Effect of mixed protein silage in feed on the digestive tract and metabolism parameters in swine

With a view to studying the effect of acid addition, weaned piglets and fattening pigs were fed graduated amounts of protein mixed silage (pH-value 3.15 by adding 20 g H2SO4/kg) in rations of equal energy and protein levels. On average, the fattening pigs were taking in 0.26 g H2SO4/kg, whilst the amounts for piglets were 0.60 and 0.72 g H2SO4/kg. Higher acid intakes had a negative effect of energy expenditure, weight gains and feed intake. The experimental animals had significantly longer small intestines, whilst the intestine's wall was found thinner and the amount of digesta reduced and with a higher water content. The microbial activity in the stomach proved significantly inhibited. However, it was higher in the caecum as compared to the control animals. Metabolic parameters suggest that water and mineral balances are under stress. The significance of acid addition for tract flora and its metabolites is discussed. Protein mixed silage is regarded a dietetically favourable feed when given at a maximum daily amount of 25 g/kg LW or 1 kg/animal. The recommendation for dosing the daily administration of inorganic acids is as follows: max. 0.5 g acid/kg LW or 20 g/animal.     

The performance of weaned piglets after a five week weaning period in relation to the weaning weight, the feed composition and the use of an effective ergotropic

In a three-factorial experiment with 216 piglets of the same age (33 +/- 4 days) but a different weight (weaning weight from 5.5 to 9 kg) a conventional piglet rearing feed containing 20% crude protein (standard), a high-energy diet and a low-protein diet (16% crude protein) were tested. In three weaning weight classes the three diets were fed without or with Bisergon [2-N-(2-hydroxyethyl)-carbamoyl-3-methylquinoxaline-1.4-dioxide] over a period of 21 days. From the 22nd to the 71st day after weaning all the piglets received the standard diet without ergotropic. Among the factors studied the Bisergon supplement had the biggest effect. The additional weight gain varied from 9% in case of heavy piglets fed the high energy diet to 150% in case of light piglets fed the low protein diet. The ergotropic improved feed conversion by 22% and lowered the frequency of gastrointestinal diseases requiring treatment by 28%. At the end of the rearing period the weight of the piglets initially fed with Bisergon (means = 34.6 kg) was significantly higher than that of the control animals (means = 31.6 kg). The weaning weight and the diets influenced the final weight especially in the groups without ergotropic. In this case the piglets fed with the high-energy diet gained 30% more and those fed with the low-protein diet 40% less compared with the standard group. The average live weight gain of the light piglets (weaning weight 6.1 kg) was 30% lower than that of the heavier piglets (weaning weight 8.5 kg). The frequency of treatment against diarrhoea of the heavy piglets was by one third lower than that of the light animals. The piglets fed with the low-protein diet appeared to show a limitation of gastrointestinal diseases, but these animals also had the lowest feed intake. Independent of the Bisergon supplementation the weaning weight clearly influenced the live weight after the 10-week experiment. The initially better development of the animals started with the high-energy diet was compensated. In contrast to this, the piglets weighing 6.1 and 7.2 kg fed with the low-protein diet could not compensate the retarded development in comparison with the piglets fed with the standard or the high-energy diet. This experiment confirms the enormous improvement of the performance and of the health status of weaned piglets caused by the ergotropic Bisergon.(ABSTRACT TRUNCATED AT 400 WORDS)     

Effect of K-diformate in starter diets on acidity, microbiota, and the amount of organic acids in the digestive tract of piglets, and on gastric alterations

The aim of this investigation was to study the effect of K-diformate on the intraluminal pH, microbial composition in digesta and feces, organic acids along the digestive tract, and alterations of the gastric epithelium of pigs. Pigs (n = 36) weaned at 28 d of age were allotted to two groups and fed without (control diet) or with 1.8% supplemental K-diformate. Fecal samples were taken from the rectum on d 0, 1, 3, 5, 7, 14, 21, and 28 postweaning. Half of the animals from each group were killed on d 7 and the other half on d 29 postweaning. Growth performance was not different for both groups (P > or = 0.73). The gastric epithelium was not negatively affected by K-diformate (P = 0.25). Potassium-diformate decreased (P < or = 0.04) or tended to decrease (P < or = 0.10) the counts of total anaerobic bacteria, lactic acid bacteria, and yeasts in feces and digesta samples from the stomach, distal small intestine, cecum, and middle segment of the colon. The pH along the gastrointestinal tract of piglets was not affected by K-diformate (P > or = 0.30). On d 7, the concentration of lactic acid along the gastrointestinal tract was similar with both diets (P = 0.15). On d 29, the concentrations of lactic acid tended to be lower along the small intestine (P < or = 0.08) and the stomach (P = 0.11) of the pigs fed K-diformate. Formic acid in digesta was detected at significant levels only in the distal segment of the small intestine of the control pigs (from 4 to 11 mmol/kg of wet digesta), whereas considerable amounts were measured in the stomach (from 23 to 40 mmol/kg of wet digesta) and all segments of the small intestine (from 7 to 25 mmol/kg of wet digesta) in the K-diformate-fed pigs on both days. On d 7, pigs fed the K-diformate diet had a tendency (P < or = 0.08) to have higher concentrations of organic acids (acetic + propionic + butyric) in the digesta of the distal small intestine, cecum, and proximal colon. On d 29, both groups had similar concentrations of these acids, irrespective of the segment of the gastrointestinal tract (P = 0.95). Our study showed that the addition of K-diformate to a starter diet for piglets decreased total anaerobic bacteria, lactic acid bacteria, coliforms, and yeasts in feces and in digesta from various segments of the gastrointestinal tract, without affecting the gastric or intestinal pH.     

Determination of the transit rates in different sections of the pig's intestine

An experiment was carried out using pigs weighing approximately 30 kg. The animals were fitted with two re-entrant cannulas in duodenum and ileum. During a 5 day period the passage of digesta through duodenum and ileum as well as the excretion by urine and faeces was estimated, taking an aliquot of 5% for N analysis. Transit of digesta amounted to 12.4 ... 13.2. kg/d in the duodenum and 2.7 ... 3.6 kg/d in the ileum. The appertaining N passage rates were 36.8 ... 42.4 resp. 8.7 ... 11.2 g N/d, corresponding to 108 ... 120% and 27 ... 32% of the N intake. The transit rate of duodenal digesta was highest immediately after feeding (1.4 ... 1.5 kg/h), decreased thereafter strongly, reaching a second lower maximum of 0.85 ... 1.0 kg/h 2 ... 3 h after feeding and then going down to 0.3 ... 0.4 kg/h just before the next feeding. The daily mean value was about 500 g/h. Endogenous N content of duodenal digesta varied between 10% after feeding and 50% 6 ... 12 h after feeding, with an average of 18.1%. In contrast the endogenous N content of ileal digesta was relatively constant amounting about 42% during the whole day. These findings correspond with those found by other authors using other rations and other live weights of the pigs. They refer to a clear diurnal rhythm of digesta transit and to the enormous dynamics of absorption and secretion processes in the intestinal tract of pigs during digestion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Weaned piglets display low gastrointestinal digestion of pea (Pisum sativum L.) lectin and pea albumin 2

A study was conducted to investigate the biochemistry of digestion of field pea (Pisum sativum L.) albumins and globulins in the stomach and along the small intestine of weaned piglets with a particular emphasis on the respective roles of these compartments in pea protein digestion. Twenty-four piglets were weaned at 28 d of age. They were allocated to 2 diets (control and pea) and 3 slaughter times (3, 6, or 9 h after the last meal) in a 2 x3 factorial arrangement of treatments in a randomized complete block design. Pea flour provided 30% of total dietary protein in the pea diet. The diets were fed for 2 wk after weaning. After slaughter, gastrointestinal tract (GIT) compartments were weighed, digesta were collected, and pH was measured. Digesta from the stomach and cranial, middle, and caudal small intestine (SI) were extracted for soluble proteins and analyzed for specific pea proteins using SDS-PAGE, immunoblotting, and mass spectrometry. Tissue weight of the whole GIT (P = 0.015), cecum (P <0.001), and colon (P <0.001) was greater in the pea diet. Digesta pH in the stomach and caudal SI was lower (P = 0.02) in the pea diet than the control diet. In the stomach, vicilin, lectin, and pea albumin 2 were not digested, whereas legumin was only partly digested. Legumin and vicilin were totally digested in the SI in less than 3 h. A resistant peptide of 15 kDa located at the N-terminus of pea albumin 2 was transiently detected at 3 h. A protein band at 20 kDa was consistently identified as lectin. It was present in high intensity in intestinal digesta of pea-fed piglets at all times after the meal compared with those fed the control diet (P <0.001). Various proteins of, presumably, endogenous origin displayed differential digestion patterns between the control and the pea-fed piglets (P<0.05). In conclusion, differences in digestion between specific pea proteins were observed along the GIT of piglets. They could be partly explained by differences in protein digestion in the stomach.     

大鼠胃肠道食糜中β-Casomorphin-7样物质的酶联免疫吸附分析

利用建立的一种酶联免疫吸附试验 (ELISA)对大鼠胃肠道食糜中的 β 酪啡呔 7(β Casomorphin 7)样物质进行了检测分析。动物试验采用30只成年大鼠 ,随机分为 5组。对照组Ⅰ ,仅喂葡萄糖盐水 ;对照组Ⅱ ,喂大豆和饮水 ;试验组Ⅰ ,仅喂牛奶 ;试验组Ⅱ ,喂不含乳的普通饲料和饮水 ;试验组Ⅲ ,喂混有乳的普通饲料和牛奶。各组均自由采食 ,4d后处死。采集胃和十二指肠食糜 ,对其中 β Casomorphin 7样物质进行定量分析。结果 :在试验组Ⅰ和Ⅲ大鼠的胃、十二指肠食糜中检测到显著量的 β Casomorphin 7样物质 ,平均含量分别为 (1 60 52± 1 0 1 9) ,(1 0 6± 6 85)ng/g和 (2 2 0 48± 1 1 91 ) ,(1 4 2 84±7 72 )ng/g。试验组Ⅱ大鼠的胃和十二指肠食糜中也检测到 β Casomorphin 7样物质 ,提示非乳源的食物蛋白质也可能是酪啡肽的潜在来源     

The energy metabolism of growing swine in the body weight range of 10-50 kg. 2. Nitrogen and energy metabolism

Investigations were carried out about nitrogen and energy metabolism feeding rations with 17-24 and 44-47% crude protein content on maintenance and growing level to castrated male hybrid pigs of line 150. In growing periods the N deposition amounted to 10 g/animal.d (15 kg live weight), 18 g/animal.d (30 kg LW) and 21 g/animal.d (greater than 40 kg LW) on lower protein feeding level. In experiments with higher protein feeding level the corresponding results were 17, 22 and 22 g N deposition/animal.d. The partial utilization of metabolizable energy for deposition amounted to 70% for the rations with 17-24% protein content and to 59% for the rations with 44-47% protein content, without correlation to the animals development and the alternation in the protein feeding level. The results of regression analysis about maintenance requirement were 814, 775 and 806 kJ metabolizable energy/kg LW0.62.d in trials feeding rations with 17-24% crude protein content as well as 764, 846 and 818 kJ metabolizable energy/kg LW0,62.d in trials feeding rations with 44-47% crude protein content. 1,5-1,8 MJ metabolizable energy were used per MJ protein energy deposition and 1,3-1,4 MJ per MJ fat energy deposition respectively. The energy deposition per kg live weight gain amounted to values between 9 (10 kg LW) and 18 MJ (60 kg LW).     

Feeding organic acids enhances the barrier function against pathogenic bacteria of the piglet stomach

The effect of coarsely ground meal feed versus finely ground heat-treated pelleted feed and the addition of lactic acid and formic acid in combination on the physico-chemical properties, microbial composition and concentration of organic acids in the stomach content of piglets was investigated. A total of 60 weaned piglets were included in a 2 × 2 factorial arrangement in 15 randomised complete blocks. After three weeks, the pigs were put down and samples of digesta from the gastrointestinal tract were analysed for dry matter (DM), pH, organic acids and microbiological enumeration. Feeding coarsely ground meal feed increased the DM percentage, the concentration of organic acids and pH in the proximal stomach and lowered the distal stomach pH compared with finely ground heat-treated pelleted feed. However, the addition of organic acids to the diets lowered the pH in the stomach and was able to reduce the population of enterobacteria in the stomach.     

Effect of benzoic acid on growth performance, nutrient digestibility, nitrogen balance, gastrointestinal microflora and parameters of microbial metabolism in piglets

In order to investigate the effects of benzoic acid on growth performance, nutrient digestibility, nitrogen balance and gastrointestinal microflora of piglets, we conducted a performance experiment and a separate balance study. The performance experiment involved four different dietary treatments: (1) basal diet (negative control); (2) basal diet supplemented with benzoic acid at 5 g/kg; (3) basal diet supplemented with benzoic acid at 10 g/kg; (4) basal diet supplemented with potassium diformate at 12 g/kg. Each dietary treatment was assigned to nine replicate groups, each consisting of two piglets. Live weight, daily weight gain, feed intake and feed conversion ratio were monitored as performance parameters over a 35-day period. Supplementation of the diet with benzoic acid resulted in a dose-dependent increase in feed intake and body weight gain and an improved feed conversion ratio. Piglets fed the diet supplemented with benzoic acid at 10 g/kg outperformed the control piglets in mean feed intake, body weight gain and feed conversion ratio by 9%, 15% and 6% respectively. Growth performance of the piglets fed the diet with benzoic acid at 10 g/kg was similar to that of piglets fed the diet supplemented with potassium diformate. In the balance experiment three groups of six piglets each were fed either a control diet or diets supplemented with benzoic acid at 5 or 10 g/kg respectively. Benzoic acid did not significantly affect nutrient digestibility but increased nitrogen retention. Piglets fed the diets supplemented with benzoic acid at 5 or 10 g/kg retained 5% and 6% more nitrogen, respectively, than control piglets. Supplementation of benzoic acid did not influence the pH value or the concentration of ammonia in the gastrointestinal tract but reduced the number of bacteria in the digesta. In the stomach the number of total aerobic, total anaerobic, lactic acid forming and gram-negative bacteria was reduced; in the duodenum the presence of benzoic acid reduced the number of gram-negative bacteria and in the ileum the number of total aerobic bacteria in a dose-dependent manner. Benzoic acid also considerably reduced the concentration of acetic acid in the duodenum. In conclusion, the data of this study suggest that benzoic acid exerts strong antimicrobial effects in the gastrointestinal tract of piglets and therefore enhances growth performance and nitrogen retention.     

Recovery of intact IgG in the gastrointestinal tract of the growing rat following ingestion of an ovine serum immunoglobulin

The aim of this study was to determine whether orally ingested ovine serum IgG partly resists digestion in the growing rat. Fifteen Sprague‐Dawley male rats were allocated to one of three diets for a 3‐week study: a control diet (CON) and two test diets containing either freeze‐dried ovine serum immunoglobulin (FDOI) or inactivated ovine serum immunoglobulin (IOI). Samples of stomach chyme and intestinal digesta from the ad libitum‐fed rats were subjected to ELISA and Western blot analysis. Amounts of intact ovine IgG for the FDOI diet were found to be 13.9, 20.0, 34.1, 13.0 and 36.9 μg in the total wet digesta from the stomach chyme, duodenal, jejunal, ileal and colonic digesta respectively. Qualitative detection by Western blot revealed the presence of intact ovine serum IgG with a ~150 kDa MW. This was detected in all of the gut segments (stomach chyme, duodenal, jejunal, ileal and colonic digesta) for growing rats fed the FDOI diet. No ovine IgG was detected in the chyme or digesta from rats fed the CON or the IOI diets. Ovine serum IgG partly resisted digestion in the growing rat fed the FDOI diet and was found throughout the digestive tract. These results provide a basis to explain the reported biological effects of orally administered immunoglobulin.     

In vitro and in vivo binding of phenylbutazone and related drugs to equine feeds and digesta

In vitro and in vivo studies of phenylbutazone binding to equine ingesta and digesta were undertaken. In vitro binding to chopped hay and powdered pony nuts in buffer solutions at 37 degrees C was found to be time-, concentration- and pH-dependent. Percentage binding generally increased with time, decreased with concentration and varied with buffer pH in an unpredictable manner. Other non-steroidal anti-inflammatory drugs (NSAIDs) also bound to hay, the degree of binding being less for meclofenamate and least for flunixin in comparison with phenylbutazone. Phenylbutazone became bound to digesta collected from eight regions of the gastrointestinal tract when they were spiked with a concentration of 1 mg.10 g-1 digesta, the amounts ranging from 80.0 per cent (duodenum) to 99.6 per cent (stomach). Binding also occurred to equine digesta following the oral administration of phenylbutazone (4.4 mg.kg-1) to three ponies. It was concluded that drug uptake by and release from equine ingesta and digesta were probably adsorptive and desorptive processes. The clinical significance of the findings for the use of NSAIDs in equine medicine was considered.     

Effect of inclusion of fermentable carbohydrates in the diet on fermentation end-product profile in feces of weanling piglets

An in vivo experiment was conducted to monitor the changes in fermentation end products in the feces of weaning piglets due to the inclusion of selected fermentable carbohydrates in the diet. The experiment involved 3 groups of 16 piglets each. Specially raised piglets (neither antibiotics nor creep feeding) were weaned abruptly at 4 wk of age. The piglets were offered 1 of 2 dietary treatments [a control diet (CON), or a fermentable carbohydrate-enriched diet (CHO)] and were subjected to 1 of the 2 fasting treatments (fasting for 2 d at the beginning of the experimental period or nonfasting). Fecal samples were collected per rectum every day during the experimental period. Piglets were slaughtered at the end of the 10-d experimental period, and digesta samples were collected from different parts of the gastrointestinal tract (GIT): the first half of the small intestine, the second half of the small intestine, the cecum, and colon. The DM, VFA profile, and ammonia concentrations were analyzed from the fecal and digesta samples. Daily feed intake was also recorded. There was no difference in concentrations of VFA in feces between the treatment groups. Ammonia concentration was lower (P < 0.05) in piglets fed the CHO diet compared with those fed the CON diet in both feces and digesta from different parts of GIT. Fasting had no effect on fermentation end products in feces. This study demonstrated that the inclusion of fermentable carbohydrates in weanling diets reduces protein fermentation along the GIT and also reduced the fecal concentration of ammonia.     

Determining of nitrogen absorption and nitrogen secretion in different sections of the pig's intestine by digesta exchange between 15N labelled and unlabelled animals

In an experiment with 3 pigs (initial live weight 30 kg, each fitted with 2 re-entrant fistulas in duodenum and ileum, one labelled with 15N), the duodenal and ileum digesta was exchanged. The N and 15N contents were estimated in faeces, urine, duodenal and ileum digesta of all experimental animals as well as in special organs and in the contents of different tract sections. The 15N excess (15N') of N compounds secreted into the gut lumen was determined using the 15N' in pancreas, gut mucosa and TCA-soluble blood serum. From measuring the digesta passage through the 3 sections of the digestive tract: 1. mouth ... duodenum, 2. duodenum ... ileum, 3. ileum ... after (Krawielitzki et al., 1989) the absorption and secretion rates of nitrogen were calculated. Secretion into the 1st section amounted to 5.3 g N/d (= 15% of intake) and the absorption to approximately 1% of intake. In the 2nd section the corresponding dates were 8.9 resp. 38.6 g N/d (= 25 resp. 110% of N intake), and in the 3rd one 1.9 resp. 8.4 g N/d (= 5.6 resp. 24% of N intake). Total absorption amounted to 134% of N intake and the over all re-absorption of endogenous N compounds secreted into the gut lumen to about 90%. During the passage the amount of endogenous N (g/d) decreased from 5.3 at the duodenum to 3.8 at the ileum to 1.6 in the faeces, but the relative portion increased (13 resp. 35 resp. 39%). An incorporation into body proteins occurred only from N compounds absorbed in the 1st and in the 2nd section. N (or 15N) absorbed in the large intestine was almost quantitatively excreted by urine. The method of digesta exchange between cannulated labelled and unlabelled pigs seems to be a suitable method to estimate absorption and secretion of exogenous and endogenous N portions in various sections of the digestive tract.     

Fermented wheat in liquid diets: effects on gastrointestinal characteristics in weanling piglets

Effects of adding fermented wheat to liquid diets on gastrointestinal characteristics in weanling piglets were studied. Gastrointestinal characteristics of 40 28-d-old weanling piglets were measured at the day of weaning (d 0) and at d 4 and 8 after weaning. Piglets were group-housed and fed twice daily. Feeding level was based on the average metabolic BW of piglets per group. Groups were fed a liquid diet with either 45% unfermented wheat (FERM_0) or 45% fermented wheat (FERM_45). The other 55% of the diet was identical. To ferment wheat, water at 30 degrees C was added to milled wheat in a 1:2.2 ratio. The pH and contents of lactic acid, acetic acid, propionic acid, and butyric acid were measured in the digesta of the stomach, three parts of the small intestine, cecum, and large intestine. In addition, changes in microbial populations in the digesta were studied during the period after weaning. Moreover, villus height, crypt depth, and villus shape were studied in the small intestine. Piglets fed FERM_45 showed lower gastric pH (P < 0.05) at d 4 and higher gastric lactic acid content (P < 0.001) at both d 4 and 8. Piglets fed FERM_45 showed in the first part of the small intestine higher villus height (P < 0.01) at d 8 and higher villus:crypt ratio (P < 0.001) at both d 4 and 8. Villus shape tended (P < 0.10) to be favorable for piglets fed FERM_45. The present study indicates that feeding a partly fermented liquid diet to weanling piglets may be a concept to prevent undesirable changes in mucosal architecture after weaning.     

Protein digestability and amino acid absorption in various segments of the digestive tract of pigs. 1. Methods of animal experimentation, protein content and amino acid patterns of the digesta in the small intestine and in feces after feeding different feeds]

Re-entrance cannulae were applied by way of operations at the end of the small intestine of a larger number of growing pigs. After a post-operative phase these animals were fed with various rations (N-free diet, fattening feed for pigs, rations with dried skim milk resp. wheat gluten + lysine and wheat + wheat gluten + lysine). During the main experiment periods the ileum digesta (24 hour-periods of collecting) and the feces were quantitatively registered. The protein and amino acid content ascertained in the feed rations, the digesta and feces samples are reported, comparatively evaluated and discussed. The amount of amino acids (in mg per kg intake of dry matter) contained in the ileum digesta after N-free feeding were statistically calculated with regard to differences occuring between the animals and days. For most amino acids a significant decrease in the ileum digesta could be detected during the course of the N-free feeding period. Moreover, the amount of amino acids in the ileum digesta was compared with the metabolic fecal amino acids, from which conclusions could be drawn concerning the disappearance rate of the individual amino acids in large intestine.     

Postileal nutrient digestibility in cattle]

Four heifers of an average live weight of 301 kg supplied with ileocaecal re-entrant cannulae received rations consisting of 4 kg hay (variants A und B), 1 kg coarse wheat meal, 0.4 kg molasses, 100 g urea and 30 g mixed minerals per animal and day. After a 14-day preliminary feeding period the ileum digesta was quantitatively collected at the re-entrant cannula over 24 h. 10% of the digesta were used for analysis, the remainder was heated to 37 degrees C and returned. Under consideration of the digesta passage through the colon the 24-hour collection of faeces was started after a 6-hour delay after the first replacement of digesta. Losses of nutrients were calculated from the values analysed from digesta and faeces. No differences could be ascertained between the two hay variants. On an average of the two rations the nutrient losses of the scaffold substances-equivalent to the digestibility in the colon-showed the following values: crude fibre = 10.6%, NDF = 10.4%, ADF = 11.9% and hemicellulose = 7.4%. The losses of the other nutrients, corresponding to their apparent digestibility, had the following values: crude protein = 12.1%, crude fat = 10.7%, N-free extracts = 18.9%, ash = 31.2%, dry matter = 17.5%. The water balance showed that 8.2 l water of the 23.4 l supplied with the ileum digesta were excreted in faeces.     

Passage of ribonucleic acid along the intestine of sheep.

Sheep (Flemish female x Texel male, 55 kg BW), fitted with a PVC cannula in the dorsal rumen and single T-shaped PVC cannulas in the proximal duodenum, distal duodenum, mid-jejunum and terminal ileum were fed hay or hay-concentrate diets at various levels of nitrogen and cell walls (NDF) (22 to 32 g N/d; 150 to 699 g NDF/d). Co-EDTA and Cr-NDF were used as markers to measure the flow rate of digesta. Ribonucleic acid (RNA) intestinal digesta and in rumen bacteria was determined with orcinol after extraction with sodium chloride, precipitation with tungstophosphoric acid and alkaline hydrolysis. The RNA:total N ratio in bacteria, harvested from the rumen, amounted to 0.70 (CV 4.4%). The apparent digestibility of RNA in different sections of the intestine was higher than of total N. About 6% of RNA entering the duodenum disappeared between the proximal and distal duodenum. At jejunum, the net disappearance of RNA amounted to 68% of the quantity which entered the proximal duodenum. A higher result of 71% was obtained at the ileum. Total net disappearance of RNA between the proximal duodenum and rectum averaged 75%. Sixteen percent of RNA leaving the ileum was apparently digested in the large intestine. The true digestibility of RNA between the proximal duodenum and the terminal ileum, as estimated by multiple regression analysis, amounted to 78%. Of the amount of RNA entering the ileum, 24% was of endogenous origin. At ileum, the RNA passage was positively related to the ileal flow of NDF (R2 = 0.67) and N (R2 = 0.94). The passage of RNA increased by 3 mg RNA per g ileal indigestible NDF. Ileal endogenous N consisting of approximately 2% of endogenous RNA-N. In conclusion, the digestion capacity in the first part of the small intestine is high. Rising flows of indigestible cell walls and nitrogen increase the loss of ileal RNA. Further, using RNA as a microbial marker to assess the amount of microbial protein entering the duodenum of ruminants, digesta samples should be collected immediately post pylorus at the proximal duodenum, in order to avoid underestimation of the microbial protein synthesis in the rumen.     

Biogenic amines in the digesta of swine

Concentrations of amines were analysed in the digesta of piglets and fattening pigs after refining using an aminoacid-analyser. Feed contained only small amounts of putrescine. In the stomach histamine, tyramine, putrescine and cadaverine were nearly equally distributed, whereas in the colon cadaverine presented the main part. Piglets with 24% CP had in stomach/small intestine/hindgut 4.2/10.2/9.6 mmol, with 18% CP-/5.5/4.9 mmol amines/kg DM digesta. Fattering pigs showed in jejunal digesta from 2.1 to 8.7 mmol, in the caecum 1 to 4.8 mmol and in the colon 0.2 to 2.2 mmol amines/kg DM. Increasing CF-contents and bactericide supplements in the diet lowered amine concentration in all gut sections not significantly.     

二甲酸钾对仔猪生长性能和肠道微生物菌群的影响

试验旨在研究二甲酸钾和黄霉素对仔猪生产性能和肠道微生物菌群的影响。试验采用2×2因子设计,二甲酸钾(0和0.6%)与黄霉素(0和25 m g/kg)为2个主效应。试验结果表明:在基础日粮中分别添加二甲酸钾和黄霉素时,仔猪断奶后0-28 d的平均日增重从345 g分别增加到383 g和392 g。日粮中添加0.6%的二甲酸钾,显著降低了胃中乳酸杆菌的数量(P=0.005),以及胃、空肠和结肠中大肠杆菌的数量(P<0.05)。添加黄霉素显著减少了胃、回肠和结肠乳酸杆菌的数量(P<0.05)。添加二甲酸钾使胃中食糜的pH值大幅降低。本研究表明二甲酸钾的促生长效果和黄霉素相当,并且可以和黄霉素有效配伍;二甲酸钾抑制了肠道微生物的生长和代谢活性,降低了胃中食糜的pH值。     

Duration of anti-adhesive and bactericidal activities of milk from vaccinated sows on Escherichia coli O149 in the digestive tract of piglets during the nursing period.

Piglets were exposed orogastrically to Escherichia coli to enable study of the duration of anti-adhesive and bactericidal activities of milk of sows vaccinated with a K88 enriched E coli vaccine. There was a marked increase in the number of the challenge strain in the digestive tract of weaned piglets of all ages (between 888 and 2144 per cent). In contrast, there was a decrease in their number (75 per cent) in the day-old colostrum-fed piglets. When the piglets were two weeks old milk was still capable of reducing the rate of proliferation of the pathogen but at five weeks it proliferated at equal rates in the digestive tract of both suckling and weaned litter-mates. The rate of adhesion of the K88 positive E coli to the small intestine of colostrum deprived piglets was high (5 x 108/g). Rate of adhesion fell gradually in weaned piglets from 5.4 x 107/g at two weeks to 2.0 x 106/g at four to five weeks of age. In contrast, resistance of the small intestine of suckling pigs to adhesion by K88-positive E coli remained relatively stable through the five week period of nursing bacterial counts ranging from 5 x 104/g to 3 x 104/g of tissue.