The effect of delays in feeding colostrum and the relationship between immunoglobulin concentration in the serum of neonatal calves and their rates of growth

Eighty-five unsuckled newborn calves, were fed 1.5 L of colostrum of known IgG concentration at either 2, 4, 6 or 8 hours after birth with no additional colostrum feeding. Another group of 11 calves were left with their dam for 16 hours after birth, before separation. Blood samples were taken from all calves 24 hours after colostrum feeding or separation from the dam and serum Ig concentrations were measured by electrophoresis. There were no significant differences in mean serum Ig concentrations between calves fed at the different times after birth. Three of the 11 calves left to suckle were hypogammaglobulinaemic. Other calves in this group had higher serum Ig concentrations than the means of all other groups. All groups had mean serum Ig concentrations higher than the suggested minimum concentration required for adequate calf health. There were a number of calves that did not reach the suggested minimum serum concentration after feeding, but calf mortality was low and all calves were healthy apart from a slight scour for a few weeks after birth. There was no significant relationship between serum Ig concentration 24 to 48 hours after birth and either calf mortality or average growth rate over an 8- to 10-month period.     

Effects of a colostrum replacement product derived from serum on immunoglobulin G absorption by calves

Calves are born hypogammaglobulinemic and rely on immunoglobulin (Ig) from colostrum to obtain passive immunity. Previous research has indicated that colostrum supplements derived from milk are less effective than is maternal colostrum in providing adequate IgG to neonatal calves. Our objective was to determine the absorption of IgG by newborn calves fed a USDA food-grade colostrum supplement derived from bovine serum or fed pooled maternal colostrum. Holstein calves (n = 20; 10 bulls) were removed from the dam within 1 h of birth and were housed in individual stalls for the 24-h study. Calves were fed 2 L of colostrum or colostrum replacer at 1.5 and 13.5 h (+/- 0.1 h). Calves were blocked by colostrum pool, and replacer was fed to provide equal intakes of IgG within blocks. Jugular blood was collected at 1 and 24 h (+/- 0.1 h) for analysis of IgG by radial immunodiffusion. At 24 h, calves were injected with 1.5 ml of Evans blue dye to estimate plasma volume. Mean plasma IgG at 24 h of age was 7.3 +/- 0.4 g/L and was affected by an interaction of block and treatment. Apparent efficiency of IgG absorption of 24 h was reduced when 750 g of the colostrum replacement product were fed but was increased when 266 g of colostrum replacement product were fed. Mean plasma volume was unaffected by treatment and was 3.5 +/- 0.2 L or 9.1% of BW. These data indicate that efficiency of IgG absorption from the colostrum replacement product may be affected by amount of material fed. Proteins other than IgG in the colostrum replacement product might have reduced the efficiency of IgG absorption.     

Concentrations of trypsin inhibitor and immunoglobulins in colostrum of Jersey cows

Colostrum samples from 49 Jersey cows were analyzed for concentrations of trypsin inhibitor, IgG, IgM, IgA, TS, fat, specific gravity, and N fractions. Colostrum (100 ml) was sampled from each cow as soon as possible after parturition. Mean concentrations of IgG, IgM, and IgA were 84.6, 3.4, and 4.5 g/L, respectively. Mean concentration of trypsin inhibitor was 56 mg of trypsin inhibited/dl of colostrum. Concentration of trypsin inhibitor was unaffected by lactation number and averaged 60, 53, and 54 mg of trypsin inhibited/dl of colostrum for cows in first, second, and third or later lactations, respectively. Colostral trypsin inhibitor and IgG were correlated (.54), although correlations between trypsin inhibitor and IgM and IgA were not significant. Trypsin inhibitor in colostrum was also positively correlated with fat, total N, protein N, noncasein N, and TS in colostrum. Variation in concentration of trypsin inhibitor from first-milking colostrum was closely related to colostral IgG concentration and may serve to protect IgG and other proteins from proteolytic degradation in the intestine of the neonatal calf.     

Immunoglobulin G concentration and neonatal survival of goat kids delivered in a pen or on open range

To determine whether kids born on open range (subjected to stress due to management practices) had lower IgG concentrations and a higher mortality risk than kids born in a pen, serum IgG concentrations in 63 one-day-old kids were determined. Median Serum IgG concentrations one day after birth tended to be lower (p = 0.09) in surviving kids born in the open than that of surviving kids delivered in pen (115 vs. 1119 mg dl-1). However, survival risk (71 and 82% for kids born on the open range and pen, respectively; n = 79) were not significantly affected by site of kidding. Median IgG concentration of surviving kids born on a pen was not significantly different (p = 0.13) compared to non-surviving kids (1118 vs. 115 mg dl-1). No differences were detected in either median serum IgG levels or death rates between male and female kids. Kids with IgG concentrations < 800 mg dl-1 showed lower survival risks than those with higher concentrations. We concluded that typical management practices of kids delivered on open range at a goat operation under extensive conditions in northern Mexico tended to reduced colostrally acquired serum immunoglobulin levels, but had no effect directly on mortality.     

Women''s opinion on abortion legalization in a middle size county in southern Brazil

To study pancreas enzyme content regulation when the diet was modified in suckling goats, a comparison was made between kids fed a milk replacer and ones fed maternal milk. A total of 25 preruminant Granadina breed goats were bottle-fed a milk replacer ad libitum from postnatal days 3 to 28 (until the age of 3 days kids had been fed colostrum). Body weight, pancreas weight, total protein concentration, and enzyme activities in pancreatic tissue were determined at 3, 7, 14, 21 and 28 days of age, and the results were compared to those previously obtained in kids fed maternal milk for the same period. Lipase activity was significantly lower in the group fed milk replacer, which was poorer in fat. Amylase activity was higher in this group, perhaps due to the starch products present in the milk substitute. However, the postnatal evolution of chymotrypsin activity followed a similar pattern regardless of diet. Our results seem to confirm that in preruminant kids there is a nutritional regulation of pancreatic amylase and lipase activities, depending on the amounts of their respective substrates in the diet, similar to that described in nonruminants.     

Randomized controlled trial of effects of Escherichia coli antiserum on serum immunoglobulin G concentrations and morbidity and mortality rates in foals

OBJECTIVE: To determine whether administration of commercially available Escherichia coli antiserum to neonatal foals would affect serum IgG concentration or morbidity and mortality rates during the first 60 days of life. DESIGN: Randomized controlled trial. ANIMALS: 271 neonatal foals on 4 well-managed farms. PROCEDURE: Foals were randomly assigned to a treatment or control group. All foals were allowed to suckle colostrum normally. In addition, treatment-group foals were given E coli antiserum (10 micromilligrams) orally between 0 and 8 hours after birth. Serum samples were obtained between 18 and 36 hours after birth, and serum IgG concentration was determined. Foals were monitored for the first 60 days after birth, and causes of disease or death were recorded. RESULTS: Groups did not differ significantly in regard to breed, sex, month of birth, season of birth, age of dams, parity of dams, duration of gestation, or specific gravity of colostrum before suckling. In addition, groups did not differ significantly in regard to mean serum IgG concentration, prevalence of complete or partial failure of passive transfer of immunity, frequency or causes of disease, or frequency of death from infectious causes. CLINICAL IMPLICATIONS: In this group of foals on well-managed farms, administration of E coli antiserum did not alter serum IgG concentrations or morbidity and mortality rates during the first 60 days of life.     

Negative effects of a high level of nutrient intake on mammary gland development of prepubertal goats

Ten French Alpine kids were used to determine whether mammary development was altered by level of nutrient intake during the prepubertal period. At 6 wk of age, kids were paired on the basis of BW and assigned to an ad libitum or restricted diet of milk from Jersey cows. Kids on the restricted diet were fed 70% of their pair mate's milk intake for 4 wk and then 50% for 9 wk. Low quality grass hay was available for all kids. The ADG was greater for kids fed for ad libitum intake. Kids fed for ad libitum intake had larger mammary glands and increased adipose deposition. Measurement of hydroxyproline indicated that connective tissue increased with gland size. Kids on the restricted diet had more DNA and protein per gram of mammary gland, indicating greater secretory development. Goats can be used as a model to study the effect of level of nutrient intake on hormones and growth factors that regulate mammary gland development.     

Effects of replacement of native fat in colostrum and milk with coconut oil on fat-soluble vitamins in serum and immune function in calves

Fat-soluble vitamins and their metabolites modulate immune function in a variety of animal species. The objective of the present study was to determine the role of fat-soluble vitamins in colostrum and milk in the development of specific aspects of immune function in the calf during the 1st wk postpartum. During this period, control calves (n = 6) were fed normal colostrum and milk, and calves in the treatment group (n = 6) were fed skimmed colostrum and skimmed milk supplemented with coconut oil. Treated calves did not experience the progressive increase in concentrations of retinol, beta-carotene, alpha-tocopherol, 1,25-dihydroxyvitamin D, or retinoic acids in serum that was observed in control calves. Acquisition of passive immunity, which is indicated by concentrations of immunoglobulin G1 in serum, was unaffected by treatment. Composition and functional capacities of populations of blood mononuclear leukocytes that were collected from birth to 7 d postpartum were also unaffected by treatment. Major changes in the function and composition of mononuclear leukocyte populations from all calves occurred during the experimental period and were unrelated to the concentrations of fat-soluble vitamins in serum. Populations of blood mononuclear leukocytes from calves were functionally hyporesponsive and compositionally different from populations of blood mononuclear leukocytes from adult nongravid cows. These differences likely reflected the immaturity of the immune system of the neonatal calf and may contribute to the increased susceptibility of the calf to infectious disease.     

Delaying colostrum intake by one day impairs plasma lipid, essential fatty acid, carotene, retinol and alpha-tocopherol status in neonatal calves

To study whether a delayed start of colostrum feeding in calves affects plasma lipids, fatty acids and fat-soluble vitamins, one group was fed colostrum (milkings 1-4) on d 1 and 2, then mature milk up to d 7, whereas two other groups were fed glucose or water on d 1, colostrum (milkings 1-4) on d 2 and 3 and then mature milk up to d 7. In calves fed colostrum on d 1, starting 5-7 h after birth, plasma concentrations of triglycerides, phospholipids, total cholesterol and of essential and nonessential fatty acids in triglyceride, phospholipid and cholesterol ester fractions as well as of carotene, retinol and alpha-tocopherol up to d 7 were significantly higher than in calves in which colostrum feeding started after >24 h of life. On the other hand, plasma concentrations of vitamin B-6, vitamin B-12 and folic acid were not influenced. Results indicated reduced efficiency of absorption of colostral fatty acids and of fat-soluble vitamins, but not of (selected) water-soluble vitamins, if colostrum is not fed on d 1 of life. In conclusion, colostrum intake within the first 24 h of life is required for an adequate plasma lipid, essential fatty acid, carotene, retinol and alpha-tocopherol status in the first week of life of calves.     

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.     

Prolonged colostrum feeding enhances xylose absorption in neonatal calves

Colostrum contains numerous components that influence gastrointestinal development in neonates. To test the influence of differences in duration of colostrum feeding in newborn calves on gastrointestinal absorptive capacity, .5 g xylose/kg BW was administered on d 5 of life. Calves of group GrC6 were fed colostrum from the first six milkings on the first 3 d and then milk replacer. Calves of group GrC1 were fed first colostrum only and then milk replacer in the same amounts as calves of group GrC6. Calves of group GrM were fed only milk replacer: they received no colostrum. The rise of plasma xylose after xylose intake was greater (P < .05) in GrC6 and GrC1 than in GrM but not significantly greater in GrC6 than in GrC1. Basal and mean plasma glucose concentrations on d 5 of life were higher in GrC6 than in GrM, but there was no difference in the magnitude of its postprandial rise. The data indicate greater xylose absorptive capacity in calves after prolonged colostrum intake compared with calves fed only milk replacer.     

Passive protection of neonatal calves against bovine coronavirus-induced diarrhea by administration of egg yolk or colostrum antibody powder

The protective effect of egg yolk and colostrum powders prepared from hens and cows vaccinated with inactivated bovine coronavirus (BCV) antigen was evaluated in a challenge model with a virulent BCV strain. Twenty three calves from BCV-free herds were randomly divided into control and several treatment groups. All calves were orally challenged with 1 x 10(9) TCID50 of the virulent Kakegawa strain of BCV at 24 to 36 h after birth. Calves in treatment groups received either egg yolk powder or cow colostrum containing BCV specific antibodies. Daily treatment with these antibody preparations started 6 h until 7 days post-challenge. Control calves which received no antibody had severe diarrhea and all died within 6 days after infection. In contrast, calves fed milk containing egg yolk or colostrum with neutralization titers of 1:2560 or 1:10,240 respectively all survived and had positive weight gain unlike the other treatment groups. These results indicate that the orally administered egg yolk and colostrum powders protected against BCV-induced diarrhea in neonatal calves and that the egg yolk used provided a higher degree of protection compared to colostrum powder on a titer basis. Treatment with whole egg yolk from immunized hens therefore provides a more efficacious alternative to the existing methods of specific passive protection against BCV.     

Survival of Mycobacterium paratuberculosis and preservation of immunoglobulin G in bovine colostrum under experimental conditions simulating pasteurization

OBJECTIVE: To determine whether Mycobacterium paratuberculosis could survive in colostrum after pasteurization. Additionally, this study investigated the effect pasteurization had on IgG concentration in colostrum. ANIMALS: Colostrum samples were collected from cattle (beef and dairy) owned by the state of Ohio. PROCEDURE: Colostrum was divided into aliquots and inoculated with variable concentrations of M paratuberculosis (ATCC No. 19698: 10(4), 10(3), and 10(2) colony-forming units/ml). Half the samples at each concentration were subjected to pasteurization temperatures (63 C) for 30 minutes and the remainder were kept at approximately 20 to 23 C. All samples were incubated (Herrold's egg yolk medium with and without mycobactin J) and observed for growth during the next 16 weeks. Additionally, the IgG concentration of colostrum was determined by radioimmunoassay before and after pasteurization. Samples that coagulated at pasteurization temperatures were mechanically resuspended before measurement of IgG concentration. RESULTS: Growth of M paratuberculosis was retarded but not eliminated by pasteurization. Growth was observed in all unpasteurized samples incubated on Herrold's egg yolk medium with mycobactin J but in only 2 of 18 pasteurized samples similarly cultured. Growth from pasteurized samples appeared 5 to 9 weeks after growth was observed from nonpasteurized samples. Mean colostral IgG concentration was 44.4 g/L in nonpasteurized samples and 37.2 g/L in pasteurized samples, a decrease of 12.3%. High-quality colostrum (> 48 g of IgG/L) had a significantly greater loss of IgG concentration than did colostrum of lesser quality (P = 0.002). CONCLUSIONS: Pasteurization lessened, but did not eliminate, growth of M paratuberculosis from experimentally inoculated colostrum samples. Pasteurization resulted in a significant decrease in colostral IgG concentration but not to an unmanageable level that would preclude the colostrum's use for passive transfer of immunity. CLINICAL RELEVANCE: Colostrum is macrophage rich and may serve as a source of M paratuberculosis infection to calves. Pasteurization of colostrum may lessen the risk of infection, but will not totally eliminate M paratuberculosis.     

Gliadin-specific and cow''s milk protein-specific IgA in human milk

The presence of gliadin-specific IgA and IgG antibodies in colostrum and serum of 140 newly delivered mothers was assessed by enzyme-linked immunosorbent assay. In addition, cow's milk protein (CMP)-specific IgA was determined in the colostrum samples. From 14 of the mothers longitudinal milk samples were obtained after 1 and 2 months of lactation and from 12 mothers after 3 months. Gliadin-specific IgA was found in 97.1% and gliadin-specific IgG in 9.3% of the colostrum samples. Gliadin-specific IgA was detected in mature samples but at significantly lower levels after 1, 2, and 3 months of lactation (p less than 0.01) as compared with colostrum. Gliadin-specific IgA was found in 2.8% of the serum samples and gliadin-specific IgG in 40%; however, the levels of both isotypes were low. CMP-specific IgA was found in 78.1% of the colostrum samples. It is concluded that IgA antibodies to two common food proteins are frequently found in human milk and that food-specific IgA present in milk may play a role in adapting the infant's immune reactions to food antigens in the gut.     

Estimation of plasma volume in Holstein and Jersey calves

The concentration of immunoglobulin (Ig) G in the blood of neonatal calves shortly after birth is a widely used criterion to determine the degree of acquisition of passive immunity. Another method used to determine the biological mechanisms of IgG absorption is calculation of the apparent efficiency of IgG absorption. Estimation of the efficiency of IgG absorption requires the estimation of plasma volume in neonatal calves. Previous estimates of plasma volume in a few calves of varying breeds have been made; the estimates ranged from 7 to 14.5% of body weight (BW). Holstein (n = 97 from four farms) and Jersey (n = 49 from one farm) calves were fed fresh maternal colostrum or colostrum that had been previously frozen. Calves were fed 2 L of colostrum at 4.1 h (SE = 0.2; range = 0.3 to 11.0 h) and 12 h later. Plasma volume was measured by determining the concentration of Evans' blue dye in a jugular blood sample collected 10 min after injection of approximately 1.5 ml of 1.5% Evans' blue dye. Factors that affected plasma volume (milliliters) were BW, breed, and age at sampling; r2 of the regression was 0.60. Factors that affected plasma volume (percentage of BW) were BW, breed, and age at sampling; r2 of the regression was 0.08. Mean plasma volume for all calves was 3162 ml (SE = 79) and was 9.86% of birth BW (SE = 0.15%). Mean plasma volume was 2250 ml (9.71% of BW) and 3623 ml (9.94% of BW) for Jersey and Holstein calves, respectively. Body weight was the best predictor of plasma volume.     

Immunoglobulin transfer in the viable, newborn calf

Parturitions of 26 dairy-cows were observed and the viability of the newborn calves assessed. Immediately after birth as well as after the first and forth colostrum intake a blood probe was taken from the neonates and investigated for the following parameters: blood gas, blood picture, total-IG, concentrations of IGG1, IGM and IGE, total proteins and albumin. Before each feeding a colostrum sample was assayed for the same parameters with the exception of blood gas, blood picture and albumin. A transferindex (KLOBASA et al., 1994) was calculated to investigate the absorption of TP, IG, IGG1, IGM and IGE. In some of the blood samples there was no IGE detectable, even after colostrum intake. High individual differences were striking and blood concentrations were not related to the milk contents or the time until first feeding. The total proteins were strongly correlated to the serum concentrations of IGG1, but only in samples taken after first colostrum feeding. Vital calves showed the following tendency: colostrum intake of less than 1 l within the first 15 hours after birth and/or colostrum intake with TP-concentrations of 80 I.U./l was partly compensated by increased absorption of TP. 24 hours after birth serum-immunoglobulinconcentrations were 6-12 mg/ml; weight gain was normal and no calf became ill. In 60% of cases the transferindex for IGM was higher than for IGG1 or IGE.     

Complement system in human colostrum: presence of nine complement components and factors of alternative pathway in human colostrum

Evidence has been obtained for the presence in human colostrum of all nine components of complement (C), C1 through C9, and factors of the alternative pathway. Samples of colostrums collected from five women at 1-4 days after normal parturition were assayed for the haemolytic activities of individual components. As compared with normal human sera, the activities of each component ranged from 0.03 to 7% of those in sera. The activities of C4, C7 and C9 were relatively high, while that of C1 was extremely low. In most of the cases, the activities of individual components gradually increased following delivery, when expressed as the activity per unit weight (g) of protein in the colostrum. When the colostrums were treated with cobra venom factor, most of the colostrums showed 10-20% reduction in the C3 activity. This finding indicates the presence of factors such as B and D which are involved in the activation of C through the alternative pathway. The role as a defense factor of the C system in human colostrum and milk is discussed in connection with the ability of secretory IgA to react with C.     

Collecting duct carcinomas of the kidney: a comparative loss of heterozygosity study with clear cell renal cell carcinoma

Lyophilizing was compared to freezing as a method of colostrum storage. Eight lots of colostrum from the first milking were divided into two equal parts; one was frozen, and the other was lyophilized. Twenty-two newborn calves were divided into two groups and fed either 2 L of frozen and thawed colostrum or 2 L of reconstituted lyophilized colostrum. The calves were bled at 12, 18, 24, and 72 h after feeding, and levels of the immunoglobulins IgG1, IgG2, IgM, and IgA were determined with a radial immunodiffusion assay, in colostrum and sera. The mean concentration of individual immunoglobulin isotypes in the sera of calves fed either frozen or lyophilized colostrum did not differ significantly. Calves fed from the same lots of colostrum had similar immunoglobulin concentrations in their sera, irrespective of the method of storage. All immunoglobulin isotypes were absorbed with equal efficiency from frozen and lyophilized colostrum as determined by calculation of the absorption coefficient.     

Systemic availability of bovine immunoglobulin G and chicken immunoglobulin Y after feeding colostrum and whole egg powder to newborn calves

In connection with a study on the prophylaxis of infectious diarrhea with specific egg yolk antibodies, the systemic availability of colostral bovine immunoglobulin G (bIgG) and chicken immunoglobulin Y (IgY) after feeding egg powder was investigated on 26 newborn calves from 23 different farms. Blood was sampled daily and at the same day time from these calves in the first 14 days of life. During the feeding of colostrum, the mean bIgG concentration was highest at day 1 post natum with a value of 9.3 mg/ml serum. Thereafter, the mean bIgG level was reduced continuously to a significant lower concentration of 4.9 mg/ml serum at day 12 post natum and remained nearly constant at 5.2 mg/ml till to the end of the observation period. Total protein concentrations in the serum did not change and plateaued at a mean value of 56.2 mg/ml (SD 11.2). The number of colostrum meals had no significant effect on the mean bIgG concentrations during that period. The individual variation of bIgG concentrations was very high on every day of the sampling period. The mean coefficient of variation was at 52.1 % (SD 5.7). After having described the individual bIgG concentration curves mathematically with a regression curve, two groups with significantly different bIgG elimination constants (k) could be obtained. Thus in one group (n = 10) with k-values of < -0.02 a mean half time of serum bIgG of 24.3 days (SD 4.6) was calculated. In the other group of calves (n = 16) with elimination constants of k > -0.02, a mean half time of 68.5 days (SD 36.7) could be calculated, possibly because these calves started earlier with their endogenous bIgG production. Additionally, to 18 of these calves 20 g egg powder with an IgY concentration of 15 mg/g was fed up to day 14. Calves had a maximal mean IgY concentration of 1.9 micrograms/ml serum if egg powder feeding started already during the first 12 hours of life. Starting at a later time resulted in a significant reduction of IgY levels. For example, the mean initial IgY concentration dropped to 0.035 micrograms/ml serum after having had the first egg powder application between 25 and 48 hours post natum. Using the individual IgY elimination constant derived from a regression analysis (r2 = 0.84) of the IgY concentration curve, a mean IgY half time of 5.0 days (SD 2.5) could be calculated. To prevent the absorption of heterologous antibodies and consecutively, also to prevent a possible systemic effect, egg powder for prophylactic purposes in newborn calves should be fed after the first 24, better 48 hour, post natum. Most important for the prophylactic effect of specific antibodies on infectious diarrhea is not their systemic but their high local intestinal availability.     

Elevated levels of bile acids in colostrum of patients with cholestasis of pregnancy are decreased following ursodeoxycholic acid therapy [see comemnts

BACKGROUND/AIMS: Intrahepatic cholestasis of pregnancy is characterised by increased levels of serum bile acids. Ursodeoxycholic acid therapy corrects the serum bile acid profile. The aims of this study were: (i) to investigate bile acid excretion into colostrum of women with intrahepatic cholestasis of pregnancy; (ii) to compare concentrations of bile acids in serum and colostrum of non-treated and ursodeoxycholic acid-treated patients; and (iii) to clarify whether ursodeoxycholic acid is eliminated into colostrum following treatment. METHODS: Bile acids were assessed by gas chromatography and high-performance liquid chromatography in serum collected at delivery, and in colostrum obtained at 2+/-1 days after labour, from patients with intrahepatic cholestasis of pregnancy, non-treated (n=9) and treated (n=7) with ursodeoxycholic acid (14 mg/kg bw per day, for 14+/-7 days) until parturition. RESULTS: The concentration of total bile acids in colostrum from patients with intrahepatic cholestasis of pregnancy was higher than in normals (23.3+/-14.8 micromol/l vs. 0.7+/-0.2 micromol/l, p<0.01) and cholic acid was a major species (19.0+/-13.1 micromol/l), reflecting the elevated concentrations in maternal serum (48.9+/-21.0 micromol/l, total bile acids; 33.9+/-16.7 micromol/l, cholic acid. Following ursodeoxycholic acid administration, total bile acids and cholic acid levels in colostrum diminished to 5.7+/-2.5 micromol/l and 3.6+/-1.5 micromol/l, respectively; the proportion of cholic acid decreased (60.6+/-8.0% vs. 76.8+/-5.0%, p<0.05). The ursodeoxycholic acid concentration in colostrum was maintained following treatment; its increased percentage (9.4+/-3.2% vs. 1.0+/-0.2%, p<0.01) was still lower than in maternal serum (20.8+/-3.6%, p<0.05). Only a small proportion (<1%) of lithocholic acid was found in colostrum following therapy. CONCLUSIONS: Bile acid concentrations are elevated and cholic acid is the major species accumulating in colostrum, reflecting serum bile acid profiles in intrahepatic cholestasis of pregnancy. Ursodeoxycholic acid therapy decreases endogenous bile acid levels in colostrum.