Topic:Carbohydrates
Carbohydrates are an essential component of the equine diet, providing a primary energy source for horses. They are classified into structural carbohydrates, such as fiber found in hay and pasture, and non-structural carbohydrates (NSC), including sugars and starches found in grains. The digestion and metabolism of carbohydrates are critical to maintaining optimal energy levels and overall health in horses. Imbalances or excessive intake of non-structural carbohydrates can lead to metabolic disorders like laminitis or equine metabolic syndrome. This page compiles peer-reviewed research studies and scholarly articles that explore the types, digestion, metabolism, and dietary management of carbohydrates in equine nutrition.
Investigation of glucagon-like peptide-1 response to six oral carbohydrates in ponies. Glucagon-like peptide-1 (GLP-1), the principal incretin in horses, may play a role in the pathophysiology of insulin dysregulation (ID). This study aimed to describe its concentration in response to three preserved forages and four dynamic tests for ID in ponies. Twelve adult ponies of mixed ID status were given a meal of hay, soaked hay or haylage, an in-feed oral glucose test (OGT), oral sugar test (OST), an oral test using a proprietary breakfast cereal (WEET) or a combined glucose-insulin tolerance test (CGIT) weekly in a randomised cross-over study. Glucose, insulin and GLP-1 concentratio...
Effects of alpha-2-adrenoceptor agonism and antagonism on equine blood insulin and glucose concentrations after oral carbohydrate load. Alpha-2-adrenoceptor agonist detomidine is a commonly used sedative agent in horses. In addition to the sedative effect, detomidine has been reported to elicit changes in energy metabolism such as hypoinsulinaemia and hyperglycaemia. This study aimed to investigate the effects of detomidine with and without peripherally acting alpha-2-adrenoceptor antagonist vatinoxan on insulin and blood glucose (BG) concentrations in horses after a standard dose of oral carbohydrates. Sixteen horses were assigned to four intravenous treatments in a randomised cross-over design: saline (SAL), detomidine (0.02...
Insulin dysregulated horses metabolic responses to forage pellets. Hyperinsulinemia-associated laminitis (HAL) is the primary concern for insulin dysregulated (ID) equids and their insulin response to the consumption of oral, nonstructural carbohydrates (NSC) has been shown to be a risk predictor for HAL development. This randomized, crossover study's objective was to examine the insulinemic responses to 3 forage pellets (1 g/kg BW) (timothy hay, TH, 9.5 % CP & 10 % NSC DM; alfalfa hay, AH, 16.3 % CP & 9.8 % NSC DM; timothy-alfalfa hay; TAH, 17.2 % CP & 9.8 % NSC DM) along with a positive (dehulled oats; OG, 14.7 % CP & 59.7 % NSC DM) and negative dietary cha...
A glucagon-like peptide-1 receptor antagonist reduces the insulin response to a glycemic meal in ponies. High plasma concentrations of insulin can cause acute laminitis. Ponies and horses with insulin dysregulation (ID) exhibit marked hyperinsulinemia in response to dietary hydrolyzable carbohydrates. Glucagon-like peptide-1 (GLP-1), an incretin hormone released from the gastrointestinal tract, enhances insulin release, and is increased postprandially in ponies with ID. The aim of this study was to determine whether blocking the GLP-1 receptor reduces the insulin response to a high glycemic meal. Five adult ponies were adapted to a cereal meal and then given two feed challenges 24 h apart of a me...
Gut microbiota changes in horses with Chlamydia. Zoonotic diseases pose a significant threat to public health. Chlamydia, as an intracellular pathogen, can colonize the intestinal tract of humans and animals, changing the gut microbiota. However, only a few studies have evaluated alterations in the gut microbiota of horses infected with Chlamydia. Therefore, this study aimed to investigate gut microbiota and serum biochemical indicators in horses with Chlamydial infection (IG) and healthy horses (HG). Fecal and blood samples were collected from 16 horses (IG: 10; HG: 6) before morning feeding for the determination of gut microbiota and serum...
Molecular insights into the lipid-carbohydrates metabolism switch under the endurance effort in Arabian horses. Recent studies have shown that in Arabian horse muscle, long-term exercise-induced expression of genes related to fatty acid degradation and the downregulation of genes belonging to the glycolysis/gluconeogenesis and insulin signalling pathways. Long-lasting physical exertion may trigger the metabolism to switch the main energy source from carbohydrates to lipids due to higher caloric content. Objective: To describe the metabolism adaptation at the whole transcriptome of blood to endurance effort in Arabian horses. Methods: In vivo experiment. Methods: Venous blood samples from 10 Arabian hors...
Exploring the Influence of Growth-Associated Host Genetics on the Initial Gut Microbiota in Horses. The influences of diet and environmental factors on gut microbial profiles have been widely acknowledged; however, the specific roles of host genetics remain uncertain. To unravel host genetic effects, we raised 47 Jeju crossbred (Jeju × Thoroughbred) foals that exhibited higher genetic diversity. Foals were raised under identical environmental conditions and diets. Microbial composition revealed that Firmicutes, Bacteroidetes, and Spirochaetes were the predominant phyla. We identified 31 host-microbiome associations by utilizing 47,668 single nucleotide polymorphisms (SNPs) and 734 taxa with...
Effect of diet composition on glandular gastric disease in horses. Nutritional factors are suggested to influence the incidence and severity of glandular gastric disease (GGD) in horses. Objective: To retrospectively assess whether dietary fermentable carbohydrates increase the severity of GGD and to prospectively evaluate whether the partial substitution of concentrates by dehydrated alfalfa would decrease GGD severity scores. Methods: In total, 82 trotters from 4 training centers exercised ≥5 days/week. Methods: Multicenter retrospective observational study, and prospective 2-arm randomized trial. Glandular mucosae were observed by gastroscopy and score...
Equine metabolic syndrome: Role of the enteroinsular axis in the insulin response to oral carbohydrate. Equine insulin dysregulation (ID) comprises amplified insulin responses to oral carbohydrates or insulin resistance, or both, which leads to sustained or periodic hyperinsulinaemia. Hyperinsulinaemia is important in horses because of its clear association with laminitis risk, and the gravity of this common sequela justifies the need for a better understanding of insulin and glucose homoeostasis in this species. Post-prandial hyperinsulinaemia is the more commonly identified component of ID and is diagnosed using tests that include an assessment of the gastrointestinal tract (GIT). There are se...
Effects of corn supplementation on serum and muscle microRNA profiles in horses. Laminitis associated with equine metabolic syndrome causes significant economic losses in the equine industry. Diets high in non-structural carbohydrates (NSC) have been linked to insulin resistance and laminitis in horses. Nutrigenomic studies analyzing the interaction of diets high in NSCs and gene expression regulating endogenous microRNAs (miRNA) are rare. This study's objectives were to determine whether miRNAs from dietary corn can be detected in equine serum and muscle and its impacts on endogenous miRNA. Twelve mares were blocked by age, body condition score, and weight and assigned to...
Acute phase proteins levels in horses, after a single carbohydrate overload, associated with cecal alkalinization. Horses submitted to carbohydrate overload can develop laminitis due to changes in cecal pH and microbiota, followed by an increase in transmural absorption of luminal content, including bacterial toxins. In response to acute injury there is hepatic overproduction of several proteins known as acute phase proteins (APP). Few studies have evaluated protein fractionation to characterize the inflammatory response in acute laminitis. The aim of this study was to test the viability of an experimental model to induce acute laminitis, using a single carbohydrate overload, and the influence of a bufferi...
Understanding the microbial fibre degrading communities & processes in the equine gut. The equine gastrointestinal tract is a self-sufficient fermentation system, housing a complex microbial consortium that acts synergistically and independently to break down complex lignocellulolytic material that enters the equine gut. Despite being strict herbivores, equids such as horses and zebras lack the diversity of enzymes needed to completely break down plant tissue, instead relying on their resident microbes to carry out fibrolysis to yield vital energy sources such as short chain fatty acids. The bulk of equine digestion occurs in the large intestine, where digesta is fermented for 3...
Gut microbial community structure and function of Przewalski’s horses varied across reintroduced sites in China. Host-associated microbiota can significantly impact host fitness. Therefore, naturally occurring variations in microbiota may influence the health and persistence of their hosts. This finding is particularly important in reintroduced animals, as they typically experience habitat changes during translocations. However, little is known about how microbiomes are altered in response to conservation translocation. Here, we accessed the gut microbiome of Przewalski's horse (Equus przewalskii) populations in China from three nature reserves (i.e. Xinjiang Kalamaili Nature Reserve, KNR; Dunhuang Xihu ...
Carbohydrate pellets to assess insulin dysregulation in horses. A glycemic challenge test is used for the diagnosis of insulin dysregulation (ID) in horses and ponies. Different forms of the test exist where the administrative route and dose of glucose vary, which makes interpretation of results challenging. Objective: To evaluate the palatability of, and blood glucose and insulin responses to, carbohydrate pellets fed as an oral glucose test (OGT), and to establish the diagnostic threshold for ID when using the pellets. Methods: University and privately-owned horses and ponies (n = 157) comprised of 31 breeds and both sexes. Methods: Multicenter cohort ...
The effect of harvest time of forage on carbohydrate digestion in horses quantified by in vitro and mobile bag techniques. Carbohydrates in forages constitute an important part of the feed ration for all horses. The aim of the present study was to investigate the effect of harvest time on carbohydrate composition and digestion of various grass species. The experiment was divided into three parts 1) characterization of the chemical composition of experimental feeds (6 grass species: meadow fescue [MF], cocksfoot [CF], perennial ryegrass [PR], smooth bromegrass [SB], tall fescue [TF], and timothy [TI], and 3 harvest times: early, medium, and late first cut), 2) measurements of the in vitro digestion of selected expe...
Identifying possible thresholds for nonstructural carbohydrates in the insulin dysregulated horse. Identifying intake levels of nonstructural carbohydrates (NSCs) that limit the postprandial insulinaemic response in the insulin dysregulated (ID) horse may help reduce hyperinsulinaemia-associated laminitis (HAL) risk. Objective: To determine if ID horses have thresholds for pure sources of starch and sugar, above which there is an augmented insulin response. Methods: Randomised crossover experiment. Methods: Fourteen adult horses (6 ID and 8 noninsulin dysregulated, NID; matched for bodyweight) were randomly fed eight dietary treatments. Dietary treatments were formulated using a base of low...
A starch-rich treat affects enteroinsular responses in ponies. To determine the effect of a starch-rich treat, added to the daily diet of ponies for 10 days, on enteroinsular responses to meal consumption. 10 mixed-breed adult ponies owned by Queensland University of Technology were used in the study. Six ponies were metabolically healthy, and 4 were insulin dysregulated at the start of the study, according to the results of an in-feed oral glucose test. A bread-based treat was offered twice daily for 10 days, adding 0.36 ± 0.04 g/kg body weight (BW) carbohydrates to the daily diet. Before and after treatment, the intestinal capacity for simple carbohydr...
Comparison of gut microflora of donkeys in high and low altitude areas. Donkeys' gut microbe is critical for their health and adaptation to the environment. Little research has been conducted on the donkey gut microbiome compared with other domestic animals. The Tibetan Plateau is an extreme environment. In this study, 6 Qinghai donkeys (QH) from the Tibetan Plateau and 6 Dezhou donkeys (DZ) were investigated, and the contents of 4 parts-stomach, small intestine, cecum, and rectum-were collected. 16S rRNA sequencing and metagenomic sequencing were used to analyze the composition and diversity of gut microbial communities in donkeys. The results showed that the flo...
Reinforcer efficacy of grain for horses. Positive reinforcement is becoming more common in horse training. Identifying effective reinforcers is critical for training success. The aim of this study was to determine relative reinforcer efficacy of different grains. Four horses learned to muzzle touch a target, after which they were tested using a progressive ratio schedule of reinforcement with different grains as the consequence. Break points were used to determine relative reinforcer efficacy of each grain and were also converted into unit price per kilocalorie to determine if caloric value impacted reinforcer efficacy. Condition 1 c...
Variations in the fecal microbiota and their functions of Thoroughbred, Mongolian, and Hybrid horses. The horse gut is colonized by a rich and complex microbial community that has important roles in horse physiology, metabolism, nutrition, and immune functions. Fewer across-breed variations in horse gut microbial diversity have been illustrated. In this article, the gut microbiota of Thoroughbred, Mongolian, and Hybrid horses [first filial generation (F1) of Mongolian (maternal) and Thoroughbred (paternal)] were studied by second-generation high-throughput sequencing technology. Differences in gut microbiota composition and function between breeds were determined using diversity and functional...
Evaluation of peripheral blood polymorphonuclear cell functions after an oral carbohydrate overload in obese and insulin dysregulated horses. Obesity and insulin dysregulation (ID) are increasingly prevalent conditions in equid populations worldwide. Immune impairment is well described in humans with metabolic dysfunction and is reported but still incompletely understood in horses. This study evaluated the effect of acute induced transient hyperglycemia on apoptosis, phagocytosis and oxidative burst activity of peripheral blood polymorphonuclear cells (PMN) of lean and obese adult horses with or without insulin dysregulation. Seventeen adult horses were allocated into three groups based on their body condition score (BCS) and metabo...
Biological Potential of Polyphenols in the Context of Metabolic Syndrome: An Analysis of Studies on Animal Models. Metabolic syndrome (MetS) is a disease that has a complex etiology. It is defined as the co-occurrence of several pathophysiological disorders, including obesity, hyperglycemia, hypertension, and dyslipidemia. MetS is currently a severe problem in the public health care system. As its prevalence increases every year, it is now considered a global problem among adults and young populations. The treatment of choice comprises lifestyle changes based mainly on diet and physical activity. Therefore, researchers have been attempting to discover new substances that could help reduce or even reverse t...
Gut Microbiome Characteristics in feral and domesticated horses from different geographic locations. Domesticated horses live under different conditions compared with their extinct wild ancestors. While housed, medicated and kept on a restricted source of feed, the microbiota of domesticated horses is hypothesized to be altered. We assessed the fecal microbiome of 57 domestic and feral horses from different locations on three continents, observing geographical differences. A higher abundance of eukaryota (p < 0.05) and viruses (p < 0.05) and lower of archaea (p < 0.05) were found in feral animals when compared with domestic ones. The abundance of genes coding for microbe-...
Water- and Ethanol-Soluble Carbohydrates of Temperate Grass Pastures: a Review of Factors Affecting Concentration and Composition. Temperate grasses contain both water- and ethanol-soluble carbohydrates. Water-soluble carbohydrates (WSCs) of temperate grasses include glucose, fructose, sucrose, and fructans (fructose-based polymers) of varying lengths. Ethanol-soluble carbohydrates (ESCs) consist of glucose, fructose, sucrose, and shorter fructans. WSCs and ESCs have been implicated in equine pasture-associated laminitis and other metabolic disorders. In this paper, the peer-reviewed literature of the past decade was summarized for selected factors influencing concentrations and composition of WSCs and ESCs in temperate g...
Diurnal Variation in Forage Nutrient Composition of Mixed Cool-Season Grass, Crabgrass, and Bermudagrass Pastures. Warm-season grasses have been suggested as alternative low non-structural carbohydrate (NSC) pasture forages. The purpose of this study was to evaluate nutrient composition and diurnal changes in soluble carbohydrates for the warm-season annual 'Quick-N-Big' crabgrass [CRB; Digitaria sanguinalis (L.) Scop.] and the warm-season perennial 'Wrangler' bermudagrass [BER; Cynodon dactylon (L.) Pers] in comparison to mixed cool-season grass [CSG; 'Inavale' orchardgrass (Dactylis glomerata [L.]), 'Tower' tall fescue (Lolium arundinaceum [Schreb.] Darbysh.), and 'Argyle' Kentucky bluegrass (Poa prat...
Age and Body Condition Influence the Post-Prandial Interleukin-1β Response to a High-Starch Meal in Horses. Older horses and those prone to obesity may be at a higher risk for inflammation than younger and leaner counterparts. Previous research indicated a postprandial elevation in plasma concentrations of interleukin-1β (IL-1β), a pro-inflammatory cytokine, after consuming 1.2 g of non-structural carbohydrates/kilogram of body weight. However, these studies utilized horses of mixed age and body condition. The current study evaluated post-prandial IL-1β concentrations in horses specifically comparing lean to over-conditioned and middle aged to older. Our results suggest that at least two weeks of...
Yield, nutrient composition, and horse condition in integrated crabgrass and cool-season grass rotational grazing pasture systems. Integration of warm-season grasses into traditional cool-season pastures can increase summer forage for grazing cattle. The aim of this study was to determine impacts of this practice on yield and nutrient composition of equine rotational pasture systems as well as horse body condition. Two 1.5 ha rotational systems (6 to 0.25 ha sections/system) were evaluated: a control system (CON) (all sections mixed cool-season grass [CSG-CON]) and an integrated rotational grazing system (IRS) (three CSG sections [CSG-IRS] and three Quick-N-Big crabgrass [Digitaria sanguinalis (L.) Scop.; CRB-IRS]). Three...
Metagenomic Analysis of Fecal Archaea, Bacteria, Eukaryota, and Virus in Przewalski’s Horses Following Anthelmintic Treatment. Intestinal microbiota is involved in immune response and metabolism of the host. The frequent use of anthelmintic compounds for parasite expulsion causes disturbance to the equine intestinal microbiota. However, most studies were on the effects of such treatment on the intestinal bacterial microbes; none is on the entire microbial community including archaea and eukaryotic and viral community in equine animals. This study is the first to explore the differences of the microbial community composition and structure in Przewalski's horses prior to and following anthelmintic treatment, and to dete...
Degradation of Monosaccharides, Disaccharides, and Fructans in the Stomach of Horses Adapted to a Prebiotic Dose of Fructooligosaccharides and Inulin. For a period of 20 days, 12 horses either received a prebiotic supplementation with fructooligosaccharides and inulin via Jerusalem artichoke meal (JAM) or corncob meal without grains (CMG) as placebo. The horses were euthanized 1 hour postprandial, gastric digesta was sampled from pars nonglandularis (PNG) and pars glandularis (PG), and concentrations of starch, mono- and disaccharides, fructans, d- and l-lactic acid, and short chain fatty acids were analyzed. Concentrations of starch and simple sugars were widely the same in JAM supplemented and not supplemented meals. However, fructans were...