Bacterial translocation in neonatal rats: the relation between intestinal flora, translocated bacteria, and influence of milk

BACKGROUND

A high incidence of bacterial translocation in neonates results not only from immaturity of host-defense functions, but also from the dominant colonization of aerobic bacteria in the intestine. Bacterial colonization develops differently among breast-fed, formula-fed, premature, and full-term infants. The purpose of this study was to examine the incidence of bacterial translocation and to identify the translocated bacterial species, relating these findings to the intestinal microflora and to the type of feeding in neonatal rats.

METHODS

Animals were divided into three groups: breast-fed normal pups (MR group), formula-fed pups fed via an intragastric cannula implanted esophageally (AR group), and breast-fed pups after the removal of the cannula (Sham group). Artificial rearing was achieved using a machine feeding system. Culture and identification of the bacteria in the intestine, mesenteric lymph nodes, liver, portal blood, and lungs were made using a simplified version of Mitsuoka's method.

RESULTS

At 14 days of age, the dominant bacteria in the feces of the MR and Sham Groups were Enterobacteriaceae, Lactobacillus, and Enterococcus, but Enterobacteriaceae and Clostridium were significantly more common in the AR group than in the MR group. The dominant bacteria in the mesenteric lymph nodes were Enterobacteriaceae, Lactobacillus, and Staphylococcus. The extent of systemic bacterial translocation decreased earlier in the Sham group than in the AR group.

CONCLUSIONS

The frequency with which species of bacteria were cultured from mesenteric lymph nodes and other peripheral sites did not mirror the composition of the intestinal flora. Among the translocated bacteria, Staphylococcus may be especially hard to recognize and difficult for the host-defense systems to destroy. Breast-feeding inhibited systemic bacterial translocation in the suckling period of the rat.

Milk supplementation of the diet of postmenopausal Chinese women on a low calcium intake retards bone loss

The Chinese diet is low in calcium (less than 500 mg/day on average), and previous observational studies have suggested an association between a low calcium intake and risk of hip and vertebral fracture. In this study, we randomly assigned 200 postmenopausal Chinese women (age range, 55-59 years) to receive 50 g of milk powder containing 800 mg of calcium per day or to a control group. The following are the mean percentage changes (and SEs) in height and bone mineral density (BMD) over 24 months: for height, -0.1 +/- 0.2 cm in the milk supplementation group and -0.2 +/- 0.1 cm in the control group; for BMD at the total hip, -0.06 +/- 0.22% in the milk supplementation group and -0.88 +/- 0.26% in the control group; for BMD at the spine (L1-L4), -0.56 +/- 0.29% in the milk supplementation group and -1.5 +/- 0.29% in the control group; for total body BMD, -0.32 +/- 0.16% in the milk supplementation group and -1.2 +/- 0.19% in the control group (p < 0.05 by analysis of covariance [ANCOVA] for repeated measures for height and BMD at all sites). The milk supplementation group had less loss in terms of both height and BMD than the control group (p < 0.05 by ANCOVA for repeated measures). Serum parathyroid hormone (PTH) concentration was lower and serum 25-hyroxyvitamin D [25(OH)D] level was higher in the milk supplementation group than the control group at 12 months (p < 0.05 by paired t-test). We conclude that supplementing the diet of postmenopausal Chinese women with high calcium milk powder retards bone loss.

Increase in milk and body temperature of cows as a sign of embryo entry into the uterus

The objective of the first stage of these studies was to investigate whether temperature increases in the milk and body of cows during the early period of pregnancy. We studied 94 pregnant and 116 nonpregnant cows, and the temperatures were measured daily beginning 24 days after insemination. In addition, progesterone levels in milk were measured twice (on Days 21 and 24 after insemination), and examinations per rectum were conducted to determine pregnancy. Data analysis showed that in almost 90% of the pregnant cows milk temperature increased by 0.64 degrees C some time between Days 5 and 12 after insemination. This increase in milk temperature was highly significant and corresponded with a 0.46 degrees C increase in body temperature. There was no increase in the milk or body temperature in nonpregnant cows. After discovering in the first stage that a high percentage of pregnant cows experienced both milk and body temperature increases, we focused our attention in the second stage of the study on the question of whether this increase in temperatures might be due to an immune response of the mother to the entry of the embryo into the uterus. In this stage we conducted three different experiments on another group of animals consisting of 309 cows and heifers. The experiments included analysis of progesterone, estradiol, cortisol and PGE2 levels in the blood serum of the cows and heifers; an estimation of the pyrogenic activity of PGE1, PGE2 and progesterone; and measurements of body temperature in the heifers before and after embryo transfer. The results of these experiments suggested that an increase in milk and body temperature could be an indicator of an immune response of the mother to the entry of the embryo into the uterus.

Short communication: influence of transglutaminase on the heat stability of milk

Skim milk powders were prepared from control and transglutaminase-treated skimmed milk. The heat stability of reconstituted transglutaminase-treated skimmed milk (9.0% total solids) was markedly increased in the pH region of minimum stability (pH 6.8 to 7.1) compared with control milk, while the heat stability of reconstituted concentrated transglutaminase-treated skimmed milk (22.5% total solids) increased progressively as a function of pH relative to control milk. The effect of transglutaminase treatment on the heat stability of skimmed milk may have commercial applications, but extensive research is necessary to gain a better understanding of the mechanism by which transglutaminase improves heat stability.

Limits to sustained energy intake

Laboratory mice (strain MF1) were used to determine whether sustainable rates of energy intake are limited during lactation. Mice raising natural-sized litters (N=71) reached an asymptote in their daily food intake between days 13 and 16 of lactation at 23.1gday−1 and also between litter sizes of 9 and 15 pups (22.8gday−1). A second group of 37 females had their litter sizes manipulated at birth to raise more or fewer offspring than they gave birth to. When the litter size was increased, females did not increase their food intake to match their new litter size. However, when litter size was decreased, females decreased their asymptotic daily food intake during late lactation in relation to the extent of reduction in litter size. Therefore, it appeared that females were limited during late lactation and with large litter sizes. The milk energy exported amounted to 44% of the gross energy intake, and the estimated daily energy expenditure was therefore considerably lower than the sustained energy intake [8.0×RMR(gross), 6.6×RMR(assimilated)], and averaged 3.1×RMR, where RMR is resting metabolic rate. It was not possible to determine whether the apparent limit on sustained energy intake was acting centrally or peripherally because of the asymptotes in both food intake and milk energy output with increasing litter size.

Role of cholecystokinin in the intestinal phase of pancreatic circulation in dogs

The regulatory mechanisms of postprandial pancreatic hyperemia are not well characterized. The aim of this study is to clarify the role of cholecystokinin (CCK) in the intestinal phase of pancreatic circulation. Pancreatic, gastric, and intestinal blood flows were measured by ultrasound transit-time blood flowmeters in five conscious dogs. Pancreatic and gastric secretion and blood pressure were also monitored. Synthetic CCK octapeptide (CCK-8) or gastrin heptadecapeptide (gastrin-17) was infused intravenously, and milk was infused into the duodenum with or without loxiglumide, a specific CCK-A receptor antagonist. CCK-8 induced dose-related increases of pancreatic, but not gastric or intestinal, blood flow and protein secretion without affecting systemic blood pressure. Gastrin-17 did not affect pancreatic blood flow. An intraduodenal infusion of milk increased pancreatic and intestinal blood flows and pancreatic protein secretion. Loxiglumide completely inhibited pancreatic blood flow and protein responses to CCK-8 and milk but not the intestinal blood flow response. CCK is a potent and specific pancreatic vasodilator, with its effect mediated by CCK-A receptors. CCK plays an important role in the regulation of the intestinal phase of the pancreatic circulation in dogs.

[Comparison of performance of dairy herds that were or were not vaccinated with a bovine herpes virus 1 marker vaccine in 1998]

This study analysed the effects of the use of bovine herpesvirus 1 (BHV1) marker vaccine on the performance of dairy cattle. In Spring of 1999, vaccination of 12 herds with the BHV1 marker vaccine resulted in severe animal health problems and mortality. The vaccines used on these farms were all from a batch that appeared to be contaminated with bovine virus diarrhoea virus type 2. This led to a general call to farmers and veterinary practitioners to report side-effects of this vaccine. As a result, more than 7000 farmers reported symptoms. The information was obtained by means of a questionnaire; there was no control group. To determine the effects of the use of the marker vaccine, it was necessary to perform a study based on objectively acquired information. The information collected by the Royal Dutch Cattle Syndicate and the office of Identification and Registration was complied into herd indices on production, udder health, reproduction, and culling. Two groups of dairy farms that had used the BHV1 marker vaccine (attenuated and inactivated vaccine) were compared with farms that were certified BHV1-free. The analyses were performed based on intra-herd comparisons, meaning that per herd each index calculated over a certain period of time after the use of the marker vaccine was compared to a similar period of time prior to the use of the marker vaccine. A total of 144 comparisons were made. Seven comparisons were statistically significant. In two comparisons, the results were in favour of the BHV1-free farms and in five comparisons, the result were in favour of the vaccinated farms. Thus use of the BHV1 marker vaccine could not be proven to affect herd performance. The sensitivity of the tests was very high, so with a high level of probability even very small differences in indices between groups would have been detected.

[Automated detection of estrus and mastitis in dairy cows]

The development and test of detection models for oestrus and mastitis in dairy cows is described in a PhD thesis that was defended in Wageningen on June 5, 2000. These models were based on sensors for milk yield, milk temperature, electrical conductivity of milk, and cow activity and concentrate intake, and on combined processing of the sensor data. The models alert farmers to cows that need attention, because of possible oestrus or mastitis. A first detection model for cows, milked twice a day, was based on time series models for the sensor variables. A time series model describes the dependence between successive observations. The parameters of the time series models were fitted on-line for each cow after each milking by means of a Kalman filter, a mathematical method to estimate the state of a system on-line. The Kalman filter gives the best estimate of the current state of a system based on all preceding observations. This model was tested for 2 years on two experimental farms, and under field conditions on four farms over several years. A second detection model, for cow milked in an automatic milking system (AMS), was based on a generalization of the first model. Two data sets (one small, one large) were used for testing. The results for oestrus detection were good for both models. The results for mastitis detection were varying (in some cases good, in other cases moderate). Fuzzy logic was used to classify mastitis and oestrus alerts with both detection models, to reduce the number of false positive alerts. Fuzzy logic makes approximate reasoning possible, where statements can be partly true or false. Input for the fuzzy logic model were alerts from the detection models and additional information. The number of false positive alerts decreased considerably, while the number of detected cases remained at the same level. These models make automated detection possible in practice.

Promoting effect of colostrum on the phagocytic activity of bovine polymorphonuclear leukocytes in vitro

Bovine colostrum contains a variety of essential nutrients, antibodies, cytokines, hormones, and growth factors that are important for nutrient supply, host defense, growth and for general neonatal adaptation. We have investigated the effect of bovine colostrum on the phagocytic activity for latex particles by normal peripheral blood polymorphonuclear leukocytes using flow cytometric analysis. The phagocytosis promoting effect was observed in colostrum. The promoting activity showed dose-dependent increase up to 25% at a concentration of colostrum. This activity was maximum in the colostrum obtained at parturition and gradually decreased with the time course of lactation as well as IgG level. Colostrum possessed the higher promoting activity than milk and normal serum. These results indicate that bovine colostrum strongly activates polymorphonuclear leukocyte phagocytosis, suggesting the concernment with development of nonspecific immune system in newborns.

Lysostaphin expression in mammary glands confers protection against staphylococcal infection in transgenic mice

Infection of the mammary gland, in addition to causing animal distress, is a major economic burden of the dairy industry. Staphylococcus aureus is the major contagious mastitis pathogen, accounting for approximately 15-30% of infections, and has proved difficult to control using standard management practices. As a first step toward enhancing mastitis resistance of dairy animals, we report the generation of transgenic mice that secrete a potent anti-staphylococcal protein into milk. The protein, lysostaphin, is a peptidoglycan hydrolase normally produced by Staphylococcus simulans. When the native form is secreted by transfected eukaryotic cells it becomes glycosylated and inactive. However, removal of two glycosylation motifs through engineering asparagine to glutamine codon substitutions enables secretion of Gln(125,232)-lysostaphin, a bioactive variant. Three lines of transgenic mice, in which the 5'-flanking region of the ovine beta-lactoglobulin gene directed the secretion of Gln(125,232)-lysostaphin into milk, exhibit substantial resistance to an intramammary challenge of 104 colony-forming units (c.f.u.) of S. aureus, with the highest expressing line being completely resistant. Milk protein content and profiles of transgenic and nontransgenic mice are similar. These results clearly demonstrate the potential of genetic engineering to combat the most prevalent disease of dairy cattle.

[Influence of the treatment of subclinical mastitis on the electric conductivity of milk before ejection]

10 cows (German Brown x Brown Swiss) with 29 infected quarters (14 Staphylococcus aureus, 10 esculin positive streptococci, 5 Staphylococcus spec.) were treated daily after morning milking over a period of 4 days. Ampicillin and cloxacillin (500 mg each per dose) were administered to all 40 quarters intracisternally. During the evening milkings on 4 test days (day 3 before treatment, day 1 of treatment, days 5 and 9 after the last treatment), electrical conductivity based on 25 degrees C (EC) was measured in fore milk. To avoid ejection of alveolar milk, EC measurement was the first contact to the udder. Independent of the initial level, EC of all quarters was elevated by 2.1 mS/cm on average at the first milking following the first treatment. 9 days after the end of treatment, EC had declined to the initial level in all quarters classified as mastitic, non specific and latent infected before treatment. By contrast, EC values of healthy quarters remained elevated compared to their initial level (p < 0.01). This might be due to increased cistern tissue permeability caused by mechanical and pharmacological effects of antibiotic treatment. Despite the fact that somatic cell count and total bacteria count were reduced by treatment (p < 0.01), results showed that EC measurement on the first days following treatment was unsuitable for checking the success of treatment.

An evaluation of a hand-held electrical resistance meter for the diagnosis of bovine subclinical mastitis in late lactation under Australian conditions

OBJECTIVE

To assess the ability of a hand-held device to differentiate between infected and noninfected bovine mammary glands according to the electrical resistance of milk, under Australian conditions.

DESIGN

A cross-sectional study.

PROCEDURE

Milk samples were collected from 236 quarters of 60 cows selected from a commercial dairy herd with a high prevalence of mastitis. The true infection status of these quarters was determined using bacteriology. Various methods were used in an attempt to relate the electrical resistance of milk from each quarter to the presence or absence of infection in that quarter.

RESULTS

Although the electrical resistance of milk from infected quarters was generally lower than that of noninfected quarters, the overlap of readings between the two populations limited the ability of this device to indicate accurately whether a quarter was infected. The use of methods comparing the readings from each of the four quarters of a single cow did not allow the reliable detection of infected cows.

CONCLUSION

Although this device may have some practical advantages in comparison with some other methods of diagnosing subclinical mastitis, the predictive value of the method was generally poor.

Heat stability of buttermilk

Buttermilk prepared on a laboratory scale from raw cream, or on a commercial scale from flash-pasteurized cream (90 degrees C for 1 to 2 s), exhibited a type B heat coagulation time-pH profile (i.e., stability increased as a function of pH). The high heat stability of buttermilk in the pH range of the minimum of a type A milk (pH approximately 6.8 to 7.0) appears to be related to differences in the serum phase constituents (i.e., a low calcium and beta-Lg concentration and a high nonmicellar kappa-CN content).

The impact of milk-derived unconditioned and conditioned negative feedback on the microstructure of ingestive behavior

We describe at the microstructural level the impact of unconditioned and conditioned negative feedback on the licking behavior of the rat. Six groups of rats were trained to ingest one of six different dilutions of sweetened milk (0.5:1, 1:1, 2:1, 4;1, 8:1, and 16:1, water to milk ratios) under real feeding conditions until intake was stable. Then they were given five sham-feeding tests with the same solution. We compared the size of the clusters (SC) and their number (NC) during the 15-min period when intake rate was declining in the real-feeding test with SC and NC during the corresponding 15-min period in the following sham-feeding test. Intake increased significantly over the five sham-feeding tests with the two highest concentrations, indicating the extinction of conditioned negative feedback. With these two solutions, we compared the microstructure of licking behavior in the first with that in the fifth sham-feeding test to determine if conditioned negative feedback affected SC or NC or both. The effect of both unconditioned and conditioned negative feedback on licking behavior was to decrease the number of clusters without affecting their size. We conclude that negative feedback derived from the accumulation of milk in the gastrointestinal tract decreases the probability of initiating a bout of licking during a pause. It has no effect on the ability to continue a bout of licking once it has begun.

Effect of administration of Lactobacillus gasseri on serum lipids and fecal steroids in hypercholesterolemic rats

The effects of milk and nonfermented milks produced from Lactobacillus gasseri on serum lipids and total bile acids and fecal steroids and microflora were estimated in rats fed cholesterol-enriched diets. Lactobacilli decreased and coliforms increased in feces of the control group; however, the concentrations of fecal lactobacilli remained unchanged when rats were fed nonfermented milks. Fecal coliforms in rats receiving milk and nonfermented milk produced from L. gasseri SBT0270 increased, while rats receiving nonfermented milk produced from L. gasseri SBT0274 had lower fecal coliform count than did the control group. Only NFM-A significantly reduced serum total cholesterol and low-density lipoprotein (LDL) cholesterol, and bile acids. High-density lipoprotein (HDL) cholesterol was significantly decreased when rats were given milk and nonfermented milks. Milk and NFM-A lowered serum triglycerides levels. Milk and nonfermented milks did not affect the total neutral steroids, but higher levels of acidic steroid were detected in the feces than the control group. The results showed that the hypocholesterolemic effect of L. gasseri SBT0270 was attributed to its ability to suppress the reabsorption of bile acids into the enterohepatic circulation and to enhance the excretion of acidic steroids in feces of hypercholesterolemic rats.

Transforming growth factor beta3 induces cell death during the first stage of mammary gland involution

Involution of the mammary gland following weaning is divided into two distinct phases. Initially, milk stasis results in the induction of local factors that cause apoptosis in the alveolar epithelium. Secondly after a prolonged absence of suckling, the consequent decline in circulating lactogenic hormone concentrations initiates remodeling of the mammary gland to the virgin-like state. We have shown that immediately following weaning TGFbeta3 mRNA and protein is rapidly induced in the mammary epithelium and that this precedes the onset of apoptosis. Unilateral inhibition of suckling and hormonal reconstitution experiments showed that TGFbeta3 induction is regulated by milk stasis and not by the circulating hormonal concentration. Directed expression of TGFbeta3 in the alveolar epithelium of lactating mice using a beta-lactoglobulin promoter mobilized SMAD4 translocation to the nucleus and caused apoptosis of these cells, but not tissue remodeling. Transplantation of neonatal mammary tissue derived from TGFbeta3 null mutant mice into syngenic hosts resulted in a significant inhibition of cell death compared to wild-type mice upon milk stasis. These results provide direct evidence that TGFbeta3 is a local mammary factor induced by milk stasis that causes apoptosis in the mammary gland epithelium during involution.

Factors affecting the shape of lactation curves of Holstein cows from the Balikesir Province of Turkey

The shape of the lactation curve for 475 Turkish Holsteins was estimated by fitting a gamma function to daily milk yields from monthly recording of 754 lactations. Lactation curve traits that were analyzed included a scaling factor associated with yield at the beginning of lactation, the inclining and declining slopes before and after peak yield, DIM at peak yield, and peak and lactation yields. Persistency of lactation yield was measured from 1) the gamma function, 2) the coefficient of variation for monthly test-day yields, and 3) the ratio of lactation yield to peak yield. The log-transformed gamma function explained 71% of variation in daily yield. Effects of farm operation, calving year, calving season, parity, and service period were significant for the various lactation curve traits. Peak and lactation yields were higher for cows that calved in fall and winter, and persistency was higher for cows that calved in summer and fall. Peak and lactation yields were lower, but persistency was higher during first lactation. Repeatability estimates were moderate for peak (0.26) and lactation (0.34) yields and lower (0.06 to 0.20) for other lactation curve traits.

Genetic change in milk, fat, days open, and body weight after calving based on three methods of sire selection

Three Holstein lines, were compared, based on different methods of sire selection, for genetic change in 3.7% FCM, fat yield, days open, and predicted body weight after calving. The three lines were 1) evaluated sires selected only for 3.7% FCM (milk line), 2) evaluated sires selected on an index that included 3.7% FCM and type traits (index line), and 3) young bulls selected on pedigree for 3.7% FCM (young line). Cows from these lines were born in 1971 through 1993 in five experimental herds owned by the State Farm Division of North Carolina Department of Agriculture. Breeding values of cows in each line computed with a repeatability model were averaged by and regressed on birth year to estimate genetic change. Genetic gains in 3.7% FCM were 81 kg/yr for the milk line, 61 kg/yr for the line selected on index, and 68 kg/yr for the young sire line. Estimates of genetic gain in fat yield were 2.99, 2.16, and 2.54 kg/ yr in the three lines, respectively. Genetic gains in 3.7% FCM and fat yield in the milk line were significantly different from the index and young sire lines, but the index and young sire lines were not significantly different. Estimates of genetic change in days open were 0.71, 0.57, and 0.63 d/yr in the milk, index, and young sire lines, respectively. These estimates were not significantly different. Average breeding values for body weight decreased for births from 1971 to 1981 then rapidly increased for later births in all lines.

Bioactive milk peptides: a prospectus

Bioactive peptides have been identified within the amino acid sequences of native milk proteins. Hydrolytic reactions, such as those catalyzed by digestive enzymes, result in their release. These peptides directly influence numerous biological processes evoking behavioral, gastrointestinal, hormonal, immunological, neurological, and nutritional responses. The specific bioreactions associated with each physiological class have been well characterized. Herein, we review the scientific literature and attempt to stimulate consideration of the continued use of bioactive peptides and their expanded development as a commercial product. Several applications have already evolved. For example, phosphopeptides derived from casein fractions are currently used as both dietary and pharmaceutical supplements. Potentially, the addition of bioactive peptides to food products could improve consumer safety as a result of their antimicrobial properties. Lastly, bioactive peptides may function as health care products, providing therapeutic value for either treatment of infection or prevention of disease.

3,5,3'-Triiodothyronine administered to rat dams during lactation increases milk yield and triglyceride concentration and hastens pups growth

It is known that lactation induces a mild hypothyroid state in rats and other mammals while thyroid hormone administration increases milk secretion in ruminants. The aim of this study was to investigate the effects of a moderate dose of 3,5,3'-triiodothyronine (T3), administered to rat dams during lactation on pups' growth and milk yield and composition. Primiparous Wistar rats with litters adjusted to 10 pups per dam received either tap water or T3 (75 microg/kg x day) in their drinking water from parturition till weaning. Food and water intake of dams and body weight of dams and pups were measured daily. In other groups of rats with similar treatments, milk yield of dams, macronutrient milk composition, and mammary arteriovenous differences for triglycerides (TG) and glucose were also determined. Dams treated with T3 ingested more food and their pups gained more weight than controls. Milk yield, milk TG concentration and glucose extraction by mammary glands were also higher in T3 treated dams. The results show that compensation of the mild hypothyroidism of the lactating rat may contribute to an increase in milk production and lipid levels, leading to an increase in growth of pups.

Effects of lactoferrin and milk on adherence of Streptococcus uberis to bovine mammary epithelial cells

OBJECTIVE

To determine whether lactoferrin (LF) or milk influenced adherence of Streptococcus uberis to bovine mammary epithelial cells.

SAMPLE POPULATION

Three strains of S uberis from cows with mastitis, pooled milk samples from 3 clinically healthy Jersey cows early in the lactation period, and bovine mammary epithelial cells from a clonal cell line.

PROCEDURES

Adherence of S uberis to bovine mammary epithelial cells in the presence of various concentrations of LF or milk and after pretreatment of bacteria with LF or milk was tested. Bacteria were cultured with mammary epithelial cell monolayers for 1 hour. The culture supernatant was removed, and the epithelial cells were lysed. Adherence index was calculated as number of colony-forming units (CFU) in the cell lysate divided by number of CFU in the supernatant times 10,000.

RESULTS

All 3 strains of S uberis were found to bind to purified LF and LF in milk. Addition of LF to the culture medium enhanced adherence of all 3 strains to mammary epithelial cells, whereas addition of milk enhanced adherence of 2 strains and decreased adherence of the third. Pretreatment of bacteria with LF or milk increased adherence of 1 of the strains but decreased adherence of the other 2. Increased adherence was antagonized by rabbit antibovine LF antibody.

CONCLUSIONS

Results suggest that LF may function as a bridging molecule between S uberis and bovine mammary epithelial cells, facilitating adherence of the bacteria to the cells.

Plasma amino acid pattern during the first month of life in calves fed the first colostrum at 0-2 h or at 24-25 h after birth

Calves are born with a mostly inadequate essential amino acid (EAA) status. Studies were designed to test the hypothesis that delaying the intake of the first colostrum for 24 h, besides its early effects, also has late effects on plasma free amino acid levels and on the protein status. There were marked and rapid elevations (within 2 h) of plasma levels of various amino acids, and especially of EAA, after the intake of the first colostrum, whereas changes after the intake of mature milk on day 28 of life were mostly absent or concentrations even decreased. The EAA and non-essential amino acid (NEAA) status was rapidly normalized after intake of the first colostrum, but normal plasma levels of some amino acids were also reached during the first 24 h of life even when the first meal was withheld. Delaying colostrum intake had only transient effects on EAA and NEAA (except hydroxyproline), in contrast to its effects on plasma immunoglobulin G and total protein levels.

Effect of administration of fermented milk containing whey protein concentrate to rats and healthy men on serum lipids and blood pressure

The effect of fermented milk supplemented with whey protein concentrate on the serum lipid level of rats was investigated. The serum total cholesterol level for the group fed fermented milk with both Lactobacillus casei TMC0409 and Streptococcus thermophilus TMC 1543 was significantly lower than that of the control group (P<0.05) in rats. Furthermore, the effect of the longterm intake of this fermented milk on the serum lipid level of twenty healthy adult men was investigated. During the 8-wk study, the volunteers consumed 200 ml of fermented milk or placebo in the morning and evening. Blood samples were drawn for analysis three times, just before taking the experimental diet, and after 4 wk and 8 wk of consumption. After 8 wk, the high density lipoprotein cholesterol level for the fermented milk group showed a significant rise after 4 wk (P<0.05), whereas that of the placebo group showed no change even after 4 wk (P>0.05). The triglyceride level for the fermented milk group lowered significantly after 4 wk (<0.05), whereas that of the placebo group showed no change even after 4 wk (P>0.05). The atherogenic index [(total cholesterol - high density lipoprotein cholesterol)/high-density lipoprotein cholesterol] for the fermented milk group decreased significantly from 4.24 to 3.52 (P<0.05). The systolic blood pressure lowered significantly by the intake of fermented milk (P<0.05) On the other hand, such effect was not observed in the placebo group (P>0.05). These results indicate potential of the development of fermented milk with multiple therapeutic effects.