High-level medium-chain triglyceride feeding and energy expenditure in normal-weight women

The objective of this study was to assess how short-term feeding of high levels of dietary medium-chain triglyceride (MCT) affect energy expenditure and postprandial substrate oxidation rates in normal-weight, premenopausal women. Eight healthy women were fed both a MCT-rich and an isocaloric long-chain triglyceride (LCT)-rich diet for two 1-week periods separated by a minimum of 21 days. The energy intake in each diet was 45% carbohydrates, 40% fat, and 15% protein. The 2 diets had either 60.81% or 1.11% of total fat energy from MCT with the remaining fat energy intake from LCT. On days 1 and 7 of each diet, resting metabolic rate and postprandial energy expenditure (EE) were measured by indirect calorimetry with a ventilated hood. Results indicated on days 1 and 7, there were no significant differences between diets for resting metabolic rate or mean postprandial EE. On both days 1 and 7, fat oxidation for the MCT-rich diet was significantly greater (0.0001 相似文献   

The influence of 5% and 10% dietary apple pectin on parameters of fermentation in faeces and caecal digesta of weaning pigs

In order to determine the effect of pectin on fermentation parameters in the faeces and caecal digesta of weaned pigs 18 castrated male crossbred pigs with an average body weight of 8 kg were fitted with T-cannulas at the caecum. The animals were randomly distributed into three groups and fed with diets supplemented with 0, 5 and 10% pectin. Faeces were collected over a period of 3 days. Thereafter the diets were withdrawn for 24 h followed by ad libitum feeding to enhance the feed intake. Caecal chyme was collected 0, 8 and 24 h postprandial. In the faeces the addition of 5% pectin to the diet lowered the content of dry matter and lactic acid. The pH and the digestibility of pectins, the concentration of total SCFA, acetate, propionate, butyrate, bicarbonate and chloride increased. Dietary pectin of 10% increased the content of total SCFA and acetate further. When the diets were withdrawn and fed ad libitum 24 h later, a decline of the pH and an increased concentration of lactate in the caecal chyme could be observed in all groups up to 8 h after feeding. With an interval of 8 to 24 h after feeding, a further decline in pH and a rise of lactate only occurred when the diet was not supplemented with pectin. It was concluded that pectin might be beneficial for the development of fermentative processes in the large intestine.     

Unique purified hydrated-gelatin diet for feeding dietary fiber to Wistar rats

A purified hydrated gelatin diet was developed for feeding dietary fibers to Wistar rats. A dry fiber mix was prepared that consisted of 54.91 dextrose, 13.80 casein, 2.97 AIN mineral mix, 1.28 AIN vitamin mix, 0.17 dl-methionine, 6.80 lard and 5.10 gelatin (g/100g total dry feed). Either cellulose, hemicellulose, lignin, or pectin (15 g/100 g total dry feed) was added to the hydrated dry fiber mix and blended until complete distribution and hydration of the fiber was achieved. After gelling, these hydrated diets were stable for up to 24 hours in environmental conditions commonly encountered in animal facilities. Gel weep was minimal thus permitting feed consumption to be monitored conveniently by weighing the residue in the feeders. In situ examination of stomach contents after feeding such hydrated diets to rats indicated that the gelatin gel was readily degraded and did not confound gel formation by fiber itself. Feed efficiency values (g gain/100 kcal digestible energy) for these diets following a 26-day feeding trial were as follows: no fiber, 6.21; cellulose, 6.38; hemicellulose, 6.23; lignin, 6.52; and pectin, 5.53.     

The influence of 5% and 10% dietary apple pectin on parameters of fermentation in faeces and caecal digesta of weaning pigs

In order to determine the effect of pectin on fermentation parameters in the faeces and caecal digesta of weaned pigs 18 castrated male crossbred pigs with an average body weight of 8?kg were fitted with T-cannulas at the caecum. The animals were randomly distributed into three groups and fed with diets supplemented with 0, 5 and 10% pectin. Faeces were collected over a period of 3 days. Thereafter the diets were withdrawn for 24?h followed by ad libitum feeding to enhance the feed intake. Caecal chyme was collected 0, 8 and 24?h postprandial. In the faeces the addition of 5% pectin to the diet lowered the content of dry matter and lactic acid. The pH and the digestibility of pectins, the concentration of total SCFA, acetate, propionate, butyrate, bicarbonate and chloride increased. Dietary pectin of 10% increased the content of total SCFA and acetate further. When the diets were withdrawn and fed ad libitum 24?h later, a decline of the pH and an increased concentration of lactate in the caecal chyme could be observed in all groups up to 8?h after feeding. With an interval of 8 to 24?h after feeding, a further decline in pH and a rise of lactate only occurred when the diet was not supplemented with pectin. It was concluded that pectin might be beneficial for the development of fermentative processes in the large intestine.     

The effects of increased dietary cellulose on the anatomy, physiology and behaviour of captive water voles, Arvicola terrestris (L.) (Rodentia: Microtinae)

1. Wild water voles and captives on high fibre diets had significantly longer and heavier digestive tracts (especially the caecum) than captives fed a low fibre diet. 2. Increasing dietary cellulose increased food intake, faecal output and metabolic rate, and decreased digestibility. Some but not all added cellulose was digested. 3. The passage of food through the digestive tract was significantly faster on the diet with added cellulose. 4. Coprophagy included eating directly from the anus and eating faecal pellets from the floor of the cage. The frequency of the latter type increased significantly for animals on a high fibre diet.     

Dietary carbohydrates affect caecal fermentation and modify nitrogen excretion patterns in rats II. Studies with diets differing in protein quality

In 2 two‐factorial experiments, each conducted on 80 growing male rats, the effects of substituting 10% raw potato starch (PS), pectins (PEC), or cellulose (CEL) for wheat starch (WS) and the addition of tannic acid to WS (WSTA) were studied using diets differing in protein quality. Casein unsupplemented or supplemented with DL‐methionine and gluten unsupplemented or supplemented with lysine, methionine and tryptophan were used as protein sources in Experiment 1 and 2, respectively. Parameters indicative of caecal fermentation intensity (pH, acetic, propionic and butyric acid contents, digesta and tissue weight) and of protein metabolism (urea blood concentration, faecal and urinary nitrogen excretion) were determined. Ten‐day balance experiments were preceded by a 10‐day adaption period to respective carbohydrates given in a diet containing balanced protein.

In both experiments the type of carbohydrates affected the caecal concentration of individual and total SCFA and other parameters of fermentation intensity. Pectins and potato starch were fermented more intensively than cellulose. Faecal N excretion was increased by all carbohydrates substituted for cereal starch, and by tannic acid. Urinary excretion was greater on CEL than on PEC and WSTA containing casein and on other diets containing gluten. In both experiments urinary N excretion was the lowest on PEC diets. Protein quality had the greatest effect on apparent biological value and net protein utilization but all indices of protein utilization were also affected by carbohydrates. It is concluded that not only the amount of N excreted in faeces but also in urine is affected by the type and fermentability of carbohydrates.     

Effect of rumen ciliates on the digestive utilization of various carbohydrate-rich diets and on the end-products formed in the rumen. II. Utilization of inulin, saccharose and lactose

Three diets rich in inulin, saccharose and lactose, respectively, were given to 10 rumen-fistulated sheep. Two animals were defaunated, two were inoculated with either Polyplastron multivesibulatum or Entodinium sp., and two others were inoculated with both. The latter two were bred in conventional conditions. All animals ingested the same amounts of carbohydrates in the three diets (21-22 g/kg P0.75/day). Dietary nitrogen content was similar (table 1). The ciliate population was improved with the inulin diet (fig. 1; table 2). With a mixed population, the Entodinium improved with the inulin diet (fig 1; table 2). With a mixed population, the Entodinium sp. genus was always predominant. Holotrich protozoa (mainly Isotricha) in the rumen of the conventional sheep represented 15 to 30% of the total ciliate biomass, indicating that they were able to metabolize these soluble sugars. We also observed that P. multivesiculatum can ferment cellulose and all the soluble carbohydrates proposed in these diets. However, Entodinium sp. development occurred mainly in the presence of the sugard produced during carbohydrate hydrolysis by other ciliates or bacteria. The highest organic matter digestibility, noted in faunated animals (table 3) was confirmed by the VFA concentration in the rumen (table 4). This could be explained either by an activation of bacterial metabolism due to predation or by the direct effect of ciliates on fermentations, or both. Modifications in the VFA composition varied with ciliate inoculation, showing that ciliate metabolism may vary with the nature of the energy in the diet or that the observed results depended on various opposite effects in which the intensity of each component was influenced by the diet. In general, the acetic acid molar proportion increased and propionic acid decreased when there was a considerable Entodinium sp. population. The effect on butyric acid was low with these diets. Higher ammonia and lactic acid concentrations were observed in the rumen of faunated than defaunated sheep, irrespective of the ciliate inoculum.     

Nuclear damage of colon epithelial cells by the food carcinogen 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) is modulated by dietary lipids

Intestinal damage in C57BL/6J female mice was quantified by measuring the frequency of nuclear aberrations in colonic crypts. The animals were maintained on the following diets: standard (5% lipids, 5% cellulose); low- and high-cellulose (0-20% cellulose); high lipids (20% maize oil or 20% olive oil). All groups of animals were treated by gavage either with saline or 250 mg/kg of the dietary carcinogen 2-amino-3-methylimidazo[4,5-f]quinoline (IQ). After 24 h their colons were removed and stained and the nuclear aberrations scored under the microscope. The administration of IQ markedly increased the number of colon aberrations in all of the treated animals. Variations in dietary fiber did not modify the colon-damaging activity of this compound. Maize oil slightly increased the colon-damaging activity, whereas significant protection was observed in the animals on a high-lipid olive-oil diet. These results show that composition of the diet may vary the genotoxic effect of this dietary carcinogen.     

Biological activity of phenolic compounds. Hepatic cytochrome P-450, cytochrome b5, and NADPH cytochrome c reductase in chicks and rats fed phenolic monomers, polymers, and glycosides

Eight experiments were conducted to determine effects of a phenolic polymer (Kraft wood lignin, Indulin), phenolic glycosides (cane molasses and wood molasses), and phenolic monomers (vanillin, vanillic acid, ferulic acid, and p-coumaric acid) on liver cytochromes P-450, cytochrome b5, and NADPH cytochrome c reductase in chicks and rats. Chicks fed 6.0% lignin had a higher (P less than 0.01) cytochromes P-450 content than did chicks fed 0% fiber, 6.0% wood cellulose (Solka Floc), or 6.0% arenaceous flour. NADPH cytochrome c reductase activity was not affected by treatment. Chicks fed 12.0% wood molasses had a higher (P less than 0.06) cytochromes P-450 level than did chicks fed 0% fiber or 6.0% wood molasses. Cane molasses incorporated at both 6.0 and 12.0% of the diet induced (P less than 0.05) cytochromes P-450 content over those of control-fed birds. Chicks fed 6.0% lignin, with or without antibiotic (bacitracin:neomycin sulfate, 2:1), had a higher (P less than 0.01) cytochromes P-450 level than did chicks fed control diets, with or without antibiotic. Additionally, chicks fed 6.0% lignin had lower (P less than 0.01) intestinal diaminopimelic acid (DAP) levels than did chicks fed 0% fiber. Rats fed 0% fiber, 6.0% wood cellulose, 6.0% arenaceous flour, or 6.0% lignin exhibited no difference in cytochrome level or activity among treatments. Chicks fed 0.5% vanillin, 0.5% vanillic acid, 0.5% ferulic acid, or 0.5% p-coumaric acid had comparable cytochromes level and activity compared with chicks fed no phenolics. Chicks fed 0.5% p-coumaric acid had lower (P less than 0.05) rates of gain than did chicks fed control or other phenolic-containing diets. Rats fed these phenolics had similar cytochromes P-450 content among treatments.     

Glycemia and insulinemia evaluation after high-sucrose and high-fat diets in lean and overweight/obese women

The study investigates the effect of weight-maintaining high-sucrose (HSD) and high-fat (HFD) diets on plasma glucose and insulin concentrations in lean and obese women, and verifies the correlation between insulin profile and body composition. Lean (G1 group, n="6", BMI=21.4 (20.2–22.8) kg/m²) and overweight/obese (G2 group, n=6, BMI 28.6 (25.1–32.1) kg/m²) women participated in the study. HSD (59% total carbohydrate with 23% sucrose; 28% lipid) or HFD (42% total carbohydrate with 1.3% sucrose; 45% lipid) diets were consumed under free-living conditions for 14 days. Anthropometry and body composition were assessed before and after HSD and HFD diets following-up. Fasting and postprandial (at 30, 60, 180 and 240 min) glucose and insulin were determined. HOMA-IR and QUICK index were also calculated. Fasting and postprandial glucose and insulin concentration did not differ significantly between groups or diets. However, there was a positive and significant correlation between plasma fasting and postprandial insulin concentrations and BMI, percentage of total body fat (%TBF) and HOMA-IR index. In addition, carbohydrate and sucrose intake presented a positive and significant correlation with insulin concentration and HOMA-IR at 180 min postprandial, after adjusting for energy intake and % TBF (p<0.05). These results suggest that altering the profile of the macronutrients in the diet can modify glycemia and insulicemia homeostasis, regardless of energy intake and adiposity. On the other hand, the overweight/obese women can maintain a stable metabolic profile with the habitual diet.     

Effect of diabetes and protein malnutrition on the rate of muscle protein breakdown in rats

Male streptocozin diabetic rats were fed ad libitum in two diets, one a control, adequate in protein and energy, and another, depleted in protein, but adequate in energy. Within each one of these dietary groups, three hormone-treated groups were made as follows: rats receiving vehicle, or 0.25 or 0.50 I.U. insulin/100 g body weight/day i.p. for 21 days. A fourth group of intact rats, receiving vehicle injection, was included as a control. Every day urine excretion was collected for urea-N and 3-methylhistidine (3-Mehis) determination. Body weight and food intake were recorded daily. At the end of the experiment, all animals were sacrificed, and a sample of blood was taken for plasma insulin assay. Liver, as well as gastrocnemius, soleus and extensor digitorum longus muscles were excised and weighed. Results showed that diabetic animals had a reduced body weight gain, although the food intake was elevated in all groups, as compared to the intact rats. Gastrocnemius and soleus muscle weights were, respectively, reduced and increased in the diabetic animals fed the low-protein diet. Urea-N output was elevated in all groups fed the control diet, but a marked reduction was observed in the protein depleted rats. A reduction in 3-Mehis output was displayed by the diabetic animals, specially those fed the low-protein diet. The results of this experiment showed that in streptocozin diabetic rats there was a reduction in the rate of myofibrillar protein breakdown, specially marked when fed a protein depleted diet.     

Effects of dietary fermentable fiber on fatty acid synthesis and triglyceride secretion in rats fed fructose-based diet: studies with sugar-beet fiber.

In an attempt to elucidate the role of the dietary fermentable fiber in reduction of hyperlipidemia, we substituted 30% wheat starch with 30% sugar-beet fiber in rats fed a fructose-based (41% fructose), low-fat (2% corn oil) diet. Male Wistar rats ate the test diets for 3 weeks. Feeding the sugar-beet fiber (SBF) diet resulted in a significant enlargement of the cecum; it also increased the concentration of volatile fatty acids compared with rats fed a fiber-free (FF) diet. Feeding SBF decreased plasma triglyceride and cholesterol concentrations in the postprandial as well as the postabsorptive period. In the liver, triglyceride levels were depressed in concert with the decreased liver lipogenesis and the post-Triton triglyceride secretion. Liver cholesterol levels were unaffected by SBF diet feeding. SBF-fed animals were markedly less fat compared with fiber-free-diet-fed rats. Adipose tissue lipogenesis was depressed in the postprandial period in SBF-fed animals. In short, this study suggests that substitution of easily digested carbohydrates by certain fermentable fibers may play an interesting role in the reduction of hyperlipidemia and obesity.     

Dietary fibre components and pectin chemical features of peels during ripening in banana and plantain varieties

The effects of the ripeness stage of banana (Musa AAA) and plantain (Musa AAB) peels on neutral detergent fibre, acid detergent fibre, cellulose, hemicelluloses, lignin, pectin contents, and pectin chemical features were studied. Plantain peels contained a higher amount of lignin but had a lower hemicellulose content than banana peels. A sequential extraction of pectins showed that acid extraction was the most efficient to isolate banana peel pectins, whereas an ammonium oxalate extraction was more appropriate for plantain peels. In all the stages of maturation, the pectin content in banana peels was higher compared to plantain peels. Moreover, the galacturonic acid and methoxy group contents in banana peels were higher than in plantain peels. The average molecular weights of the extracted pectins were in the range of 132.6-573.8 kDa and were not dependant on peel variety, while the stage of maturation did not affect the dietary fibre yields and the composition in pectic polysaccharides in a consistent manner. This study has showed that banana peels are a potential source of dietary fibres and pectins.     

Effects of Exposure to Dietary Chromium on Tissue Mineral Contents in Rats Fed Diets with Fiber

This study evaluated the effects of diets with fiber (cellulose and/or pectin) supplemented with chromium(III) on homeostasis of selected minerals in femurs, thigh muscles, livers, and kidneys of rats. For 6 weeks, male rats were fed experimental diets: a fiber-free diet (FF), a diet containing 5 % cellulose (CEL), 5 % pectin (PEC), or 2.5 % cellulose and 2.5 % pectin (CEL?+?PEC). These diets had 2.53 or 0.164 mg Cr/kg diet. The tissue levels of Ca, Mg, Zn, Fe, and Cr were determined by using atomic absorption spectrometry. Supplementing diets with Cr resulted in significantly higher Cr levels in the femurs of rats fed the CEL diet and significantly higher Cr and Fe levels in the rats fed the CEL?+?PEC diet compared to the rats fed FF diet. Muscle Ca content was significantly lower in the rats fed the CEL?+?PEC?+?Cr diet compared to the rats fed FF?+?Cr diet. The rats consuming the PEC?+?Cr diet had the highest liver Cr content. The highest kidney Zn content was observed in the rats fed diets containing Cr and one type of fiber. These results indicate that diets containing chromium at elevated dose and fiber have a significant effect on the mineral balance in rat tissues.     

Concentration effect of soluble dietary fibers on postprandial glucose and insulin in the rat

The effects of different soluble fibers on blood glucose and insulin responses to voluntary meals in the rat were investigated. Rats (165-180 g) were adapted for 2 weeks to a fiber-free control diet or fiber diets made by dilution of the fiber-free diet with the fiber. Fibers and concentrations used were carboxymethylcellulose (1.25, 2.5, and 5%), guar gum, oat beta-glucan (2.5, 5, and 7.5%), and mustard mucilage (5, 10, and 15%) as the soluble fibers, and cellulose (20%) as the insoluble fiber. Meal challenges (0.75 g/100 g body weight offered for consumption within a period of 15 min) were made with the adaptation diet. Soluble fibers reduced food intake and growth with a concentration effect, while cellulose increased food intake. All fibers reduced dry matter and nitrogen digestibilities but had no effect on the protein efficiency ratio. Only carboxymethylcellulose (at 5%) reduced postprandial glycemia at 30 min (p less than 0.05). Cellulose had no effect on plasma insulin which was markedly reduced with a concentration effect by all soluble fibers (except mustard mucilage) in the following decreasing order: carboxymethylcellulose, guar gum, beta-glucan, and mustard mucilage. The effect of fibers seemed closely related to the viscosity of fiber solutions in the presence of the diet ingredients. The present findings demonstrate the positive effect of fibers on postprandial insulinemia but with only a slight effect on glycemia. They indicate that the physicochemical interaction of the fibers with other dietary ingredients is important.     

Dietary self-selection for organic acids by the piglet

Two feeding trials using 48 weaned crossbred piglets each were carried out to determine the effect of acidifying diets with potassium diformate (K-diformate), formic or sorbic acid on dietary preferences in piglets. In Exp. 1 two reference groups were fed either an unacidified diet or a diet containing 2.4% of K-diformate with no choice for selection. Furthermore, piglets in choice group 1 and 2 had the choice between an unacidified diet and a diet supplemented with 1.2 and 2.4% K-diformate, respectively. In Exp. 2, animals of three reference groups received exclusively an unacidified diet or diets supplemented with 1.2% formic acid or 1.2% sorbic acid, respectively. The animals of the choice groups had the choice between an unacidified diet and diets with 1.2% formic acid or 1.2% sorbic acid, respectively. In Exp. 1 average daily feed intake, daily gain and feed conversion ratio were 751?g, 458?g and 1.64?kg/kg, respectively, with no significant differences between treatments. In both choice feeding groups animals chose the diets on offer at random (each around 50%). In Exp. 2 growth and feed intake were not affected by the treatment, but feed conversion ratio was enhanced due to the 1.2% formic acid supplementation. Animals of both organic acid choice groups showed a significant preference for the unacidified diets in each experimental week. The formic acid and sorbic acid diets represented on average only 13.5% and 23.5% of the total feed intake. The present results demonstrate that the inclusion of 1.2% sorbic or formic acid or 2.4% of K-diformate in piglet diets has no negative impact on feed intake, but in a situation of choice feeding, piglets will refuse diets acidified with 1.2% formic or sorbic acid, presumably because of negative taste cues. Acidifying the diets with varying amounts of a K-diformate had no effect on dietary preferences of piglets.     

Dietary self-selection for organic acids by the piglet

Two feeding trials using 48 weaned crossbred piglets each were carried out to determine the effect of acidifying diets with potassium diformate (K-diformate), formic or sorbic acid on dietary preferences in piglets. In Exp. 1 two reference groups were fed either an unacidified diet or a diet containing 2.4% of K-diformate with no choice for selection. Furthermore, piglets in choice group 1 and 2 had the choice between an unacidified diet and a diet supplemented with 1.2 and 2.4% K-diformate, respectively. In Exp. 2, animals of three reference groups received exclusively an unacidified diet or diets supplemented with 1.2% formic acid or 1.2% sorbic acid, respectively. The animals of the choice groups had the choice between an unacidified diet and diets with 1.2% formic acid or 1.2% sorbic acid, respectively. In Exp. 1 average daily feed intake, daily gain and feed conversion ratio were 751 g, 458 g and 1.64 kg/kg, respectively, with no significant differences between treatments. In both choice feeding groups animals chose the diets on offer at random (each around 50%). In Exp. 2 growth and feed intake were not affected by the treatment, but feed conversion ratio was enhanced due to the 1.2% formic acid supplementation. Animals of both organic acid choice groups showed a significant preference for the unacidified diets in each experimental week. The formic acid and sorbic acid diets represented on average only 13.5% and 23.5% of the total feed intake. The present results demonstrate that the inclusion of 1.2% sorbic or formic acid or 2.4% of K-diformate in piglet diets has no negative impact on feed intake, but in a situation of choice feeding, piglets will refuse diets acidified with 1.2% formic or sorbic acid, presumably because of negative taste cues. Acidifying the diets with varying amounts of a K-diformate had no effect on dietary preferences of piglets.     

Effects of dehydrated lucerne and soya bean meal on milk production and composition,nutrient digestion,and methane and nitrogen losses in dairy cows receiving two different forages

Dehydrated lucerne is used as a protein source in dairy cow rations, but little is known about the effects of lucerne on greenhouse gas production by animals. Eight Holstein dairy cows (average weight: 582 kg) were used in a replicated 4×4 Latin square design. They received diets based on either maize silage (M) or grass silage (G) (45% of diet on dry matter (DM) basis), with either soya bean meal (15% of diet DM) completed with beet pulp (15% of diet DM) (SP) or dehydrated lucerne (L) (30% of diet DM) as protein sources; MSP, ML, GSP and GL diets were calculated to meet energy requirements for milk production by dairy cows and degradable protein for rumen microbes. Dry matter intake (DMI) did not differ among diets (18.0 kg/day DMI); milk production was higher with SP diets than with L diets (26.0 v. 24.1 kg/day), but milk production did not vary with forage type. Milk fatty-acid (FA) composition was modified by both forage and protein sources: L and G diets resulted in less saturated FA, less linoleic acid, more trans-monounsaturated FA, and more linolenic acid than SP and M diets, respectively. Enteric methane (CH₄) production, measured by the SF₆ tracer method, was higher for G diets than for M diets, but did not differ with protein source. The same effects were observed when CH₄ was expressed per kg milk. Minor effects of diets on rumen fermentation pattern were observed. Manure CH₄ emissions estimated from faecal organic matter were negatively related to diet digestibility and were thus higher for L than SP diets, and higher for M than G diets; the resulting difference in total CH₄ production was small. Owing to diet formulation constraints, N intake was higher for SP than for L diets; interaction between forage type and protein source was significant for N intake. The same statistical effects were found for N in milk. Faecal and urinary N losses were determined from total faeces and urine collection. Faecal N output was lower for M than for G diets but did not differ between protein sources. Urinary N output did not differ between forage types, but was lower for cows fed L diets than for cows fed SP diets, potentially resulting in lower ammonia emissions with L diets. Replacing soya bean meal plus beet pulp with dehydrated lucerne did not change CH₄ production, but resulted in more N in faeces and less N in urine.     

Effect of Dietary Carbohydrate Source on the Development of Obesity in Agouti Transgenic Mice**

Objectives: Our objective was to evaluate the effects of a qualitative change in dietary carbohydrate source on body weight and adiposity in a rodent model of diet‐induced obesity. Research Methods and Procedures: We evaluated the effects of high‐fat diets (basal) varying in carbohydrate source in aP2‐agouti transgenic mice. In the ad libitum study, animals were given free access to the basal diet or one of four test diets for 6 weeks. In two of the diets, dietary carbohydrate was derived from a single source: mung bean noodles (MUNG) or rolled oats (ROLL). The remaining diets were designed to mimic commercially available instant oatmeal with added sugar (IO‐S) or flavored instant oatmeal (IO‐F). In the energy‐restricted study, animals were given ad libitum access to the basal diet for 6 weeks. Subsequently, animals were assigned to one of six treatment groups for 6 weeks. One group was continued on the basal diet ad libitum. The remaining groups were maintained with energy restriction (70% ad libitum) on either the basal, MUNG, ROLL, IO‐S, or IO‐F diet. Results: Subcutaneous fat pad mass was significantly higher (p < 0.05) in the energy‐restricted basal and IO‐S groups compared with the energy‐restricted ROLL diet. Similarly, visceral fat pad mass was significantly lower with ROLL and MUNG diets (p < 0.05 for both) compared with basal and IO‐S diets, and the insulin:glucose ratio was reduced (by 23% to 34%, p < 0.05) in these two diets compared with all others. In ad libitum‐fed animals, liver fatty acid synthase expression was 43% to 62% lower (p < 0.05) with ROLL and MUNG diets compared with all others. Discussion: These data suggest that a qualitative change in dietary carbohydrate source modulates body weight and adiposity.     

Effects of insoluble dietary fibre differing in lignin on performance, gut microbiology, and digestibility in weanling piglets

The study aimed to investigate the effects of insoluble dietary fibre differing in lignin content on performance and parameters of gut microbiology in 48 weanling piglets (8.5 kg mean body weight) fed common diets ad libitum. Fibre sources tested were wheat bran (low lignin) and pollen from Chinese Masson pine (Pinus massoniana) as model of fibre rich in lignin, added to diets as follows: no addition (control), 3.0% wheat bran, 1.27% pine pollen and 2.55% pine pollen. In colonic chyme, bacterial colony counts remained unaffected by treatment, but ammonia contents were reduced by fibre additions (up to -38%). The effects on ammonia were best explained by added cellulose and lignin. Fibre additions reduced apparent (faecal) digestibility of dry matter (DM) and crude protein (CP) up to -3.5 and -4.3% units with cellulose and lignin being the major determinants for changes in CP digestibility.