Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MILK”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11Linked to original sources
PubMed1999

Lactose-derived oligosaccharides in the milk of elephants: comparison with human milk.

Human milk is commonly considered to be unique when compared with the milk of other species with regard to its high content of complex fucosylated and sialylated lactose-derived oligosaccharides. We describe the application of high-pH anion-exchange chromatography with pulsed amperometric detection and TLC to characterize and quantitate neutral and sialylated lactose-derived oligosaccharides in milk from three Asian elephants and human milk. The lactose contents of elephant and human milks were 25-30 g/l and about 66 g/l respectively, whereas total oligosaccharide concentration was about three times higher in elephant milk and comprised up to 40% (10% in human milk) of the carbohydrate content. The ratio neutral: acidic components was different in the milk of the two species; in elephant milk, the N-acetylneuraminic acid-containing oligosaccharides made up almost half of the total amount v. 30% in human milk. Most oligosaccharides in elephant milk were more fucosylated and/or sialylated compared with human milk components. By mild acid hydrolysis, fucose and N-acetylneuraminic acid were cleaved off from complex components, and this resulted in increased amounts of fucose, galactose, N-acetylneuraminic acid, lactose and lacto-N-neo-tetraose. Unique to elephant milk are the high levels of 3'-galactosyllactose (up to 4 g/l) and lacto-N-neo-tetraose which are present in human milk only in trace amounts. Elephant and human milks have high levels and unique patterns of oligosaccharides which may reflect the relative importance of these components in neonatal host defence, in endothelial leucocyte interactions or in brain development.

Animals↗
PubMedDate not supplied

Milking strategy in subantarctic fur seals Arctocephalus tropicalis breeding on Amsterdam Island: evidence from changes in milk composition.

Milk composition was investigated throughout the 10-mo pup-rearing period in subantarctic fur seals (Arctocephalus tropicalis) breeding on Amsterdam Island. The mean milk composition was 42.8% +/- 5.7% lipid, 12.1% +/- 1.5% protein, and 42.6% +/- 7.3% water. Subantarctic fur seals breeding on Amsterdam Island produced one of the richest milks ever reported in otariids (20.4 +/- 2.9 kJ/g), with lipid content contributing 85% of total gross energy. The high lipid levels measured in the milk of subantarctic fur seals breeding on Amsterdam Island is consistent (i) with the relatively long time lactating females spend at sea, due to the relatively poor local trophic conditions near the colony that necessitate that they travel long distances to reach the foraging grounds, and (ii) with the consequently short time mothers spend with their pups ashore. Milk composition changed according to the time mothers were fasting ashore: milk produced during the first 2 d spent ashore, when more than 80% of milk transfer occurred, had higher levels of lipids, proteins, and gross energy than milk produced later during the visit ashore, suggesting that the pups were fed with two types of milk during a suckling period. Throughout the year, mothers in good condition produced milk of higher lipid content than others, suggesting that individual foraging skills contribute to enhance milk quality. Milk lipid and gross energy content varied with pup age, according to quadratic relationships, increasing during the earlier stages of lactation before reaching asymptotic values when pups were 180 d old. The stage of lactation appears to be a better predictor of milk lipid content than the duration of the preceding foraging trip, suggesting that either changes in the nutritional requirements of the pup and/or seasonal changes in trophic conditions act on milk composition. These changes in milk quality may also be related to changes in maternal care; lactating subantarctic fur seals apparently reallocate their body reserves toward gestation rather than lactation at the end of the pup-rearing period.

Animals↗
PubMed1999

Relation between weak HLA-DR expression on human breast milk macrophages and cow milk allergy (CMA) in suckling infants.

The precise role of breast milk leukocytes is unknown. We therefore studied the cellular composition of breast milk and the activation of breast milk macrophages in mothers with a cow milk-allergic infant and in those with a healthy infant. Further, we sought to determine the influence of the cellular composition of mother's milk on the infant's risk of developing cow milk allergy. Thirty-six asymptomatic mothers (26 with atopic constitution) whose babies had challenge-proven cow milk allergy and 24 asymptomatic mothers (17 with atopic constitution) with healthy infants were recruited. Geometric mean ages of the infants were 3.2 mo (95% confidence interval [CI], 2.3 to 4.4) and 2.4 mo (95% CI, 1.6 to 3.7), respectively. After separation of the fat layer, breast milk cells were incubated with fluorescein-labeled MAb to CD antigens (CD14, 45, 3, 4, 8, 19, 23, and HLA-DR) and analyzed by flow cytometry. Breast milk samples, collected with a breast pump, were processed immediately. Cytospin preparations of milk samples, made after separation of the fat layer, were stained with May-Grunwald-Giemsa and examined with a light microscope. HLA-DR expression on breast milk macrophages was significantly lower in the mothers whose infant was allergic to cow milk, 58.3% (95% CI, 44.9 to 75.6), than in the mothers of a healthy infant, 86.9% (95% CI, 78.7 to 96.1), p=0.012 (ANOVA). There was also a significant difference in the total number of breast milk leukocytes between the mothers with an allergic child, 0.17 x 10(6)/mL (95% CI, 0.12 to 0.25), and those with a healthy child, 0.08 x 10(6)/mL (95% CI, 0.05 to 0.14), p=0.019 (Mann-Whitney U test). These results suggest impaired function of breast milk macrophages in mothers whose infants had cow milk allergy. They may also reflect decreased antigen presentation to the inexperienced T cells in the gut or on other mucosal surfaces of the suckling infant, leading to subsequent development of food or respiratory allergies, e.g. asthma.

Analysis of Variance↗
PubMed1999

Suckling reinitiated milk secretion in beef cows after an early postpartum hiatus of milking or suckling.

We determined whether milk secretion in beef cows could be reinitiated by renewed suckling after a hiatus from milking or suckling. Fifty-three Angus x Hereford cows were suckled ad libitum by their own calves for 13 to 18 d postpartum and then assigned to treatments for 4 wk in which cows were 1) neither milked nor suckled (weaned; n = 18), 2) milked 2 x daily (milked; n = 18), or 3) suckled by their own calves (suckled; n = 17). Thereafter, all calves (including earlier weaned calves) suckled their own dams until permanent weaning at 203 d of age, except when their dams were milked once after receiving (i.m.) 40 IU of oxytocin at reinitiation of suckling (0 wk) and again 1 and 5 wk later. Prolactin was increased in milked and suckled cows during 20 min after milking or suckling at the termination of treatments (0 wk). Concentrations of insulin-like growth factor-I were greater for weaned than suckled cows; milked cows had intermediate concentrations. At 0 wk, milk yield was greater for suckled than milked or weaned treatment cows. After 1 wk of renewed suckling, milk secretion of weaned treatment cows increased, and by 5 wk, composition of milk was normal, but yield was still reduced. We concluded that milk secretion was renewed by suckling in early postpartum cows after they were neither suckled nor milked for 4 wk.

Animals↗
PubMed2001

Formula milk versus preterm human milk for feeding preterm or low birth weight infants.

BACKGROUND: Preterm human breast milk, compared with artificial formula milk, may provide insufficient nutrition for preterm or low birth weight infants. However, human milk may confer advantages in terms of a decreased incidence of gastrointestinal and neurodevelopmental adverse outcomes. OBJECTIVES: To determine if formula milk compared with preterm human milk leads to improved growth and development without significant adverse effects in preterm or low birth weight infants. SEARCH STRATEGY: The standard search strategy of the Cochrane Neonatal Review Group was used. This included electronic searches of the Cochrane Controlled Trials Register, MEDLINE, EMBASE and previous reviews including cross references. SELECTION CRITERIA: Randomised controlled trials comparing feeding with formula milk versus preterm human milk in preterm or low birth weight infants. DATA COLLECTION AND ANALYSIS: Data were extracted using the standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by each author and synthesis of data using relative risk and mean difference. MAIN RESULTS: Only one small trial fulfilled the pre-specified inclusion criteria (Gross 1983). In preterm and low birth weight infants, enteral feeding with protein-enriched standard calorie formula milk compared with unfortified donated preterm human milk resulted in a greater rate of short term weight gain, but not of increase in length or head circumference. In the group randomised to receive formula milk, there was an increase in the risk of feed intolerance of borderline statistical significance, but no evidence of an effect on necrotising enterocolitis. There are no data on long term growth parameters or on neurodevelopmental outcomes. There are no randomised comparisons of feeding with the preterm milk of the infant's mother versus formula milk. REVIEWER'S CONCLUSIONS: There are very limited data from randomised trials of feeding preterm or low birth weight infants with formula milk compared with preterm human milk. This may relate to a perceived difficulty of allocating an alternative enteral feed to an infant in cases where the infant's mother wishes to feed with expressed breast milk.

Enteral Nutrition↗
PubMed1998

Milking procedure alters the electrolyte composition of spontaneously hypertensive and normotensive rat milk.

A number of groups, including our own, have shown that the severity of hypertension expressed by the adult spontaneously hypertensive rat (SHR), which is primarily considered to be a genetic model of hypertension, can be reduced as a result of exposure to the behavioural and nutritional environment provided by a normotensive foster mother. It has been suggested that the hypertensive influence of the SHR dam may involve increased sodium delivery to the pups and there have been some reports of elevated sodium concentrations in the milk of SHR dams. However, these studies used either a long (> or =6 h) dam-pup separation period before collecting milk or repeated milking of the same dams, both of which have been shown to alter the trace element content of rat milk. Therefore, we have compared the electrolyte content of milk collected by these methods with milk derived from SHR and normotensive Wistar-Kyoto (WKY) dams separated from their litters for 2 h prior to a single-milking session. Long separation and repeated milking resulted in variable effects on the electrolyte content of both SHR and WKY dams' milk, compared with milk collected after 2 h from dams which had not previously been milked. The most notable effects were the abolition of significant strain differences, observed following 2-h separation, for milk sodium (WKY 22.1+/-1.4 vs. SHR 27.5+/-2.1 mmol/liter, p < 0.05) and calcium (WKY 92.3+/-4.3 vs. SHR 69.4+/-2.9 mmol/liter, p < 0.05) when dams were separated for 6 h or were serially milked. These data suggest that the electrolyte content of SHR and WKY dams' milk can be altered by the collection procedure and it is recommended that dams be milked on only one occasion following a short separation period from their litter.

Animals↗
PubMed1994

Machine milking of dairy goats during lactation: udder anatomy, milking characteristics, and blood concentrations of oxytocin and prolactin.

Forty-four goats were milked and milk flow recorded without or with 1 min manual prestimulation in early, mid and late lactation. Ultrasound measurements of cross sections of the whole mammary gland were performed in a water bath. In additional experiments with 15 goats, milk flow was recorded and frequent blood samples were taken for the determination of oxytocin and prolactin concentrations. Milk yield increased from the first to the third lactation and decreased markedly during the course of lactation. Average and peak milk flow rates were closely related to the actual milk yield. The ultrasound cisternal area was 27.4 +/- 1.5% of the entire udder half cross section. Milking characteristics were scarcely different without or with prestimulation, although oxytocin was released within 30 s after the start of prestimulation, whereas oxytocin concentrations without prestimulation increased only after the start of milking. Concentrations of prolactin were higher during July and August than in April, and increased similarly with or without prestimulation during milking. In contrast to dairy cows, prestimulation and an opportune release of oxytocin during milking does not significantly influence the course of milk flow in goats, and this is probably because large amounts of cisternal milk allow milk ejection to be induced only after the start of milking without causing bimodal or otherwise reduced milk flow.

Animals↗
PubMed2004

Supplementation of grazing dairy cows with rumen-protected tuna oil enriches milk fat with n-3 fatty acids without affecting milk production or sensory characteristics.

The present study was conducted to determine the pattern of incorporation of dietary EPA and docosahexaenoic acid (DHA) into milk, and to evaluate consequent changes in milk fat composition and sensory characteristics. Fourteen multiparous cows in early lactation were divided into two groups and were offered supplements for 10 d. While individual stalls after each morning milking, one group was offered a mixture of rumen-protected tuna oil (RPTO)-soyabean supplement (2 kg; 30:70, w/w; +RPTO) and the second group was offered the basal ration without RPTO (-RPTO). Both groups grazed together on a spring pasture after supplementation. Feeding supplemental RPTO increased the concentrations of EPA and DHA in milk fat from undetectable levels in -RPTO cows to 6.9 and 10.1 g/kg milk fat respectively. Total n-3 PUFA concentration in milk fat was increased three- to fourfold by tuna-oil supplementation (8.4 to 32.0 g/kg milk fat). There were no significant effects on milk production (35.4 v. 33.9 l/d), milk protein (28.2 v. 30.1 g/kg) or milk fat (36.2 v. 40.4 g/kg for -RPTO and +RPTO respectively). The concentration of total saturated fatty acids in milk fat was significantly reduced (568 v. 520 g/kg total fatty acids) and there was a 17 % reduction in the atherosclerotic index of milk after tuna-oil supplementation. Untrained consumer panellists (n 61) rated milk from both groups of cows similarly for taste and smell. We conclude that it is possible to enrich milk with n-3 PUFA without deleterious effects on yield, milk composition or sensory characteristics.

Animal Nutritional Physiological Phenomena↗
PubMed1999

Modified milk fat reduces plasma triacylglycerol concentrations in normolipidemic men compared with regular milk fat and nonhydrogenated margarine.

BACKGROUND: A modified milk fat with reduced cholesterol was developed by fractionation technology. OBJECTIVE: The effect of this modified milk fat on the lipoprotein profile of 21 normolipidemic men was compared with that of regular milk fat and nonhydrogenated margarine. DESIGN: A crossover design was used for the administration of the 3 experimental diets, which provided 13240 kJ as 16% protein, 51% carbohydrates, 33-34% lipids, and 21 g fiber/d. The ratio of polyunsaturated to saturated fat was 1.3:1 for the margarine diet and 0.3:1 for the milk-fat diets. The cholesterol content of the modified milk-fat and margarine diets was similar (248 and 254 mg/d, respectively), but was significantly higher (428 mg/d) for the regular milk-fat diet. RESULTS: Modified and regular milk fats did not change plasma total and LDL cholesterol significantly, but margarine did (P < 0.01). Furthermore, modified milk fat maintained initial HDL(2)-cholesterol concentrations, but margarine reduced this variable significantly (P < 0.05). These results can be explained by the lower ratio of polyunsaturated to saturated fat in the modified and regular milk-fat diets than in the margarine diet. Men who ingested modified milk fat had significantly (P < 0.05) lower total and VLDL-triacylglycerol and VLDL-cholesterol concentrations than did those who ingested either regular milk fat or margarine. This may have been, in part, because of the lower intestinal fat absorption with modified milk fat than with regular milk fat and margarine arising from changes in the melting properties of milk fat with fractionation. CONCLUSION: A reduction in plasma triacylglycerol concentrations after the consumption of modified milk fat may prevent the onset of hypertriacylglycerolemia.

Adult↗
PubMed1971

The effects of oxytocin and milk removal on milk secretion in the goat.

1. When goats were milked each hour after being given a dose of synthetic oxytocin within the range thought to be released by the pituitary, there was a progressive rise in milk yield becoming statistically significant by 5 hr. The effect was reduced if the milk was not removed from the gland each hour.2. Milking transplanted glands each hour without injecting oxytocin also increased milk yield. The yield of the unmilked glands on the same animals was not affected. Massaging the transplanted glands had no effect on the milk yield.3. Oxytocin treatment and, to a lesser extent, frequent milking without oxytocin, altered milk composition. [Na], [Cl] and [non-casein protein] increased; [K] and [lactose] decreased.4. Oxytocin infusions permitted the leakage of [(14)C]lactose from milk to plasma and [(14)C]sucrose from plasma to milk.5. In some goats very small doses of oxytocin caused changes in milk composition and in one such animal these changes were mimicked by the close arterial infusion of bradykinin.6. Reasons are given for believing that the changes in composition are incidental to the main action of oxytocin in expelling milk and could be caused by a small number of leaks between the tight junctions connecting secretory cells.7. The increase in the rate of milk secretion following milk removal is probably of greater physiological significance than the small changes in milk composition and supports Levy's idea of a local negative feed-back via a chemical component of milk.

Animals↗
PubMed1997

Public health and the safety of milk and milk products from sheep and goats.

Goats and sheep rank third and fourth in terms of global milk production from different species, but unlike cow milk, which has stringent hygiene and quality regulations, microbiological standards for the production and distribution of goat milk and sheep milk are more relaxed. Difficulties in managing the sanitary quality of sheep and goat milk derive from a series of factors including the low level of production per head, the milking system, the difficulty involved in machine milking, the conditions under which the herds or flocks are raised, adverse climatic conditions and the spread of production over a wide geographic area. Fresh goat milk is consumed by infants and others with allergies to cow milk and is also used for on-farm manufactured cheese, with or without thermal treatment. The high fat content and peculiar taste of cheeses made from ewe milk are also very popular. These cheese varieties, which are mostly still of 'artisan-type', are not covered by regulatory definitions and the dispute over the use of raw versus pasteurised milk is still alive. However, in documented intoxications recorded after the consumption of cheese, there has always been evidence of incorrect temperature control during pasteurisation, the deliberate addition of raw milk, or contamination during storage. Compositional differences between the milk from cows, ewes and goats (chemical composition of lipids, phosphatase level, freezing point, natural bacterial inhibitor levels, somatic cell count, etc.) preclude the nondiscriminatory use of bovine standards for regulatory purposes. Quality standards adjusted for the specifics of ewe/goat milk should be considered. The production of safe cheese is linked to a series of conditions which ensure consumer health, primarily pasteurisation. In the absence of pasteurisation, all cheeses made from raw milk should be subjected to strict periodic controls.

Animals↗
PubMed1999

Technical note: machine milking of sows--lactational milk yield and litter weights.

This study was designed to 1) determine milk yield of sows that were machine milked; 2) assess the effects of pulsation rate, pulsation ratio, and pig removal on milk yield; and 3) assess litter weights. In Exp. 1, four sows were milked daily to 60 d postpartum. There were differences (P < .05) in milk yield among sows, the greatest being 1,898 mL/d. Daily milk yield peaked between 15 and 25 d postpartum. Litter weights were 18.0 +/- 1.0 kg at farrowing and 60.8 +/- 12.1 kg at d 60. In Exp. 2, four sows were milked daily for 28 d. Pulsation rate and ratio (150/min and 28:72, milk:rest, and 60/min and 50:50) were alternated on a daily basis and pigs were isolated for either 0 or 60 min before milking. The higher pulsation rate resulted in more milk per milking (202 +/- 13 vs 168 +/- 13 mL; P < .05). Pig removal resulted in 221 +/- 11 vs 148 +/- 14 mL milk (P < .01). Pig removal times and pulsation characteristics affect the amount of milk obtained, but milk removal from sows has a severe effect on litter weight. This system can be used to harvest sow's milk for pharmaceutical purposes, but supplementation of the pigs is necessary.

Animal Husbandry↗
PubMed2000

Evaluation of an experimental milking pulsation system for effects on milking and udder health.

This study was to test whether cows milked by an experimental pulsation method differed from cows milked with conventional pulsation milking in somatic cell count (SCC), intramammary infections (IMI) defined by milk bacteriological culture results, teat end condition, or milk flow rate. The study design was a 1-yr trial with a completely randomized block crossover. Holstein cows were blocked into 15 pairs of contemporaries. Both cows from each pair were milked with experimental pulsation and with conventional pulsation for 6 mo, in reverse order from each other. The SCC (217,000/ml) of experimentally milked cows was not significantly different from SCC of conventionally milked cows (175,000/ml). Mean milk flow rate was 5.2 lb/min (2.4 kg/min) for experimentally milked cows and 5.3 lb/min (2.4 kg/min) for conventionally milked cows, not significantly different. Differences among the experimentally and conventionally milked cows, respectively, in new (13.5 and 12.7%), chronic (12.9 and 8.9%), and negative (73.6 and 78.4%) quarter culture results were not significant. New IMI per 100 d of lactation were 1.50 and 1.46, and chronic IMI per 100 d were 1.85 and 1.27, for experimentally and conventionally milked cows, respectively. These IMI rates were not significantly different between pulsation types. There were more new Staphylococcus aureus IMI associated with conventional pulsation, but overall cases of Staph. aureus were similar between the two types of pulsation. Teat end scores for the experimentally and conventionally milked cows, respectively, were good (6.5 and 11.7%), intermediate (68.2 and 66.9%), and poor (25.3 and 21.4%), not significantly different. These results support previous studies, which have found that except for complete failure of pulsation, differences in pulsation characteristics apparently have little effect on milking and udder health.

Animals↗
PubMed1996

Milk yield, oxytocin and beta-endorphin gradually normalize during repeated milking in unfamiliar surroundings.

procedure previously shown to inhibit oxytocin release and milk ejection. Two control milkings were performed in familiar surroundings. After milk flow had ceased, two i.v. injections of 1 i.u. oxytocin were given to remove the remaining milk. Milk flow was recorded continuously and blood samples were taken every minute during milking and 10 min after milking. During the first milking in unfamiliar surroundings, no oxytocin was released. Thereby, only 13 percent of the total milk yield, the cisternal milk, was available and the alveolar milk fraction could only be removed after injection of oxytocin. During subsequent relocations oxytocin release steadily increased toward the control level, although the timing of oxytocin release remained delayed as compared with controls. However, the milk fraction available before oxytocin injection increased with increasing number of removals, following an asymptotic approach to control levels. The concentrations of beta-endorphin, cortisol (and perhaps also of prolactin) gradually declined with the number of times the animal was moved to unfamiliar surroundings, i.e. hormone concentrations gradually adjusted to control level. During milking, concentrations of prolactin and cortisol increased, while beta-endorphin concentrations decreased (except for the first relocation). We conclude that milking-related oxytocin release and therefore milk ejection adapted gradually to repeated relocations to unfamiliar surroundings. This adaptation was inversely related to beta-endorphin concentrations, so it is possible that oxytocin release was suppressed by high circulating beta-endorphin concentrations.

Animals↗
PubMed2004

Milking regimes to shorten milking duration.

Four milking regimes using automatic cluster removers (ACR) were tested over a 19-week period, from mid to late lactation. Each treatment group consisted of 16 slow-milking cows. The milking regimes used were: an ACR setting of 200 ml/min (Control); raised ACR setting from 200 to 500 in steps of 100 ml/min (Raised ACR); raised ACR as above in conjunction with pre-milking teat stimulation (Raised ACR+Stim); and terminating the milking when an ACR threshold of 200 ml/min was reached or when a predetermined maximum milking duration was reached (Timer). All incremental treatments were applied in blocks of 6 or 7 weeks duration. ACR thresholds were raised from 200 to 500 ml/min without observed loss of milk production when compared with controls. However, even up to an ACR setting of 500 ml/min there was little reduction in the group milking duration even when used with teat stimulation. In contrast, the Timer treatment resulted in a 34% reduction of the maximum milking duration for the group without significant loss of milk yield. For all groups, including Control, strip yield was occasionally very high and highly variable. Willingness of cows to enter the milking platform, behaviour during milking, teat condition and incidence of mastitis were similar for all treatment groups. The results indicated that simple truncation of milking at a predetermined maximum duration could be a most potent and inexpensive method of milking a herd more quickly. Such a method could be employed by using a simple timer in any dairy regardless of the level of sophistication of the milking system.

Animals↗
PubMed1993

Antibodies against nematodes in serum, milk and bulk milk samples as possible estimators of infection in dairy cows.

Antibodies against Ostertagia spp., Cooperia spp. and Dictyocaulus viviparus were assessed in serum and individual milk samples of cows and in bulk milk samples from the refrigerating tank. Titres in milk samples were related to serum titers, but also influenced by milk yield, lactation stage and age of the cow. Correlation coefficients between serum and individual milk samples were highly significant, and varied from 0.42 to 0.56. Correlations between herd means of serum titres and herd means of individual milk titres varied from 0.41 to 0.61, and those between herd means of serum titres and means of bulk milk samples from 0.43 to 0.67. Finally, the correlations between herd means of individual milk samples and means of bulk milk samples varied from 0.52 to 0.82. This variation was dependent upon worm species and whether or not correction for milk yield was applied. The discrimination of herds was evaluated by the between/within herd ratio of variances. F-values for all types of samples were highly significant, and at least as high for milk samples as for serum samples. If, as has been shown for serum samples, a positive relationship exists between the milk yield response to anthelmintic treatment and the mean herd titre of milk samples or bulk milk samples, assessment of these titres could offer a rational basis for treatment of dairy cows.

Age Factors↗
PubMed2000

Variation of the ganglioside compositions of human milk, cow's milk and infant formulas.

The ganglioside compositions of human milk, cow's milk and infant formulas were compared. The results showed that there was a drastic change in the ganglioside composition from the colostrum to later human milk, and that both the patterns and contents of gangliosides in human milk, cow's milk and infant formulas differed markedly. In human milk, the total lipid-bound sialic acid level was two times higher than those in cow's milk and infant formulas. The major ganglioside in the later human milk, GM3 (27.7%), was only a minor component in the colostrum, cow's milk and infant formulas (3.3, 2.8 and 0.4-2.6%, respectively). GD3 represented 49.0, 61.0 and 72.4-86.6%, respectively, of the colostrum, cow's milk and infant formulas, compared to 31.8% of the later human milk gangliosides. Another four gangliosides, which were assumed to be c-series gangliosides, were detected in the colostrum and the later human milk. They represented 33-38% of total lipid-bound sialic acid, and were tentatively designated as GX1, GX2, GX3 and GX4, respectively. However, only GX1 and GX2 were observed in cow's milk and infant formulas. The variation of the gangliosides in human and cow's milk, and infant formulas might have some biological significance regarding neonatal brain development, allergies, infant growth and non-immunoglobulin prophylactic activities against some bacterial toxins.

Animals↗
PubMed1990

Milk yield and mammary function in dairy cows milked four times daily.

Groups of lactating cows and heifers were milked four times daily in two diagonally opposed glands for 4 weeks, and the effects on milk yield studied relative to twice-daily milked glands as controls. Mammary enzyme activities, in vitro synthesis rates of milk constituents and histological scoring were determined in mammary biopsy samples obtained at the end of this period. These were used for assessment of mammary function. Frequent milking increased milk yield only in the treated glands, the contralateral control glands continuing to decline in yield at approximately 2%/week. There was no significant difference in response between cows and heifers; the mean increase in yield was 10.4%. The rate of decline in milk yield tended to decrease with frequent milking, to approximately 1%/week. Consequently the yield of the treated glands continued to be elevated above that of the controls for some time after reversion to overall twice daily milking. Milk protein content was increased slightly by frequent milking. Mammary enzyme activities were approximately 18% higher in the treated glands than in the controls. Synthesis rates of lactose, casein and total protein were unaffected by milking frequency, but were all lower in the gland selected for the second biopsy, reflecting the reduction in milk yield caused by the first biopsy. DNA synthesis was increased by milking frequency, as were the size and number of epithelial cells in histological sections.

Animals↗