PubMed Health⌕ Search

Biomedical subjects

R Toullec

Publications and source records attributed to R Toullec.

At least 37 records · Page 2Linked to original sources
PubMed1995

Hydrolyzed soy protein isolate sustains high nutritional performance in veal calves.

Milk replacers containing skim milk powder or a mixture of whey and soy protein provided by a hydrolyzed soy protein isolate or a heated soybean flour were fed to 1-mo-old calves for 101 d. The isolate and the flour provided 56 and 72% of dietary proteins, respectively. Digestibility of feed constituents was measured between 9 to 14 d and 65 to 70 d of treatment. Digestive function was evaluated by measurement of ruminal pH, plasma kinetics of triglyceride and glucose concentrations, and xylose absorption. Antibody production was also recorded. Growth and carcass characteristics were satisfactory for the control diet and the diet based on soy isolate, partly because of high apparent digestibility of protein and lack of antibody synthesis in response to soy isolate. In contrast, protein from soybean flour was poorly digested and highly immunogenic. Ruminal pH at 2.5 h after the meal was unaffected by dietary treatments. Postprandial changes in concentrations of triglycerides and glucose in plasma suggested a lack of abomasal clotting with both diets based on soy. Xylose concentration in plasma was only slightly affected by dietary treatment and calf age. Hydrolyzed soy protein is suitable for veal calves and can account for at least half of protein intake.

Animal Nutritional Physiological Phenomena↗
PubMed1994

Local and systemic immune responses to soybean protein ingestion in early-weaned pigs.

The development of local and systemic immune responses to soybean proteins was investigated in early-weaned pigs. Pigs were given either antigenic (ASP, n = 10 pigs) or non-antigenic (NASP, n = 8 pigs) soybean products (6 g of protein/d) from d 5 to 9 of age by stomach tube. After weaning at d 21, pigs were fed diets containing the corresponding soybean products and slaughtered between d 28 to 30. Diarrhea was 2.4-fold more frequent, the size of duodenal villi was reduced by 24 to 36%, and the eosinophil density in the duodenal mucosa was 13 times greater (P < .02) in the ASP pigs compared with the NASP pigs. A larger erythema area (P = .006) was observed in the ASP group than in the NASP group 30 min after an intradermal injection of glycinin, but no significant difference could be detected with alpha- or beta-conglycinin or whole soybean extracts. No difference in skin fold thickness was apparent between groups 24 h later. Intestinal, mesenteric lymph node, and blood lymphocytes did not proliferate when cultured with soybean proteins, regardless of dietary treatment. By ELISA, no difference between groups was observed in the circulating levels of total immunoglobulins (Ig) and IgM. Immunoblotting patterns of raw soybean with sera from 28-d-old pigs showed two bands (22 and 36 kDa) recognized by IgA and IgM, respectively, in the ASP group only. Finally, the adverse effects observed with antigenic soybean flour can be overcome by the use of alcohol-treated products.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1994

In vivo and in vitro gastric emptying of milk replacers containing soybean proteins.

Gastric digestion of three milk replacers for which protein was provided either exclusively by milk powder or partially (50%) by heated soybean flour or soybean protein concentrate was studied in vivo and in vitro. In vivo gastric emptying of protein fractions of the diets was measured in six preruminant calves fitted with reentrant duodenal cannulas and used in a double 3 x 3 Latin square design. In vitro gastric emptying was studied after hydrochloric acid and rennet digestion in an artificial stomach. In vivo and in vitro flow rates of 12% TCA-insoluble N and total N were higher for the soybean diets than for the milk protein diet, indicating that the incorporation of soybean protein prevented casein from clotting. Because of this faster gastric emptying, proteolysis in the stomach was reduced. However, gastric emptying of NPN (12% TCA-soluble N) was significantly decreased only in vitro. No difference existed between the two milk replacers containing either soybean flour or soybean protein concentrate. In vivo and in vitro results were correlated, suggesting that the in vitro method could be used to predict gastric digestion of protein fractions in vivo.

Animal Feed↗
PubMed1993

Digestibility and amino acid composition of digesta at the end of the ileum in preruminant calves fed soyabean protein.

The ileal digestion of 3 milk substitutes in which skim milk powder was either the only protein source (control diet) or was partially replaced (50%) by a heated soybean flour (SF diet) or an alcohol-treated soyabean protein concentrate (SC diet) was studied in 6 preruminant calves which were fitted with an ileo-caecal re-entrant cannula. The apparent digestibility of total nitrogen and amino acids was lower with the SF and SC diets than with the control diet (0.89, 0.89 and 0.94, respectively, for amino acid nitrogen). Assuming that true digestibility was complete with the control diet, the values were lower with the SF and SC diets, especially for cystine, threonine, valine, isoleucine, leucine and histidine. With the SF and SC diets, digesta contained more aspartic acid and glutamic acid but less threonine, sulfur amino acids, lysine, serine and alanine than with the control diet. The additional undigested fractions obtained with the SF and SC diets compared to the control diet were rich in aspartic and glutamic acids, and poor in arginine, suggesting that partially degraded dietary fractions different from the whole soyabean escaped digestion in the small intestine; these fractions probably originated mainly from glycinin. No significant differences were observed between the 2 soyabean diets.

Amino Acids↗
PubMed1992

Activity distribution of seven digestive enzymes along small intestine in calves during development and weaning.

Ten groups of calves were used to study the changes in activity levels and distribution of seven hydrolases in the intestinal mucosa during development and weaning. The calves in the first group were sacrificed at birth while those in the remaining nine groups were either milk-fed until slaughter on days 2, 7, 28, 56, 70, and 119; or weaned between days 28 and 56 and then slaughtered on days 56, 70, and 119, respectively. The small intestine was immediately cut off and divided into five segments, ie, duodenum, proximal jejunum, median jejunum, distal jejunum, and ileum. In the milk-fed animals, the activity levels of aminopeptidases A and N, alkaline phosphatase, lactase, and isomaltase were maximum at 2 days of age, and then declined sharply between days 2 and 7 but did not change significantly thereafter. By contrast, the maltase activity increased between days 7 and 119, while no sucrase activity was detected. Weaning resulted in a decrease in the activity of lactase and an increase in that of aminopeptidase N, maltase, and isomaltase. The distribution of all these enzymes along the small intestine was slightly influenced by age but not at all by weaning.

Animals↗
PubMed1992

Early-life patterns of plasma gut regulatory peptide levels in calves. Effects of age, weaning and feeding.

1. The effects of age, weaning and feeding on the release of seven gut regulatory peptides [gastrin, cholecystokinin (CCK), secretin, vasoactive intestinal peptide (VIP), pancreatic polypeptide (PP), motilin and somatostatin] were studied in calves either exclusively milk-fed between birth and 91 days (P group) or weaned between 22-56 days of age (R group). 2. During the first 3 weeks, the basal plasma immunoreactive levels increased with age for secretin, CCK and PP, decreased for gastrin, motilin and somatostatin and were unaffected for VIP. The changes were particularly rapid for somatostatin and gastrin. After 3 weeks, no significant trend was observed with age in the P group. 3. Weaning resulted in an increase of basal gastrin, CCK, PP and VIP and in a decrease of basal secretin and somatostatin. 4. In the P group, the morning meal was followed 1 hr later by an increase of gastrin and CCK, and by a fall of secretin, PP, motilin and somatostatin, but no significant effect was observed in VIP. Weaning resulted in a reduction of the differences between the fasting and the post-feeding values. 5. These changes suggest a large involvement of endocrine cells in the adaptation of gut tissues, secretions and motility at birth, during the maintenance at the pre-ruminant stage and at weaning.

Aging↗
PubMed1992

Plasma and tissue levels of digestive regulatory peptides during postnatal development and weaning in the calf.

Changes in the concentrations of cholecystokinin, gastric inhibitory peptide, gastrin, motilin, pancreatic polypeptide, secretin, somatostatin, and vasoactive intestinal peptide in calf plasma and antral, duodenal and/or pancreatic tissues were assessed by radioimmunoassay during postnatal development and after weaning in 50 male Holstein-Friesian calves (randomly distributed into 10 groups of 5 animals each). The calves in the first group were killed at birth while those in 6 other groups were colostrum-fed for 2 days and then milk-fed until 7, 28, 56, 70 or 119 days of age. Those in the remaining 3 groups were given the same diets until day 28, were then weaned between day 29-56, and slaughtered on days 56, 70 or 119. In milk-fed animals, changes in plasma and tissue concentrations of almost all digestive regulatory peptides were observed during the 1st month of postnatal life, especially at day 2. Weaning was accompanied by variations in the plasma concentrations of somatostatin, secretin, gastrin, pancreatic polypeptide and gastric inhibitory peptide but not by any apparent change in peptide tissue concentrations (except VIP in the duodenum). Thus, the variations in tissue concentrations are primarily age-related, while plasma concentrations were modified by age and weaning.

Aging↗
PubMed1992

Gastric and pancreatic enzyme activities and their relationship with some gut regulatory peptides during postnatal development and weaning in calves.

Changes in the activities of three gastric and nine pancreatic enzymes plus colipase were determined during postnatal development and weaning in calves. In calves exclusively milk-fed for 2, 7, 28, 56, 70 and 119 d, the enzyme activities per kilogram of empty live weight increased with age for chymotrypsin, elastase, carboxypeptidases A and B, ribonuclease and alpha-amylase, decreased for chymosin, lysozyme and colipase but showed no change in the case of pepsin, trypsin, lipase and phospholipase A2 compared with animals at birth. The greatest increase was that in alpha-amylase activity (about 50-fold between d 2 and 119). In calves weaned between d 28 and 56, all the activities were higher than in milk-fed animals, except that of chymosin (which was slightly lower) and that of colipase (which did not change). At 119 d of age, chymotrypsin, carboxypeptidase A, alpha-amylase and lipase were 1.6- to fourfold higher in ruminants than in preruminants. Thus, most enzyme activities were modified first by colostrum and milk intake, and again upon weaning by development of the forestomachs and ingestion of solid food. These ontogenic patterns might be under the control of many gut regulatory peptides, the plasma concentrations of which changed simultaneously. Some gastric and pancreatic enzymes were correlated to plasma concentrations of these gut regulatory peptides.

Abomasum↗
PubMed1992

Early-life patterns of plasma gut regulatory peptide levels in calves: effects of the first meals.

The effects of the first meals on the release of seven gut regulatory peptides were studied in newborn calves fed colostrum either at serial intervals during the first day of life or at 28 h only. Fasted animals showed no significant variation of plasma peptides until the first feed, except for somatostatin, which peaked at 4-5 h and declined thereafter. As assessed before and 1 h after feeding, the first meal tended to induce rises in plasma gastrin, cholecystokinin and pancreatic polypeptide, while the other peptides were unaffected. Repeated colostrum feeds induced marked increases in plasma gastrin, cholecystokinin, secretin and vasoactive intestinal peptide from 10 h on. Pancreatic polypeptide was transiently increased from 4 to 16 h. Feeding was followed by a transitory reduction of plasma somatostatin and by a prolonged decrease of plasma motilin. We conclude that colostrum feeding potently modulates the release of several regulatory peptides shortly after birth in calves. These responses may be important for the adaptation of gut growth, secretions and motility to food ingestion in the neonatal period.

Animals↗
PubMed1992

In vivo and in vitro gastric emptying of protein fractions of milk replacers containing whey proteins.

In vivo and in vitro gastric emptying of protein fractions of three milk replacers containing either milk protein (control), a mixture (50:50 on a CP basis) of milk protein and native whey protein concentrate, or a mixture (50:50 on a CP basis) of milk protein and heated whey protein concentrate was studied. In vivo gastric emptying was measured in three preruminant calves fitted with reentrant duodenal cannulas and used in a 3 x 3 Latin square design. In vitro gastric emptying was determined after enzymatic digestion in an artificial stomach. In vivo and in vitro flow rates of protein N (12% TCA-insoluble N) and total N were higher for milk replacers containing whey proteins than for control. Gastric emptying of NPN (12% TCA-soluble N) was slightly higher for diets containing whey proteins than for that containing milk proteins. Gastric emptying of all protein fractions was similar for the two milk replacers containing whey proteins. In vivo and in vitro results were significantly correlated, suggesting that the in vitro method reproduced conditions for proteolysis and could be used to predict gastric digestion of protein fractions.

Animals↗
PubMed1992

Effects of raw pea flour on nutrient digestibility and immune responses in the preruminant calf.

Two milk substitute diets for which the protein was provided either exclusively by skim milk powder (control) or partially (34%) by dehulled raw pea flour were given for 2 and 4 wk, respectively, to five preruminant calves, each fitted with a reentrant ileocecal cannula. Ileal apparent digestibility was lower with the pea diet during wk 1 than with the control diet. Four of the cannulated calves exhibited significant intolerance to the pea diet, resulting in lower digestibility during wk 4. In contrast, fecal digestibility of the pea diet, measured in four additional calves without reentrant cannulas, did not significantly decrease between wk 1 and 4. The AA composition of ileal digesta from the first group of calves did not vary greatly, suggesting that the differences observed in their apparent digestibility of proteins were due mainly to changes in the loss of endogenous proteins. However, pea legumin survived digestion in the small intestine in amounts generally equivalent to 1 to 3% of intake. Most of that undigested fraction was smaller than the native legumin: 40 to 200 kDa instead of 360 kDa. Also, a 45-kDa fragment was detected in the urine. Increased intestinal permeability could have favored the development of the high systemic anti-pea antibody titers that were observed in all of the calves.

Amino Acids↗
PubMed1991

Cloning and nucleotide sequence of a bovine pancreatic preprocarboxypeptidase A cDNA.

A full-length cDNA clone encoding bovine pancreatic preprocarboxypeptidase A was isolated and sequenced. The 1405-base pair insert contains a 26-nucleotide 5'-noncoding region, a 1260-nucleotide open reading frame and a 76-nucleotide 3'-noncoding fragment plus a poly(A) tail of at least 43 nucleotides. The open reading frame encodes a protein of 419 amino acids, including the 16 amino acid signal peptide. The mature enzyme (309 residues) has two additional C-terminal amino acids, as compared with the amino acid sequence of the protein which was reported more than 20 years ago. In addition, four residues deduced from the nucleotide sequence differed from those identified in the reported amino acid sequence from their net charge: Asp-89, Asp-114, Gln-122, and Asp-185 instead of Asn-89, Asn-114, Glu-122, and Asn-185, respectively. A high degree of identity exists between the nucleotide sequences (81.3%), on the one hand, and the amino acid sequences (78.3%), on the other hand, of bovine preprocarboxypeptidase A and rat preprocarboxypeptidase A1.

Amino Acid Sequence↗
PubMed1990

Isolation and nucleotide sequence of cDNA clone for bovine pancreatic anionic trypsinogen. Structural identity within the trypsin family.

A cDNA clone encoding an anionic form of bovine trypsinogen was isolated from a pancreatic cDNA library. The corresponding 855-nucleotide mRNA contains a short 5' noncoding region of 8 nucleotides and a long 3' noncoding region of 56 nucleotides in addition to a poly(A) tail of at least 50 nucleotides. The deduced amino acid sequence for the anionic pretrypsinogen (247 residues) includes the N-terminal 15-amino-acid signal peptide followed by an 8-amino-acid activation peptide. The zymogen (232 residues) contains an additional C-terminal serine, compared with the amino acid sequence of bovine cationic trypsinogen. The identity between the anionic and cationic forms of bovine trypsinogen (65%) is lower than that existing between the anionic protein and other mammalian anionic trypsinogens (73-85%), suggesting that trypsin gene duplication in mammals occurred prior to the evolutionary events responsible for the species divergence. Bovine pancreatic anionic trypsin possesses all the key amino acids characteristic of the serine protease family.

Amino Acid Sequence↗
PubMed1990

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.

Aging↗