High-starch Diet Research Articles

Mulberry leaf extract improves non-specific immunity and antioxidant capacity of largemouth bass (Micropterus salmoides) fed a high-starch diet

A 70-day experiment was conducted to investigate the effects of mulberry leaf extract (MLE) on growth, proximate compositions, antioxidant and plasma biochemical parameters, and indices of non-specific immunity of largemouth bass (Micropterus salmoides) fed a high-starch diet. Two hundred eighty largemouth bass (initial body weight, 68.00 ± 0.19 g) were randomly fed seven diets: basal-starch diet (BSD; 8.88% starch), high-starch diet (HSD; 11.42% starch), and HSD diets supplemented with 0.05%, 0.10%, 0.20%, 0.50%, and 1.00% MLE (MLE1, MLE2, MLE3, MLE4, and MLE5, respectively). The results indicated that HSD and MLE did not significantly affect the growth performance of largemouth bass during the experimental period compared with that of the BSD, but the supplementation with more than 0.20% (MLE3, MLE4, and MLE5) MLE significantly decreased the hepatosomatic index (HSI) values, and 1.00% (MLE5) MLE significantly decreased the viscerosomatic index (VSI) values. The whole-body moisture of fish fed an HSD decreased significantly, while the whole-body lipid content increased significantly in the HSD group compared with the BSD group. Compared with HSD, MLE supplementation significantly decreased the moisture and lipid contents in the whole body. Supplementation with more than 0.20% MLE (MLE3, MLE4, and MLE5) significantly decreased the moisture content in the muscle. Supplementation with 1.00% MLE significantly decreased the content of hepatic and muscle glycogen. The malondialdehyde (MDA) content of the HSD group was significantly increased compared to that of the BSD group, whereas more than 0.10% (MLE2, MLE3, MLE4, and MLE5) MLE significantly decreased the MDA content. Additionally, the total antioxidant capacity (T-AOC), catalase (CAT), and glutathione peroxidase (GSH-Px) activities of MLE5 were significantly higher than those of the HSD group. The complement-3 (C3) content and globulin (GLB) in the plasma of the HSD group were significantly lower than those of the BSD group. Plasma C3 levels in the MLE3, MLE4, and MLE5 groups were significantly higher than those in the HSD group. In addition, glucose (GLU) levels in the MLE3, MLE4, and MLE5 groups were significantly lower than those in the HSD group. Supplementation with 0.50% (MLE4) MLE significantly increased the lysozyme (LYZ) content and decreased the activities of alanine transaminase (ALT) and aspartate transaminase (AST). Supplementation with 1.00% MLE significantly increased complement-4 (C4) and GLB contents and alkaline phosphatase (ALP) activity. Overall, these findings suggest that MLE could improve antioxidant capacity, immune function, and glycolipid metabolism, thereby alleviating the negative effects of a high-starch diet in M. salmoides.

Effects of concentrate starch level and free-choice provision of straw on performance, feeding behaviour and feed sorting of fattening lambs

The importance of forage in small ruminants’ behaviour is well known, but very few experimental studies have investigated the feeding behaviour of lambs offered ad libitum and as a free choice provision of concentrate and wheat straw. This experiment was conducted to investigate the effect of concentrate starch level on growth performance and behaviour, preference toward straw and rumen fermentation in lambs offered ad libitum forage and concentrate. Twenty-four Iranian Arabic male lambs (mean ± standard deviation; 18.8 ± 2 kg of BW) were used in a completely randomized design with 3 treatments (8 lambs per treatment) for a period of 84 days. Experimental treatments were included 3 levels of starch (27.1%, 35.4% and 43.6% of dietary dry matter (DM)) and wheat straw was offered as a free-choice provision. Total DMI was not different among treatments; however, intakes of straw (P < 0.01), peNDF (P = 0.003), water (P = 0.05), and ME (P = 0.005) linearly increased with increasing level of starch in the concentrates. The increased dietary starch concentration linearly increased total gain (P = 0.02), and average daily gain (P = 0.01), but linearly decreased feed conversion ratio (P = 0.02). Increasing starch in the concentrates linearly increased sorting for straw particles retained on the 19-mm sieve and tended to increase sorting for particles retained on the 8-mm sieve. In contrast, sorting against the fine particles was observed with increasing starch content of the concentrates. Eating time decreased linearly as the amount of starch in the diets increased. Time spent ruminating per kg DM and NDF intake linearly increased with increasing starch in the diet. Standing time increased linearly (P = 0.04) as starch content of the diets increased. Lambs fed low starch diet had higher pH values than medium starch (at 2, 4, and 6 h post-feeding) and high starch (at 0, 2, 4 and 6 h post-feeding) diets. These findings suggest that under free-choice provision of straw and concentrate lambs are able to adjust their sorting behaviour in favor of physically effective NDF and more forage intake with increasing concentrate starch level, which could be an adaptive response to attenuate low rumen pH.

PSIX-4 Rumen Microbial Meta-Proteome and Milk Whey Proteome in Holstein Cows fed with High Starch and low Fiber Diet

Abstract Identifying milk biomarkers impacted by dietary starch and fiber profiles can support optimization of feeding and concurrent promotion of animal health. The objective of this study was to characterize the rumen meta-proteome and milk whey proteome in Holstein cows fed different levels of physically effective undigestible NDF (peuNDF240) and rumen fermentable starch (RFS). Eight ruminally cannulated Holstein cows were included in a 4 x 4 Latin square design with four 28-day periods. From this study, samples were collected from cows in each period receiving one of two dietary treatments: 1) low peuNDF240, high RFS (LNHR) or 2) high peuNDF240, low RFS (HNLR). Rumen fluid and milk samples were collected at the end of each period at three timepoints, snap-frozen, and stored at -800C. Rumen microbial proteins and milk whey proteins were isolated, quantified, isobarically labeled, and analyzed by LC-MS/MS. The acquired product ion spectra from rumen fluid and the milk samples were searched against 71 composite databases and a cattle database, respectively. Data were analyzed using the PROC MIXED procedure in SAS 9.4. Of the 130 rumen-associated proteins identified across 22 searched microbial species, the abundances of 13 proteins were impacted by diet across eight microbial species. Six of these proteins were associated with core metabolism. Among the 159 quantified milk proteins, the abundances of 17 proteins were impacted by diet. Many of these proteins were associated with host defense, nutrient synthesis, and transportation. The abundance of CD14 and lactadherin was less with the LNHR diet (P &amp;lt; 0.05), whereas Prostaglandin-H2 D-isomerase and lipoprotein lipase abundances were greater with LNHR diet (P &amp;lt; 0.05). Our results indicate feeding a higher concentration of RFS has a greater influence on milk whey proteome than the rumen meta-proteome profile and highlight the potential use of milk whey proteins as biomarkers indicative of nutrition.

Effects of Autolyzed Yeast Supplementation in a High-Starch Diet on Rumen Health, Apparent Digestibility, and Production Variables of Lactating Holstein Cows.

Simple SummaryFeeding high-starch (HS) diets has negative implications on the ruminal health and milk production of dairy cattle. Autolyzed yeast (AY) supplementation may alleviate the negative effects of an HS diet fed to dairy cows. Therefore, the objectives of this study were to determine the effects of the supplementation of commercially available AY in HS diets on lactation performance, rumen pH, N utilization, apparent digestibility (AD), and blood metabolites in lactating Holstein cows. This study postulated that AY supplementation may improve the rumen environment (rumen pH and AD) when feeding HS diets, thus improving lactation performance and altering blood metabolites.Fifteen multiparous rumen-cannulated Holstein cows were assigned to one of five treatments in a replicated 5 × 5 Latin square design. The treatments were low-starch (LS) (22.8 ± 1% of dry matter; DM) without autolyzed yeast (AY; LS0, control), high-starch (HS) (31.2 ± 4% of DM) without AY (HS0), and HS with either 15 g (HS15), 30 g (HS30), or 45 g (HS45) of AY supplementation. Cows in HS0 had increased (p < 0.03) dry matter intake (DMI; 24.9 kg/d) and energy-corrected milk (ECM; 34.4 kg/d) compared to cows in LS0 (19.9 and 31.3 kg/d, respectively). There was a tendency for a quadratic treatment effect for feed efficiency (ECM/DMI, p = 0.07) and crude protein (CP) apparent digestibility (AD) (p = 0.09). Cows in HS45 tended (p = 0.09) to have increased DMI (25.6 kg/d) compared to cows in HS0 (24.9 kg/d). Cows in HS0 had greater (p < 0.04) milk protein nitrogen (N; 166 g/d) and microbial N production (161 g/d) than those in LS0 (140 and 138 g/d, respectively). In conclusion, the addition of AY tended to improve DMI, feed efficiency, and CP AD when cows were fed the HS diet.

Gut health of horses: effects of high fibre vs high starch diet on histological and morphometrical parameters

BackgroundThe conventional feeding management of horses is still characterized by high starch and low fibre diets, which can negatively affect horse’s gastrointestinal health. Thus, the aim of this study was to compare the effects of a high-starch (HS) vs. a high-fibre (HF) diet on gut health in horses. A total of 19 Bardigiano horses destined for slaughter and aged 14.3 ± 0.7 months were randomly allotted to two dietary groups: HS (5 fillies and 4 colts,) and HF group (7 fillies and 3 colts). They received the same first-cut meadow hay but different complementary feeds for 72 days: HS group was fed 8 kg/animal/day of a starch-rich complementary feed while HF group was fed 3.5 kg/animal/day of a fibre‐rich complementary feed. At slaughter, stomachs were separated and washed for the evaluation of the glandular and squamous regions. Also, duodenum, jejunum, ileum, apex of the caecum, sternal flexure, pelvic flexure, right dorsal colon, rectum and liver were excised and submitted to histomorphometrical evaluation.ResultsThe glandular region of HS group presented more severe gastric mucosa lesions compared to the HF group (P = 0.006). Moreover, a statistical tendency (P = 0.060) was found for the squamous region, presenting a higher score in HS than HF diet. Regarding morphometry, in jejunum villus height to crypt depth (Cd) ratio was influenced by sex, being greater in males than in females (P = 0.037) while in ileum Cd depended on interaction between sex and diet, being greater in males of HS group (P = 0.029). Moreover, in the duodenum and right dorsal colon the severity of the inflammation depended on sex (P = 0.024 and 0.050), being greater in females than in males. On the contrary, in the jejunum and in the pelvic flexure, inflammation was influenced by diet, being more severe in HS than in HF group (P = 0.024 and 0.052).ConclusionsThese results suggested that HS diet provoked more severe mucosa lesions in the glandular region of the stomach and a higher inflammation both in the jejunum and pelvic flexure. The present study can represent a starting point for further investigations on gut health in horses.

Mechanism Analysis of Metabolic Fatty Liver on Largemouth Bass (Micropterus salmoides) Based on Integrated Lipidomics and Proteomics.

Metabolic fatty liver disease caused by high-starch diet restricted the intensive and sustainable development of carnivorous fish such as largemouth bass. In this study, the combination liver proteomic and lipidomic approach was employed to investigate the key signaling pathways and identify the critical biomarkers of fatty liver in largemouth bass. Joint analysis of the correlated differential proteins and lipids revealed nine common metabolic pathways; it was determined that FABP1 were significantly up-regulated in terms of transporting more triglycerides into the liver, while ABCA1 and VDAC1 proteins were significantly down-regulated in terms of preventing the transport of lipids and cholesterol out of the liver, leading to triglyceride accumulation in hepatocyte, eventually resulting in metabolic fatty liver disease. The results indicate that FABP1, ABCA1 and VDAC1 could be potential biomarkers for treating metabolic fatty liver disease of largemouth bass.

Associating changes in the bacterial community of rumen and faeces and milk fatty acid profiles in dairy cows fed high-starch or starch and oil-supplemented diets.

The experiment reported in this research paper aimed to evaluate the effects of high-starch or starch and oil-supplemented diets on rumen and faecal bacteria, and explore links between the structure of bacterial communities and milk fatty acid (FA) profiles. We used four Holstein dairy cows in a 4 × 4 Latin square design. Cows were fed a diet rich in cereals (high-starch diet with 23% starch content on dry matter (DM) basis), a diet supplemented with saturated FA from Ca salts of palm oil + 18% DM starch, a diet with high content of monounsaturated FA (from extruded rapeseeds) + 18% DM starch or a diet rich in polyunsaturated FA (from extruded sunflower seeds) + 17% DM starch. At the end of each experimental period, cows were sampled for rumen and faecal contents, which were used for DNA extraction and amplicon sequencing. Partial least squares (PLS) regression analysis highlighted diet-related changes in both rumen and faecal bacterial structures. Sparse PLS discriminant analysis was further employed to identify biologically relevant operational taxonomical units (OTUs) driving these differences. Our results show that Butyrivibrio discriminated the high-starch diet and linked positively with higher concentrations of milk odd- and branched-chain FA. YS2-related OTUs were key taxa distinguishing diets supplemented with Ca salts of palm oil or sunflower seeds and correlated positively with linoleic acid in milk. Similarly, diets modulated faecal bacterial composition. However, correlations between changes in faecal and rumen bacteria were poor. With this work, we demonstrated that high-starch or lipid-supplemented diets affect rumen and faecal bacterial community structure, and these changes could have a knock-on effect on milk FA profiles.

Feed efficiency of lactating Holstein cows is repeatable within diet but less reproducible when changing dietary starch and forage concentrations

Improving feed efficiency has become an important target for dairy farmers to produce more milk with fewer feed resources. With decreasing availability of arable land to produce feeds that are edible for human consumption, it will be important to increase the proportion of feeds in the diets for dairy cattle that are less edible for human consumption. The current research analyzed the ability of lactating dairy cows to maintain their feed efficiency when switching between a high starch diet (HS diet: 27% starch, 29% NDF, 47.1% forages on a DM basis) and a low starch diet (LS diet: 13% starch, 37% NDF, 66.4% forages on a DM basis). Sixty-two lactating Holstein cows (137 ± 23 days in milk (DIM) at the start of experiment), of which 29 were primiparous cows, were utilized in a crossover design with two 70-d experimental periods, including a 14-d adaption period for each. Feed efficiency was estimated as the individual deviation from the population average intercept in a mixed model predicting DM intake (DMI) with net energy in milk, maintenance and BW gain and loss. Repeatability was estimated within each diet by comparing feed efficiency estimated over the first 28-day period and the second 28-day period within each diet, using Pearson’s and intraclass correlations, and the estimation of error of repeatability. Similarly, reproducibility was estimated by comparing the second 28-day period of one diet with the first 28-day period of the other diet. Feed efficiency was less reproducible across diets than repeatable within the same diet. This was shown by lower intraclass correlations (0.399) across diets compared to that in the HS diet (0.587) and LS diet (0.806), as well as a lower Pearson’s correlation coefficient (0.418) across diets compared to that in the HS diet (0.630) and LS diet (0.809). In addition, the estimation of error of repeatability was higher (0.830 kg DM/d) across diets compared to that in the HS diet (0.761 kg DM/d) and LS diet (0.504 kg DM/d). This means that the feed efficiency of dairy cows is more likely to change after a diet change than over subsequent lactation stages. Other determinants, such as digestive processes, need to be further investigated to determine its effects on estimating feed efficiency.

Preliminarily curative effectiveness of long-term bitter melon Momordica charantia saponins administration for the glucose homeostasis of juvenile common carp (Cyprinus carpio) fed a high-starch diet

Momordica charantia saponins (MCS) was supplemented to a high-starch diet to ssess the effect on the growth performance, glucose homeostasis modulating factors concerning the attenuated hyperglycemia, hyperlipemia and insulin resistance. Five iso-nitrogenous (30.48%) and iso-lipidic (5.41%) diets were formulated containing 30% starch (control group, HS), and were supplemented with 100 mg/kg (HS-MCS100), 400 mg/kg (HS-MCS400), 1600 mg/kg (HS-MCS1600) and 6400 mg/kg (HS-MCS6400) MCS on the basis of the HS diet. 450 common carp weighing (6.43 ± 0.02) g were randomly divided into 5 groups, with three replicates in each group and 30 fish in each replicate. Results revealed that dietary MCS effectively enhanced the growth and feed efficiency and significantly attenuated the glucose homeostasis and insulin resistance triggered by the HS diet. Moreover, 1600 mg/kg of MCS administration fulfilled more efficient and significant improvement of weight gain rate (WGR), specific growth rate (SGR), feed conversion rate (FCR), protein efficiency ratio (PER), protein and lipid deposition in the whole body. Alterations of serum biochemical indices revealed that 1600 mg/kg of MCS administration remarkably suppressed the hyperglycemia and hyperlipemia and elevated the insulin sensitivity. Enzyme activity and gene expression analysis of glycometabolism indicated that 1600 mg/kg of MCS administration could attenuate the hepatopancreas insulin resistance by enhancing glycolysis ability, promoting the glycogen synthesis and inhibiting the gluconeogenesis through activating PI3K/AKT signaling pathway. On all accounts detail, appropriate MCS administration have potential value in the alleviation of insulin resistance, thereby effectually maintain the glucose homeostasis and giving play to growth promoting effect for common carp fed with a high-carbohydrate diet.

Feed intake, rumen fermentation and performance of dairy cows fed diets formulated at two starch concentrations with either conventional urea or slow-release urea

This study evaluated the effects of high and moderate starch diets by substituting corn grain with wheat and rice bran in diets containing slow-release urea (SU, protected into lipids matrix microencapsulation) or conventional urea (CU) on the performance of high producing dairy cows. Twenty-four multiparous (days in milk = 83 ± 14; milk yield = 47 ± 4.5 kg/d) and sixteen primiparous (days in milk = 83 ± 12; milk yield = 37.5 ± 2.5 kg/d) Holstein dairy cows were randomly assigned to 1 of 4 treatments in a 2 × 2 factorial arrangement of treatments with 2 dietary starch concentrations [moderate starch (MS; 260 g/kg of dry matter, DM) vs. high starch (HS; 320 g/kg of DM)] and two sources of urea (SU vs. CU). The experiment lasted 52 days (d), consisting of 10 d for covariate period, 21 d for adaptation, and 21 d for sampling. In a preliminary in vitro gas test, the gas production was higher for SU than CU at 0.5, 1, 2, 6, and 24 h post-incubation (P < 0.01). There were interactions between urea source and starch level for dry matter intake (DMI, P < 0.01), propionate proportion (P = 0.04), milk urea nitrogen (MUN, P = 0.09) and rumen NH3-N (P = 0.07) concentrations; the DMI (P = 0.01) was higher and propionate proportion (P = 0.05), MUN (tendency, P = 0.08) and rumen NH3-N (tendency, P = 0.06) were lower with high than moderate starch level in CU diet, but it was not different between the two starch levels in SU diet. Furthermore, the urea source and starch level interaction was significant for butyrate proportion (P = 0.04); the butyrate proportion (P = 0.03) was lower with high than moderate starch level in SU diet, but it was not different between the two starch levels in CU diet. Cows fed CU had greater milk fat (P < 0.01) and protein (P = 0.04) yield and milk fat content (P = 0.05) and tended to have a greater 35 g/kg fat corrected milk yield (P = 0.09) than cows fed SU. The total volatile fatty acids concentrations (P = 0.04) and milk protein content (P < 0.01) were greater in HS-fed cows than in MS-fed cows. Blood urea nitrogen concentration was higher at 2 (P = 0.02) and 4 (P = 0.03) h after feeding in CU-fed cows than in SU-fed cows. Apparent digestibility of starch was greater in HS-fed cows than in MS-fed cows (P < 0.01) and in CU-supplemented cows than in those who received SU (P = 0.05). Overall, the SU product used in this study reduced the rate of ruminal nitrogen release compared to CU; however, no advantages are observed with the addition of SU when compared with CU on high-production dairy cow performance. Moreover, the results suggest that the performance of high-producing dairy cows can be maintained when wheat and rice bran are used instead of corn grains at 150 g/kg of DM.

Proteomic analysis of hepatic fibrosis induced by a high starch diet in largemouth bass (Micropterus salmoides)

Largemouth bass is sensitive to the dietary starch level and excess starch can induce metabolic liver diseases (MLD). Hepatic fibrosis is a typical pathological phenotype of MLD in largemouth bass, but the molecular basis underlying is largely unclear. This study fed fish with a low or high starch diet for 4 weeks. Liver tissues with or without fibrotic symptoms were recognized through histopathological and molecular markers analysis of hepatic fibrosis, following TMT Quantitative proteomics and conducted Parallel Reaction Monitoring (PRM) analyses. 2455 differentially expressed proteins with 1618 up-regulated and 837 down-regulated were identified in this study. In GO terms, up-regulated proteins were correlated with cytoskeleton organization, supramolecular fiber, cytoskeleton protein binding, and actin-binding, while down-regulated proteins were involved in mainly metabolism-related processes, and molecular binding activity. Down-regulated proteins were enriched in 63 KEGG pathways and concentrated in metabolism-related pathways, especially glucose, lipid, and amino acid metabolism. 70 KEGG pathways of up-regulated proteins mainly included immunity and inflammation-related pathways. The expression trends of 11 differentially expressed proteins were consistent with proteome results by PRM analysis. In conclusion, the development of hepatic fibrosis induced by high starch may be related to multi-signaling pathways, metabolism processes, and targets, which provides important data for further study on revealing the molecular mechanism of hepatic fibrosis.

A high-starch vs. high-fibre diet: effects on the gut environment of the different intestinal compartments of the horse digestive tract

BackgroundHorses are often fed high amounts of starch in their diets despite the well-established benefits of a fibre-based diet to promote gut health and animal welfare. The aim of the present study was to compare the effects of two different diets – one based on high amounts of starch (HS) vs. one base on high amounts of fibre (HF) – on specific parameters of the gut environment across different intestinal compartments of the horse digestive tract. To this end differences in the gastrointestinal environment between HS vs. HF fed horses were assessed in terms of dry matter, organic matter and ash content; the particle size distribution and volatile fatty acid composition were also investigated.ResultsNineteen Bardigiano horses of 14.3 ± 0.7 months of age and destined to slaughter were divided into two group pens – one fed with high amounts of starch (HS; n = 9; 43% hay plus 57% starch-rich pelleted feed); vs. fed with high amounts of fibre (HF; n = 10; 70% hay plus 30% fibre-rich pelleted feed). Horses fed HS diet presented a higher dry matter content in the right dorsal colon. Moreover, they showed a higher organic matter and ash content in the sternal flexure, pelvic flexure, right dorsal colon and rectum. In these latter intestinal compartments, horses fed a HS diet also showed a higher proportion of particles retained on an 8 mm sieve and a higher proportion of particles that washed through the finest sieve (< 1 mm). Moreover, the total amounts of volatile fatty acids as well as valeric acid were found to be significantly higher in horses fed the HS vs. HF diet.ConclusionsA high-starch diet causes significant changes in the horse gut environment. We observed an increase in the dry matter content in the right dorsal colon, as well as reduced particle sizes and an increase in the production of valeric acid in all the gut compartments studied. High-starch diets should be avoided in favour of fibre-based diets with the goal of safeguarding gut health in horses.

Effects of High Starch and Supplementation of an Olive Extract on the Growth Performance, Hepatic Antioxidant Capacity and Lipid Metabolism of Largemouth Bass (Micropterus salmoides).

An 8-week feeding trial was conducted to investigate the effects of high-starch diets and the supplementation of an olive extract (OE) on the growth performance, liver health and lipid metabolism of largemouth bass (Micropterus salmoides). Four isonitrogenous and isolipidic diets were prepared: two basal diets containing low (9.0%) and high (14.4%) levels of starch (named as LS and HS), and 0.125% OE was supplemented to each basal diet (named LSOE and HSOE). The results show that high-starch diets had significant negative effects on growth performance, with lower FR, SGR and higher FCR, whereas OE significantly lowered FCR, determined by two-way ANOVA analysis. High-starch diets induced oxidative stress, inflammatory response and liver function injury, with significant increases in the content of plasmatic AKP, AST, ALT, hepatic SOD and MDA, and up-regulation of hepatic TNFα, IL1β, and TGFβ1 gene expression. In addition, a high-starch diet decreased the phosphorylation of AMPK and upregulated the expression of SREBP, together with higher hepatic liver lipid and HSI. The oxidative stress and lipid metabolism disorders indicate metabolic liver disease (MLD) of largemouth bass fed high-starch diets. Feeding on OE-supplemented diets increased the hepatic antioxidant capacity by decreasing the content of MDA and SOD. Fish fed the HSOE diet had an activated phosphorylation of JNK and decreased expression of pro-inflammatory IL1β compared with those fed the HS diet, which strongly indicated that the degree of inflammatory responses was reduced after OE supplementation. Interestingly, this study demonstrated that OE regulates hepatic lipid metabolism in fish by inhibiting the expression of hepatic lipogenesis genes (ACC1 and FASN) and promoting lipolysis (ATGL) and β-oxidation (CPT1α) to prevent TG accumulation. In conclusion, high-starch feed induced oxidative stress and lipid metabolic disorder of largemouth bass, while supplementation with OE improved its antioxidant capacity, anti-inflammatory responses and lipid metabolism. However, hepatic histopathological results suggested that OE supplementation could not completely repair the MLD caused by the high level of starch in largemouth bass.

Energy utilisation efficiencies of digestible protein, fat and carbohydrates for African catfish (Clarias gariepinus)

In this study, the effect of dietary macronutrient composition on the energy utilisation efficiency for growth using the digestible energy (DE) approach was evaluated for African catfish (Clarias gariepinus). Furthermore, the energy utilisation efficiencies of digestible protein, fat and carbohydrates for growth were estimated using the net energy (NE) approach. The experiment had a 4 × 2 factorial design. C. gariepinus (71.6 g) were fed one of four diets, each at two feeding levels (12 vs 22 g.kg−0.8.d−1), for 30 days. Diets were formulated with the aim to create large contrasts in the digestible protein (dCP), fat (dFat) and carbohydrate (dCarb) content among the four diets. These contrasts in dietary composition and feeding levels enabled multiple regression analysis of energy retention (RE) as a function of dCP, dFat and dCarb intake. Using the DE approach, the dietary macronutrient content affected the energy utilisation efficiency (kgDE) of C. gariepinus. Increasing the dietary carbohydrate content reduced the kgDE from 93.5% to 78.5% in low starch diets compared to high starch diets. Thus the relationship between DE and RE is affected by the dietary macronutrient composition. With the NE approach, energy utilisation efficiencies of digestible protein, fat and carbohydrates for growth of C. gariepinus were estimated at 86%, 95% and 59%, respectively. Results of the present study indicated the probability of biases in feed evaluation and formulation when using the DE approach. Thus the NE approach is advisable as means for energy evaluation of feed/ingredients for C. gariepinus.

Differences in Metabolic Profiles of Healthy Dogs Fed a High-Fat vs. a High-Starch Diet.

Obesity is a common problem in dogs and overconsumption of energy-rich foods is a key factor. This study compared the inflammatory response and fecal metabolome of dogs fed a high-fat vs. a high-starch diet. Ten healthy lean adult beagles were equally allocated into two groups in a cross-over design. Each group received two diets in which fat (horse fat) and starch (pregelatinized corn starch) were exchanged in an isocaloric way to compare high fat vs. high starch. There was a tendency to increase the glucose and glycine concentrations and the glucose/insulin ratio in the blood in dogs fed with the high-fat diet, whereas there was a decrease in the level of Non-esterified fatty acids and a tendency to decrease the alanine level in dogs fed with the high-starch diet. Untargeted analysis of the fecal metabolome revealed 10 annotated metabolites of interest, including L-methionine, which showed a higher abundance in dogs fed the high-starch diet. Five other metabolites were upregulated in dogs fed the high-fat diet, but could not be annotated. The obtained results indicate that a high-starch diet, compared to a high-fat diet, may promote lipid metabolism, anti-oxidative effects, protein biosynthesis and catabolism, mucosal barrier function, and immunomodulation in healthy lean dogs.

Influence of reducing starch in the diets with similar protein and energy contents on lactation performance, ruminal fermentation, digestibility, behaviour and blood metabolites in primiparous and multiparous dairy cows

BackgroundIt is not clearly known whether parity can affect the outcomes of starch reduction in the diet of lactating dairy cows.IntroductionA 2 × 2 factorial study was conducted to evaluate the effects of reducing starch in the diets with similar protein and energy contents on lactation performance, ruminal fermentation, nutrient digestibility, behaviour and blood metabolites in primiparous (PP) and multiparous (MP) dairy cows.MethodsTwenty PP cows (DIM = 37 ± 10; 40 ± 5 kg/day of milk; mean ± SD) and 20 MP cows (DIM = 37 ± 9; 48 ± 5 kg/day of milk) were used in present study. Treatments were a factorial arrangement of two levels of starch (high vs. low) and two parity categories (PP vs. MP): (1) high‐starch diet (29.2% ± 0.70) and PP cows (HS‐PP); (2) low‐starch diet (22.3% ± 0.52) and PP cows (LS‐PP); (3) high‐starch diet and MP cows (HS‐MP) and (4) low‐starch diet and MP cows (LS‐MP). All diets were formulated to be similar in crude protein (16.1 % of dry matter) and NEL (1.60 Mcal/kg of dry matter) contents. The amount of metabolise protein was 2688 g/day in high‐starch diet and 2728 g/day in low‐starch diet. The experiment was conducted over two consecutive periods and included 4 weeks for adaptation and 3 weeks for data collection.ResultsDry matter intake and the yield of milk true protein and lactose increased but milk fat: protein ratio and nutrient digestibility decreased for cows fed the HS diets compared with the LS diets. The ruminal proportion of propionate was greater but acetate, the acetate to propionate ratio and sorting against long particles (19 and 8 mm) were lower for cows fed the HS diets than the LS diets. Multiparous cows had a greater nutrient intake and milk yield, longer rumination meal length, greater BW, but lower plasma total antioxidant capacity, non‐esterified fatty acids, faeces pH compared with PP cows. An interaction between parity and the dietary level of starch was detected on feed efficiency measured as FCM yield/DMI in the way that only within PP cows low‐starch diet was more efficient than HS diets. We found another interaction effect of parity × starch on back fat thickens (BFT) change in the way that only within PP cows BFT change was greater for HS compared with LS diet.ConclusionOverall, regardless of the benefit derived from feeding a reduced‐starch diet by partially replacing grains with sugar beet pulp in the diets on nutrient digestibility, a reduced‐starch diet may be used more efficiently in PP than in MP cows but at expense of body reserves (i.e. BFT) loses.

Does a high dietary intake of resistant starch affect glycaemic control and alter the gut microbiome in women with gestational diabetes? A randomised control trial protocol

BackgroundGestational Diabetes Mellitus (GDM) is prevalent with lasting health implications for the mother and offspring. Medical nutrition therapy is the foundation of GDM management yet achieving optimal glycaemic control often requires treatment with medications, like insulin. New dietary strategies to improve GDM management and outcomes are required.Gut dysbiosis is a feature of GDM pregnancies, therefore, dietary manipulation of the gut microbiota may offer a new avenue for management. Resistant starch is a fermentable dietary fibre known to alter the gut microbiota and enhance production of short-chain fatty acids. Evidence suggests that short-chain fatty acids improve glycaemia via multiple mechanisms, however, this has not been evaluated in GDM.MethodsAn open-label, parallel-group design study will investigate whether a high dietary resistant starch intake or resistant starch supplement improves glycaemic control and changes the gut microbiome compared with standard dietary advice in women with newly diagnosed GDM. Ninety women will be randomised to one of three groups - standard dietary treatment for GDM (Control), a high resistant starch diet or a high resistant starch diet plus a 16 g resistant starch supplement. Measurements taken at Baseline (24 to 30-weeks’ gestation), Day 10 and Day 56 (approximately 36 weeks’ gestation) will include fasting plasma glucose levels, microbial composition and short-chain fatty acid concentrations in stool, 3-day dietary intake records and bowel symptoms questionnaires. One-week post-natal data collection will include microbial composition and short-chain fatty acid concentrations of maternal and neonatal stools, microbial composition of breastmilk, birthweight, maternal and neonatal outcomes. Mixed model analysis of variance will assess change in glycaemia and permutation-based multivariate analysis of variance will assess changes in microbial composition within and between intervention groups. Distance-based linear modelling will identify correlation between change in stool microbiota, short-chain fatty acids and measures of glycaemia.DiscussionTo improve outcomes for GDM dyads, evaluation of a high dietary intake of resistant starch to improve glycaemia through the gut microbiome needs to be established. This will expand the dietary interventions available to manage GDM without medication.Trial registrationAustralian New Zealand Clinical Trial Registry, ACTRN12620000968976p. Registered 28 September 2020

Yeast culture improved the growth performance, liver function, intestinal barrier and microbiota of juvenile largemouth bass (Micropterus salmoides) fed high-starch diet

The present study was conducted to investigate the effects of yeast culture on the growth, health and microflora of the juvenile largemouth bass fed high-starch diet. The experiment set three isonitrogenous and isolipidic diets, control (high-starch diet), HSY1 (high-starch diet with 1% yeast culture) and HSY3 (high-starch diet with 3% yeast culture). A feeding trial was conducted in largemouth bass juveniles for 8 weeks. The results indicated fish fed with 3% yeast culture not only could improve specific growth rate (SGR), but also significantly decreased hepatic lipid content, hepatic glycogen content, and hepatopancreas somatic index (HSI) compared with the control group (p<0.05). The total superoxide dismutase (T-SOD) and catalase (CAT) activities of HSY3 group significantly increased while malondialdehyde (MDA) content significantly reduced in liver compared with the control group (p<0.05). Meanwhile, the mRNA expression levels of hepatic Sod and Cat were up-regulated (p<0.05), and liver metabolism showed 111 metabolites were significantly changed in HSY3 group, liver lipid metabolism pathway remarkably changed. Besides, the intestinal anti-inflammatory cytokines were significantly up-regulated, and the pro-inflammatory cytokines were significantly down-regulated as the inclusion of yeast culture (p<0.05). Notably, HSY3 group diet up-regulated the expression of Zo-1, Claudin and Occludin in intestine compared with the other groups (p<0.05). Serum d-lactate (D-lac), diamine oxidase (DAO) and lipopolysaccharide (LPS) decreased significantly with the inclusion of yeast culture (p<0.05). Furthermore, the abundance of probiotics (such as Lactobacillus, Bacillus and Bifidobacterium) increased significantly, and the abundance of intestinal potential pathogenic bacteria (Plesiomonas) decreased in HSY3 group (p<0.05). The phenotypic analysis showed that gram-negative bacteria significantly decreased while gram-positive bacteria increased in HSY3 group (p<0.05). All in all, this study revealed that supplementation of 3% yeast culture can improve the growth performance and the health of juvenile largemouth bass, and has the potential to be used as an effective synbiotics for M. salmoides.

Effects of metabolizable energy intake on post weaning lamb growth performance, carcass tissue composition and internal fat depend on animal characteristics: A meta-analysis

This study aimed to establish the quantitative relationship between metabolisable energy intake (MEI) and growth performance, carcass tissue composition and internal fat, taking into consideration animal precocity, maturity and tail nature. Data from 67 publications were used in the meta-analysis. Diets were characterized and three classes were identified (low medium and high energy density diets). Breeds were characterized according to tail nature, precocity and maturity stage. Average daily gain (ADG) responded to MEI in all animals weighing less than 60% of their adult weight regardless their precocity or their tail nature. At the same level of MEI, the higher the diet energy density, the higher the ADG. In animals weighing less than 42% of adult weight and receiving a high starch diet, carcass muscle and internal fat responded to MEI. Whereas, for animals that weighed between 43% and 75% of adult weight, increases in MEI influenced carcass adipose tissue.

Modulation of Plasma and Milk Sphingolipids in Dairy Cows Fed High-Starch Diets.

Bovine milk is a significant source of sphingolipids, dietary compounds that can exert anti-inflammatory actions, and which can modulate the host’s microbiome. Because sphingolipid synthesis can be modified by diet, we hypothesized that dietary conditions which reduced FFA availability may result in reduced sphingolipid synthesis. Twelve ruminally cannulated cows (120 ± 52 DIM; 35.5 ± 8.9 kg of milk/d; mean ± SD) were randomly assigned to treatment in a crossover design with 21-d periods. Treatments were (1) High starch (HS), (2) Control. The HS diet contained 29% starch, 24% NDF, and 2.8% fatty acids (FA), whereas the Control diet contained 20% starch, 31% NDF, and 2.3% FA. Plasma and milk samples were obtained on d 21 of each period and sphingolipids were quantified using targeted metabolomics. Univariate and multivariate analyses of generalized log-transformed and Pareto-scaled data included ANOVA (fixed effects of treatment) and discriminant analysis. The lipidomics analysis detected 71 sphingolipids across plasma and milk fat, including sphinganines (n = 3), dihydro-ceramides (n = 8), ceramides (Cer; n = 15), sphingomyelins (SM; n = 17), and glycosylated ceramides (n = 28). Followed by Cer, SM were the most abundant sphingolipids detected in milk and plasma, with a preponderance of 16:0-, 23:0-, and 24:0-carbon sidechains. Although no effects of HS diets were observed on plasma sphingolipids, we detected consistent reductions in the concentrations of several milk Cer (e.g., 22:0- and 24:0-Cer) and SM (17:0- and 23:0-SM) in response to HS. Discriminant analysis revealed distinct metabolite separation of HS and Control groups, with several Cer and SM being distinctively predictive of dietary treatment. We conclude that HS diets can reduce the secretion of milk Cer and SM, even in the absence of changes in circulating sphingolipids.