and feeding substrates: insights on starch digestibility and external digestion

Black soldier fly larvae (BSFL; Hermetia illucens) hold promise for converting biowaste into proteins and lipids for feed. Dietary starch is efficiently digested by the larvae and influences larval performance, but the mechanisms of starch digestion remain poorly understood. This study investigated changes in individual weight and amylase activity in BSFL after 4, 7 and 11 days of feeding for five substrates varying in starch content and type: chicken feed (CF), corn gluten feed (CGF), wheat bran (WB), wheat distillers grain (WDG) and discarded potatoes (DP). Substrate amylase activities were also measured with and without larvae (feeding and fermenting trays, respectively) over time in order to explore external digestion. Feed conversion ratio (FCR) and estimated digestibility (ED) of DM and starch were assessed at the end of the experiment. The ranking for best FCR was CF, WB, CGF, WDG and DP. In feeding trays, ED of DM was 69.8 ± 1.8, 59.5 ± 2.9, 58.6 ± 0.7, 45.4 ± 0.6 and 19.5 ± 0.8% in CF, DP, WB, CGF and WDG, respectively. Estimated digestibility of starch reached 100% with WB and CGF, followed by CF (88.2 ± 2.3%), DP (85.2 ± 1.2%) and WDG (43.1 ± 1.0%). Larval amylase activity increased with growth for all substrates and dropped when approaching pupation. No relationship was found between larval amylase activity and substrate starch or other nutrient content, but a negative correlation was reported with the reducing sugar content of the larvae, suggesting glucose repression of amylase production. Amylase activity decreased with time in all feeding and fermenting substrates except WDG and DP. In vitro degradation assays indicated that BSFL amylase was nine times more efficient on raw corn or wheat starch than on raw potato starch, highlighting that starch structure is a major driver of digestibility. Western blot analysis revealed the presence of BSFL amylase in the feeding substrate, hinting at external digestion. Larval amylase was purified to identify its optimal pH (5.0–6.5) and temperature (70 °C). These results highlight that starch content is not a major driver of amylase activity in BSFL and suggest that other non-investigated factors could have had a crucial impact on the activity of larval digestive enzymes, such as microbial community of the substrate and presence of amylase inhibitors. This study also provides insights into the evolution of BSFL digestive activity during their development and the occurrence of external digestion.

Comparing effects of high starch diet or high lipid diet supplemented with different levels of zinc on intestinal barrier and microbe community in largemouth bass Micropterus salmoides

Zinc is essential for normal growth and reproduction in all animals and plays a crucial role in many biological processes. The present study aimed to compare the intervention effects of zinc on intestinal health in a high lipid diet or high starch diet. Seven iso-nitrogenous (∼520 g kg−1) diets were formulated containing a positive control diet (115 g kg−1 lipid + 115 g kg−1 starch + 20 mg kg−1 Zn), three high starch diets (HS, 166 g kg−1 starch) and three high lipid diets (HL, 182 g kg−1 lipid), with 0 (HS-LZn, HL-LZn), 20 (HS-MZn, HL-MZn) and 150 (HS-HZn, HL-HZn) mg kg−1 Zn being supplemented. High starch diet and high lipid diet promoted feed efficiency, as evidenced by the lower feed conversion ratio. Three-way factorial ANOVA analysis showed high starch diet (166 g kg−1) significantly decreased final body weight and weight gain compared to the normal starch level (115 g kg−1). Diamine oxidase in serum significantly increased in diets HS-LZn and HL-LZn. In addition, distal intestinal mucosal fold damage and inflammatory infiltration were observed in the HS-LZn, HS-HZn, HL-LZn and HL-HZn groups. Fish fed HL diets (HL-LZn, HL-MZn, HL-HZn) showed lower expressions of claudin 5 and claudin 34, and higher IgD and IgM. Diets HL-LZn and HL-MZn significantly up-regulated C4 and C7. Proinflammatory cytokines including il8, il1β and tnfα significantly up-regulated in diet HL-LZn, even higher than the HS-LZn. Intestinal microbial composition indicated the abundance of Cetobacterium in HL-LZn was significantly higher than the control and HL-MZn diets. Similarly, LEfSe showed that Cetobacterium (P = 0.039) significantly enriched in the HL-LZn group. This study clarified high energy diet induced intestinal damage, which can be alleviated by zinc.

PSVII-20 Effect of starch content in the concentrate of finishing bison on meat nutritional composition, quality, and palatability

Abstract According to the Saskatchewan Bison Association, in the last few years producers have not been able to fill the increasing demand for bison meat. Indeed, one of the main challenges faced by the bison industry is their ability to produce a consistent product in a relatively short period of time. Hence, it is necessary to optimize the productivity and profitability of feeding bison calves while ensuring the quality of the end product. This study aimed to evaluate the effects of different starch contents in the concentrate of finishing bison on meat nutritional composition, quality, and palatability. Yearling bison bulls [n = 48; commercial Wood × Plains, 435 ± 13.4 kg body weight (BW)] were homogenously distributed into 12 pens (4 bulls/pen) based on BW, and each pen randomly assigned (n = 6) to receive either a high- [51.4% dry matter basis (DM); n = 24 bison bulls) or moderate-starch (25.8% DM; n = 24 bison bulls) concentrate, alongside free access to water and grass hay bales. After 156 d of feeding, bison bulls were slaughtered in a commercial abattoir in AB, Canada. At 3 d postmortem, color values were measured at the ribeye between the 11 and 12th ribs. Subsequently, striploins from the left carcass sides were collected, weighed, vacuum packaged, and transported under refrigeration conditions to the AAFC-Lacombe Research and Development Centre, AB, Canada. On d 6 of ageing, striploins were unpacked and weighed to measure purge losses, and pH was collected. Subsequently, six 2.5-cm thick steaks were obtained for further nutritional analyses (minerals, cholesterol, vitamin B3, protein, fat, moisture, and fatty acids), shear force, color in retail display for 4 d, and descriptive sensory and flavor profile analyses performed by trained panelists. The dietary starch content did not affect the nutritional composition as well as the pH, 3-d color values, moisture losses, and shear force value of the bison meat (P &amp;gt; 0.1). However, the high-starch concentrate increased the meat luminosity (L*) after 4 d in retail display (P &amp;lt; 0.05) and initial and overall tenderness (P &amp;lt; 0.001), and decreased the amount of perceived connective tissue (P &amp;lt; 0.001). Additionally, spongy and rubbery textures were less frequently found by trained panelists in meat from bison fed a high-starch than a moderate-starch concentrate (P &amp;lt; 0.01 and 0.05, respectively). Regarding meat flavor, the high-starch concentrate decreased salty taste (P &amp;lt; 0.05) and burnt and livery aromas (P = 0.071 and 0.069, respectively) but increased metallic flavor (P &amp;lt; 0.01) and bitter taste (P = 0.076). In conclusion, the starch content in the concentrate of finishing bison did not affect the meat nutritional value. However, some positive effects on meat color and palatability were found when feeding bison a high-starch concentrate.

91 Awardee Talk: Using respiration calorimetry to estimate energy balance to estimate energy balance and methane emissions

Abstract Understanding relationships between chemical components of the diet and methane production will allow nutritionists to develop formulation strategies to decrease methane emissions. Diets that produce acetate liberate hydrogen that can be used by methanogenic archaea to produce methane. Propionate is a hydrogen sink and diets that lead to increased propionate production decrease acetate and methane production. The objective was to evaluate relationships between methane emissions and dietary chemical components and feed intake using published databases and make diet formulation recommendations that could be used to decrease methane production in finishing beef cattle. A total of 263 treatment mean observations from respiration calorimetry studies with beef cattle and dairy steers and heifers were used to evaluate relationships between methane emissions, dietary chemical components, and feed intake. Among the chemical components evaluated, dietary neutral detergent fiber and starch were strongly related to methane yield. The relationship between dietary ether extract and methane yield was variable and there was no relationship between dietary crude protein concentration and methane yield. Additionally, the ratio of metabolizable energy relative to gross energy intake had a strong relationship to methane yield. Formulation strategies to increase dietary starch and decrease dietary neutral detergent fiber should allow the feedlot industry to decrease enteric methane production.

Reduced fat content of fried batter-breaded fish nuggets by adding dietary fibers: Insight into wheat starch and gluten conformations, fiber properties and anti-fat absorption capacities

Dietary fibers with excellent processing characteristics and water-holding capacity garnered significant attention in low-fat fried products manufacturing, but further research is lacking to elucidate fat reduction mechanisms. Three dietary fibers were added to the batter of fried batter-breaded fish nuggets, the increased maximum wavelength, fluorescence intensity, surface hydrophobicity value, and S-S/free-SH ratio revealed the enhanced exposure and interaction of hydrophobic groups within gluten. Conversion from both -SH into S-S bonds, and α-helix into β-turn confirmed the establishment of the gluten gel network and a substantially increased gel strength. X-ray diffraction demonstrated the inhibition of amylose-lipid complex formation due to the competitive amylose binding to dietary fiber. Finally, reduced oil effects were evident in surface and penetrated oil contents and oil distribution fluorescence diagram. The work clarified the interactions among dietary fiber, wheat starch and gluten, indicating the composite gel network formation and the crust characteristics alterations, ultimately inhibiting oil penetration.

Dietary starch structure modulates nitrogen metabolism in laying hens via modifying glucose release rate

The objective of this study was to investigate the effects of starch structure (Amylopectin/Amylose, AP/AM) in a low-protein diet on production performance, nitrogen utilization efficiency, and cecal flora in laying hens. Four hundred eighty 45-wk-age Hy-Line Gray laying hens were randomly allocated to five dietary groups and subjected to a 12-wk feeding trial. The AP/AM ratios of the five experiment diets were 1.0, 1.5, 2.0, 3.0, and 4.0. The results indicated that compared to other groups, laying hens fed with AP/AM 4.0 diets showed significantly improved average egg weight and feed conversion ratio (P < 0.05). Furthermore, as the AP/AM ratio increased, there was a significant linear enhancement in intestinal amino acids apparent digestibility, apparent metabolizable energy, and villus area (P < 0.05). Compared to the high AP groups, high-AM diets significantly increased eggshell thickness, crude protein digestibility, and reduced energy supply from amino acid oxidation in ileum (P < 0.05). Additionally, moderate-AM diets enriched with short-chain fatty acid-producing bacteria in the cecum, such as Lactobacillus, Rikenellaceae_RC9_gut_group, and Christensenellaceae_R-7_group, which are associated with the promoting nitrogen utilization. These findings may offer useful information on optimizing starch structure for the design of food products and relevant therapies due to the potential effects on nutrient metabolism and gut homeostasis.

Dietary starch, non-starch polysaccharides and their interactions affect nutrient digestibility, faecal waste production and characteristics differentially in three salmonids: Rainbow trout, Atlantic salmon and Arctic charr

Waste management has emerged as a critical issue in aquaculture. In this study, we examined the impact of dietary starch and non-starch polysaccharides (NSP) content on nutrient digestibility, faecal waste production, faecal removal efficiency and the faecal characteristics in three salmonid species, namely rainbow trout (Oncorhynchus mykiss), Atlantic salmon (Salmo salar) and Arctic charr (Salvelinus alpinus). Four diets were formulated according to a 2 × 2 factorial design. The first factor, starch, was tested by including 0% gelatinised wheat flour (low starch) or 20% gelatinised wheat flour (high starch) in a plant-based basal diet. The second factor, NSP, was tested by adding 0% NSP source (low NSP) or 10% NSP source (high NSP). High NSP level was achieved by adding an equal mixture of soya hull (5%) and wheat bran (5%). Diets were tested in triplicates for each species and feeding was done restrictively. Experimental duration was 42 days for rainbow trout and Atlantic salmon and 49 days for Arctic charr. Among the three species investigated, Arctic charr had the lowest digestibility values for most nutrients, whereas rainbow trout and Atlantic salmon values were comparable. High starch level in the diet reduced the macronutrient (protein, fat and ash) digestibility in all three species. High starch and high NSP levels in the diet increased faecal waste production, with the effect being more pronounced for the NSP content of the diet. High dietary starch levels increased the proportion of smaller-sized particles, while high NSP content increased the ability of faecal particles to withstand mechanical stress. The high starch level in the diet lowered faecal removal efficiency but increased by high NSP content. The highest and lowest faecal removal efficiency was recorded for Atlantic salmon and Arctic charr, respectively. The amount of non-removed faeces accumulating in the system was increased by the high starch levels in rainbow trout and Atlantic salmon but remained unaffected by the NSP content of the diet across the species. No interaction effect between starch and NSP content of diets was observed for faecal removal efficiency and non-removed faeces. Among the three species investigated, Arctic charr had the maximum amount of non-removed faeces per kilogram of dry matter feed.

Fibrobacter sp. HC4, a newly isolated strain, demonstrates a high cellulolytic activity as revealed by enzymatic measurements and in vitro assay.

Despite their low quantity and abundance, the cellulolytic bacteria that inhabit the equine large intestine are vital to their host, as they enable the crucial use of forage-based diets. Fibrobacter succinogenes is one of the most important intestinal cellulolytic bacteria. In this study, Fibrobacter sp. HC4, one cellulolytic strain newly isolated from the horse cecum, was characterized for its ability to utilize plant cell wall fibers. Fibrobacter sp. HC4 consumed only cellulose, cellobiose, and glucose and produced succinate and acetate in equal amounts. Among genes coding for CAZymes, 26% of the detected glycoside hydrolases (GHs) were involved in cellulolysis. These cellulases belong to the GH5, GH8, GH9, GH44, GH45, and GH51 families. Both carboxymethyl cellulase and xylanase activities of Fibrobacter sp. HC4 were detected using the Congo red method and were higher than those of F. succinogenes S85, the type strain. The in vitro addition of Fibrobacter sp. HC4 to a fecal microbial ecosystem of horses with large intestinal acidosis significantly enhanced fibrolytic activity as measured by the increase in gas and volatile fatty acids production during the first 48 h. According to this, the pH decreased and the disappearance of dry matter increased at a faster rate with Fibrobacter sp. HC4. Our data suggest a high specialization of the new strain in cellulose degradation. Such a strain could be of interest for future exploitation of its probiotic potential, which needs to be further determined by in vivo studies.IMPORTANCECellulose is the most abundant of plant cell wall fiber and can only be degraded by the large intestine microbiota, resulting in the production of volatile fatty acids that are essential for the host nutrition and health. Consequently, cellulolytic bacteria are of major importance to herbivores. However, these bacteria are challenged by various factors, such as high starch diets, which acidify the ecosystem and reduce their numbers and activity. This can lead to an imbalance in the gut microbiota and digestive problems such as colic, a major cause of mortality in horses. In this work, we characterized a newly isolated cellulolytic strain, Fibrobacter sp. HC4, from the equine intestinal microbiota. Due to its high cellulolytic capacity, reintroduction of this strain into an equine fecal ecosystem stimulates hay fermentation in vitro. Isolating and describing cellulolytic bacteria is a prerequisite for using them as probiotics to restore intestinal balance.

Effects of liquid-based diets with breweries grains enriched with isolated starch and fish oil on veal quality

Since veal production has declined in the U.S., American veal producers are currently making efforts to implement new production standards to improve product quality and animal welfare. In this study, we hypothesized that diets containing brewery grains, starch and omega-3 fatty acids could lower a blood stress indicator and improve meat quality, mostly from a nutritional value stand point. Holstein bull calves with approximately 94.67 ± 12.07 kg of body weight and two months old were randomly assigned to 1 of 3 dietary treatments. Diets were formulated with nonmedicated milk replacer, microbreweries spent grains, and a mineral mix (CONTROL); CONTROL + isolated maize starch (STARCH); and CONTROL +3% fish oil (OMEGA-3). Veal calves fed all three diets were heavier than calves of the same age from experiments reported in the existing literature. Dietary treatments did not affect carcass weights, pH, color, moisture, sensory attributes, volatile profile, and fat quality indexes. Calves fed STARCH and OMEGA-3 showed the lowest levels of blood cortisol. Veal fed CONTROL and OMEGA-3 had higher concentrations of ΣMUFA when compared with STARCH. Veal fed OMEGA-3 had the highest concentrations of EPA, DHA, and Σn-3. Veal from all treatments had very high concentrations of ΣMUFA, mostly driven by high levels of c-9 18:1 n-9 from the milk replacer. Feeding OMEGA-3 lowered blood cortisol and increased levels of EPA and DHA without harming sensory attributes. Overall, including brewery grains, starch and fish oil in liquid diets containing milk replacer can improve veal production.

Effects of High Dietary Starch Levels on the Growth Performance, Liver Function, and Metabolome of Largemouth Bass (Micropterus salmoides)

In this study, we conducted a 16-week feeding trial to investigate the effects of a high-cassava starch diet on growth performance, liver function, and metabolism in largemouth bass (Micropterus salmoides). We formulated five diets containing varying levels of cassava starch: 12%, 9%, 6%, 3%, and 0% (termed M12, M9, M6, M3, and M0, respectively). We distributed these diets among largemouth bass with the initial body weight of 83.33 ± 0.55 g via an in-pond “raceway” aquaculture system. Our findings suggest that high level (12%) of cassava starch dietary inclusion adversely affected growth performance metrics such as weight gain rate and specific growth rate, along with feed utilization efficiency indicators, including protein efficiency, protein deposition rate, and the apparent digestibility of dry matter and protein. This negative impact was accompanied by a decrease in intestinal amylase activity. Through further transcriptomic analysis, we identified several key genes associated with carbohydrate metabolism, which underwent changes influencing liver function. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed the involvement of these differentially expressed genes (DEGs) in the tricarboxylic acid cycle (TCA cycle). Comparative metabolomics analysis further indicated that the M9 group showed significant enrichment in pathways related to amino acid metabolism and alterations in the levels of metabolites involved in carbohydrate metabolism. In conclusion, our study demonstrates that incorporating up to 9% cassava starch in the diet can enhance growth performance in largemouth bass by stimulating digestive enzyme activities and promoting glucose utilization.