Jan Erik Lindberg

Changes in faecal bacteria associated with concentrate and forage‐only diets fed to horses in training

REASONS FOR PERFORMING STUDY Diets rich in readily fermentable carbohydrates, fed traditionally to meet the increased energy requirements of the performance horse, are associated with a number of gastrointestinal disorders that involve disturbances in the intestinal microbiota, however, these changes are poorly understood. OBJECTIVES With the long-term objective of improving intestinal health and to increase understanding of the relationship between diet and microbiota, the effect of feeding Standardbred horses a high-energy forage-only (F) diet was studied compared to a more traditional forage-concentrate (C) diet on faecal microbiota. METHODS Diets were fed in a cross-over design to 6 mature geldings on a scheduled training regime, both periods consisting of 29 days. DNA was extracted from faecal samples collected at 4 time points from each period, bacterial 16S rRNA genes were amplified and community composition assessed by terminal-restriction fragment length polymorphism, cloning and sequencing. Faecal pH and cultivable lactic acid bacteria (LAB) and enterobacteria were also assessed on the final collection day of each period. RESULTS Diet F resulted in a microbial composition that was more stable between sampling periods and had lower counts (P < 0.05) of cultivable LAB and specifically members of the Streptococcus bovislequinus complex. Motile and swarming Lactobacillus ruminis was present in all horses on diet C and not in horses on diet F. Diet C also resulted in the increase (P < 0.05) in members of Clostridiaceae cluster III and a concomitant reduction (P < 0.05) in an unknown group of Bacteroidales. CONCLUSIONS AND POTENTIAL RELEVANCE The greater microbial stability and reduction in LAB and members of the Streptococcus bovis/equinus complex on diet F indicate an opportunity to develop feeding strategies that support equine health and welfare. Novel changes identified in the faecal microbiota that resulted from carbohydrate inclusion merit further investigation.

Evaluation of Dietary Nitrogen Utilization in Dairy Cows Based on Urea Concentrations in Blood, Urine and Milk, and on Urinary Concentration of Purine Derivatives

Abstract The effects of level and degradability of dietary protein on urea in blood, urine and milk, and on the urinary purine derivatives and creatinine in dairy cows, were studied. Diurnal variation in urinary concentration of urea, allantoin and creatinine was also studied. A total of 24 multiparous lactating dairy cows were selected from a production experiment and divided into two 12-cow groups according to their lactation stage (LG1, 14th-16th week of lactation; and LG2, 26th-30th week of lactation). Within groups, cows were fed four different rations (three cows per treatment). Four concentrate mixtures with two levels of protein [19 and 14% of crude protein on dry matter (DM) basis] and two different rumen degradabilities (72 and 52%) of the dominating protein feed rapeseed meal, were fed to the cows together with pasture silage and hay. In both groups of cows the urea concentration in plasma, urine and milk increased (p<0.05) with increasing protein intake. Based on the pooled data from both lact...

Influence of soaking, fermentation and phytase supplementation on nutrient digestibility in pigs offered a grower diet based on wheat and barley

The effects of 1-h soaking, fermentation and phytase supplementation of a pig diet based on wheat and barley on ileal and total tract apparent digestibility in growing pigs fitted with a post valve T-caecum (PVTC)-cannula were studied. Eight animals in a two-period change-over design were used, subjecting four animals to each treatment (dry, soaked, microbial phytase supplemented or fermented diet). Acid insoluble ash was used as an indigestible marker for calculating apparent digestibility coefficients. Fermentation improved ( P , 0·05) the ileal apparent digestibility coefficients of organic matter (OM), nitrogen and amino acids, while there was no effect of 1-h soaking and phytase supplementation. The total tract apparent digestibility coefficient of OM was also improved by fermentation. The ileal apparent digestibility coefficient of phosphorus (P) was higher for fermentation ( P , 0·05) than for dry food and 1-h soaking. The total tract apparent digestibility coefficient of P was higher ( P , 0·05) for treated food (soaked, fermented and supplemented with microbial phytase) compared with dry food. Fermentation improved ( P , 0·05) the ileal apparent digestibility coefficient of calcium compared with dry and soaked food, and had no effect on the total tract apparent digestibility coefficient of calcium. Food inositol phosphates were affected by treatment ( P , 0·05), with a reduction of P bound to inositol hexaphosphate (IP6) of 10% in the 1-h soaked food and of 80% in the fermented food. Degradation of IP6 in the gastro-intestinal tract of the animals was lower in the fermented food than in the other treatments. The content of neutral-detergent fibre in the food was reduced ( P , 0·05) in the soaked and fermented food by 4% and 14%, respectively, compared with the dry food. In conclusion, fermentation of food can improve digestibility of OM, degrade IP6 and increase ileal digestibility of phosphorus, nitrogen and amino acids.

Determination of free amino acids in pig plasma by precolumn derivatization with 6-N-aminoquinolyl-N-hydroxysuccinimidyl carbamate and high-performance liquid chromatography

A high-performance liquid chromatographic method for measuring amino acids in pig plasma has been developed by using 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate as a precolumn derivatization reagent. With the method presented here it was possible to separate 24 amino acids in pig plasma within one single run in 45 min, while only 18 amino acids were properly separated with the original AccQ.Tag conditions used for analysis of hydrolysate samples. The recovery was above 90% for most amino acids, and the mean coefficient of variation of the retention times below 0.30%. The within- and between-assay reproducibility for the determination of plasma amino acids showed C.V.s below 2.2% and 4.5%, respectively, for most amino acids analyzed. In the present work, most of the plasma amino acids were assayed with high sensitivity, accuracy and good reproducibility in a relatively short time and on very small amounts of sample.

Associative effects on total tract digestibility in horses fed different ratios of grass hay and whole oats

Abstract The present experiment was performed according to a 4×4 Latin square design with diets composed of (on dry matter (DM) basis) the following ratios of grass hay to whole oats: 100:0 (O0), 80:20 (O20), 60:40 (O40) and 40:60 (O60). Four mature Standardbred geldings weighing 493 (S.D. 34) kg were used. The digestibility of DM, organic matter and energy (dE) increased in a curvilinear pattern with the increasing inclusion levels of oats. It is suggested that this was a reflection of the significantly lowered digestibility of nutrients and particularly of fibrous components for the O60 diet as compared with the other three rations, thus resulting in negative associative effects between grass hay and oats. On the basis of the present data, and excluding the results of the O60 diet, the digestibility of dE of oats was estimated to be 75%. As an expression of the associative effect at the O60 level, the dE of the total diet was estimated to be 58%, as compared with 63% when estimated on the oats value of 75% and the O0 diet, resulting in a depression of dE of the total diet by 8%, mainly affecting the utilization of fibrous components. Urinary energy losses decreased with increasing level of oats.

Absorption and metabolism of nivalenol in pigs.

The absorption and metabolism of nivalenol (NIV) were studied in pigs fed 0.05 mg NIV/kg BW, twice daily. Blood samples were taken during the first and third day, through catheters in the hepatic portal vein and peripheral mesenteric artery. Nivalenol was detected in most of the earliest blood samples, taken twenty minutes after the start of feeding. During 7.5 hrs after feeding, 11-43% of the NIV dose was absorbed. The systemic peak concentrations were 3-6 ng NIV/ml, mostly occurring 2.5-4.5 h after feeding. Sixteen hours after feeding, NIV was still being absorbed from the intestine, and the systemic concentrations were 1-3 ng NIV/ml. Nivalenol was mainly excreted in faeces, which contained concentrations up to 3.2 mg NIV/kg. No metabolites of NIV were found in plasma, urine, and faeces, either as glucuronic acid or sulphate conjugates, or as de-epoxy-NIV, indicating a lack of metabolism. The feeding of NIV did not cause feed refusal, and measured clinical plasma parameters were within the normal ranges.

Fermentable non-starch polysaccharides increases the abundance of Bacteroides-Prevotella-Porphyromonas in ileal microbial community of growing pigs

Most plant-origin fiber sources used in pig production contains a mixture of soluble and insoluble non-starch polysaccharides (NSP). The knowledge about effects of these sources of NSP on the gut microbiota and its fermentation products is still scarce. The aim of this study was to investigate effects of feeding diets with native sources of NSP on the ileal and fecal microbial composition and the dietary impact on the concentration of short-chain fatty acids (SCFA) and lactic acid. The experiment comprised four diets and four periods in a change-over design with seven post valve t-cecum cannulated growing pigs. The four diets were balanced to be similar in NSP content and included one of four fiber sources, two diets were rich in pectins, through inclusion of chicory forage (CFO) and sugar beet pulp, and two were rich in arabinoxylan, through inclusion of wheat bran (WB) and grass meal. The gut microbial composition was assessed with terminal restriction fragment (TRF) length polymorphism and the abundance of Lactobacillus spp., Enterobacteriaceae, Bacteroides-Prevotella-Porphyromonas and the β-xylosidase gene, xynB, were assessed with quantitative PCR. The gut microbiota did not cluster based on NSP structure (arabinoxylan or pectin) rather, the effect was to a high degree ingredient specific. In pigs fed diet CFO, three TRFs related to Prevotellaceae together consisted of more than 25% of the fecal microbiota, which is about 3 to 23 times higher (P<0.05) than in pigs fed the other diets. Whereas pigs fed diet WB had about 2 to 22 times higher abundance (P<0.05) of Megasphaera elsdenii in feces and about six times higher abundance (P<0.05) of Lactobacillus reuteri in ileal digesta than pigs fed the other diets. The total amount of digested NSP (r=0.57; P=0.002), xylose (r=0.53; P=0.004) and dietary fiber (r=0.60; P=0.001) in ileal digesta were positively correlated with an increased abundance of Bacteroides-Prevotella-Porphyromonas. The effect on SCFA was correlated to specific neutral sugars where xylose increased the ileal butyric acid proportion, whereas arabinose increased the fecal butyric acid proportion. Moreover, chicory pectin increased the acetic acid proportion in both ileal digesta and feces.

The nutritive value of barley-based diets with forage meal inclusion for growing pigs based on total tract digestibility and nitrogen utilization

Digestibility, and retention of energy and nitrogen in growing pigs fed barley-based diets with forage meal (lucerne, white clover, red clover and perennial ryegrass) inclusions (10 and 20%) were studied in change-over experiments. The digestibility of organic matter (OM) was reduced (P<0.05) by the inclusion of forage meals in the barley-based basal diet, while total fibre (TF), acid detergent fibre (ADF) and crude fibre (CF) digestibilities were increased (P<0.05). No effect of forage meal inclusion was observed on the digestibility of neutral detergent fibre (NDF). There was a reduction (P<0.05) in energy digestibility (dE), digestible energy and metabolizable energy (ME) contents of the diets when forage meals were included. The dE was the highest for red clover meal (0.67), and was followed in descending order by white clover meal (0.59), perennial ryegrass meal (0.51) and lucerne meal (0.50). The dE decreased linearly by 0.58, 0.93, 1.02 and 1.15 per percentage unit increase of TF, NDF, ADF and CF in dry matter, respectively. The dietary ME content (MJ/kg DM) decreased by approximately 0.1, 0.2 and 0.3 MJ per percentage unit increase of TF, NDF and CF in dry matter, respectively. Daily N intake and faecal N excretion were increased (P<0.05) when forage meal replaced barley in the diet. Mainly as a result of the increasing N intake, urinary energy losses were increased (P<0.05) with forage meal inclusion. The present data suggest that forages have a potential as energy and protein sources in modern pig meat production.

Fiber effects in nutrition and gut health in pigs

Dietary fiber is associated with impaired nutrient utilization and reduced net energy values. However, fiber has to be included in the diet to maintain normal physiological functions in the digestive tract. Moreover, the negative impact of dietary fiber will be determined by the fiber properties and may differ considerably between fiber sources. Various techniques can be applied to enhance nutritional value and utilization of available feed resources. In addition, the extent of fiber utilization is affected by the age of the pig and the pig breed. The use of potential prebiotic effects of dietary fiber is an attractive way to stimulate gut health and thereby minimize the use of anti-microbial growth promoters. Inclusion of soluble non-starch polysaccharides (NSP) in the diet can stimulate the growth of commensal gut microbes. Inclusion of NSP from chicory results in changes in gut micro-environment and gut morphology of pigs, while growth performance remains unaffected and digestibility was only marginally reduced. The fermentation products and pH in digesta responded to diet type and were correlated with shifts in the microbiota. Interestingly, fiber intake will have an impact on the expression of intestinal epithelial heat-shock proteins in the pig. Heat-shock proteins have an important physiological role in the gut and carry out crucial housekeeping functions in order to maintain the mucosal barrier integrity. Thus, there are increasing evidence showing that fiber can have prebiotic effects in pigs due to interactions with the gut micro-environment and the gut associated immune system.

Inclusion of Chicory (Cichorium intybus L.) in Pigs' Diets Affects the Intestinal Microenvironment and the Gut Microbiota

ABSTRACT The content and composition of prebiotic plant fiber in the diet is important in promoting gut-related health. This study investigated the effects of the dietary inclusion of chicory forage and roots on the intestinal microenvironment of pigs. Thirty-seven-week-old pigs were fed 1 of 5 diets for 18 days, including a cereal-based control diet and 4 diets with the inclusion of 80 and 160 g kg−1 of body weight chicory forage (CF80 and CF160), 80 g kg−1 chicory root (CR80), and a mix of 80 g kg−1 forage and 80 g kg−1 chicory root (CFR). The animals maintained good performance and health irrespective of diet. Bacterial community structure and diversity in ileal and colonic samples was assessed using terminal restriction fragment length polymorphism (T-RFLP), combined with cloning and sequencing. Samples clustered perfectly according to gut segment with a higher bacterial diversity in colon than ileum. Distal ileum was dominated by lactic acid bacteria (LAB), and the relative amount of this group was increased by the CF160 and CFR diets. The colonic bacterial community was dominated by butyrate-producing bacteria and Prevotella. The increased relative abundance of butyrate-producing bacteria in the colon was positively correlated with the molar proportion of acetic acid and furthermore linked to the chicory forage diets (CF80 and CF160). Diets including chicory roots (CR80 and CFR) were correlated with a higher colonic abundance of Megasphaera elsdenii. The fermentation products and pH in digesta responded to diet type and were correlated with shifts in the microbiota, showing that chicory influences the intestinal microenvironment of pigs.