Starch is a carbohydrate that serves as a significant energy source in equine diets. It is primarily found in grains and is broken down into glucose during digestion, providing energy for various physiological activities in horses. The digestion and metabolism of starch can influence a horse's energy levels, performance, and overall health. Excessive starch intake, however, may lead to digestive disturbances or metabolic issues. This page compiles peer-reviewed research studies and scholarly articles that explore the digestion, metabolism, and dietary implications of starch in equine nutrition, as well as its impact on horse health and performance.
Laroche N, Grimm P, Julliand S, Sorci G.The use of anthelminthic drugs has several drawbacks, including the selection of resistant parasite strains. Alternative avenues to mitigate the negative effects of helminth infection involve dietary interventions that might affect resistance and/or tolerance by improving host immunity, modulating the microbiota, or exerting direct anthelmintic effects. The aim of this study was to assess the impact of diet on strongyle infection in horses, specifically through immune-mediated, microbiota-mediated, or direct anthelmintic effects. Horses that were naturally infected with strongyles were fed eit...
de Laat MA, Fitzgerald DM, Harris PA, Bailey SR.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...
Varasteh F, Ebrahimi SH, Naserian AA, Zerehdaran S, Miri VH.This study aimed to 1) evaluate the interaction of corn grain micronization and starch levels per meal on equine plasma glucose, and 2) determine if micronization affects the risk of hindgut acidosis. Six mature (aged 6 to 10 years), healthy, non-pregnant mares (initial body weight [BW]: 301 to 463 kg) were used in a 2×3 factorial cross-over design. The treatments included two forms of corn grain (ground and micronized flaked) at three levels of starch (1, 1.5, and 2 g/kg BW per meal). The blood was sampled before and 30, 60, 90, 120, 180, 240, and 300 min after morning feeding and the glucos...
Martin A, Lepers R, Vasseur M, Julliand S.Large amounts of high-starch concentrates are traditionally fed to horses in training. However, this has been associated with digestive or muscle diseases and behavioural modifications. In parallel, it has been demonstrated that horses fed high-fibre, low-starch diets achieve the same performance over an exercise test as the ones fed high-starch diets. However, whether the same performance level can be maintained over a longer training cycle is still being determined. This study aimed to compare the evolution in physical performance and cardiorespiratory responses of two groups of French Trott...
de Medeiros Ferreira JR, Mello Cerbaro AE, Bastos FL, Pereira RA, Duarte MA, Araújo Júnior ÂMC, da Silva AH, de Oliveira Gobesso AA.High amounts of grains in the equine diet led to high starch intake, causing gut alterations. Aimed at reducing harmful effects, extract (MCE) is a phytogenic additive that stands out for its antibiotic and anti-inflammatory effects proven in different species. However, there is no useful information for horses. The objective of this study was to evaluate the effects of different levels of the inclusion of commercial MCE on body weight (BW), body condition score (BCS), total apparent digestibility (AD) of nutrients, faecal pH and fermentative products, on ponies fed a high-starch diet. Eight ...
Bustamante CC, de Paula VB, Rabelo IP, Fernandes CC, Kishi LT, Canola PA, Lemos EGM, Valadão CAA.Starch overload in horses causes gastrointestinal and metabolic disorders that are associated with microbiota changes. Therefore, we identified the fecal microbiota and hypothesized that intracecal injection of alkaline solution (buffer; Mg(OH)2 + Al(OH)3) could stabilize these microbiota and clinical changes in horses submitted to corn starch overload. Ten crossbred horses (females and geldings) were allocated to group I (water−saline and starch−buffer treatments) and group II (water−buffer and starch−saline treatments). Clinical signs, gross analysis of the feces, and fecal microbiot...
Thorringer NW, Weisberg MR, Jensen RB.The competition for customers increases the search for new grain processing methods for equine feed, but the effect on starch digestibility and metabolic responses varies. Therefore, to evaluate the effect of the processing methods, toasting and micronizing, on starch digestion and the effect on metabolic responses, the mobile bag technique (MBT) and plasma glucose and insulin concentrations in the blood were used to estimate nutrient disappearance and metabolic responses pre-cecally. Further, cecal pH, ammonium nitrogen (N), and short-chain fatty acid (SCFA) concentrations were used to estima...
Grimm P, Combes S, Pascal G, Cauquil L, Julliand V.Starchy diets can induce hindgut dysbiosis in horses. The present study evaluated the impact of a yeast (Saccharomyces cerevisiae) and microalgae (Aurantiochytrium limacinum) supplementation on caecal, colonic and faecal microbial ecosystem and on blood inflammatory parameters of horses fed high-fibre or high-starch diets. Six fistulated geldings in a 2 × 2 Latin-square design were alternatively supplemented and received during each period 100 % hay (4 weeks) followed by a 56/44 hay/barley diet (3 weeks). Caecal, colonic and faecal samples were collected 4 h after the morning meal three times...
Langner K, Vervuert I.The hindgut microbiota of the horse is a complex structure which can be highly influenced by the diet or nutrients such as starch. For instance, a diet rich in starch promotes the growth of bacteria that can utilize starch and produce lactate while it reduces the growth of fiber fermenting cellulolytic bacteria. Therefore, attempts are made to balance the hindgut microbiota and to minimize the impacts of feeds which are rich in starch such as the supplementation of probiotics. Up to date only different strains of the yeast (SC) are officially registered probiotics for horses in the European U...
Pyles MB, Fowler AL, Bill VT, Crum AD, Hayes SH, Harlow BE, Flythe MD, Lawrence LM.Dietary starch source has been shown to affect fecal bacterial communities of horses fed minimally processed cereal grains. However, processing may increase foregut starch digestibility, reducing effects of starch source on fecal bacterial communities. This study aimed to determine the effect of starch source in pelleted concentrates on fecal Lactobacillus spp., amylolytic bacteria, and cellulolytic bacteria in broodmares mares, during the prepartum and postpartum period. Thoroughbred mares (n = 18) were paired by last breeding date then randomly assigned to either an oat-based or a corn and ...
Schaafstra FJWC, van Doorn DA, Schonewille JT, Roelfsema E, Westermann CM, Dansen O, Jacobs M, Lee JY, Spronck EA, Blok MC, Hendriks WH.Exercise and physical training are known to affect gastrointestinal function and digestibility in horses and can lead to inaccurate estimates of nutrient and energy digestibility when markers are used. The effect of exercise on apparent nutrient digestibility and faecal recoveries of ADL and TiO2 was studied in six Welsh pony geldings subjected to either a low- (LI) or high-intensity (HI) exercise regime according to a cross-over design. Ponies performing LI exercise were walked once per day for 45 min in a horse walker (5 km/h) for 47 consecutive days. Ponies submitted to HI exercise were gra...
Warzecha CM, Coverdale JA, Janecka JE, Leatherwood JL, Pinchak WE, Wickersham TA, McCann JC.The objective of this study was to determine bacterial community profiles of the equine cecum in response to abrupt inclusion of varying levels of dietary starch. Seven cecally cannulated Quarter Horse geldings (497 to 580 kg) were used in a crossover design with two 28-d periods and a 28-d washout between each. Horses were randomly assigned to dietary treatments consisting of a commercial concentrate offered as fed at either 0.6 (low starch [LS]) or 1.2% BW (high starch [HS]) daily that was divided into 2 meals at 12-h intervals. Prior to the start of each period, horses were allowed ad libit...
Harlow BE, Lawrence LM, Hayes SH, Crum A, Flythe MD.Starch from corn is less susceptible to equine small intestinal digestion than starch from oats, and starch that reaches the hindgut can be utilized by the microbiota. The objective of the current study was to examine the effects of starch source on equine fecal microbiota. Thirty horses were assigned to treatments: control (hay only), HC (high corn), HO (high oats), LC (low corn), LO (low oats), and LW (low pelleted wheat middlings). Horses received an all-forage diet (2 wk; d -14 to d -1) before the treatment diets (2 wk; d 1 to 14). Starch was introduced gradually so that horses received 50...
Harlow BE, Donley TM, Lawrence LM, Flythe MD.The goal was to determine the effect of starch source (corn, oats and wheat) and concentration on: (i) total amylolytic bacteria, Group D Gram-positive cocci (GPC), lactobacilli and lactate-utilizing bacteria, and (ii) fermentation by equine microbiota. Results: When faecal washed cell suspensions were incubated with any substrate amylolytics increased over time. However, at 24 h there were 10 and 1000-fold more amylolytics with corn than wheat or oats respectively. Predominant amylolytics isolated were Enterococcus faecalis (corn, wheat) and Streptococcus bovis (oats). GPC increased with any ...
Philippeau C, Sadet-Bourgeteau S, Varloud M, Julliand V.This study aimed at assessing the impact of four barley forms on total tract apparent digestibility of dietary fibre in horses fed a large amount of starch in the morning meal (0.27% BW). Processed barley forms had a greater pre-caecal starch digestibility than the whole form. Based on this result, we hypothesised that using barley-processing methods would limit the potential dumping of undegraded starch in the hindgut of horses and, consequently, the potential negative effect on fibre degradation in the hindgut. In a 4×4 latin square design, four mature geldings fitted with a right ventral c...
Philippeau C, Varloud M, Julliand V.To determine prececal starch digestibili-ty and estimate glucose uptake from the digestion of 4 forms of barley in the small intestine, 4 mature cecally fistulated geldings (449 ± 41 kg BW) fed a 62:38 (wt/wt) meadow hay:concentrate diet at 1.7 kg DM/100 kg BW were included in a 4 × 4 Latin square design experiment. During each period, horses received 80% DM of their concentrate as 1 of the 4 forms of a same batch of barley, whole grain, 2.5 mm ground, steam flaked, and pelleted. Hay was offered in 2 equal meals and concentrate in 2 unequal meals. The starch supply in the morning meal amount...
Brøkner C, Austbø D, Næsset JA, Knudsen KE, Tauson AH.The working hypothesis was that a minor postprandial caecal pH decline would affect apparent total tract digestibility (ATTD) of the fibre fraction in horses and, hence, that soluble fibre would amplify fermentation and consequently increase ATTD of fibre. This study was a 4 × 4 Latin Square design with a sequence of 17 days adaptation to the ration followed by 8 sampling days. The feed rations consisted of only timothy hay (Group H), hay plus molassed sugar beet pulp combined with either whole oats (Group OB) or barley (Group BB) and hay plus loose chaff based concentrate (Group M). Four hor...
Vervuert I, Voigt K, Hollands T, Cí·¯ord D, Coenen M.The aim of this study was to investigate the effects of feeding oats alone before or after feeding chopped alfalfa or, in admixture with the alfalfa on the glycaemic and insulinaemic responses of horses as well as post-prandial breath hydrogen and methane excretion. Horses were fed in a randomized order, chopped alfalfa as a source of dietary fibre and unprocessed oats as a source of starch. Chopped alfalfa intake was adjusted to a crude fibre intake of 0.5 g/kg bodyweight (BW) per meal and the oats intake was adjusted to a starch intake of 2 g/kg BW per meal. The feeds were offered in three d...
Vervuert I, Voigt K, Hollands T, Cí·¯ord D, Coenen M.The aim of this study was to investigate the effect of increasing the intake of starch on the glycaemic and insulinaemic responses of horses. A cross-over study design was used in which four horses were fed increasing amounts of a compound feed (0.5-3.5 kg) to provide 0.3, 0.6, 0.8, 1.1, 1.4 and 2 starch/kg bodyweight (BW)/meal. The glycaemic response increased with starch intake (P<0.05), while feeding <1.1 g starch/kg BW resulted in a lowered response, compared to when 1.1-2 g starch/ kg BW was fed (P<0.01). The results suggested that insulin responses may be more appropriate to def...
Swyers KL, Burk AO, Hartsock TG, Ungerfeld EM, Shelton JL.A study was conducted to determine whether direct-fed microbials (DFM) could be used to increase digestibility and minimize the risk of acidosis associated with feeding an increase in the amount of starch fed to horses. Fifteen mature Thoroughbred geldings were randomly assigned to 1 of 3 treatments in a 3 x 3 Latin square design balanced for carryover effects. Within each 26-d period, horses were offered grass hay + low-starch concentrate (LS; 1.2 g of starch x kg of BW(-1) x meal(-1)) from d 1 to 13 and then were abruptly changed to hay + high-starch concentrate (HS; 2.4 g of starch.kg of BW...
Vervuert I, Bothe C, Coenen M.This study was conducted to evaluate the effects of different barley processing techniques on the glycaemic and insulinaemic responses in horses. It was hypothesized that the changes in pre-caecal starch digestibility caused by barley processing would affect metabolic responses. Six horses were fed in random order: whole (WB), finely ground (FGB), steamed (SB), steam-flaked (SFB) and popped barley (PB). The total barley intake was adjusted to 630 g starch/horse/day (1.2-1.5 g starch/kg BW/day). During a 10-day stabilization period, the horses also received 6 kg grass hay/horse/day. On the bloo...
Richards N, Hinch G, Rowe J.A survey of 72 thoroughbred trainers in several regions of NSW was conducted to better define current grain feeding practices, and the risks involved with grain feeding in the Australian thoroughbred racing industry. Results from the survey indicate that horses in the industry are currently being fed an average of 7.3 +/- 0.23 kg of grain concentrate per day, with oats, commercial pre-mixed diets and corn most commonly used. The feeding of extruded, micronised and steam flaked grains was uncommon. The results of grain and faecal sample analyses conducted during the survey indicate that incompl...
de Fombelle A, Veiga L, Drogoul C, Julliand V.This trial was conducted to determine the extent of prececal starch digestibility depending on the botanical origin of starch and on diet characteristics (i.e., composition and feeding pattern). The prececal disappearance of six substrates (oats, barley, corn, horse bean, potato, and wheat) was measured in four cannulated horses fed (as-fed basis) 11.8 g/kg BW of a high-fiber (HF) or high-starch (HS) pelleted feed and 10.0 g/kg BW of meadow hay using the mobile bag technique (MBT). The daily feeding pattern was either three meals (two meals of pellets and one meal of hay) or five meals (three ...
Vervuert I, Coenen M, Bothe C.This study was conducted to evaluate the effects of different corn processing techniques on the glycaemic and insulinaemic responses in horses. It was hypothesized that the changes in pre-caecal starch digestibility caused by various types of corn processing would alter the post-prandial glycaemic and/or insulinaemic response. Six horses were fed in random order: untreated, finely ground, steamed, micronized, steam-flaked and popped corn. The total corn intake was adjusted to 630 g starch/horse/day (1.2-1.5 g starch/kg BW/day). During a stabilization period of 10 days, horses also received 6 k...
Métayer N, Lhôte M, Bahr A, Cohen ND, Kim I, Roussel AJ, Julliand V.Feeding practices have been associated with colic in horses. If meal size and composition have an effect on gastric emptying, this could be one of the mechanisms by which feeding practices are related to the occurrence of colic. Objective: To evaluate the effect of meal size and starch content on solid phase gastric emptying. Methods: Solid phase gastric emptying of 3 different radiolabelled meals, small low-starch (SmLS), small high-starch (SmHS) and large high-starch (LgHS) meals, was measured in 5 horses by scintigraphy using 99mTc-disofenin. Data were compared among meals using nonlinear m...
Medina B, Girard ID, Jacotot E, Julliand V.Eight horses were allotted into pairs consisting of one cecum- and right ventral colon-fistulated animal and one cecum-fistulated animal. They were fed daily at the same level of intake either a high-fiber (HF) or a high-starch (HS) diet without or with 10 g of a Saccharomyces cerevisiae preparation, in a 4 x 4 Latin square design. The HS diet provided a starch overload (i.e., 3.4 g starch x kg(-1) BW x meal(-1)) while maintaining a high amount of fiber intake (i.e., dietary NDF/starch ratio was 1.0). A 21-d period of adaptation to the treatments occurred before cecal and colonic contents were...
Kienzle E, Pohlenz J, Radicke S.Structure of starch in feed and chyme of horses (7 with a cannula at the caudal end of the jejunum and 2 with a cecal fistula) after feeding high starch diets (maize: whole, broken, ground, expanded and as silage, oats: whole, rolled or ground, rolled barley, raw potatoes, and tapioca) was investigated by light and electron microscopy. Structure of feed starch and morphology or starch degradation in the chyme corresponded to data on preileal starch digestibility which was investigated in a parallel study. Barriers for starch digestion in the gastrointestinal tract of the horse were structure o...
Meyer H, Radicke S, Kienzle E, Wilke S, Kleffken D, Illenseer M.In this study preileal starch digestibility of starchy feeds (oats, corn, barley, potatoes, manioc) was determined in seven jejunofistulated horses. The grains were fed whole (oats, corn), rolled (oats, barley), crushed, ground and expanded (corn); the potatoes were fresh, the manioc rolled. Ground corn was also fed in combination with amylase. The feeds were fed partly isolated or in combination with alfalfa meal or hay (Table 1). At least four horses with a cannula in the terminal jejunum were used for each diet. Two meals per day were offered at 12 h intervals. The starch intake was mostly ...
McDaniel AL, Martin SA, McCann JS, Parks AH.The objective of this study was to examine the effects of Aspergillus oryzae fermentation extract on the in vitro equine cecal fermentation of soluble starch, amino acids/peptides, coastal bermudagrass hay, and alfalfa hay. Cecal contents were obtained from a cecally fistulated Quarter Horse gelding fed coastal bermudagrass and grain (70:30) either unadapted or adapted to dietary A. oryzae supplementation (2 g/d). Mixed cecal microorganisms were incubated in anaerobic media for either 24 h (soluble starch, amino acids) or 48 h (bermudagrass hay, alfalfa hay). A. oryzae was added to the incubat...
Medina B, Girard ID, Jacotot E, Julliand V.Eight horses were allotted into pairs consisting of one cecum- and right ventral colon-fistulated animal and one cecum-fistulated animal. They were fed daily at the same level of intake either a high-fiber (HF) or a high-starch (HS) diet without or with 10 g of a Saccharomyces cerevisiae preparation, in a 4 x 4 Latin square design. The HS diet provided a starch overload (i.e., 3.4 g starch x kg(-1) BW x meal(-1)) while maintaining a high amount of fiber intake (i.e., dietary NDF/starch ratio was 1.0). A 21-d period of adaptation to the treatments occurred before cecal and colonic contents were...
Harlow BE, Lawrence LM, Hayes SH, Crum A, Flythe MD.Starch from corn is less susceptible to equine small intestinal digestion than starch from oats, and starch that reaches the hindgut can be utilized by the microbiota. The objective of the current study was to examine the effects of starch source on equine fecal microbiota. Thirty horses were assigned to treatments: control (hay only), HC (high corn), HO (high oats), LC (low corn), LO (low oats), and LW (low pelleted wheat middlings). Horses received an all-forage diet (2 wk; d -14 to d -1) before the treatment diets (2 wk; d 1 to 14). Starch was introduced gradually so that horses received 50...
Grimm P, Combes S, Pascal G, Cauquil L, Julliand V.Starchy diets can induce hindgut dysbiosis in horses. The present study evaluated the impact of a yeast (Saccharomyces cerevisiae) and microalgae (Aurantiochytrium limacinum) supplementation on caecal, colonic and faecal microbial ecosystem and on blood inflammatory parameters of horses fed high-fibre or high-starch diets. Six fistulated geldings in a 2 × 2 Latin-square design were alternatively supplemented and received during each period 100 % hay (4 weeks) followed by a 56/44 hay/barley diet (3 weeks). Caecal, colonic and faecal samples were collected 4 h after the morning meal three times...
Warzecha CM, Coverdale JA, Janecka JE, Leatherwood JL, Pinchak WE, Wickersham TA, McCann JC.The objective of this study was to determine bacterial community profiles of the equine cecum in response to abrupt inclusion of varying levels of dietary starch. Seven cecally cannulated Quarter Horse geldings (497 to 580 kg) were used in a crossover design with two 28-d periods and a 28-d washout between each. Horses were randomly assigned to dietary treatments consisting of a commercial concentrate offered as fed at either 0.6 (low starch [LS]) or 1.2% BW (high starch [HS]) daily that was divided into 2 meals at 12-h intervals. Prior to the start of each period, horses were allowed ad libit...
Harlow BE, Donley TM, Lawrence LM, Flythe MD.The goal was to determine the effect of starch source (corn, oats and wheat) and concentration on: (i) total amylolytic bacteria, Group D Gram-positive cocci (GPC), lactobacilli and lactate-utilizing bacteria, and (ii) fermentation by equine microbiota. Results: When faecal washed cell suspensions were incubated with any substrate amylolytics increased over time. However, at 24 h there were 10 and 1000-fold more amylolytics with corn than wheat or oats respectively. Predominant amylolytics isolated were Enterococcus faecalis (corn, wheat) and Streptococcus bovis (oats). GPC increased with any ...
Swyers KL, Burk AO, Hartsock TG, Ungerfeld EM, Shelton JL.A study was conducted to determine whether direct-fed microbials (DFM) could be used to increase digestibility and minimize the risk of acidosis associated with feeding an increase in the amount of starch fed to horses. Fifteen mature Thoroughbred geldings were randomly assigned to 1 of 3 treatments in a 3 x 3 Latin square design balanced for carryover effects. Within each 26-d period, horses were offered grass hay + low-starch concentrate (LS; 1.2 g of starch x kg of BW(-1) x meal(-1)) from d 1 to 13 and then were abruptly changed to hay + high-starch concentrate (HS; 2.4 g of starch.kg of BW...
Richards N, Hinch G, Rowe J.A survey of 72 thoroughbred trainers in several regions of NSW was conducted to better define current grain feeding practices, and the risks involved with grain feeding in the Australian thoroughbred racing industry. Results from the survey indicate that horses in the industry are currently being fed an average of 7.3 +/- 0.23 kg of grain concentrate per day, with oats, commercial pre-mixed diets and corn most commonly used. The feeding of extruded, micronised and steam flaked grains was uncommon. The results of grain and faecal sample analyses conducted during the survey indicate that incompl...
Philippeau C, Sadet-Bourgeteau S, Varloud M, Julliand V.This study aimed at assessing the impact of four barley forms on total tract apparent digestibility of dietary fibre in horses fed a large amount of starch in the morning meal (0.27% BW). Processed barley forms had a greater pre-caecal starch digestibility than the whole form. Based on this result, we hypothesised that using barley-processing methods would limit the potential dumping of undegraded starch in the hindgut of horses and, consequently, the potential negative effect on fibre degradation in the hindgut. In a 4×4 latin square design, four mature geldings fitted with a right ventral c...
Meyer H, Radicke S, Kienzle E, Wilke S, Kleffken D, Illenseer M.In this study preileal starch digestibility of starchy feeds (oats, corn, barley, potatoes, manioc) was determined in seven jejunofistulated horses. The grains were fed whole (oats, corn), rolled (oats, barley), crushed, ground and expanded (corn); the potatoes were fresh, the manioc rolled. Ground corn was also fed in combination with amylase. The feeds were fed partly isolated or in combination with alfalfa meal or hay (Table 1). At least four horses with a cannula in the terminal jejunum were used for each diet. Two meals per day were offered at 12 h intervals. The starch intake was mostly ...
Métayer N, Lhôte M, Bahr A, Cohen ND, Kim I, Roussel AJ, Julliand V.Feeding practices have been associated with colic in horses. If meal size and composition have an effect on gastric emptying, this could be one of the mechanisms by which feeding practices are related to the occurrence of colic. Objective: To evaluate the effect of meal size and starch content on solid phase gastric emptying. Methods: Solid phase gastric emptying of 3 different radiolabelled meals, small low-starch (SmLS), small high-starch (SmHS) and large high-starch (LgHS) meals, was measured in 5 horses by scintigraphy using 99mTc-disofenin. Data were compared among meals using nonlinear m...
Kienzle E, Pohlenz J, Radicke S.Structure of starch in feed and chyme of horses (7 with a cannula at the caudal end of the jejunum and 2 with a cecal fistula) after feeding high starch diets (maize: whole, broken, ground, expanded and as silage, oats: whole, rolled or ground, rolled barley, raw potatoes, and tapioca) was investigated by light and electron microscopy. Structure of feed starch and morphology or starch degradation in the chyme corresponded to data on preileal starch digestibility which was investigated in a parallel study. Barriers for starch digestion in the gastrointestinal tract of the horse were structure o...
de Fombelle A, Veiga L, Drogoul C, Julliand V.This trial was conducted to determine the extent of prececal starch digestibility depending on the botanical origin of starch and on diet characteristics (i.e., composition and feeding pattern). The prececal disappearance of six substrates (oats, barley, corn, horse bean, potato, and wheat) was measured in four cannulated horses fed (as-fed basis) 11.8 g/kg BW of a high-fiber (HF) or high-starch (HS) pelleted feed and 10.0 g/kg BW of meadow hay using the mobile bag technique (MBT). The daily feeding pattern was either three meals (two meals of pellets and one meal of hay) or five meals (three ...
Brøkner C, Austbø D, Næsset JA, Knudsen KE, Tauson AH.The working hypothesis was that a minor postprandial caecal pH decline would affect apparent total tract digestibility (ATTD) of the fibre fraction in horses and, hence, that soluble fibre would amplify fermentation and consequently increase ATTD of fibre. This study was a 4 × 4 Latin Square design with a sequence of 17 days adaptation to the ration followed by 8 sampling days. The feed rations consisted of only timothy hay (Group H), hay plus molassed sugar beet pulp combined with either whole oats (Group OB) or barley (Group BB) and hay plus loose chaff based concentrate (Group M). Four hor...
Philippeau C, Varloud M, Julliand V.To determine prececal starch digestibili-ty and estimate glucose uptake from the digestion of 4 forms of barley in the small intestine, 4 mature cecally fistulated geldings (449 ± 41 kg BW) fed a 62:38 (wt/wt) meadow hay:concentrate diet at 1.7 kg DM/100 kg BW were included in a 4 × 4 Latin square design experiment. During each period, horses received 80% DM of their concentrate as 1 of the 4 forms of a same batch of barley, whole grain, 2.5 mm ground, steam flaked, and pelleted. Hay was offered in 2 equal meals and concentrate in 2 unequal meals. The starch supply in the morning meal amount...
Vervuert I, Voigt K, Hollands T, Cí·¯ord D, Coenen M.The aim of this study was to investigate the effect of increasing the intake of starch on the glycaemic and insulinaemic responses of horses. A cross-over study design was used in which four horses were fed increasing amounts of a compound feed (0.5-3.5 kg) to provide 0.3, 0.6, 0.8, 1.1, 1.4 and 2 starch/kg bodyweight (BW)/meal. The glycaemic response increased with starch intake (P<0.05), while feeding <1.1 g starch/kg BW resulted in a lowered response, compared to when 1.1-2 g starch/ kg BW was fed (P<0.01). The results suggested that insulin responses may be more appropriate to def...
Vervuert I, Coenen M, Bothe C.This study was conducted to evaluate the effects of different corn processing techniques on the glycaemic and insulinaemic responses in horses. It was hypothesized that the changes in pre-caecal starch digestibility caused by various types of corn processing would alter the post-prandial glycaemic and/or insulinaemic response. Six horses were fed in random order: untreated, finely ground, steamed, micronized, steam-flaked and popped corn. The total corn intake was adjusted to 630 g starch/horse/day (1.2-1.5 g starch/kg BW/day). During a stabilization period of 10 days, horses also received 6 k...
McDaniel AL, Martin SA, McCann JS, Parks AH.The objective of this study was to examine the effects of Aspergillus oryzae fermentation extract on the in vitro equine cecal fermentation of soluble starch, amino acids/peptides, coastal bermudagrass hay, and alfalfa hay. Cecal contents were obtained from a cecally fistulated Quarter Horse gelding fed coastal bermudagrass and grain (70:30) either unadapted or adapted to dietary A. oryzae supplementation (2 g/d). Mixed cecal microorganisms were incubated in anaerobic media for either 24 h (soluble starch, amino acids) or 48 h (bermudagrass hay, alfalfa hay). A. oryzae was added to the incubat...
Schaafstra FJWC, van Doorn DA, Schonewille JT, Roelfsema E, Westermann CM, Dansen O, Jacobs M, Lee JY, Spronck EA, Blok MC, Hendriks WH.Exercise and physical training are known to affect gastrointestinal function and digestibility in horses and can lead to inaccurate estimates of nutrient and energy digestibility when markers are used. The effect of exercise on apparent nutrient digestibility and faecal recoveries of ADL and TiO2 was studied in six Welsh pony geldings subjected to either a low- (LI) or high-intensity (HI) exercise regime according to a cross-over design. Ponies performing LI exercise were walked once per day for 45 min in a horse walker (5 km/h) for 47 consecutive days. Ponies submitted to HI exercise were gra...
Vervuert I, Voigt K, Hollands T, Cí·¯ord D, Coenen M.The aim of this study was to investigate the effects of feeding oats alone before or after feeding chopped alfalfa or, in admixture with the alfalfa on the glycaemic and insulinaemic responses of horses as well as post-prandial breath hydrogen and methane excretion. Horses were fed in a randomized order, chopped alfalfa as a source of dietary fibre and unprocessed oats as a source of starch. Chopped alfalfa intake was adjusted to a crude fibre intake of 0.5 g/kg bodyweight (BW) per meal and the oats intake was adjusted to a starch intake of 2 g/kg BW per meal. The feeds were offered in three d...
Pyles MB, Fowler AL, Bill VT, Crum AD, Hayes SH, Harlow BE, Flythe MD, Lawrence LM.Dietary starch source has been shown to affect fecal bacterial communities of horses fed minimally processed cereal grains. However, processing may increase foregut starch digestibility, reducing effects of starch source on fecal bacterial communities. This study aimed to determine the effect of starch source in pelleted concentrates on fecal Lactobacillus spp., amylolytic bacteria, and cellulolytic bacteria in broodmares mares, during the prepartum and postpartum period. Thoroughbred mares (n = 18) were paired by last breeding date then randomly assigned to either an oat-based or a corn and ...
Wolter R, Nouwakpo F, Durix A.A complete pelleted diet (table 1) containing 11 p. 100 of crude protein and 17 p. 100 of cellulose (ADF-lignine according to the method of Van Soest) was distributed to ponies and rabbits. Total digestibilities, partial cumulative digestibilities in different compartments of the digestive tract (stomach, small intestine, caecum, proximal and distal colon) and changes in biochemical composition, measured by pH, VFA, lactic acid and ammonia concentrations, were compared. Total digestibilities (table 2). There was no significant difference in dry matter between the two species. Crude protein dig...
Langner K, Vervuert I.The hindgut microbiota of the horse is a complex structure which can be highly influenced by the diet or nutrients such as starch. For instance, a diet rich in starch promotes the growth of bacteria that can utilize starch and produce lactate while it reduces the growth of fiber fermenting cellulolytic bacteria. Therefore, attempts are made to balance the hindgut microbiota and to minimize the impacts of feeds which are rich in starch such as the supplementation of probiotics. Up to date only different strains of the yeast (SC) are officially registered probiotics for horses in the European U...
Thorringer NW, Weisberg MR, Jensen RB.The competition for customers increases the search for new grain processing methods for equine feed, but the effect on starch digestibility and metabolic responses varies. Therefore, to evaluate the effect of the processing methods, toasting and micronizing, on starch digestion and the effect on metabolic responses, the mobile bag technique (MBT) and plasma glucose and insulin concentrations in the blood were used to estimate nutrient disappearance and metabolic responses pre-cecally. Further, cecal pH, ammonium nitrogen (N), and short-chain fatty acid (SCFA) concentrations were used to estima...
Vervuert I, Bothe C, Coenen M.This study was conducted to evaluate the effects of different barley processing techniques on the glycaemic and insulinaemic responses in horses. It was hypothesized that the changes in pre-caecal starch digestibility caused by barley processing would affect metabolic responses. Six horses were fed in random order: whole (WB), finely ground (FGB), steamed (SB), steam-flaked (SFB) and popped barley (PB). The total barley intake was adjusted to 630 g starch/horse/day (1.2-1.5 g starch/kg BW/day). During a 10-day stabilization period, the horses also received 6 kg grass hay/horse/day. On the bloo...
Frape DL, Tuck MG, Sutcliffe NH, Jones DB.1. The rate of passage of chromic oxide (Cr) was similar in the pony and rhinoceros. 2. Higher apparent amounts digested were found using 4N-HCl-insoluble ash (AIA) than those determined by Cr, but overall digestibilities were similar for the two species. 3. An abrupt increase in the starch content of the horse diets increased the number of faecal ciliate protozoa. Only when the overall feed intake was increased in horses receiving a high dietary proportion of starch were the numbers depressed. 4. When the rhinoceros received 109 kJ apparent DE per kg bodyweight daily (716 kJ/W0.75 daily) it m...
Bustamante CC, de Paula VB, Rabelo IP, Fernandes CC, Kishi LT, Canola PA, Lemos EGM, Valadão CAA.Starch overload in horses causes gastrointestinal and metabolic disorders that are associated with microbiota changes. Therefore, we identified the fecal microbiota and hypothesized that intracecal injection of alkaline solution (buffer; Mg(OH)2 + Al(OH)3) could stabilize these microbiota and clinical changes in horses submitted to corn starch overload. Ten crossbred horses (females and geldings) were allocated to group I (water−saline and starch−buffer treatments) and group II (water−buffer and starch−saline treatments). Clinical signs, gross analysis of the feces, and fecal microbiot...
de Medeiros Ferreira JR, Mello Cerbaro AE, Bastos FL, Pereira RA, Duarte MA, Araújo Júnior ÂMC, da Silva AH, de Oliveira Gobesso AA.High amounts of grains in the equine diet led to high starch intake, causing gut alterations. Aimed at reducing harmful effects, extract (MCE) is a phytogenic additive that stands out for its antibiotic and anti-inflammatory effects proven in different species. However, there is no useful information for horses. The objective of this study was to evaluate the effects of different levels of the inclusion of commercial MCE on body weight (BW), body condition score (BCS), total apparent digestibility (AD) of nutrients, faecal pH and fermentative products, on ponies fed a high-starch diet. Eight ...
Martin A, Lepers R, Vasseur M, Julliand S.Large amounts of high-starch concentrates are traditionally fed to horses in training. However, this has been associated with digestive or muscle diseases and behavioural modifications. In parallel, it has been demonstrated that horses fed high-fibre, low-starch diets achieve the same performance over an exercise test as the ones fed high-starch diets. However, whether the same performance level can be maintained over a longer training cycle is still being determined. This study aimed to compare the evolution in physical performance and cardiorespiratory responses of two groups of French Trott...
Varasteh F, Ebrahimi SH, Naserian AA, Zerehdaran S, Miri VH.This study aimed to 1) evaluate the interaction of corn grain micronization and starch levels per meal on equine plasma glucose, and 2) determine if micronization affects the risk of hindgut acidosis. Six mature (aged 6 to 10 years), healthy, non-pregnant mares (initial body weight [BW]: 301 to 463 kg) were used in a 2×3 factorial cross-over design. The treatments included two forms of corn grain (ground and micronized flaked) at three levels of starch (1, 1.5, and 2 g/kg BW per meal). The blood was sampled before and 30, 60, 90, 120, 180, 240, and 300 min after morning feeding and the glucos...
