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Fiber Digestion in Horses Fed Typical Diets with and Without Exogenous Fibrolytic Enzymes
Abstract
Fiber digestion was characterized in 8 yearling geldings (mean initial body weight, 341 kg) fed 4 typical diets differing in ingredient composition, with and without a commercial product that contained microbial xylanase and cellulase. The experimental design was a 4 x 4 Latin square with repeated measures in which horses were fed Coastal Bermudagrass hay at a rate of 1.5% of body weight daily (as-fed basis) plus sufficient textured sweet feed, pelleted concentrate, whole oats, or alfalfa cubes to meet National Research Council requirements for digestible energy and crude protein; enzyme status represented a within-unit repeated measures factor. Each experimental period consisted of a 10-day acclimation to dietary treatments, a 2-day fecal collection, a 7-day acclimation to exogenous enzyme administration, and another 2-day fecal collection during which enzyme was administered. Horses were introduced to successive diet treatments for 7 days between experimental periods, and feed allowance was increased as needed to ensure that horses maintained a body condition score of approximately 5. Diets were fed twice daily at 12-hour intervals, and water and plain salt were available for ad libitum consumption. Enzyme product was administered orally as a molasses slurry via syringe at time of feeding. Fecal samples were collected with rectal grab at 8-hour intervals advanced by 4 hours on the second day of collection, and apparent digestibility coefficients for plant cell wall constituents were calculated with reference to acid-insoluble ash concentrations in feed and fecal dry matter (DM). Digestibility of DM was lower (P < .05) for the alfalfa-based diet than for other diets (62.0% versus 69.4%), and a diet x enzyme interaction was observed such that digestibility of DM in the alfalfa-based diet was decreased (P < .10) and in the sweet feed-based diet was increased (P < .10) when enzyme was administered. Digestibility of neutral detergent fiber tended to be lower (P < .12) for the alfalfa-based diet than for other diets (53.9% versus 60.0%), and a diet x enzyme interaction was observed such that digestibility of neutral detergent fiber in the alfalfa-based diet was decreased (P < .10) and in the oats-based and sweet feed-based diets was increased (P < .10) when enzyme was administered. Digestibility coefficients for acid detergent fiber (ADF) and hemicellulose were not different among diets, but diet x enzyme interactions were observed such that digestibility of ADF in the alfalfa-based diet was decreased (P < .10) and digestibility of both ADF and hemicellulose in the oats-based and sweet feed-based diets were increased (P < .10) when enzyme was administered. Results suggest that exogenous fibrolytic enzymes have the potential to improve digestibility of plant cell wall constituents in typical graminaceous feeds fed to horses, thereby reducing the amount of feed that would be needed to meet digestible energy requirements. Further research is needed to elucidate why exogenous fibrolytic enzymes were ineffective when administered with the alfalfa-based diet and actually resulted in decreased digestibility of DM and plant cell wall constituents.
... Although, Hainze et al [13] reported that the use of exogenous xylanase and cellulase enhances cell wall digestibility in horse forage rations and the use of these enzymes can reduce the need for concentrate feeds for providing of digestible energy in the horse. However, limited research activity has been carried out on the use of exogenous enzymes to improve microbial digestion and fermentation of agricultural byproducts using horse digestive tract microorganisms. ...
... However, limited research activity has been carried out on the use of exogenous enzymes to improve microbial digestion and fermentation of agricultural byproducts using horse digestive tract microorganisms. Since, the potential of exogenous enzymes to enhance the digestion of plant structural carbohydrates in the hindgut of the equine working in synergism with endogenous microorganisms is inconclusive [13]. Therefore, this investigation was conducted to study of effect of Natuzyme enzyme mixture on microbial digestibility as well as fermentation of wheat straw and alfalfa hay in Arabian horse. ...
... Cellulase improved cecal fermentation and enhanced attachment and colonization of cecal microorganisms to the plant cell wall and acts as synergism with cecal endogenous microbial enzymes. The researcher reported that cellulase administration to grass hay in horses improved the digestion of NDF and acid detergent fiber in the oats and textured feeds, but decreased the digestion of NDF and acid detergent fiber in the alfalfa hay [13,20]. Murray et al [21] reported a significant reduction in in vivo digestibility of the fibrous fractions of dry alfalfa hay treated with enzyme. ...
The aim of this study was to evaluate the effect of Natuzyme enzyme mixture (0, 3, and 6 g/kg dry matter [DM]) on microbial digestion as well as fermentation of wheat straw and alfalfa hay in Arabian horse. Four female Arabian horses (3–4 years, average body weight 400 kg) were fed with diet containing 35% commercial concentrate +65% forage (wheat straw and alfalfa hay) for 2 weeks. The fermentation and gas production of wheat straw and alfalfa hay with different levels of Natuzyme enzyme were determined using standard in vitro gas production protocol (6 replicates). The DM and neutral detergent fiber (NDF) digestibility were determined using specific media (four replicates per time). Addition of enzyme had no effect on gas production rate of alfalfa hay (P >.05), but the potential of gas production was increased with alfalfa hay at 3 and 6 g/kg DM of enzyme compared with control. The addition of enzyme to alfalfa did not affect partitioning factor, microbial biomass, microbial biomass efficiency, and cell wall degradability (P >.05). DM digestibility of alfalfa hay after 24, 48, and 72 hours of incubation with mixed cecum contents was not affected by enzyme (P >.05), but NDF digestibility at 24, 48, and 72 hours was increased (P <.05). The enzyme supplementation decreased microbial biomass efficiency and increased potential of gas production, DM, and NDF digestibility at 24 hours for straw. The highest value was obtained for straw treated with 3 and 6 g/kg DM of enzyme. Gas production parameters, DM, and NDF digestibility of straw at 48 and 72 hours of incubation were not influenced by enzyme addition. In conclusion, addition of Natuzyme enzyme mixture caused the proper fermentation, gas production, and digestibility of alfalfa hay and straw without affecting the DM digestibility by cecal microorganisms, thereby suggesting the additive role of this enzyme in Arabian horse nutrition.
... Numerous studies have been conducted with ruminants to investigate the potential benefits of exogenous fibrolytic enzyme supplementation in improving total tract nutrient digestibilities [7]. Supplementing the diet of horses with exogenous fibrolytic enzymes has gained substantial interest in recent years [6,8]. However, the potential of exogenous enzymes to enhance the digestion of plant structural carbohydrates in the hindgut of the equine working in synergism with endogenous microorganisms is inconclusive [8]. ...
... Supplementing the diet of horses with exogenous fibrolytic enzymes has gained substantial interest in recent years [6,8]. However, the potential of exogenous enzymes to enhance the digestion of plant structural carbohydrates in the hindgut of the equine working in synergism with endogenous microorganisms is inconclusive [8]. Hainze et al [8] fed horses a diet of grass hay with textured concentrate, pelleted concentrate, whole oats, or alfalfa-lucerne (Medicago sativa) supplemented with cellulase and reported that cellulase administration improved the digestion of neutral detergent fiber (NDF) and acid detergent fiber (ADF) in the oats and textured feeds, but decreased the digestion of NDF and ADF in the alfalfa-lucerne. ...
... However, the potential of exogenous enzymes to enhance the digestion of plant structural carbohydrates in the hindgut of the equine working in synergism with endogenous microorganisms is inconclusive [8]. Hainze et al [8] fed horses a diet of grass hay with textured concentrate, pelleted concentrate, whole oats, or alfalfa-lucerne (Medicago sativa) supplemented with cellulase and reported that cellulase administration improved the digestion of neutral detergent fiber (NDF) and acid detergent fiber (ADF) in the oats and textured feeds, but decreased the digestion of NDF and ADF in the alfalfa-lucerne. In contrast, Murray et al [9] reported a significant reduction in in vivo digestibility of the fibrous fractions of enzyme-treated high-temperature dried lucerne and ensiled lucerne. ...
... Numerous studies have been conducted with ruminants to investigate the potential benefits of exogenous fibrolytic enzyme supplementation in improving total tract nutrient digestibilities [7]. Supplementing the diet of horses with exogenous fibrolytic enzymes has gained substantial interest in recent years [6,8]. However, the potential of exogenous enzymes to enhance the digestion of plant structural carbohydrates in the hindgut of the equine working in synergism with endogenous microorganisms is inconclusive [8]. ...
... Supplementing the diet of horses with exogenous fibrolytic enzymes has gained substantial interest in recent years [6,8]. However, the potential of exogenous enzymes to enhance the digestion of plant structural carbohydrates in the hindgut of the equine working in synergism with endogenous microorganisms is inconclusive [8]. Hainze et al [8] fed horses a diet of grass hay with textured concentrate, pelleted concentrate, whole oats, or alfalfa-lucerne (Medicago sativa) supplemented with cellulase and reported that cellulase administration improved the digestion of neutral detergent fiber (NDF) and acid detergent fiber (ADF) in the oats and textured feeds, but decreased the digestion of NDF and ADF in the alfalfa-lucerne. ...
... However, the potential of exogenous enzymes to enhance the digestion of plant structural carbohydrates in the hindgut of the equine working in synergism with endogenous microorganisms is inconclusive [8]. Hainze et al [8] fed horses a diet of grass hay with textured concentrate, pelleted concentrate, whole oats, or alfalfa-lucerne (Medicago sativa) supplemented with cellulase and reported that cellulase administration improved the digestion of neutral detergent fiber (NDF) and acid detergent fiber (ADF) in the oats and textured feeds, but decreased the digestion of NDF and ADF in the alfalfa-lucerne. In contrast, Murray et al [9] reported a significant reduction in in vivo digestibility of the fibrous fractions of enzyme-treated high-temperature dried lucerne and ensiled lucerne. ...
... Horses obtain energy effectively through fermentation by the gut microbiota in the hindgut. The hindgut serves as a fermentation chamber, where anatomical and physiological properties are favorable for the gut microbiota to degrade and ferment plant-derived polysaccharides [1]. Therefore, horses can digest and metabolize a high-fiber plant diet using the enzymes produced by the gut microbiota [2]. ...
... To date, there are only limited numbers of studies on the horse microbiome using NGS compared to those for ruminants. Although several studies were conducted to investigate the relationship between gut microbiota and digestion [1], disease [2,3,18], and exercise [19,20], the roles of the horse gut microbiota are not entirely understood. However, as widely acknowledged, the microbiota play a vital role in maintaining the host's health, including horses [18]. ...
(1) Background: The large intestine of horses is an anaerobic fermentative chamber filled with fibrolytic bacteria that play essential roles in digesting and absorbing nutrients for energy production. Although Jeju horses are a prominent local breed in Korea, few studies have investigated the gut microbiota of Jeju horses; (2) Methods: This study performed sequencing of V3 and V4 hypervariable regions of the partial 16S rRNA genes obtained from horse fecal samples and compared the gut microbiota between Jeju and Thoroughbred horses. Thirty and 24 fecal samples were obtained from Jeju and Thoroughbred horses, respectively; (3) Results: The gut microbiota belonged to 23 phyla and 159 families. Firmicutes and Bacteroidetes were the most abundant and predominant phyla, followed by Verrucomicrobia, Euryachaeota, and Spirochaete. The ratio of Firmicutes to Bacteroidetes (F/B), which is known as a relevant marker of gut dysbiosis, was 1.84 for Jeju horses, whereas it was 1.76 for Thoroughbred horses. Moreover, at the genus level, 21 genera were significantly different between the Jeju and Thoroughbred horses (p < 0.05); (4) Conclusions: The Thoroughbred horse’s gut microbiotas had significantly higher diversity than the Jeju horses (p < 0.05). In addition, beneficial commensal bacteria that produce short-chain fatty acids thus providing a significant source of energy are also more abundant in Thoroughbred horses. These results provide novel information on the horse gut microbiota and insights for further studies related to the horse gut microbiota.
... Administration of cellulase to the diets of Arabian geldings fed a cereal based ration actually decreased dry matter intake and fibre digestibility (O'Connor-Robison et al., 2007). In contrast it was demonstrated that horse diet supplementation with a solid-state fermentation enzyme product improved carbohydrate digestion (Hainze et al., 2003). However, in both of these studies, horses were not trained, so the possible effect of physical activity on enzyme supplementation is unknown. ...
... In the present experiment, the potential value of fibrolytic enzymes in traditional fibrous rations based on hay and whole oats has been examined. Carbohydrase preparation has previously been shown to decrease the DM digestibility of diet based on an alfalfa hay and had no effect on the DM digestibility of whole oat grains (Hainze et al., 2003). The present work in this respect is partly consistent as it suggests that acid detergent fibre (ADF) digestibility coefficients have not been improved by enzyme supplementation, but the neutral detergent fibre (NDF) digestibility has clearly increased. ...
The aim of the study was to investigate the effects of dietary enzymes and training on carbohydrate digestibility, blood morphology and biochemistry in horses. A group of 10 animals was divided into two treatments: control (C) and supplemented with enzymes (ES). For 14 days, group C was fed a diet based on 6 kg of hay and 6 kg of whole grains of oat, while the ES group was fed the same diet with the addition of xylanase/cellulase. After 14 days of the experimental period and 5 days of the washout process, the treatments were reversed for another 14 days. During the whole experiment, horses were trained 6 days a week including walk, trot and gallop. Blood and faeces sample were analysed. Blood parameters were measured before and after training. Sieve analysis of ES horse faeces showed fewer large particles in comparison to C animals. Neutral detergent fibre digestibility was higher in ES horses. Starch digestibility was also elevated in ES animals. Enzyme supplementation did not affect blood parameters or most of the biochemical blood indices, although reductions in blood cholesterol and urea concentrations were noted in ES horses. Leptin concentration was increased and obestatin level was decreased in ES horses. Training increased the number of erythrocytes and leukocytes, haematocrit value and haemoglobin concentration. In addition, it influenced the factors responsible for anabolic/catabolic pathways and turnover of carbohydrates, lipids and proteins, including a decrease in blood insulin level. The study showed that dietary supplementation with fibrolytic enzymes improves feed digestibility and energy balance in horses, and has no visible side effects during exercise.
... In horses fed a diet of grass hay supplemented with either textured concentrate, pelleted concentrate, whole oats, or alfalfa cubes, cellulase administration improved the digestion of NDF and ADF in the oat and textured feedÀsupplemented diets, but decreased digestion of NDF and ADF in the alfalfa-supplemented diet. 6 Clearly, further research is needed to identify benefits from feeding supplementary fibrolytic enzymes, such as cellulase, to the horse. The hypothesis of this study was that feeding horses a cellulase supplement in addition to their regular diet would improve fiber digestion. ...
... 4 This is also true when horses are supplemented with fibrolytic enzymes on either high-grain or high-forage diets, because enzyme addition increased DM and fiber digestibility only in the high-grain diets. 6 Nsereko et al 10 demonstrated that there is a negative correlation between concentrations of exogenous b-linked glucan hydrolases, such as cellulase, and fiber digestion in the rumen, suggesting that the hydrolases may block enzyme sites needed by microbial enzymes. In a study by Murray et al, 11 ponies fed low concentrations of enzyme-treated forages had decreased apparent digestibility of organic matter and NDF. ...
Six mature Arabian geldings were used in a two-period crossover study to investigate the effects of cellulase supplementation on fiber digestion. Horses were randomly assigned to either a control (CO; n = 3) or a cellulase (CE; n = 3) treatment for the first period and then treatments were switched for period 2. Each period consisted of a 10-day diet adaptation followed by a 3-day total fecal collection. The enzyme mixture contained 40,000 cellulase units/g and was fed at a rate of 3 g/day split evenly between two feedings. During the diet adaptation period, horses had ad libitum access to timothy hay and were also fed 165 g whole oats as a carrier for the supplement. When eating the CO treatment, horses consumed 16% more hay than when on the CE treatment (P = .004). Fecal output also tended to be greater when horses consumed the CO treatment as compared with CE treatment (P = .07). No differences were found between treatments for fecal percent dry matter (DM%), fecal neutral detergent fiber (NDF), fecal acid detergent fiber (ADF), fecal nitrogen (N), or fecal gross energy (GE). There was a trend for horses consuming the CO treatment to digest more NDF than when consuming the CE treatment (34.6% ± 1.5 vs 31% ± 1.5; P = .07). Horses also digested a greater %ADF, %N, and Mcal of energy when consuming the CO treatment than when consuming the CE treatment (P < .05). Cellulase addition to a hay-based horse diet decreased digestion of fiber components.
... The collected concentrate, forage, forage residue, and dried fecal samples were pulverized in a grinder (multifunctional high-speed grinder, 400 g upright type; Tohe Electromechanical Technology (Shanghai) Co., Ltd., Shanghai, China), passed through a 0.4-mm sieve, and analyzed using the Chinese national standard routine nutrient content determination [12] method to determine DM, crude ash (ash), CP, Ca, P, and OM contents. These values were calculated as OM = (100% − ash%). ...
Background
As the foal grows, the amount of breast milk produced by the donkey decreases. In such cases, early supplemental feeding is particularly important to meet the growth needs of the foal. Foals have an incompletely developed gastrointestinal tract with a homogenous microbiota and produce insufficient amounts of digestive enzymes, which limit their ability to digest and utilize forage. Improving the utilization of early supplemental feeds, promoting gastrointestinal tract development, and enriching microbial diversity are the hotspots of rapid growth research in dairy foals. Plant-based feeds usually contain non-starch polysaccharides (NSPs), including cellulose, xylan, mannan, and glucan, which hinder nutrient digestion and absorption. In addition, proteins and starch (both biomolecules) form a composite system mainly through non-covalent interactions. The proteins wrap around the surface of starch granules and act as a physical obstacle, thereby inhibiting water absorption and expansion of starch and decreasing the enzyme's catalytic effect on starch. Glyanase, β-mannanase, β-glucanase, cellulase, protease, and amylase added to cereal diets can alleviate the adverse effects of NSPs. The current study determined the effects of adding multienzymes (glyanase, β-mannanase, β-glucanase, cellulase, protease, and amylase) to the diet of 2-month-old suckling donkeys on their growth performance, apparent nutrient digestibility, fecal volatile fatty acid (VFA) and pH, fecal bacterial composition, and blood biochemical indices.
Results
On day 120 of the trial, fecal samples were collected from the rectum of donkeys for determining bacterial diversity, VFA content, and pH. Moreover, fresh fecal samples were collected from each donkey on days 110 and 115 to determine apparent digestibility. The multienzymes supplementations did not affect growth performance and apparent nutrient digestibility in the donkeys; however, they tended to increase total height gain (P = 0.0544). At the end of the study, the multienzymes supplementations increased (P < 0.05) the Observed species, ACE, Chao1, and Shannon indices by 10.56%, 10.47%, 10.49%, and 5.01%, respectively. The multienzymes supplementations also increased (P < 0.05) the abundance of Firmicutes, Oscillospiraceae, Lachnospiraceae, Christensenellaceae, Christensenellaceae_R-7_group, and Streptococcus in feces, whereas decreased (P = 0.0086) the abundance of Proteobacteria.
Conclusions
Multienzymes supplementations added to a basal diet for suckling donkeys can increase fecal microbial diversity and abundance.
... Addition of such enzymes will help in breaking the ligno cellulosic bonds in these feeds which are usually not been acted by animal enzymes (Beauchemin et al., 2001). Research have reported that use of exogenous xylanase and cellulase enhances cell wall digestibility in horse forage rations thereby reducing the concentrate requirement (Hainze et al., 2003). In addition, there are reports suggesting the use of Natuzyme enzyme has helped for the proper fermentation and gas production of alfalfa hay and wheat straw without affecting the DM digestibility by cecum bacteria in Arabian horse nutrition (Mohammadabadi et al., 2018). ...
... Horses have evolved from ancestors with an intestinal system designed to process large quantities of low-quality forage, containing high levels of structural plant polysaccharides, ingested on an almost continuous basis to meet their nutrient demands. The large intestine (hindgut) of the horse is anatomically specialised to accommodate microorganisms capable of degrading and fermenting structural polysaccharides of the plant cell wall, which are generally resistant to pre-caecal digestion (1) . The fermentation of feedstuffs in the hindgut results in the production of volatile fatty acids that, when absorbed, constitute a significant proportion (30 %) of the digestible energy intake of the animal; particularly in horses fed high-fibre diets (2) . ...
There is a need to further our understanding of the role that the equine hindgut ecosystem plays in digestive processes and diseases. The aim of the present study was to utilise the real-time PCR technique to determine the abundance of candidate cellulolytic (Ruminococcus flavefaciens; Fibrobacter succinogenes) and non-cellulolytic (Streptococcus bovis) bacteria in lumen contents from the caecum, ventral and dorsal colon, and rectum of healthy horses (n 14). Total DNA was extracted from frozen and lyophilised lumen contents, and PCR primers and Taqman probes were designed based on 16S rDNA sequences for specific detection of candidate bacterial species. Overall, in frozen and lyophilised digesta, there were significantly (P F. succinogenes > S. bovis (P < 0.05), while in lyophilised digesta R. flavefaciens was present in significantly (P < 0.05) greater amounts than F. succinogenes and S. bovis. R. flavefaciens and F. succinogenes were abundant at significantly (P < 0.05) greater levels in lyophilised digesta v. frozen digesta, with no difference in S. bovis levels. These data indicate that for these bacteria at least, faeces are a suitable model for studying the bacterial ecosystem within the equine colon. The present study also indicates that the preservation method of digesta affects levels of bacteria detected.
Equines and ruminants have evolved as grazing herbivores with specialized gastrointestinal tracts capable of utilizing a wide range of fibrous feeds. In China, agricultural by-products, including corn straw, wheat straw, peanut vine, wheat husk, rice husk, and grass hay, have been extensively included in both equine and ruminant diets. These plant materials, which are composed predominantly of cellulose, hemicellulose, noncellulosic polysaccharides, and lignin, are largely undegradable by equines and ruminants themselves. Their breakdown is accomplished by communities of resident microorganisms that live in symbiotic or mutualistic associations with the host. Information relating to microbial composition in the hindgut and rumen has become increasingly available. Rumen fermentation is unique in that plant cell wall breakdown relies on the cooperation between microorganisms that produce fibrolytic enzymes and that ruminant animals provide an anaerobic fermentation chamber. Similar to the rumen, the equine hindgut is also an immensely enlarged fermentative chamber that includes an extremely abundant and highly complex community of microorganisms. However, few studies have characterized the microbial functions and their utilization process of lignocellulosic feeds within the equine hindgut. The process of understanding and describing plant cell wall degradation mechanisms in the equine hindgut ecosystem is important for providing information for proper feeding practices to be implemented. In the present study, we gather existing information on the rumen and equine ecosystem and provide scientific insights for understanding the process of plant cell wall breakdown within the hindgut.
This review was written to summarise knowledge available on the use of markers to determine total tract apparent digestibility in horses, and to quantify differences in estimates obtained between marker techniques and total collection of faeces. Differences were quantified with a unitless standardised effect size (Hedges's g) and effect sizes within marker, diet (all-forage, forage and concentrate) and nutrients were combined with random effects models to account for unexplained heterogeneity among experiments. Digestibility of all-forage diets estimated by total faecal collection was not different to measurements obtained with acid detergent insoluble ash, 2 N HCl acid insoluble ash, or the n-alkanes C27, C29 and C31. With diets containing forage and concentrate, acid detergent insoluble ash, chromic oxide, indigestible acid detergent fibre, indigestible cellulose or n-alkanes presented similar nutrient digestibility coefficients, and 2 N HCl acid insoluble ash higher dry matter digestibility, compared to total faecal collection. Acid detergent lignin resulted in lower apparent digestibility coefficients with both types of diets. However, combined effect sizes for acid detergent insoluble ash and n-alkanes were based on 2–3 experiments conducted in few (1–2) studies, and should be interpreted accordingly. It is concluded that acid insoluble ash currently presents the most reliable marker that, with certain precautions, could be applied to determine apparent total tract apparent digestibility in horses.
The aim of the review is to present mechanisms of digestion in horses through a functional description of the digestive system’s structure with emphasis on nutrient digestibility. In the era of an increasingly intensive and specialised sport usage of horses, also the significance of balancing their dietary nutrient value in accordance with individual requirements of these animals is gaining in importance. At the same time, it is not possible to meet nutritional requirements of a sport horse without knowledge about feed utilisation. In many farm animal species, digestibility is measured post mortem or via complicated and expensive cannulation of the digestive system. In horses, these methods are not applied due to ethical approaches or other limitations (e.g. sport horses); therefore, the importance of marker-based techniques is growing, although not much data is published in the available literature (Sales 2012). Moreover, in contrast to other non-ruminants, horses are naturally adapted to a constant intake of large quantities of roughages. However, during intensive sport training, they are primarily fed concentrated diets with high amounts of easily digestible, non-structural carbohydrates and reduced amounts of dietary fibre fractions. Therefore, the risk of metabolic diseases and behavioural disorders in the horse increases.
Two experiments were conducted to evaluate the effects of a fibrolytic enzyme preparation on the nutritive value of lucerne for equids. In both experiments four mature Welsh-cross pony geldings were used in a 4×4 Latin-square design to assess the effect of a fibrolytic enzyme treatment on the nutritive value of either high-temperature dried (HT) lucerne (experiment 1) or ensiled lucerne (experiment 2) for equids. Experiment 1 consisted of four levels of enzyme treatment (0 [WC], 2.3 [DE1], 4.7 [DE2] and 8.9 L tonne−1 dry matter (DM) [DE3]), whilst in experiment 2 the four levels of enzyme treatment were: 0 (WS), 2.7 (WE1), 5.5 (WE2) and 10.2 L tonne−1 DM (WE3). Each diet was fed to give a DM intake of 17.5 g kg−1 of liveweight per day, offered in two equal meals at 12 h intervals. Digestibility was determined by total faecal collection. Feed and faecal samples were analysed for DM, OM, CP, ADFom, NDFom, starch, WSC, GE, Na, Ca, P, K, Mg and non-starch polysaccharide (NSP) content and composition. Silages were also analysed for pH, VFA, lactate, TN, ammonia–N and aerobic stability. In experiment 1, enzyme treatment significantly (P
Equine Nutrition Conference for Feed Manufacturer, Hannover, GERMANY, 2005.
An in vitro study was conducted to investigate mechanisms by which fibrolytic enzymes improve fiber degradation in ruminants. Alfalfa hay was pre-treated with fibrolytic enzymes (Depol 40, Sumizyme X, Liquicell 2500, an experimental preparation and Multifect xylanase; DP, SX, LQ, PB and MX, respectively), diluted in buffer (pH 6.5), or with buffer alone (control) at 39°C, without (0h pre-treatment) or with a 2h incubation (2h pre-treatment). The hay was then autoclaved to denature enzymic activities and washed extensively to remove hydrolysis products. The solid residue was dried and incubated with mixed rumen microorganisms for 12 and 48h. The 0h pre-treatment with MX, PB and SX increased NDF degradation at 48h (P
SUMMARY Comparisons were made of the total fecal collection method and Acid-Insoluble Ash (AIA) natural marker method for determina- tion of dry matter digestibility coefficients of rations by sheep. Three laboratory analytical procedures (Concentrated (Cone.) He1, 4N HCI and 2N HCI) which differed in ashing sequence, ashing temperature and acid strength, were used to determine the AIA content of feed and fecal samples. The dry matter digestibility coefficients esti- mated by the AIA marker method, by all three analytical procedures, were not significantly different from the coefficients determined by the traditional total fecal collection method. However, the digestibility coefficients esti- mated using the 4N HCI marker were higher (P
The average composition of diets and di- gesta is shown in table 2. The percentage of dry matter in the digesta of the colon was greater (P
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The ef-fects of fibrolytic enzymes on ruminal digestion kinetics of whole barley grain
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Krause M, Farr BI, Rode LM, Beauchemin KA, Norgaard P. The ef-fects of fibrolytic enzymes on ruminal digestion kinetics of whole barley grain. Can J Anim Sci 1997;77:541-2.
The effects of fibrolytic enzymes on ruminal digestion kinetics of whole barley grain
- Krause