Invited review: Use of butyrate to promote gastrointestinal tract development in calves.

Promotion of microbial butyrate production in the reticulorumen is a widely used method for enhancing forestomach development in calves. Additional acceleration of gastrointestinal tract (GIT) development, both the forestomach and lower parts of the GIT (e.g., abomasum, intestine, and also pancreas), can be obtained by dietary butyrate supplementation. For this purpose, different sources (e.g., butyrate salts or butyrins), forms (e.g., protected or unprotected), methods (e.g., in liquid feed or solid feed), and periods (e.g., before or after weaning) of butyrate administration can be used. The aim of this paper was to summarize the knowledge in the field of butyrate supplementation in feeds for newborn calves in practical situations, and to suggest directions of future studies. It has been repeatedly shown that supplementation of unprotected salts of butyrate (primarily sodium salt) in milk replacer (MR) stimulates the rumen, small intestine, and pancreas development in calves, with a supplementation level equating to 0.3% of dry matter being sufficient to exert the desired effect on both GIT development and growth performance. On the other hand, the effect of unprotected butyrins and protected forms of butyrate supplementation in MR has not been extensively investigated, and few studies have documented the effect of butyrate addition into whole milk (WM), with those available focusing mainly on the growth performance of animals. Protected butyrate supplementation at a low level (0.3% of protected product in DM) in solid feed was shown to have a potential to enhance GIT development and performance of calves fed MR during the preweaning period. Justification of this form of butyrate supplementation in solid feed when calves are fed WM or after weaning needs to be documented. After weaning, inclusion of unprotected butyrate salts in solid feed was shown to increase solid feed intake, but the effect on GIT development and function has not been determined in detail, and optimal levels of supplementation are also difficult to recommend based on available reports. Future studies should focus on comparing different sources (e.g., salts vs. esters), forms (e.g., protected vs. unprotected), and doses of supplemental butyrate in liquid feeds and solid feeds and their effect not only on the development of rumen, abomasum, and small intestine but also the omasum and large intestine. Furthermore, the most effective source, form, and dose of supplemental butyrate in solid feed depending on the liquid feed program (e.g., MR or WM), stage of rearing (e.g., pre- or postweaning), and solid composition (e.g., lack or presence of forage in the diet) need to be determined.

Pancreatic enzyme deficiency depends on dietary protein origin in milk-fed calves.

In young mammals, milk proteins and their substitutes are used in milk formula. Protein substitution modifies diet digestibility and pancreatic secretions. The aim of this study was to test if milk protein substitution could generate pancreatic deficiency in milk-fed calves. The effect of pancreatic juice on the digestibility of proteins was studied. Measurement of apparent fecal nutrient digestibility was used to estimate digestion. Ten calves (60 to 130 d old) were chronically fitted with pancreatic accessory duct cannulas and 2 duodenal cannulas to provide precise measurement, sampling, and reintroduction of pancreatic juice as well as additional infusions. Animals were fed milk formula based on skim milk powder or soybean concentrate. Level of deficiency depended on dietary protein origin. Twice as much protein or trypsin was required with a soybean concentrate diet than with a skim milk powder diet to obtain maximal nutrient digestibility. Pancreatic protein concentration in the juice can be used to differentiate between normal and deficient animals. Among these proteins, trypsin measurement is a good pancreatic deficiency marker. These results confirmed the major role of exocrine pancreatic secretions in producing optimal digestion in young calves. Furthermore, practical applications of these results can be applied for the young in other animal species and in humans.

Effect of method of delivery of sodium butyrate on rumen development in newborn calves.

The effect of sodium butyrate (SB) supplementation in milk replacer (MR) or in starter mixture (SM) or in both MR and SM on performance, selected blood parameters, and rumen development in newborn calves was determined. Twenty-eight male calves with a mean age of 5 (±1) d were randomly allocated into 1 of 4 groups (7 animals per group) and fed (1) MR and SM, both without SB (MR(-) and SM(-), respectively); (2) MR(-) and SM supplemented with SB encapsulated within a triglyceride matrix (SM(+), 0.6% as fed; 30:70 butyrate-to-triglyceride matrix); (3) MR supplemented with crystalline SB (MR(+), 0.3% as fed) and SM(-); or (4) MR(+) and SM(+). The MR was offered in an amount equal to 10% of the initial body weight (BW) of each calf. The SM was blended with whole corn grain (50/50; wt/wt) and offered ad libitum as a starter diet (0.3% encapsulated-within-triglyceride matrix SB when SM(+) was fed) from the first day of the trial. Calves were slaughtered at d 21 of a trial (mean age 26±1 d). Addition of SB into MR (MR(+)) positively affected BW and average daily gain, tended to decrease the number of days with electrolyte therapies from d 0 to 7, and tended to positively affect fecal consistency from d 8 to 14 of the trial. Inclusion of SB into SM (SM(+)) increased starter diet intake from d 15 to 21, decreased the number of days with scours, and tended to decrease the number of days with electrolyte therapies in the whole trial period. Both MR(+) and SM(+) increased plasma glucose in the whole trial period and MR(+) increased total serum protein at d 14. The SM(+) increased plasma glucagon-like peptide-2 (GLP-2) concentration at d 7 of the trial when compared with the concentration at d 0. Both MR(+) and SM(+) increased reticulorumen weight and papillae length and width. Based on these results, it can be concluded that addition of SB in MR positively affected BW gain, health, and some metabolic intermediates of calves and it stimulated rumen development indirectly, whereas SB supplementation in SM stimulated rumen development directly. Addition of SB both in MR and SM could be recommended for rearing calves.

From the gut to the peripheral tissues: the multiple effects of butyrate.

Butyrate is a natural substance present in biological liquids and tissues. The present paper aims to give an update on the biological role of butyrate in mammals, when it is naturally produced by the gastrointestinal microbiota or orally ingested as a feed additive. Recent data concerning butyrate production delivery as well as absorption by the colonocytes are reported. Butyrate cannot be detected in the peripheral blood, which indicates fast metabolism in the gut wall and/or in the liver. In physiological conditions, the increase in performance in animals could be explained by the increased nutrient digestibility, the stimulation of the digestive enzyme secretions, a modification of intestinal luminal microbiota and an improvement of the epithelial integrity and defence systems. In the digestive tract, butyrate can act directly (upper gastrointestinal tract or hindgut) or indirectly (small intestine) on tissue development and repair. Direct trophic effects have been demonstrated mainly by cell proliferation studies, indicating a faster renewal of necrotic areas. Indirect actions of butyrate are believed to involve the hormono-neuro-immuno system. Butyrate has also been implicated in down-regulation of bacteria virulence, both by direct effects on virulence gene expression and by acting on cell proliferation of the host cells. In animal production, butyrate is a helpful feed additive, especially when ingested soon after birth, as it enhances performance and controls gut health disorders caused by bacterial pathogens. Such effects could be considered for new applications in human nutrition.

Dietary sodium butyrate supplementation increases digestibility and pancreatic secretion in young milk-fed calves.

The aim of this study was to test, in 8 calves fed milk formula based on soybean protein, the ability of sodium butyrate (SB) supplementation to improve nutrient digestibility and daily pancreatic secretions and to modify the kinetics of these secretions. Additionally, effects of duodenal SB infusion were evaluated. Plasma levels of gastrin, secretin, and cholecystokinin were measured. Butyrate supplementation in milk formula increased nutrient digestibility and total daily pancreatic secretions. For juice volume, this increase was most important from 12 to 17h after the morning meal. During the 3-h postprandial period, oral SB supplementation reduced the physiological decrease of postprandial pancreatic secretion (while duodenal digesta flow rate was maximal) and had a minor effect on plasma gut regulatory peptide concentrations. Compared with the diet without SB, ingestion of SB stimulated pancreatic secretion. Taken together, these results could explain the measured increase in nutrient digestibility. The data obtained after duodenal SB infusion did not indicate an effect on pancreatic secretion, apart from elevated lipase output compared with control. The mechanisms responsible for these events are not known and circulating gut regulatory peptides do not seem to be implicated. Our work brings new results regarding SB as a feed additive in young calf nutrition.

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.

Sodium-butyrate as a growth promoter in milk replacer formula for young calves.

In milk-fed calves, the effects of sodium-butyrate (Na-butyrate) to replace flavomycin on growth performance and some mechanisms involved were studied. Pancreatic and intestinal morphology, digestive enzyme activities, plasma gut regulatory peptide concentrations, and expression of their receptors in the gastrointestinal tract were measured. Gastrointestinal tract defense systems were examined by measuring protein levels of 2 heat-shock proteins (HSP27 and HSP70). The calves were randomly allocated into 2 groups fed the same basic diet with flavomycin as an antimicrobial growth promoter or with Na-butyrate (3 g/kg of dry matter). Sodium-butyrate disappeared quickly in the upper gut and was not found in circulating blood. Supplementation with Na-butyrate enhanced growth rate and improved feed conversion into body weight gain compared with the flavomycin group. Supplementation with Na-butyrate was likely associated with an improvement in efficacy of the gastrointestinal tract digestive capacities expressed by enhanced production of digestive enzymes and increased absorptive capacities in the upper small intestine. The effects could have been controlled by insulin-like growth factor-1 but probably not by any of the cholecystokinin/gastrin peptide family. Concentrations of HSP27 and HSP70 were increased in stomach and colon of calves receiving Na-butyrate, thereby assuring protection of cells with intensive metabolism (chaperone function). In conclusion, beneficial effects of Na-butyrate on maturation of gastrointestinal functions were shown in milk-fed calves and may be applied to young mammals of other species.

Gastrin, cholecystokinin and gastrointestinal tract functions in mammals.

The aim of the present review is to synthesise and summarise our recent knowledge on the involvement of cholecystokinin (CCK) and gastrin peptides and their receptors in the control of digestive functions and more generally their role in the field of nutrition in mammals. First, we examined the release of these peptides from the gut, focusing on their molecular forms, the factors regulating their release and the signalling pathways mediating their effects. Second, general physiological effects of CCK and gastrin peptides are described with regard to their specific receptors and the role of CCK on vagal mucosal afferent nerve activities. Local effects of CCK and gastrin in the gut are also reported, including gut development, gastrointestinal motility and control of pancreatic functions through vagal afferent pathways, including NO. Third, some examples of the intervention of the CCK and gastrin peptides are exposed in diseases, taking into account intervention of the classical receptor subtypes (CCK1 and CCK2 receptors) and their heterodimerisation as well as CCK-C receptor subtype. Finally, applications and future challenges are suggested in the nutritional field (performances) and in therapy with regards to the molecular forms or in relation with the type of receptor as well as new techniques to be utilised in detection or in therapy of disease. In conclusion, the present review underlines recent developments in this field: CCK and gastrin peptides and their receptors are the key factor of nutritional aspects; a better understanding of the mechanisms involved may increase the efficiency of the nutritional functions and the treatment of abnormalities under pathological conditions.

Specific regulation of the gene expression of some pancreatic enzymes during postnatal development and weaning in the calf.

The construction of cDNA library from calf pancreas allowed us to examine the mRNA levels of four pancreatic hydrolases (chymotrypsin, lipase, trypsin and amylase) during postnatal development in preruminant and ruminant animals. The lack of parallel variations in the levels of the enzyme specific activities suggested that protein synthesis was not coordinately regulated. In preruminant calves, the change in chymotrypsin and lipase mRNA concentrations (0-28 day period) and in trypsin mRNA concentrations (0-119 day period) was opposite to that in the corresponding specific activities. In contrast, both the activity and mRNA profiles of amylase during the latter period, on the one hand, and those of chymotrypsin and lipase during the 28-119 day period, on the other hand, were comparable. However, the extent to which the specific activity and mRNA concentration of each enzyme were increased did not necessarily coincide. The observed changes in mRNA levels probably resulted from some transcriptional control of the gene expression and/or variation in mRNA stability. Moreover, a translational regulation of the messengers could explain the existence of non-parallel mRNA and specific activity profiles. In sharp contrast with the multiple control of protein synthesis during postnatal development in preruminant calves, weaning was found to induce the same increase in enzyme activity and corresponding mRNA for each of the four pancreatic enzymes, suggesting that pretranslational modulation of gene expression was mainly, if not exclusively, concerned.

Differential expression of A- and B-subtypes of cholecystokinin/gastrin receptors in the developing calf pancreas.

Cholecystokinin (CCK)/gastrin receptors were characterized in calf pancreatic plasma membranes from newborns, 28- and 119-day-old milk-fed preruminants, and 119-day-old weaned ruminants. Scatchard analysis of [125I]Bolton-Hunter reagent-[Thr28,Nle31]CCK-(25-33) binding indicated two classes of binding sites: high affinity sites exhibited significant higher affinity and binding capacity (P < 0.05) in 119-day-old ruminants than in 119-day-old preruminants (Kd = 0.13 +/- 0.02 vs. 0.35 +/- 0.08 nM; binding capacity (Bmax) = 53 +/- 12 vs. 18 +/- 5 fmol/mg protein). Pharmacological analysis using selective agonists and antagonists indicated the expression of the CCK-A receptor at birth, whereas the CCK-B receptor predominated at postnatal stages. At all stages, the binding was inhibited by guanosine 5'-[gamma-thio]triphosphate. Binding site identification by photoaffinity labeling showed that at birth, the labeling occurred mainly on a 78- to 96-kilodalton (kDa) component. In milk-fed animals, aged 28 and 119 days, two membrane-binding components were labeled at 78-96 and 43-52 kDa. In 119-day-old ruminants, labeling occurred mainly on a 40- to 47-kDa protein. Deglycosylation by endo-beta-N-acetylglucosaminidase-F of the 40- to 47- and 43- to 52-kDa components resulted in the formation of a 37-kDa membrane protein. Consequently, this study demonstrated 1) the differential expression of CCK-A and -B receptors in developing calf pancreas, 2) the predominance of CCK-B receptors in normal pancreas, and 3) the maturation of CCK-B receptors during the weaning period, which includes the glycosylation level. These results suggest that CCK may play a predominant role during the early postnatal development, while gastrin and CCK-B receptors can function progressively to regulate proliferation and exocrine secretion in the calf pancreas, especially from the weaning period.

Exogenous leptin controls the development of the small intestine in neonatal piglets.

Leptin, a hormone produced and secreted by adipose tIssue, muscles and stomach, is involved in the regulation of adipose tIssue mass, food intake and body weight in neonatal animals. It is also produced in the mammary glands and secreted into the colostrum and milk. Since leptin receptors are widely distributed in the small intestine mucosa, the aim of the present study was to investigate the effect of exogenous leptin on the development of the small intestine in neonatal piglets. Male neonatal piglets were fed with sow's milk or artificial milk formula. Every 8 h the latter received either vehicle or leptin (2 or 10 microg/kg body weight). The animals were either killed after 6 days of treatment and the small intestine sampled for histology and brush border enzyme activities or were tested for marker molecule (Na-fluorescein and BSA) absorption in vivo. Feeding milk formula slowed the maturation of small intestinal mucosa compared with feeding sow's milk. However, after leptin treatment the length of the small intestine was increased, and intestinal villi length, but not crypt size, was reduced compared with controls. The mitotic index was increased and the percentage of vacuolated enterocytes was reduced in the entire small intestine. Enterocyte brush border protease and lactase activities were reduced in the jejunum. Na-fluorescein marker molecule absorption did not change but that of BSA was reduced 3.8-fold. In conclusion, exogenous leptin administered in physiological doses reversed the maturation of the small intestinal mucosa to the range found in sow-reared piglets.

Small intestinal and pancreatic microstructures are modified by an intraduodenal CCK-A receptor antagonist administration in neonatal calves.

The aim of the present study was to investigate the role of CCK on the upper gut and pancreas microstructure and on pancreatic juice secretion in neonatal calves assessed by a repetitive intraduodenal administration of FK480, a CCK-A receptor antagonist, during the first 6 days of life. The experiment was performed on 10 neonatal calves surgically fitted with a pancreatic accessory duct catheter and duodenal cannulas. Calves were sacrificed on day 7 for tissue sampling. Treatment with FK480 resulted in: reduction of preprandial pancreatic juice secretion at days 1-3, smaller size of pancreatic acini and number of cells per acinus, reduction in intestinal crypt depth (except in the duodenal bulb), numerous modifications of intestinal villi length and width, lower mitotic index of crypt cells, and increased number and size of enterocytes with 'empty vacuoles'. In conclusion, the blockade of CCK-A receptors during early life both reduced pancreatic exocrine secretion and induced complex changes in pancreatic microstructure. The influence of CCK on the upper gut microstructure in neonatal calves could be either direct via activation of CCK-A receptors located in the mucosa of the upper gut or indirect by modulation of the secretion of pancreatic juice.

Specific regulation of pancreatic elastase I and II mRNA expression during postnatal development in the calf: reverse transcriptase-polymerase chain reaction analysis.

The specific regulation of pancreatic elastase I and II mRNA expression as well as of the protein, RNA, and DNA contents were determined during ontogeny in the calf. Specific activities and mRNA concentrations were quantified by spectrophotometry and reverse transcriptase-polymerase chain reaction, respectively. Calves were either milk-fed or weaned until slaughter at different ages. The biosynthesis of elastases I and II was modulated by postnatal development and weaning, leading to specific gene expression profiles. The levels of elastase I activity and of the corresponding mRNAs were found to evolve in a roughly similar way. On the contrary, elastase II activity level decreased sharply during postnatal development, while no changes were observed in the corresponding mRNA levels. After weaning, elastase I activity and mRNA levels, as well as elastase II mRNA levels, increased. However, the magnitudes of elastase I activity and mRNA inductions were different. Therefore, the expression of each gene in the calf pancreas is more or less independently regulated and the regulation is mainly pretranslational (elastase I) or translational (elastase II) during postnatal development and both pretranslational and translational at weaning. The translational efficiency of elastase I and II mRNAs might be influenced by the nature of dietary proteins.

Molecular cloning, developmental expression and pharmacological characterization of the CCKB/gastrin receptor in the calf pancreas.

We have cloned the calf predominant pancreatic cholecystokinin B (CCKB)/gastrin receptor cDNA. It encodes a 454 amino acid protein with 90% identity with the CCKB/gastrin receptor cloned in other species and tissues. However, the calf pancreatic CCKB/gastrin receptor contains a pentapeptide cassette within the third intracellular loop which is absent in the cloned human brain and stomach receptor. Quantification of the CCKB/gastrin receptor mRNA levels by reverse transcription polymerase chain reaction demonstrated the same level of transcripts at birth, +7 and +28 days. On the other hand, binding study with pancreatic membranes showing a dramatic increase (600-fold) in the number of CCKB/gastrin receptor sites between at birth and +28 days indicates that the development of the calf pancreatic CCKB/gastrin receptor occurs during the first 4 weeks of post-natal life. COS monkey cells (COS-7 cells) transiently transfected by the cloned cDNA exhibit binding of 125I-Bolton-Hunter-[Thr28,Ahx31]CCK-(25-33) and 125I-Bolton-Hunter-[Leu15]human gastrin-(2-17) to two affinity classes of sites. Kd values of the high affinity binding components indicate a 4-fold higher affinity of the receptor for sulfated gastrin than for CCK. Finally, the recombinant receptor is coupled to G proteins and [Ca2+]i mobilization, and is expressed as a glycoprotein of 82 kDa.

Differential tissular expression of the CCK(A) and CCK(B) gastrin receptor genes during postnatal development in the calf.

Local and temporal expression of CCK(A) and CCK(B)/gastrin receptor genes was studied in the calf with a quantitative Reverse Transcription-Polymerase Chain Reaction (RT-PCR) method. Cerebral cortex, antrum, fundus, gall bladder, pancreas and liver were analyzed in calves at 0, 2, 7, 21, 28 and 150 days of age. Cerebral cortex and pancreas expressed both receptor genes with a ratio between CCK(A) and CCK(B)/gastrin receptor transcripts varying according to the age. Gall bladder and fundus showed an exclusive expression of CCK(A) and CCK(B)/gastrin receptor mRNAs, respectively, with the highest levels of transcripts in newborn and 28-day-old calves. The rank order for CCK(A) receptor mRNA expression was gall bladder > pancreas > cerebral cortex >>> antrum and that for CCK(B)/gastrin receptor mRNA expression was cerebral cortex / pancreas / fundus >> antrum. No CCK(A) and CCK(B)/gastrin receptor mRNA was detected in liver, regardless of the age of calves. The present data represent a basis for a better understanding of the ontogeny of physiological functions linked to the CCK(A) and CCK(B)/gastrin receptors.

Bovine pancreatic preproelastases I and II: comparison of nucleotide and amino acid sequences and tissue specific expression.

Clones encoding bovine preproelastases I and II were isolated from a pancreatic cDNA library and were sequenced in order to define the structural characteristics of these enzymes. The bovine 947- and 884-nucleotide preproelastase I and II cDNAs encode proteins containing a signal peptide of the same length (16 amino acids), but with a slightly different number of amino acids for the activation peptide (10 and 12, respectively) and the mature enzyme (240 and 241, respectively). Considering amino acid sequences, each enzyme shares a high degree of identity (76-86%) within species. In contrast, only 55.3% identity is found between bovine elastases I and II. This difference could explain partly their own specificity. Analysis of the expression of the elastases in various bovine tissues demonstrated that they are specifically expressed in high levels in the pancreatic gland. These two approaches (structure and expression) allowed us to characterize the bovine pancreatic elastases I and II.

Outer ear temperature and time of death.

From a research sample of 138 corpses, divided into four subgroups of ambient storage temperature (0-5 degrees C, 6-10 degrees C, 11-15 degrees C and 16-23 degrees C) four linear regression formulae of actual versus estimated post-mortem interval were obtained ('interval' formulae) using a single outer ear temperature measurement on both sides. This method showed the best correlation coefficient among five other methods previously proposed for time of death determination (rectal temperature, vitreous K+, CSF K+, blood log NA+/K+ and log Cl-), however its results were less accurate than those obtained with a multivariate equation combining several of the above mentioned methods. Eventually an equation expressing time of death (TOD) as a function of outer ear temperature (OE T degrees) and ambient temperature was also established from the whole research sample ('global' formulae). On a different sample of 141 corpses the regression formulae ('interval' and 'global') for the outer ear temperature were compared to three methods based on a single rectal temperature measurement ('rule of thumb' 1 and 2, Henssge nomogram) and therefore useful at the scene; the results of all methods were compared within the four subgroups of ambient temperature as well as in three subgroups of different post-mortem interval lengths (< 7 h, < 10 h, < 15 h). In all cases the outer ear temperature formulae provided better results than the rectal temperature methods (especially Henssge nomogram and rule of thumb 1). Moreover they did not show any post-mortem plateau which was present in almost 30% of cases when rectal temperature was measured in corpses kept at ambient temperature above 15 degrees C. Our results show that outer ear temperature measurement is the method which provides the best simplicity/quality ratio and should therefore be proposed for use at the scene when conditions are similar to those of our experiment (within buildings). A software equipped thermometer is required in order to use in each case the appropriate formula and confidence interval.

Structural and functional development of small intestine in intrauterine growth retarded porcine offspring born to gilts fed diets with differing protein ratios throughout pregnancy.

Protein level in the maternal diet plays a crucial role in fetal programming during pregnancy. Low or high protein level increases the risk of intrauterine growth retardation (IUGR). The aim of this study was to investigate the structural and functional development of the small intestine in piglets from sows fed a control (C, 12.1% protein), a high protein (HP, 30% protein), or a low protein (LP, 6.5% protein) diet during pregnancy. Newborns were classified as IUGR (birth weight ≤1.18 kg) and non-IUGR (birth weight >1.18 kg). The piglets were euthanized on postnatal day (PD)1, PD28 and PD188. The LP diet in non-IUGR neonates resulted in decreased body weight on PD1. The LP and HP diets resulted in both decreased body weight and delayed catch-up growth in the IUGR piglets. The HP and LP-diets increased the length of villi on PD1 in non-IUGRs but not in IUGRs. At birth, the expressions of Ki67 and active caspase 3 in mid-jejunum epithelium of HP and LP non-IUGR neonates were significantly lower as compared to C non-IUGRs whilst in IUGRs the respective expressions were as high as in C non-IUGRs. The postnatal dynamics of brush border enzyme activities and vacuolated enterocytes disappearance showed significant drop in enterocyte maturation in IUGR as compared to non-IUGR neonates. In conclusion, both HP and LP diets led to retarded development of non-IUGR piglets. In IUGR piglets both HP and LP diets resulted in delayed catch-up growth, without adaptive changes in brush border digestive enzymes.

Gastrointestinal tract and digestion in the young ruminant: ontogenesis, adaptations, consequences and manipulations.

Young calves have to deal with at least three major situations that require profound physiological and digestive adaptations: adaptation to extra-uterine life (up to the first postnatal week), maintenance at a pre-ruminant stage over a long period (3 to 5 months or more), and weaning. This paper reports results obtained on the development (growth and differentiation) of the gastrointestinal tract, and on digestive enzyme activities as well as some aspects of the regulation by gut regulatory peptides. In the newborn calf, the maturation of the small intestine depends on pregnancy duration (preterm vs. full term) and ingestion of colostrum from first milking. The function of gut enterocytes evolves along with the changes from fetal to adult enterocytes. The origin of dietary protein in pre-ruminant and weaning calves modifies SI morphology. Chymosin, elastase II and lactase are typical postnatal enzymes, whereas pepsin, ribonuclease and amylase become important especially following weaning. Nitrogen digestibility increases during the first month of life and is modified by replacement of skim milk powder with non-milk proteins. Milk formula supplementation with Nabutyrate increases pancreatic secretions and digestibility. The gastrointestinal tract development depends on gut regulatory peptides plasma and luminal concentrations. The response to exogenous peptides is in relation with their number and type of functional receptors and with the animal age. Experimental work with young ruminants is important not only for the species involved, but also for its implications to other mammalians.

Adverse effects of nutritional programming during prenatal and early postnatal life, some aspects of regulation and potential prevention and treatments.

Nutritional programming, regulation and some ways for prevention/treatment to ameliorate or normalize adverse outcomes of programming are discussed. Epidemiological studies in human and animal experiments showed that nutrition during fetal and neonatal life may lead to related disorders in adulthood. But several argues may question its validity arising the question of the adequate models used to reproduce human situations. Protein level in milk formula intake by infant during neonatal life is discussed. Body weight at birth reflects the product growth trajectory during fetal life. Low birth weight is considered as the result of an adverse growth trajectory and is often associated with later metabolic diseases in adult age. But, the sum of prenatal growth trajectory, rapid growth in early infancy (catch up growth), early adiposity rebound in childhood must be considered to determine the origins of later diseases in adulthood. The review focuses the regulation of nutritional imprinting on hormonal and epigenetic mechanisms which are complementary. The HPA axis and GH-IGF axis may have a crucial role in the regulation induced by nutritional programming. The persistent alterations seem to be a consequence, at least in part, of elevated insulin levels during "critical periods" of pre- and early postnatal development. Also, leptin seems to play an important role in this complex system. New knowledge about these mechanisms involved suggest the development of new, rational, and effective preventive and/or therapeutic options before and/or after birth. Thus, early infancy may provide an opportunity for intervention aimed at reducing later disease risk.