Effect of maternal supplementation with essential fatty acids and conjugated linoleic acid on metabolic and endocrine development in neonatal calves.

We tested the hypothesis that the maternal supply of essential fatty acids (EFA), especially α-linolenic acid, and conjugated linoleic acid (CLA), affects glucose metabolism, the endocrine regulation of energy metabolism and growth, and the intestinal development of neonatal calves. We studied calves from dams that received an abomasal infusion of 76 g/d coconut oil (CTRL; n = 9), 78 g/d linseed oil and 4 g/d safflower oil (EFA; n = 9), 38 g/d Lutalin (BASF SE) containing 27% cis-9,trans-11 and trans-10,cis-12 CLA (CLA; n = 9), or a combination of EFA and CLA (EFA+CLA; n = 11) during the last 63 d of gestation and early lactation. Calves received colostrum and transition milk from their own dam for the first 5 d of life. Insulin-like growth factor (IGF)-I, leptin, and adiponectin concentrations were measured in milk. Blood samples were taken before first colostrum intake, 24 h after birth, and from d 3 to 5 of life before morning feeding to measure metabolic and endocrine traits in plasma. On d 3 of life, energy expenditure was evaluated by a bolus injection of NaH13CO3 and determination of CO2 appearance rate. On d 4, additional blood samples were taken to evaluate glucose first-pass uptake and 13CO2 enrichment after [13C6]-glucose feeding and intravenous [6,6-2H2]-glucose bolus injection, as well as postprandial changes in glucose, nonesterified fatty acids (NEFA), insulin, and glucagon. On d 5, calves were killed 2 h after feeding and samples of small intestinal mucosa were taken for histomorphometric measurements. The concentrations of IGF-I, adiponectin, and leptin in milk decreased during early lactation in all groups, and the concentrations of leptin in first colostrum was higher in EFA than in CTRL cows. Plasma glucose concentration before first colostrum intake was higher in EFA calves than in non-EFA calves and was lower in CLA calves than in non-CLA calves. Plasma IGF-I concentration was higher on d 1 before colostrum intake in EFA calves than in EFA+CLA calves and indicated an overall CLA effect, with lower plasma IGF-I in CLA than in non-CLA calves. Postprandial NEFA concentration was lowest in EFA and CLA calves. The postprandial rise in plasma insulin was higher in EFA than in non-EFA calves. Plasma adiponectin concentration increased from d 1 to d 2 in all groups and was higher on d 3 in CLA than in non-CLA calves. Plasma leptin concentration was higher on d 4 and 5 in EFA than in non-EFA calves. Maternal fatty acid treatment did not affect energy expenditure and first-pass glucose uptake, but glucose uptake on d 4 was faster in EFA than in non-EFA calves. Crypt depth was lower, and the ratio of villus height to crypt depth was higher in the ilea of CLA than non-CLA calves. Elevated plasma glucose and IGF-I in EFA calves immediately after birth may indicate an improved energetic status in calves when dams are supplemented with EFA. Maternal EFA and CLA supplementation influenced postprandial metabolic changes and affected factors related to the neonatal insulin response.

Effects of ad libitum milk replacer feeding and butyrate supplementation on the epithelial growth and development of the gastrointestinal tract in Holstein calves.

Intensive milk feeding and butyrate supplementation in calves stimulate body growth and affect gastrointestinal development. The aim of the present study was to investigate the synergistic effects of ad libitum milk replacer (MR) feeding and butyrate supplementation of MR on rumen and small intestinal growth and on gene expression in the small intestine related to growth and energy metabolism at weaning. Male Holstein calves (n = 32) received colostrum from birth to d 3 of age and MR either ad libitum (Adl) or restrictively (Res; 6 L of MR/d; 12.5% solids) with (AdlB+, ResB+) or without (AdlB-, ResB-) 0.24% butyrate from d 4 until wk 8 of age. From wk 9 to 10, all calves were weaned and were fed 2 L/d until the end of the trial. Concentrate, hay, and water were freely available. At d 80, calves were slaughtered, volatile fatty acids were measured in rumen fluid, and rumen and small intestine samples were taken for histomorphometric measurements. The expression of mRNA associated with the local insulin-like growth factor (IGF) system and glucose metabolism as well as lactase and maltase activities were measured in the intestinal mucosa. The small intestine was 3 m longer in Adl than in Res. In the atrium ruminis, papilla width was greater in Res than in Adl. Villus circumference, cut surface, and height in the duodenum, proximal jejunum, and ileum were greater in Adl than in Res and in the proximal, mid, and distal jejunum and ileum were greater in calves treated with butyrate. Crypt depth in the duodenum and proximal jejunum was greater in Adl than in Res and in the ileum was smaller in calves treated with butyrate. The villus height:crypt depth ratio was greatest in AdlB+ calves. In the proximal and mid jejunum, IGF1 mRNA abundance was lower in calves treated with butyrate. In the proximal jejunum, INSR mRNA abundance was greater in Res than in Adl. The abundance of PCK2 mRNA was greater in Res than in Adl in the duodenum and was greatest in ResB- in the mid jejunum. Lactase activity tended to be greater in Res than in Adl and after butyrate treatment in the proximal jejunum. The results indicated an elevated growth of the small intestinal mucosa at weaning due to intensive milk feeding and butyrate supplementation, and the local IGF system was involved in intestinal growth regulation. Rumen development was not affected by butyrate supplementation of MR and was slightly delayed due to ad libitum MR feeding.

Muscle characteristics in chicks challenged with Salmonella Enteritidis and the effect of preventive application of the probiotic Enterococcus faecium.

The present study was conducted to assess the effects of the probiotic Enterococcus faecium AL41 (EF) and of the enteric pathogen Salmonella Enteritidis PT4 (SE) on the development of posthatch pectoralis major muscle (PM) of broiler chicks. The four experimental groups were control (CON), EF, SE, and EF+SE (EFSE). EF and SE were given per os from days 1 to 7 and at day 4 posthatch, respectively. Muscle samples from 6 chicks per group were taken at day 8 (D8) and day 11 (D11) to evaluate PM myofiber growth, capillarization, DNA, RNA, and protein content, as well as enzyme activities (isocitrate dehydrogenase, lactate dehydrogenase, creatine kinase). PM growth rate was 7.45 ± 2.7 g/d in non-SE groups (CON, EF) and 5.10 ± 1.82 g/d in SE-infected groups (P < 0.02). Compared with group CON, application of bacteria (groups EF and SE) reduced the fiber cross-sectional area (246 and 262 vs. 347 ± 19 µm2) and the number of myonuclei per fiber (0.66 and 0.64 vs. 0.79 ± 0.03). At D11, hypertrophic myofiber growth normalized in the EF group, but negative effects persisted in SE and EFSE birds contributing to lower daily PM gain. In addition, SE infection strongly disturbed PM capillarization. Negative effects on capillary cross-sectional area and on the area (%) covered by capillaries persisted until D11 in the SE group, whereas pre-feeding of EF restored capillarization in the EFSE group to control levels. We conclude that supplementation of the probiotic bacteria EF AL41 had positive effects on PM capillarization and, thus, on delivery of O2, supply of nutrients, and removal of metabolites. Supplementation of probiotic bacteria might therefore reduce energetic stress and improve muscle health and meat quality during SE infection.

Effects of feeding unlimited amounts of milk replacer for the first 5 weeks of age on rumen and small intestinal growth and development in dairy calves.

The development of the gastrointestinal tract in newborn calves is essential for sufficient nutrient uptake. An intensive milk feeding during the neonatal period may impair the rumen development in calves. The aim of this study was to investigate effects of milk replacer (MR) feeding in unlimited amounts for the first 5 wk of age on the gastrointestinal growth and development in preruminant calves at wk 9 of age. Twenty-eight newborn Holstein and Holstein × Charolais crossbred calves (19 male and 9 female) were fed MR ad libitum (ADLIB) or in restricted amounts (6 L per day; RES) until wk 5 of age. Thereafter, the MR intake of ADLIB was gradually reduced at wk 6 and 7, and all calves received 6 L of MR per day until wk 9 of age. In wk 9, calves were slaughtered and carcass and organ weight as well as rumen papilla size in the atrium, ventral sac, and ventral blind sac, and villus size of the mucosa in the small intestine (duodenum; proximal, mid, and distal jejunum; and ileum) were determined. The expression of mRNA associated with the local insulin-like growth factor (IGF) system was measured in the rumen epithelium. Ad libitum MR feeding increased MR intake and growth in ADLIB without influencing concentrate intake compared with RES. Carcass weight in wk 9 was greater in ADLIB than in RES. The density of the rumen papillae in the atrium and ventral blind sac was greater in RES than in ADLIB calves, but surface area of the epithelium was not different between groups in the investigated regions of the rumen. The mRNA abundance of IGF1 in the atrium tended to be greater and the IGFR1 mRNA abundance in the ventral sac tended to be lower in the ADLIB than in the RES feeding group. The rumen pH and volatile fatty acid concentrations were not affected by MR feeding intensity. In mid-jejunum, villus circumference was greater in ADLIB than in RES calves. In the distal jejunum, villus surface area and the villus height/crypt depth ratio were greater and the villus circumference and height tended to be greater, whereas crypt depth was smaller in ADLIB than in RES calves. The findings from this study indicate that ad libitum MR feeding for 5 wk of age followed by its gradual reduction promotes growth performance without any negative influence on gastrointestinal growth and development in dairy calves at 9 wk of age.

Morphology, proliferation, and ribonucleic acid and fractional protein syntheses in the small intestinal mucosa of young goats fed soy protein-based diets with or without amino acid supplementation.

The study was designed to examine whether feeding soy protein isolate as partial replacement of casein (CN) affects jejunal protein synthesis and whether effects may be ameliorated by supplementation of those AA known to be at lower concentrations in soy protein isolate than in CN. Goat kids (14 d) were fed comparable milk protein diets, in which 50% of the crude protein was CN (CAS), soy protein isolate (SPI), or soy protein isolate supplemented with AA (SPIA) for 43 d (n=8 per group). On d 42, plasma concentrations of protein, urea, and AA were measured before and after morning feeding. In the morning of d 43, [15N]RNA from yeast [13 mg/kg of body weight (BW)] was given with the diet to measure the reutilization of dietary RNA precursors for mucosal RNA biosynthesis. Four hours later, an oral dose of l-[1-(13)C]leucine (180 mg/kg of BW) was administered and blood samples were collected between -15 and +45 min relative to tracer administration for analysis of plasma 13C alpha-ketoisocaproic acid and 13C recovery in blood CO2. Kids were killed 60 min after the tracer application, and jejunal tissue was collected to determine mucosal morphology, cell proliferation, enzyme activities, RNA synthesis, and fractional protein synthesis rate. Plasma protein concentrations were higher in CAS than in SPI and SPIA. Plasma concentrations of Thr were higher in CAS than in SPI and SPIA, and those of Met were lower in SPI than in CAS and SPIA. In mid-jejunum, villus circumferences were higher in CAS than in SPI and SPIA, and villus height and villus height:crypt depth ratio were higher in CAS than in SPI. In mid-jejunum, mucosal protein concentrations were higher in CAS than in SPI and SPIA and mucosal activities of aminopeptidase N tended to be higher in CAS than in SPI, whereas activities of dipeptidyl peptidase IV tended to be lower in SPI than in SPIA. Activities of 5' nucleotidase and xanthine oxidase were lower in CAS than in SPI. The 13C recovery in blood CO2 tended to be higher in SPI than in CAS. In mid-jejunum, 15N enrichment of RNA tended to be higher in CAS than in SPI, and 13C enrichment of protein-bound Leu was higher in SPI than in CAS. In mid-jejunum, the fractional protein synthesis rate tended to be higher in SPI than in CAS. Our results revealed changes in intestinal growth after soy protein feeding that were associated with effects on intestinal RNA and protein synthesis but that were not ameliorated by AA supplementation.

The effect of probiotic microorganisms and bioactive compounds on chemically induced carcinogenesis in rats.

Diet interventions and natural bioactive supplements have now been extensively studied to reduce risks of colon cancer, which is one of the major public health problem throughout the world. The objective of our investigation was to study the effects of probiotic, prebiotic, nutritional plant extract, and plant oil on selected biochemical and immunological parameters in rats with colon cancer induced by N,N dimethylhydrazine (DMH). Male and female Wistar albino rats were were fed by a high-fat (HF) diet (10% fat in the diet) and were divided into 9 groups: Control group; PRO group - HF diet supplemented with probiotic Lactobacillus plantarum to provide 3 x 109 c.f.u. of strain/1 ml of medium; PRE group - HF diet supplemented with inulin enriched with oligofructose (2% of HF diet); HES group - HF diet supplemented with plant extract of Aesculus hippocastanum L. (1% of HF diet); OIL group - HF diet comprised Linioleum virginale (2% of HF diet); and combination of probiotic microorganisms and bioactive compounds in the groups - PRO-PRE, PRO-HES, PRO-OIL, PRE-OIL. Carcinogenesis was initiated with subcutaneous injection of DMH (20 mg/kg) two times at week interval and dietary treatments were continued for the six weeks. Application of probiotic microorganisms and bioactive compounds in all treated groups significantly decreased the activities of bacterial enzymes (p<0.001), the fecal bile acids concentration (p<0.01; p<0.001) and significantly increased serum TNFalpha level (p<0.001) in comparison to the control rats. The number of coliforms was reduced in PRO, PRO-PRE, PRO-OIL and PRE-OIL groups and significantly higher count of lactobacilli (p<0.05) was observed in PRO-PRE, PRO-OIL and PRE-OIL groups in compare with the controls. In conclusion, the results of this study indicate that probiotic microorganisms and bioactive compounds could exert a preventive effect on colon carcinogenesis induced by DMH.

Alterations in the jejunum of young goats caused by feeding soy protein-based diets.

This study was designed to investigate whether soy protein or soy protein supplemented with indispensable amino acids (AA) change the protein expression pattern and utilization of pre-cursors for RNA biosynthesis in jejunal mucosa in relation to casein and whether these changes affect mucosal cell growth. Kids were fed comparable diets based on cow;s milk, of which 50% of crude protein were replaced by either casein (CAS), soy protein (SP) or soy protein supplemented with indispensible AA (SPA) for 34 days (n = 4/group). Jejunal tissue was collected 5 h after adding a single dose of (15)N-RNA to the diet, in order to determine morphology, protein repertoire by two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry, and RNA biosynthesis by isotope ratio-mass spectrometry. In mid-jejunum, morphological alterations induced by partial replacement of casein with soy protein were accompanied by changes in mucosal proteins related to generation of the cytoskeleton and in pathways for mucosal RNA biosynthesis, resulting in a smaller re-utilization of dietary RNA pre-cursors and in an increased activity of enzymes involved in nucleic acid breakdown. Soy protein supplemented with indispensible aminoacids tended to revise mucosal growth retardation with no impact on salvage of dietary RNA pre-cursors for mucosal RNA biosynthesis, but changes in cytoskeleton generation. Feeding soy protein with supplementation of indispensible AA does not ameliorate soy protein effects on mucosal morphology and RNA metabolism in the jejunum in a significant manner.

Prebiotic foodstuffs and their health benefits in experiment.

OBJECTIVES: The aim of the present experimental study was to evaluate the effect of prebiotic on chemically induced carcinogenensis in rats fed with high fat diet (HF). METHODS: Wistar albino rats were divided into control and experimental groups. In experimental group rats were treated with prebiotic at the dose of 2% of HF diet. N,N-dimethylhydrazine (DMH) injections were applicated in dose 20 mg/kg b.w., two times at week interval. In the end of eight weeks experimental period blood samples and feaces were taken from the rats and used for laboratory analysis. RESULTS: Treatment with prebiotic inulin significantly (p < 0.001) decreased enzymatic activity of bacterial enzymes in feaces. Similar tendency was noticed in concentration of bile acids and lipid parameters. Prebiotic undergo fermentation in the colon and enhanced short chain fatty acid production. CONCLUSION: Prebiotics may have potential health implications for protection against colon cancer (Tab. 2, Fig. 1, Ref. 14).

A milk diet partly containing soy protein does not change growth but regulates jejunal proteins in young goats.

Soy protein is known to alter intestinal function and structure. We determined in young goats whether a diet partly containing soy protein differently affects intestinal morphology and the jejunal and hepatic proteome as compared with a milk diet. Fourteen male 2-wk-old White German dairy goat kids were fed comparable diets based on whole cow's milk in which 35% of the crude protein was casein (milk protein group; MP) or soy protein supplemented by indispensable AA (SPAA) for 34 d (n = 7/group). Body weight gain and food efficiency were not different. Jejunal and hepatic tissue was collected to determine intestinal morphology by microscopy and protein repertoire by 2-dimensional gel electrophoresis and mass spectrometry. Jejunal crypt depth was reduced and villus height to crypt depth ratio was higher in SPAA than in milk protein. Out of 131 proteins identified, 32 proteins were found to be differently expressed in both groups. In SPAA, down-regulated jejunal proteins were involved in processes related to cytoskeleton generation, protein, lipid, and energy metabolism. Downregulated hepatic proteins were related to glycolysis and Krebs cycle. Thirteen proteins were upregulated in SPAA. Among these, 2 hepatic proteins were related to carbohydrate breakdown. The other 11 jejunal proteins were involved in cytoskeleton assembly, proteolysis, and carbohydrate breakdown. In addition, glutathione-S-transferase was found to be upregulated in the medial jejunum. In conclusion, a SPAA diet as compared with a milk diet was related to changes in jejunal morphology and jejunal proteins relevant for protein turnover, energy metabolism, and cytoskeleton assembly with no apparent impact on animal BW gain.

Effect of a soy protein-based diet on ribonucleic acid metabolism in the small intestinal mucosa of goat kids.

This study was designed to investigate the effect of soy protein inclusion in milk replacer diets for goat kids on protein, RNA, and DNA contents in small intestinal mucosa, on the importance of RNA biosynthesis from dietary RNA precursors for mucosal RNA synthesis, and on the activities of enzymes involved in nucleotide degradation in small intestinal mucosa. Diets were based on cow's milk. In the control group, 35% of the milk protein was replaced by casein (CN) protein, and in the soy group (SPAA), the same amount of milk protein was replaced by soy protein supplemented with essential AA known to be at lower concentrations in soy than in CN (Thr, Val, Ile, Leu, His, Lys, Met). Diets were isonitrogenous and isoenergetic. At 47 d of age, goats were harvested and samples of proximal, middle, and distal jejunal mucosa were collected 5 h after feeding 15N-labeled RNA from yeast (13 mg/kg of body weight). Growth and feed conversion did not differ between the control and SPAA kids. Mucosal protein concentrations were lower in the SPAA than the control kids. Concentrations of RNA and DNA did not differ between feeding groups, but in all kids mucosal RNA concentrations were higher in proximal than in middle and distal jejunum. Protein:RNA ratios were higher in the control than the SPAA kids and were lowest in proximal jejunum. Activities of alkaline phosphatase in enterocytes were higher in proximal than in middle and distal jejunum. Activities of mucosal xanthine oxidase were highest in distal jejunum and were higher in the SPAA than the control kids, especially in the middle and distal sites. The 15N-enrichment of mucosal RNA was higher in the control than the SPAA kids, especially in distal jejunum, and was lowest in distal jejunum. In contrast, 15N-enrichment of urea in plasma tended to be higher and Gly concentration in plasma was lower in the SPAA than the control kids. Data indicate that protein content and the protein:RNA ratio were lower in jejunal mucosa of goat kids fed milk replacer with partial replacement of CN protein by soy protein. These findings were accompanied by a lower level of reutilization of preformed dietary RNA precursors for RNA biosynthesis in jejunal mucosa and a higher activity of xanthine oxidase. Thus, feeding soy protein instead of CN protein reduced the incorporation of preformed dietary RNA precursors for RNA biosynthesis in the mucosa and activated key enzymes involved in nucleic acid breakdown.

Effects of protozoa on methane production in rumen and hindgut of calves around time of weaning.

Effects of the presence or absence of ciliate protozoa on methanogenesis in the rumen and hindgut were investigated in young calves during a 7-week period. Ten Holstein calves, aged 7 days, were divided in two groups (n = 5) and fed an increasing amount of a commercial milk replacer and small amounts of a calves starter. One group was inoculated with ciliate fauna on two occasions, week 5 and 6, while the second remained ciliate-free. The absence of protozoa in the rumen decreased rumen empty weight (-23%, P < 0.01), and rumen pool size of N (-36%, P < 0.01) and crude fat (-37%, P < 0.05). Rumen bacteria of non-faunated calves contained a higher proportion of total amino acid-N per 16 g N (+3%, P < 0.01) and D-alanine-N per 16 g N (+13%, P < 0.05) compared to faunated calves. Further results contain a reference for a higher bacterial mass in the ciliate-free rumen with an increased number of bacteria adherent to rumen mucosa. The CH4 production in the rumen increased exponentially with the increase in protozoa population size (R2 = 0.68). In presence of 46 x 10(4) protozoa per ml rumen fluid, the in vitro CH4 production of rumen fluid per mol total VFA was about 34% higher in faunated than in non-faunated calves (P < 0.001). Hydrogen (2H) recovery of rumen fermentation was positively correlated (R2 = 0.55) to the CH4 production rate. Methanogens were attached on rumen mucosa. Methanogenesis, induced by rumen mucosa attached bacteria, was stimulated by ruminal protozoa. In the absence of protozoa in the rumen, the acetate-propionate ratio and butyrate proportion of VFA were reduced. In vivo, in the absence of protozoa not only the whole animal CH4 production (-30%, P < 0.05) but also the digestibility of carbohydrates (-4%, P < 0.05) was reduced. Thereby no difference was observed in the intake of ME per kg DM between the groups. In conclusion, the methanogenesis in the rumen, but not in hindgut, is associated with the development of the ruminal protozoa population. The level of methanogenesis (mol/mol VFA) in the hindgut amounts to 20% of the ruminal methanogenesis.

Research note: Postnatal development of electrolyte transport in calf rumen as affected by weaning time.

In a previous study we found a positive correlation between early weaning in calves and morphological parameters which were indicative of ruminal development, i.e. the length and width of the papillae. The objective of the present study was to determine to what extent this observation could be reflected by modulations of absorptive and secretory functions of the rumen mucosa. For this purpose the short-circuit currents (Isc) as a measure of electrogenic net ion fluxes and the transepithelial conductances (G(T)) as a measure of the overall tissue permeability were measured in vitro applying the Ussing-chamber technique. Simultaneously, the unidirectional flux rates of sodium and chloride across rumen wall epithelia were determined in the absence of electrochemical gradients. Under these conditions, significant positive net flux rates (Jnet) clearly indicate active mechanisms for electrolyte absorption. For the experiments 12 male Holstein calves 7 d of age were assigned to three groups of 4 animals each: milk group (I, slaughtered after 6 weeks of age), late weaning group (II, slaughtered after 9 weeks of age) and early weaning group (II, weaned after 6 weeks of age and slaughtered after 9 weeks of age). Whereas G(T) values remained unaffected by different age and feeding, Isc values were significantly affected by early weaning but were not influenced by age. Irrespective of weaning time active absorption of Na+ tended to be higher by about 60% in 9 weeks old animals. Active absorption of chloride was significantly increased in milk fed 9 weeke old calves and this effect was further stimulated by early weaning. In conclusion, the data show an increasing active Na+ absorption with age in calf rumen that could not be influenced by early weaning. Similarly, active Cl- absorption was initially increased during postnatal development and this effect could be stimulated further by early weaning.

Morphological and functional development of the rumen in the calf: influence of the time of weaning. 1. Morphological development of rumen mucosa.

The objective of this study was to determine whether the nutritional regimen of rearing calves would influence the morphometric and histological development of rumen mucosa. Twelve male Holstein calves 7 d of age were assigned to three groups of 4 animals each: milk group (I), early weaned (6 weeks) group (II) and late weaned (9 weeks) group (III). All animals received additional solid feed. Animals of group I were slaughtered after 6 weeks of age, whereas those in groups II and III were slaughtered after 9 weeks of age. At slaughter, the ruminal digesta amounted to 2035 g (milk group), 3092 g (late weaned group) and 5374 g (early weaned group). The differences in the ruminal molar percentage of SCFA were not significant. There was a trend for lower pH and higher SCFA concentrations in the order late weaned, early weaned and milk fed animals (pH: 6.4, 6.6 and 6.7, respectively; SCFA: 96, 87 and 77 mmol/l, respectively). The mean length (1.07 mm in milk group, 1.45 mm in late weaned group and 1.87 mm in early weaned group), width (0.43, 0.58 and 0.71 mm, respectively) and surface of papillae (190, 232 and 241 mm2/cm2 mucosa, respectively) increased with both the age of the animals and the elevated intake of solid feed, whereas the number of papillae (210, 140 and 92 per cm2 mucosa, respectively) decreased. In both milk-fed groups type A and B corneal cells were present in the Stratum corneum, whereas in the earlier weaned calves type C-cells could be also seen. These findings indicate a more advanced stage of development of the rumen epithelium in the earlier weaned calves fed higher amounts of concentrate and hay.

Influence of dietary concentrate to forage ratio on the development of rumen mucosa in calves.

Effects of structural and non-structural carbohydrates on the development of rumen fermentation and ruminal mucosa in calves were examined during the weaning period. Barley/soybean meal (SBM) group was fed a concentrate starting from 2 weeks of age, whereas alfalfa group received a mixture of concentrate and alfalfa hay in which the proportion of the latter was gradually increased from 20% to 70% between weeks 2 and 9 of age. The total volatile fatty acid concentration in rumen fluid of calves increased with age, but at 9 weeks there were no significant differences between the two diets (barley/SBM group 153 mmol/l, alfalfa group 150 mmol/l). Rumen papillae at 9 weeks of age, as compared to 6 weeks of age, were longer and fewer in number per square centimetre mucosa, with larger cut surface. This resulted in a higher surface of papillae per square centimetre mucosa at 9 weeks (barley/SBM group 286 mm2/cm2, alfalfa group 245 mm2/cm2) than at 6 weeks of age (barley/SBM group 217 mm2/cm2, alfalfa group 198 mm2/cm2). At 9 weeks of age, the pH (barley/SBM 5.0, alfalfa 5.7), the acetate to propionate ratio (barley/SBM 2.2, alfalfa 3.2) as well as the length of the papillae in the ventral ruminal sac (barley/SBM 1.96 mm, alfalfa 2.37 mm) were increased in the alfalfa group when compared to the barley/SBM group (P < 0.1). In the former group, the proportion of butyrate revealed significantly increased values at 4 and 6 weeks of age. In animals of the barley/SBM group at 9 weeks of age, characteristic protrusions with proliferated thick epithelium occurred on the papillae and increased the surface for absorption. On the epithelium (Stratum corneum) desquamating cells with parakeratosis could be observed. In the alfalfa group the papillae of the ventral ruminal sac were longer, without protrusions. The morphotypes of the adhering rumen microflora differed between the groups. It can be concluded that feeding greater amounts of non-structural carbohydrates increases the surface for absorption of the rumen epithelium in calves. The absence of hyperkeratosis and rumenitis in the barley/SBM group indicated that there is no reason to limit high starch diets in the early weaning period of calves.

The effect of lactic acid bacteria on intestinal metabolism and metabolic profile in gnotobiotic pigs.

The effect of inoculation of Lactobacillus casei on selected parameters of metabolic profile and intestinal metabolism of gnotobiotic piglets was investigated during the first three weeks of their life. The experiment was carried out on 8 germ-free piglets. The experimental group was inoculated once a day with the Lactobacillus casei subsp. casei strain. The inoculum contained 1 x 10(8) microorganisms in 1 ml. The control group of piglets received no inoculum. Lactobacillus casei colonized jejunum and ileum in the numbers from 5.63 to 6.06 log 10 cm-2 and their numbers in the jejunal and ileal contents were in the range 8.38-9.87 log 10.ml-1. The daily consumption of milk by the inoculated animals was significantly higher (p < 0.001). The average weight of inoculated piglets at the end of the period investigated was higher by 29.7%. Lactobacillus casei affected several parameters investigated. Piglets inoculated with lactobacilli showed significantly lower (p < 0.05-0.01) values of pH of the jejunal content, numbers of erythrocytes, values of haematocrit, urea, glucose, total lipids, cholesterol and calcium in the serum and significantly higher values (p < 0.05-0.01) of lactic acid in the jejunal content. The values of phagocytic activity and the index of phagocytic activity in the piglets of the experimental group were two to three-fold higher in comparison with those detected in the control group. The application of Lactobacillus casei affected positively the growth of gnotobiotic piglets, their intestinal metabolism, the level of cholesterol in the serum and phagocytic activity.

The effect of white-rot basidiomycetes on chemical composition and in vitro digestibility of wheat straw.

Five white-rot basidiomycetes were evaluated for their potential to improve ruminal degradation of wheat straw. Polyorus brumalis, Lyophyllum ulmarium III, Trametes gibbosa, Pleurotus ostreatus, and a Pleurotus ostreatus mutant were incubated on wheat straw for 30 d at 28 degrees C. Detergent fiber, crude protein and in vitro dry matter digestibility (IVDMD) were determined. The results showed increasing crude protein and ash contents in fungus-treated straw. IVDMD values were increased in straws treated with P. ostreatus, P. ostreatus mutant and T. gibbosa only. Relative to untreated wheat straw the detergent fiber content-neutral detergent fiber (NDF), and acid detergent fiber (ADF) was reduced in fungus-treated straw and out of three fractions-hemicellulose, cellulose, and lignin, hemicellulose showed the largest proportionate loss whereas lignin the smallest one in all 5 samples of fungus treated straw.

[Mineral metabolism in young beef cattle during the period of changing from winter feed rations to grazing]. / Minerálny metabolizmus mladého výkrmového dobytka v období prechodu zo zimnej krmnej dávky na pasu.

Concentrations of calcium, inorganic phosphorus, magnesium, sodium and potassium were observed in the blood serum of beef bullocks after their transfer from winter feed ration to grazing and in the successive grazing cycles within two years. Blood samples were taken by puncture from the vena jugularis from the identical six bullocks. In the first year of observation, blood collection took place a week before transfer to grazing while in the second year of observation twice in weekly intervals before grazing. In the period of grazing, the biological material was sampled in weekly intervals from week 1 to week 5 (May--Ist cycle, June--IInd cycle), then in week 10 (July--IIIrd cycle) and in week 14 (August--IVth cycle of grazing). Calcium concentrations in the blood serum of beef bullocks (Fig. 1) decreased after transfer from stable feeding to grazing while this drop was significant in the second year of observation (P < 0.05). That period was followed by an increase in serum calcium concentrations in both target groups. The concentrations of inorganic phosphorus in the serum of beef bullocks (Fig. 2) dropped after transfer to grazing but a gradual increase in the values was recorded in week 4 in the first year of observation and in week 5 of grazing in the 2nd year of observation. These changes were not statistically significant. The concentrations of serum magnesium in beef bullocks (Fig. 3) statistically significantly dropped (P < 0.05) after transfer from stable feeding to grazing in week 3 in the first year of observation and in week 4 of grazing in the second year of observation.(ABSTRACT TRUNCATED AT 250 WORDS)

Rumen fermentation and metabolic profile in conventional and gnotobiotic lambs.

Observations were carried out of actual acidity, volatile fatty acid (VFA) concentrations, enzyme activity in the rumen, total protein, urea, total lipid and glucose in the serum of conventional (CL) and gnotobiotic lambs (GL) in the period of milk nutrition. The inoculum of gnotobiotic lambs contained Streptococcus bovis, Prevoxella ruminicola, Butyrivibrio fibrisolvens and Selenomonas ruminantium at a concentration of 1.10(6) each. Throughout the observation period the pH of the rumen contents of gnotobiotic lambs ranged within 6.5-6.8 with a significant difference at an age of 7 weeks. Total VFA concentrations in the rumen contents were increased in the CL throughout milk nutrition: the differences at 4 and 5 weeks of age were significant. Total VFA in the conventional lambs revealed an increasing tendency between weeks 4 and 7, reaching higher levels at 7 weeks of age (57.1 mmol.l-1), whereas in the gnotobiotic animals the range (24.3-30.1 mmol.l-1) was narrow and the peak occurred at 6 weeks of age. In GL significantly increased molar proportions of acetic acid were observed whereas in CL the molar proportions of propionic acid proved to be significant increased. The molar proportions of butyric and valeric acids were increased in CL but the group differences were not significant. In GL no isoacids were found. Alpha amylase (E.C.3.2.1.1.) activity of the rumen contents was significantly increased in GL between weeks 2 and 6 of age whereas cellulase (endoglucanase E.C.3.2.1.4. and cellobiohydrolase E.C.3.2.1.91.) activity was significantly increased in 4-week-old CL. Over the whole period of milk nutrition no significant differences were observed in urease (E.C.3.5.1.5.) activity of the rumen contents in the examined groups. At 5 weeks of age significantly increased total protein levels were observed in the conventional animals with maximum levels occurring at 4 weeks of age (CL-59.5 g.l-1 GL-55.3 g.l-1). Urea levels in 6-week old conventional lambs were significantly higher than in the gnotobiotic animals (CL-6.4 mmol.l-1 vs. GL-1.9 mmol.l-1). As to glycaemia no significant group differences were recorded. In the conventional animals total lipid levels were significantly increased at 1 and 6 weeks of age with a peak occurring in the first week of life (7.5 g.l-1) whereas in the gnotobiotic lambs a significant increase was observed at 3 weeks of age, the peak being recorded in 4 week-old animals (4.3 g.l-1). Throughout the period of interest the mean daily weight gains in the conventional and gnotobiotic lambs presented 0.164 and 0.162 kg, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Volatile fatty acid concentrations, enzyme activities and microflora in the rumen contents of heifers during transition to pasture.

Observations were carried out on volatile fatty acid (VFA) concentrations, enzyme activities and the microflora of the rumen contents in heifers during transition from winter to pasture feeding and in the subsequent gazing cycles. After turn-out to pasture, total VFA concentrations in the rumen contents of heifers significantly decreased from 107.7 to 88.7 mmol.l-1 (P < 0.01). After subsequent increase the total VFA concentrations reached their highest value (117.0 mmol.l-1) in the 8th week of grazing. The proportion of the molar acetic acid concentration in the rumen content increased insignificantly whereas that of propionic acid decreased insignificantly. In the molar proportion of butyric acid no significant differences could be stated. In the subsequent weeks the molar proportions of acetic acid were rather balanced and ranged within 66.2 and 68.0 mol%; the molar proportion of propionic acid insignificantly increased in the 4th week (18.7 mol%). Molar proportions of butyric acid on pasture insignificantly increased in week 3 (15.2 mol%) and appeared as balanced, later acquiring values between 14.0 and 14.8 mol%. The energetic yield of VFA production in the rumen of heifers decreased insignificantly from 73.6 to 72.15; the acetate: propionate ratio revealed an insignificant increase from 3.66 to 4.18. The enzyme activity of cellulase (endoglucanase E.C.3.2.1.4 and cellobiohydrolase E.C.3.2.1.91.) decreased significantly from 17.83 to 16.64 micrograms.ml-1 (P < 0.01); in the subsequent weeks, however, a significant increase could be observed. The enzyme activity of alpha-amylase (E.C.3.2.1.1.) decreased significantly (P < 0.05). In the 4th week a significant increase of the former occurred. The numbers of cellulolytic bacteria in the rumen content decreased significantly from 8.08 to 7.61 log 10.ml-1 (P < 0.01) and then a significant increase to 8.39 log 10.ml-1 was observed again in the 3rd week of grazing (P < 0.05). During pasture, a significant increase of the numbers of lactate-utilizing bacteria was recorded. As to the numbers of lactobacilli a significant decrease (P < 0.05) with a subsequent insignificant increase during grazing could be observed. Throughout the grazing season, the numbers of Streptococci reached values that surpassed those recorded during the winter feeding period. After transition from winter feeding to pasture the adaptation of rumen fermentation took four weeks.

[Colonization of the digestive tract by defined lactoflora in gnotobiotic and conventional lambs]. / Kolonizácia tráviaceho traktu gnotobiotických a konvencných jahniat definovanou laktoflórou.

The effect of Lactobacillus casei 249/89 on the colonization of the intestinal tract and selected indicators of the metabolic profile of gnotobiotic and conventional lambs from the viewpoint of its possible utilization in the prevention of diarrhoeal syndrome of bacterial etiology in young animals has been studied. Five gnotobiotic and three conventional lambs were used in these studies. The lambs were slaughtered at 3, 6, 10, 15 and 21 days of age. The population of L. casei colonizing the intestinal epithelium was at the age dynamics on average higher in gnotobiotic lambs compared with lactobacilli in conventional lambs (Fig. 1). The significant difference (p < 0.001) was noted at the age of 3 days (gnotobiotic lambs = 3.40 log 10/cm2 and conventional lambs = 1.08 log 10/cm2). Also the counts of lactobacilli colonizing individual sections of the intestine (Fig. 2) was on average higher in gnotobiots with significant differences in jejunum and colon (p < 0.05). In both groups, the highest number of lactobacilli was observed on the intestinal epithelium in lower sections of the digestive tract. In gnotobiots, the population of L. casei colonizing the duodenum was highest at the age of 3 days (3.49 log 10/cm2), in jejunum (3.74 log 10/cm2) and in ileum 4.37 log 10/cm2) at the age of 6 days and in the colon (4.7 log 10/cm2) at the age of 15 days (Fig. 3). In conventional lambs, the population of lactobacilli colonizing individual sections of the intestinum was increasing with age (Fig. 4). The number of L. casei in the intestinal content of gnotobiotic lambs was on average higher than that in conventional animals but the differences were not significant. In both groups, the highest number of lactobacilli was noted at the age of 10 days (gnotobiotic lambs = 5.9 log 10/ml; the conventional lambs = 4.6 log 10/ml). From the viewpoint of individual sections of the intestine, the population of L. casei in the intestinal content of gnotobiotic lambs was higher than the lactobacilli count in conventional animals with significant difference in jejunum (p < 0.01). In gnotobiots, the highest lactobacilli count was in the colon (6.17 log 10/ml); in conventional lambs in the ileum (4.71 log 10/ml).(ABSTRACT TRUNCATED AT 400 WORDS)