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PubMed1991

A comparative study of cells and anti-microbial proteins in colostrum of mothers delivering pre- and full-term babies.

The different anti-infective factors in the colostrum of 25 mothers delivering pre-term (33.04 +/- 2.18 weeks gestation) and 10 mothers full delivering term (39.1 +/- 0.87 weeks gestation) babies were measured. The mothers of both the groups were comparable with respect to age, parity, nutrition, and haemoglobulin levels. Although the mean volume of colostrum (12 hours) was significantly lower in pre-term (32.28 +/- 7.92 ml) than in full term (44 +/- 4.83 ml) colostrum (P less than 0.05), the concentrations of total protein, sIgA, lysozyme, and lactoferrin were significantly higher in preterm than in full-term colostrum. IgG and IgM levels were similar in both the groups of colostrum. In both the groups, s-IgA was the predominant immunoglobulin. Moreover, the absolute counts of total cells, macrophages, lymphocytes, and neutrophils were significantly higher in pre-term compared to full-term colostrum. Macrophage were the predominant cells. Degree of prematurity has been found to have profound influence on the volume, protein concentration, and cell and macrophage counts of colostrum. Thus, more pre-term the newborn was, the mother produced less amount of colostrum. Total protein concentration and absolute cell count were significantly higher in the colostrum samples of mothers delivering between 28 and 32 weeks as compared to those delivering between 33 and 36 weeks. It is concluded that the colostrum of mothers delivering pre-term, though less in amount, is rich in soluble anti-infective agents and cells. The higher concentration of protective factors compensates for the limited capacity of milk intake in the pre-term infant.

Adult↗

PubMed1998

Alpha-1 antichymotrypsin levels are actively increased in normal colostrum.

BACKGROUND: It is well known that human colostrum has important antiinflammatory functions. The purpose of the current study was to determine antiprotease levels in colostrum and serum and to assess the importance of local synthesis and the electrophoretic differences in both locations. METHODS: Five protease inhibitors were determined by radical immunodiffusion in colostrum and serum samples taken simultaneously from 50 healthy women, 36 to 72 hours after delivery. RESULTS: Antithrombin II, inter-alpha trypsin inhibitor, and alpha-2 macroglobulin levels were undetectable in colostrum. Mean antitrypsin levels in colostrum were 6% of serum levels, but colostrum alpha-1 antichymotrypsin was higher than expected (0.39+/-0.34 g/l) in relation according to the albumin passive transport, and their mean value was 41% of serum levels. Colostrum antichymotrypsin levels did not correlate with serum antichymotrypsin levels or with colostrum albumin levels. The antichymotrypsin molecule in colostrum had a slower electrophoretic mobility when compared with that of serum antichymotrypsin, and it showed a different pattern in Western blot analysis, with a predominating 80-kDa molecule. CONCLUSIONS: Although the origin of colostral antichymotrypsin is unclear, local production in breast epithelial cells is likely. Antichymotrypsin is increased in colostrum, and its molecule has some characteristic differences, suggesting that it has an important and specific role in infant nutrition during breast milk feeding.

Colostrum↗

PubMed1991

Cellular composition including lymphocyte subsets in preterm and full term human colostrum and milk.

The cellular composition of colostrum (within 72 hours post partum) and mature milk samples (5th-7th day post partum) from 20 mothers delivering preterm babies and 20 mothers delivering full term babies was examined. Lymphocyte subsets including T cells, B cells, T4 and T8 cells were quantitated by indirect immunoperoxidase staining using specific monoclonal antibodies. The mean total cell count in preterm colostrum (9,338/mm3) was significantly higher than in full term colostrum (5,594/mm3). Similarly, counts for macrophages, neutrophils and lymphocytes were significantly higher in preterm colostrum and milk as compared to full term colostrum and milk. B and T lymphocytes including T4 and T8 cells were identified in both preterm and full term breast milk. The absolute count of T, B, T4 and T8 cells was significantly higher in preterm colostrum compared to term colostrum, though the relative percentage distribution of lymphocyte subsets showed no significant difference between the two groups. T and B cells constituted about 74% and 26% of total lymphocytes, respectively in preterm as well as full term colostrum and about 69% and 31% in preterm and full term milk. The mean T4/T8 ratio was higher in preterm colostrum than term colostrum, being 1.82 and 1.60 respectively. However, this difference was not significant statistically and did not change statistically in the milk sample.

B-Lymphocytes↗

PubMed2001

Serum immunoglobulin G concentrations in calves fed fresh and frozen colostrum.

OBJECTIVE: To determine whether serum IgG concentrations in neonatal calves are adversely affected by short-term frozen storage of colostrum. DESIGN: Prospective study. SAMPLE POPULATION: Experiment 1 consisted of 10 pairs of Holstein calves (n = 20) fed matched aliquots of either fresh (n = 10) or frozen and thawed (10) colostrum. In experiment 2, 26 Holstein calves were fed either fresh (n = 13) or frozen and thawed (n = 13) colostrum. PROCEDURE: Experiment 1 consisted of calves resulting from observed parturitions; calves were randomly assigned to treatment groups (fresh or frozen and thawed colostrum) in pairs. Calves were fed 4 L aliquots of colostrum via oroesophageal intubation at 3 hours of age. Serum IgG concentrations at 2 days of age were compared between the 2 groups by use of a paired t-test. Experiment 2 consisted of calves resulting from observed parturitions; calves were randomly assigned to treatment groups (fresh or frozen and thawed colostrum). Calves were fed 4 L aliquots of colostrum via oroesophageal intubation at 3 hours of age. Regression analysis was used to determine whether calf serum IgG concentration was a function of colostral IgG concentration and colostrum storage group. RESULTS: Significant differences were not observed between the 2 groups in experiment 1. No significant relationship was observed between colostrum storage group and serum IgG concentration in experiment 2. The model that best predicted serum IgG concentrations accounted for 20% of the variability in serum IgG concentration. CONCLUSION AND CLINICAL RELEVANCE: Frozen colostrum is an adequate source of IgG for calves.

Animal Feed↗

PubMed2003

Dexamethasone and colostrum feeding affect hepatic gluconeogenic enzymes differently in neonatal calves.

Plasma glucose concentrations in neonates are influenced by colostrum feeding and by glucocorticoids. We have tested whether a high-glucocorticoid status after birth, as well as colostrum feeding, influences glucose metabolism in association with changes of hepatic expression and activities of gluconeogenic enzymes phosphoenolpyruvate carboxykinase (PEPCK; EC 4.1.1.32) and pyruvate carboxylase (PC; EC 6.4.1.1) in neonatal calves. Calves (n = 14 per group) were fed either colostrum or a milk-based formula with nutrient and energy contents similar to colostrum. Half the calves in each feeding group were treated with dexamethasone (DEXA; 30 microg/[kg BW x d]). Pre- and postprandial blood samples were taken on d 1, 2, 4, and 5 and liver samples were collected on d 5 of life. Dexamethasone treatment increased (P < or = 0.05) plasma concentrations of glucose, insulin, and glucagon more in colostrum-fed than in formula-fed calves but increased (P < or = 0.05) urea concentrations and decreased (P < or = 0.05) concentrations of NEFA, ACTH, and cortisol independent of colostrum vs. formula feeding. Colostrum feeding increased (P < 0.05) plasma glucose, but decreased (P < 0.05) plasma urea concentrations. Glucagon-to-insulin ratios in DEXA-treated and colostrum-fed calves were decreased (P < 0.05). Dexamethasone treatment decreased hepatic mRNA levels and activities of PC (P < 0.001 and P < 0.10) and activities of PEPCK (P < 0.001) but increased (P < 0.001) the glycogen content. Colostrum feeding increased (P < 0.05) mitochondrial PEPCK mRNA levels and PEPCK activities in calves not treated with DEXA but decreased (P < 0.1) amounts of PC mRNA. In conclusion, increased plasma glucose concentrations after DEXA treatment were not associated with a stimulation of hepatic gluconeogenic enzyme activities; however, colostrum feeding probably raised plasma glucose concentrations because of increased hepatic gluconeogenic activities.

Adrenocorticotropic Hormone↗

PubMed1987

Characteristics of frozen colostrum thawed in a microwave oven.

Use of a microwave oven to thaw frozen colostrum was evaluated. Colostrum was collected from nine cows, four of which were immunized to produce specific colostral antibodies. Colostrum from each cow was frozen, subsequently thawed, and pooled. One-liter aliquots of the pooled colostrum were frozen and assigned randomly to three thawing treatments. Colostrum was thawed using one of three regimens: 10 min in a microwave oven at full power (650 W), 17 min in a microwave oven at half power (325 W), and 25 min in 45 degrees C water. Colostrum thawed in the microwave oven was slightly coagulated and had lower volume and total protein content than colostrum thawed in water. Casein and pH were not different among treatments. Both concentration and total content of immunoglobulin A were higher in the control than in microwave treatments. Neither amount nor concentration of immunoglobulin G and immunoglobulin M were different among treatments. Immunological activity, measured by a hemolytic test, was lower for microwave treatments than the control but did not differ between microwave treatments. Frozen colostrum thawed in a microwave oven should provide a reasonable source of colostrum when fresh high quality colostrum is not available.

Animals↗

PubMed1993

Low molecular weight branched-chain and n-chain fatty acids in caprine and bovine colostrum.

Colostrum from French-Alpine and Anglo-Nubian goats and Holstein cows was collected and analyzed for both total and FFA of 12 and fewer carbon atoms. Short-chain VFA were separated from long-chain fatty acids using simultaneous distillation extraction. The n-butyl esters of fatty acids were quantified by gas chromatography, and their identity was confirmed by gas chromatography-mass spectrometry. The concentration of decanoic acid was 33 and 83% less in Holstein colostrum than in colostrum from Alpine and Nubian goats, respectively. Colostrum from Nubian goats had twice as much decanoic acid as colostrum from Alpine goats. The FFA in colostrum that differed between species but not between goat breeds were octanoic and decanoic acids. These respective fatty acids were approximately two and three times greater in colostrum from goats than in colostrum from Holsteins. The quantity of decanoic acid was different between goat breeds and between animal species. The ratio of total fatty acid concentration to free-state concentration for hexanoic acid appeared to be useful for differentiating between Nubian and Alpine goat colostrum as well as between Nubian and Holstein colostrums.

Animals↗

PubMed1976

Opsonic activity and O-agglutinins against Escherichia coli in bovine colostrum.

Anticolibacillus antibody activity was examined in 16 samples of bovine colostrum by O-agglutination test with 6 serotypes of Escherichia coli, and its correlation with the manifestation of diarrhea was analyzed for newborn calves fed these colostrums. The 4 colostrums fed to newborn calves having diarrhea within a few days after birth had significantly lower agglutinin titers for all the serotypes tested than did the other colostrums. Other newborn calves fed on the remaining 12 colostrums did not manifest clinical signs of enteric disorders. The agglutinin spectrum against the E coli serotypes was similar between colostrum samples from the same stockfarm, but variable among the farms from which the colostrum had been collected. The agglutinin activity was sensitive to 2-mercaptoethanol and was found mainly in the macroglobulin fraction of gel filtration, indicating that the activity was due to antibodies of the immunoglobulin M type. This was evidenced directly by the agglutination test of purified immunoglobulins. Opsonic activity of colostrum and immunoglobulins purified therefrom was estimated by the rate of decrease in the number of viable E coli injected into mouse peritoneal cavity. The results indicated that the opsonic activity in colostrum was also attributed mainly to immunoglobulin M antibodies, although the contribution of immunoglobulin A and G antibodies was not ruled out. A part of the opsonic activity in colostrum seemed due to heat-labile component(s) as well.

Agglutinins↗

PubMed1994

[Chemical changes in colostrum fermented with sorghum].

Colostrum from Holstein cows was collected during the first three days post partum. Ground sorghum (7.5%) was added to it. Untreated colostrum used as control, and sorghum treated colostrum samples were allowed to ferment for 0, 8 or 21 days at 18-20 degrees C in glass containers; pH, moisture, crude protein, digestible protein, ammonia, lactic acid and total energy were analyzed in untreated and treated samples. Crude protein was not significantly different (P > 0.01) in control colostrum (7.12, 5.76, 5.70%) and treated colostrum (6.66, 5.71, 5.98%) at 0, 8 and 21 days of fermentation respectively. Digestible protein was higher (P < 0.01) in the untreated (90.0, 93.0%) than in the treated colostrum (89.0, 81.0, 86.0%). Ammonia content was also higher (P < 0.01) in the control (0.25, 1.31, 1.37%) than in the treated one (0.23, 0.97, 1.20%). Lactic acid was lower (P < 0.01) in the untreated colostrum (0.82 g/100 ml) than in the treated colostrum (1.24 g/100 ml) after 21 days of fermentation. Total energy values were lower (P < 0.01) at 8 and 21 days of fermentation in the untreated (0.91, 0.84 Kcal/g) than in the treated colostrum (1.16, 0.97 Kcal/g). The addition of sorghum to colostrum reduced the crude, protein degradation and the ammonia content after 8 and 21 days of fermentation, increasing total energy and lactic acid content after 21 days of fermentation.

Ammonia↗

PubMed1981

The serum-free growth of cultured cells in bovine colostrum and in milk obtained later in the lactation period.

Seven established cell lines, including both epithelial cells and fibroblasts (MDCK, Vero, CV-1, NRK, 3T3, F2408, and NIL8) and four early passage cell strains (bovine articular chondrocytes, bovine smooth muscle cells, human foreskin fibroblasts, and rat embryo cells) were cultured in serum-free medium supplemented with milk obtained 1 day after birth (colostrum) or 80 days after birth (older milk). MDCK, Vero, CV-1, NRK, and 3T3 grew readily in colostrum and attained saturation densities ranging from 22% to 63% of that in serum. There was no growth of F2408, NIL8, or the early passage strains in bovine colostrum. None of the 11 cell cultures grew in older milk. The temporal dependence of growth in milk was examined in detail using MDCK cells. Growth equivalent to that in serum occurred in 3% colostrum and in 15% milk obtained 2 days after birth. Milk obtained 3 days and 10 days after birth was not effective as a growth supplement for MDCK cells at any concentration. Those cells, unable to grow in colostrum or in older milk, could be induced to grow if culture dishes were precoated with fibronectin. In addition to fibronectin, it was necessary in some cultures to supplement colostrum or older milk with insulin and/or transferrin in order to achieve growth. In the presence of fibronectin and appropriate factors, the final saturation density attained in colostrum or older milk ranged from 25% to 100% of that in serum. The fibronectin contents of bovine colostrum and milk were determined. The fibronectin level of colostrum was found to be approximately 5% of bovine serum. There was no detectable fibronectin in the 80-day-old milk.

Animals↗

PubMed1992

Passive immunizations of suckling mice and infants with bovine colostrum containing antibodies to human rotavirus.

After immunizing 8-month pregnant Holstein cows with the human rotavirus MO strain, cow colostrum containing neutralizing antibody to four different serotypes of human rotavirus, designated Rota colostrum, was obtained. Oral inoculation of human rotavirus MO strain into 5-day-old BALB/c mice causes gastroenteritis characterized by diarrhea. Using this small animal model, passive protection of suckling mice against human rotavirus infection was achieved with the use of Rota colostrum. Rota colostrum completely protected against rotavirus infection, but purified IgG and IgA obtained from Rota colostrum were unable to protect against infection. After grouping randomly 20 infants from a baby care center, 10 infants received 20 ml of Rota colostrum per day for 2 weeks and 10 control infants did not. Rotavirus-associated diarrhea developed in 7 of 10 infants in the control group. None of the three infants in the every day recipient group of Rota colostrum had such symptoms, and one of three infants in the every other day recipient group developed rotavirus-induced diarrhea. All four infants who received Rota colostrum after symptoms appeared developed diarrhea. Oral administration of Rota colostrum seems to be an effective and safe means of preventing diarrhea caused by human rotavirus infection.

Age Factors↗

PubMed1985

Prevention of rotavirus infection by oral administration of cow colostrum containing antihumanrotavirus antibody.

After immunizing 8-month pregnant Holstein cows with human rotavirus, Wa strain, cow colostrum containing neutralizing antibody to human rotavirus, designated as Rota colostrum, was obtained. After randomly grouping 13 infants from a single orphanage, 6 infants received 20 ml of Rota colostrum every morning and 7 control infants received 20 ml of market milk. One month later, rotavirus associated diarrhea was observed in 6 of the 7 infants given milk and 1 out of the 6 infants given Rota colostrum. Orally administered Rota colostrum significantly protected infants from diarrhea caused by rotavirus (P less than 0.05). Two out of 5 Rota colostrum recipients who were free from diarrhea showed rises in complement fixation (CF) antibody titer after the rotavirus infection epidemic. Thus, Rota colostrum prevented the outbreak of diarrhea but did not prevent immunological responses to natural rotavirus infection. In the therapeutic trial Rota colostrum had no effect on duration of diarrhea, bowel movements or virus shedding in stool. However, there were no side-effects of Rota colostrum.

Administration, Oral↗

PubMed1984

Treatment of multiple sclerosis with anti-measles cow colostrum.

Previous virological and immunological studies have suggested that multiple sclerosis (MS) is an auto-immune disease triggered by a virus infection. In order to inhibit the growth of measles virus in the patient's jejunum, we obtained an IgA-rich cow colostrum containing anti-measles lactoglobulin resistant to proteases. This colostrum was orally administered to patients with MS to investigate its effect on the course of the disease. Measles-positive antibody colostrum was orally administered every morning to 15 patients with MS at a daily dosage of 100 ml for 30 days. Similarly, measles-negative antibody (less than 8) control colostrum was orally administered to 5 patients. As a clinical assessment, disability scores developed by the International Federation of Multiple Sclerosis Societies were used. As a result, of 7 high NT titre (512-5120) anti-measles colostrum recipients 5 patients improved and 2 remained unchanged. Among 8 low NT titre (8-32) anti-measles colostrum recipients 5 patients improved and 3 remained unchanged. However, of 5 negative NT titre (less than 8) colostrum recipients 2 patients remained unchanged and 3 worsened. No side-effects were observed in colostrum recipients. These findings suggest the efficacy of orally administered anti-measles colostrum in improving the condition of MS patients (P less than 0.05).

Adolescent↗

PubMed2005

Combined effects of bovine colostrum and glutamine in diclofenac-induced bacterial translocation in rat.

BACKGROUND AND AIMS: The aim of this study was to examine whether the combined administration of bovine colostrum and glutamine was able to prevent the non-steroidal anti-inflammatory drug (NSAID)-induced gut damage and bacterial translocation (BT) in the rats. METHODS: The animal model population of the study consisted of six groups; control group, diclofenac group, diclofenac with milk group, diclofenac with colostrum group, diclofenac with glutamine group and diclofenac with colostrum and glutamine group. The animals with milk, colostrum or glutamine were fed with low fat milk, liquid colostrum or glutamine by orogastric gavage for 5 days before the diclofenac administration. Intestinal permeability, serum biochemical profiles and intestinal adhesion for assessment of the gut damage, and enteric bacterial overgrowth and BT at the mesenteric lymph nodes, liver, spleen and systemic blood were measured. RESULTS: Diclofenac caused the increase in gut damage, enteric bacterial numbers and BT. Supplements with colostrum or glutamine reduced these changes induced by diclofenac, but this result was not seen for supplementation with low fat milk. Combined administration of colostrum and glutamine reduced diclofenac-induced gut damage and BT as compared to the use of bovine colostrum alone or glutamine alone. CONCLUSIONS: This study suggested that the combined administration of bovine colostrum and glutamine might effectively reduce NSAID-induced gut damage and BT in the rat.

Animals↗

PubMed2004

Relative contribution of colostrum from Maedi-Visna virus (MVV) infected ewes to MVV-seroprevalence in lambs.

Maedi-visna virus (MVV) seroprevalence associated with consumption of colostrum from seropositive ewes was investigated in 276 housed lambs from birth to 300 days-old. At birth, lambs were allocated to five experimental groups according to the maternal MVV-serological status, source and mode of feeding colostrum (bovine or ovine and bottle fed or suckled from the dam) and type of horizontal MVV-exposure (raised with the dam or separately with other lambs). The risk of being seropositive at 300 days-old was associated with feeding ovine colostrum from seropositive ewes and increased with intake of bottle-fed ovine colostrum and was higher in lambs separated from their dams and raised with other experimental lambs compared to lambs raised with their dams. Approximately 75-87% of ELISA-positive results in lambs that had ovine colostrum was attributable to colostrum itself. However, approximately only 16% of naturally raised and 29-61% of bottle-fed ovine colostrum lambs were ELISA-positive as a result feeding ovine colostrum. These results confirm that ovine colostrum from seropositive ewes can be a major source of MVV but its overall contribution to seroprevalence in natural conditions is relatively low, and shows that horizontal MVV transmission can be an important source of infection in new-born lambs.

Aging↗

PubMed1997

Delaying colostrum intake by one day has important effects on metabolic traits and on gastrointestinal and metabolic hormones in neonatal calves.

Effects on metabolic and endocrine traits of feeding colostrum on d 1 and 2, then mature milk up to d 7, or glucose or water on d 1, colostrum on d 2 and 3 and then mature milk up to d 7 were studied in calves. Calves fed colostrum within the first 24 h after birth had significantly higher rectal temperatures, heart rates and respiratory frequencies than calves provided only water or glucose. Significantly elevated plasma nonesterified fatty acid and bilirubin concentrations on d 1 and 2 of life in calves fed only water on d 1 compared with calves of the other groups mirrored reduced energy intake. Fecal consistency was significantly higher during wk 1 of life, and gastrin and glucose-dependent insulinotropic polypeptide increased only on d 1 and/or 2 of life in calves already fed colostrum on d 1, expressing improved functioning of the gastrointestinal tract. Significantly higher plasma globulin levels up to d 7 in calves fed colostrum on d 1 than in those starting colostrum intake only on d 2 demonstrated significantly enhanced efficiency of gamma-globulin absorption. Furthermore, significantly higher circulating glucose, albumin, insulin, insulin-like growth factor-I concentrations and significantly lower urea levels in calves fed colostrum on d 1 compared with those fed colostrum starting on d 2 of life indicated stimulation of anabolic processes. In conclusion, colostrum intake by calves within the first 24 h of life is needed not only for an adequate immune status, but also to produce the additional important and favorable effects on metabolic and endocrine traits and on vitality.

Animal Nutritional Physiological Phenomena↗

PubMed1997

Colostrum enhances the nutritional stimulation of vital organ protein synthesis in neonatal pigs.

Our objective was to determine the relative importance of the macronutrient components of colostrum in the stimulation of vital organ protein synthesis in neonatal pigs. We studied colostrum-deprived newborn pigs within 4-6 h after birth (unfed) and three groups fed for 24 h mature milk, colostrum, or a formula containing a macronutrient composition comparable to that of colostrum. We measured protein synthesis in vivo using a flooding dose of 3H-phenylalanine. The fractional rates of protein synthesis (Ks) in the brain, heart, lung, kidney and spleen were significantly higher in all fed groups than in the unfed newborns. Among the three fed groups, brain and heart protein synthesis rates were greater in colostrum-fed than in either milk- or formula-fed pigs. Kidney and spleen protein synthesis rates in colostrum- and formula-fed pigs were not significantly different, but both were higher than in milk-fed pigs. The stimulation of kidney protein synthesis in response to feeding was primarily a consequence of greater protein synthetic efficiency; however, protein synthetic capacity in the heart, lung and spleen was generally greater in colostrum- and formula-fed pigs than in unfed newborns. Our results suggest that the predominant stimulus for vital organ protein synthesis in colostrum-fed neonatal pigs is nutrient intake. However, there was a specific stimulation of both brain and heart protein synthesis in colostrum-fed pigs that cannot be attributed to macronutrients.

Amino Acids↗

PubMed2006

Influence of colostrum deprivation and concurrent Cryptosporidium parvum infection on the colonization and persistence of Escherichia coli O157 : H7 in young lambs.

Escherichia coli O157 : H7 and Cryptosporidium parvum infections of man have been associated with direct contact with small ruminants. Colostrum protects neonates against gastrointestinal pathogens, and orphan lambs, which are common on petting farms, may be deprived of this protection. In a recent study, it was demonstrated that high shedding of E. coli O157 : H7 by an 8-week-old goat kid was associated with coincidental C. parvum infection. Furthermore, both pathogens were co-located in the distal gastrointestinal tract. It was hypothesized that colostrum deprivation and pre-infection with C. parvum predisposed young ruminants to colonization and increased shedding of E. coli O157 : H7. To test this, 21 lambs 5 weeks of age were divided into four groups as follows: (A) colostrum-deprived and inoculated with E. coli O157 : H7, (B) colostrum-deprived and inoculated with C. parvum and then E. coli O157 : H7, (C) conventionally reared and inoculated with E. coli O157 : H7, (D) conventionally reared and inoculated with C. parvum and then E. coli O157 : H7. C. parvum was detected between 8 and 12 days post-inoculation in most of the infected lambs. At 24 h post-inoculation with E. coli O157 : H7, all lambs were shedding between 5 x 10(4) and 5 x 10(7) c.f.u. E. coli O157 : H7 per gram of faeces. E. coli O157 : H7 was shed in higher numbers in the groups pre-inoculated with C. parvum, whether conventionally reared or colostrum-deprived. Interestingly, for the colostrum-deprived lambs on day 3, a significant difference in shedding of E. coli O157 : H7 was observed (P = 0.038), with the lambs inoculated with E. coli alone yielding higher counts than those pre-inoculated with C. parvum. From day 15 onwards, shedding of E. coli O157 : H7 was highest from the colostrum-deprived C. parvum-infected lambs, then (in descending order of shedding) the colostrum-deprived lambs, the conventionally reared lambs infected with C. parvum, and the conventionally reared animals. In total, four animals were euthanized, two at 24 h and two at 96 h post inoculation with E. coli O157 : H7 (two conventionally reared and two colostrum-deprived). All animals euthanized were from groups pre-inoculated with C. parvum prior to challenge with E. coli O157 : H7. On examination of tissues, in three of the four animals examined, multifocal attaching and effacing lesions were observed in the caecum, colon, rectum and at the recto-anal junction, and were confirmed by immunohistochemistry to be associated with E. coli O157 : H7.

Animals↗