Milk and water intakes of foals sucking grazing mares.

Intakes of milk and milk nutrients were determined for 8 foals at 11-18 days of age and for 10 foals at 30-44 days and 60-74 days of age while sucking grazing mares. Water intakes (sources other than milk) of the foals were determined at 30-44 days and 60-74 days of age. Five of the 10 mares were fed a protein supplement (24% crude protein) in addition to grazing during the stud season. The protein supplement did not influence foal intakes of milk and milk nutrients, milk composition, weight gains of the mares or the growth rate of the foals. Foal milk intakes increased (P less than 0.05) from 16.9 kg/day at 11-18 days to 18.1 kg/day at 60-74 days of age. The water intakes of the foals increased (P less than 0.01) from 3.9 kg/day at 30-44 days to 5.5 kg/day at 60-74 days of age. Total fluid intakes per kg foal liveweight were 246, 202 and 172 g at 11-18, 30-44 and 60-74 days of age, respectively. For each kg of weight gain, foals consumed 12.8, 15.7 and 16.4 kg milk at 11-18, 30-44 and 60-74 days of age. Stage of lactation had a significant effect on the total solids, lactose and protein content of milk. The fat and gross energy content of milk remained constant.

Nonspecific antibacterial factors in milk from cows immunized with human oral bacterial pathogens.

Both the immunoglobulins and non-specific antibacterial factors in milk from cows immunized with pathogenic oral bacteria have the potential to influence the oral microflora during passive immunization studies. The first six milks after calving were collected from 2 cows immunized with adjuvant and from 14 cows immunized with adjuvant and heat-killed strains of periodontopathic Actinomyces, Porphyromonas, Prevotella, and Fusobacterium. Analysis of the products from the first to the sixth milks revealed that the protein and lysozyme content decreased approximately 66 and 72%, respectively; the mean specific activity of the enzyme remained relatively constant. In contrast, the mean lactoperoxidase activity increased 2.3-fold in the second milking and increased further in the fourth and sixth milkings. The mean iron-binding activity increased 1.2-fold from the first to the second milkings and then decreased 3.6-fold through the sixth milking. Cows immunized with adjuvant alone showed similar responses. Per unit volume, the milk contained approximately 150 times less lysozyme than whole human saliva obtained from six subjects but higher concentrations of lactoperoxidase and iron-binding components. Purified bovine nonspecific factors prevented the growth of the bacteria used for immunization when bacteria were tested at concentrations similar to those found in saliva and milk. Because bovine nonspecific antibacterial factors could influence both the pathogenic target bacteria and the indigenous microflora in oral passive immunization studies with bovine immunoglobulins, the presence of these proteins should be considered.

Effects of feeding lactating dairy cows diets containing whole soybeans and tallow.

Four multiparous Holstein cows averaging 133 d postpartum and fitted with ruminal cannulas were utilized in a 4 x 4 Latin square design to investigate the effects of feeding diets containing whole soybeans and tallow. Treatments were 1) control, no added fat; 2) control and 10% whole raw soybeans; 3) control, 10% whole raw soybeans, and 2.5% tallow; and 4) control, 10% whole raw soybeans, and 4.0% tallow. Cows were fed for ad libitum intake a diet of alfalfa haylage, corn silage, and concentrate (45:5:50, DM basis). Intakes of DM and production of milk, milk CP, milk SNF, and 4% FCM were not affected by feeding supplemental fat. Production of milk fat and weight percentages and yields of long-chain fatty acids in milk fat were increased, whereas weight percentages and yields of short- and medium-chain fatty acids were decreased by feeding supplemental fat. Digestibilities of DM, OM, energy, cellulose, and fatty acids were decreased slightly when fat was added to the diet, but utilization of energy and N for production of milk was not altered. Supplemental fats increased concentrations of NEFA and cholesterol in plasma. These data indicate that relatively large amounts of unprotected fat can be added to the diet of lactating dairy cows without deleterious effects on milk composition, ruminal fermentation, or nutrient digestibilities.

Lactational responses of dairy cows fed unsaturated dietary fat and receiving bovine somatotropin.

Feeding unsaturated dietary fat to lactating dairy cows receiving bST may effectively alter the fatty acid composition of milk fat. This was tested using 16 Holstein cows assigned to one of four treatments during midlactation. Treatments were control, control diet with 15.5 mg of bST/d per cow, dietary fat from sunflower seeds and bST, or dietary fat from safflower seeds and bST. Diets were formulated to contain 19% CP and contained 25% corn silage, 25% alfalfa hay, and 50% concentrate mix on a DM basis. Milk yield was not significantly higher when bST was administered and increased with added fat diets (29.5, 32.7, 40.0, and 34.1 kg/d for the control, control with bST, sunflower seed with bST, and safflower seed with bST treatments, respectively). Percentage of milk fat was similar for all treatments. Concentrations of long-chain and unsaturated fatty acids in milk were increased slightly by bST and substantially with added fat. Milk protein percentages were not influenced by bST but were reduced by approximately .2 unit with added fat. Added unsaturated dietary fat coupled with bST increased milk yield and produced a greater concentration of unsaturated fatty acids in milk.

Selenium content of goat milk and its distribution in protein fractions.

This study reports on selenium distribution in goat milk. Skim milk was found to contain the major part (94%) of total milk selenium. The selenium distribution over casein and whey protein fractions depends on the separation method used, but irrespective of these methods, skim milk selenium is mainly associated with the casein fraction (greater than 69%). Approximately 9%, 7% and 24% of selenium is removed by dialysis (molecular cutoff 10-12 kDa) from skim milk, casein and whey respectively, indicating a major association of selenium with milk proteins. This observation is confirmed by selenium analysis of individual caseins and whey proteins isolated through ion-exchange chromatography and gel filtration. Selenium concentrations of the different isolated milk proteins show considerable variation (caseins: 294-550 ng Se/g; whey proteins: 217-457 ng Se/g).

Assessment of the mammary system.

Assessing the health status of the mammary gland is a complex and often perplexing endeavor. One must use all of the faculties available to come up with an accurate diagnosis. A detailed history of the individual and the herd or flock plus a thorough physical examination that includes specific attention paid to the mammary gland are essential. One cannot overlook these basic tenets in favor of more sophisticated means of evaluation such as somatic cell counts and milk microbiology. A holistic approach to mastitis diagnosis, treatment, and, most importantly, control is necessary.

Fluoride intake from beverage consumption in a sample of North Carolina children.

Since the 1940's, the prevalence of dental fluorosis has increased in the US, concomitant with a reduction in dental decay. These changes have been attributed in part to the widespread use of systemic and topical fluorides. Various sources of increased systemic fluoride exposure have been investigated. However, little is known regarding fluoride intake from beverages in a sample of children of ages susceptible to dental fluorosis. The purpose of this study was to estimate the amount of fluoride ingested from beverages by a sample of North Carolina (NC) children of ages 2-10 years. Data on beverage consumption were collected by means of a diary format. A questionnaire was included so that demographic information and self-assessment on the accuracy of the diaries could be obtained. Beverages reported in the diaries were purchased, and their fluoride content was assayed. Daily total fluid intake ranged from 970 to 1240 mL, and daily beverage consumption ranged from 585 to 756 mL. The estimated mean daily fluoride intakes from beverages for children 2-3, 4-6, and 7-10 years of age were 0.36, 0.54, and 0.60 mg, respectively.

Influence of dietary protein and supplemental niacin on lactational performance of cows fed normal and low fiber diets.

Forty-seven cows (24 primiparous) were assigned to one of four normal (20.5%) ADF diets for wk 2 to 5 postpartum. Dietary treatments in a 2 x 2 factorial design were diets of 13.8 versus 18.8% CP and 0 versus 12 g/d of niacin per cow. During wk 6 to 13 postpartum, cows were fed low (11.8%) ADF diets while maintaining CP and niacin treatments. Low CP diets contained solvent-extracted soybean meal; rumen soybean meal with enhanced undegradable protein was used in high CP diets. High CP diets increased milk protein percentage in multiparous cows and yields of milk, 4% FCM, fat, protein, and SNF in primiparous cows during the normal fiber period. High dietary CP also increased yields of 4% FCM, fat, protein, and SNF in primiparous cows fed normal fiber diets. When switched to low fiber diets, primiparous cows fed high CP diets decreased more in 4% FCM and fat yields than those fed low CP. Primiparous cows fed niacin decreased more in 4% FCM than controls. High dietary CP increased DMI in primiparous cows fed normal fiber diets, but those fed low CP diets increased more in DMI when switched to low fiber diets. Supplemental niacin appeared to interact with dietary CP in multiparous cows, increasing blood glucose and decreasing blood beta-hydroxybutyrate and NEFA concentrations with the high CP, normal fiber diet. Increased dietary CP improved yields of milk and milk components in primiparous cows.

Response of Holstein cows to corn gluten meal used to increase undegradable protein in early or later lactation.

Supplemental corn gluten meal was used to raise CP by 1.1 to 1.5 percentage units and undegradable intake protein from 35 to 39% of CP in the corn-based diet of parity 1 or greater Holstein cows to study effects of undegradability, parity, stage of lactation, and interactions on DMI, milk yield and composition, BW, and related traits during complete lactations. Cows were assigned at calving to treatments (n = 30, 8 primiparous): control, supplement wk 1 to 8 postpartum (early), or supplement wk 9 to 44 postpartum (late). Total lactation means were not affected significantly by treatments. Supplementation with undegradable protein enhanced forage and, thus, total DMI in later lactation by pluriparous cows; it apparently spared BW loss wk 1 to 8 postpartum and enhanced BW recovery thereafter in first lactation cows with no effect in older cows. Effects of supplementation on milk yield were small, and they were negative in early lactation and generally positive in late lactation; effects were positive on fat test in early lactation for both parity categories but distinctly negative for parity 1 cows in late lactation. Supplementation of undegradable protein in late lactation also decreased milk protein content in parity 1 cows and raised it in older cows. Data suggest that Lys may have been first-limiting, followed by Ile in early lactation and Met in late lactation, and that AA adequacy may be more important than undegradability in ration protein balancing. For most traits measured, treatment by parity interactions were significant, indicating that parity 1 cows did not respond in the same way as older ones to protein supplementation.

Infusion of long-chain fatty acids varying in saturation and chain length into the abomasum of lactating dairy cows.

Free long-chain fatty acids were infused into the abomasum of lactating dairy cows to determine postruminal effects on feed intake, production and composition of milk, nutrient digestibilities, and metabolites in blood. Four Holstein cows averaging 120 DIM and fitted with ruminal cannulas were used in a 4 x 4 Latin square design with 14-d periods. Treatments were abomasal infusions of 1) control, 168 g/d of meat solubles (carrier for fatty acids), 2) control plus 450 g/d of mostly saturated fatty acids (C16:C18 = .75), 3) control plus 450 g/d of a mixture of saturated and unsaturated fatty acids (C16:C18 = .40), and 4) control plus 450 g/d of mostly unsaturated fatty acids (C16:C18 = .11). Production of milk and milk components, DMI, and intake of digestible energy decreased linearly as unsaturation and chain length of infused fatty acids increased. Percentages of fat, CP, and SNF in milk and total tract apparent digestibilities of DM, OM, ADF, NDF, energy, and fatty acids were not affected significantly by treatments. Infusing fatty acids decreased proportions and yields of short- and medium-chain fatty acids and increased proportions and yields of unsaturated C18 fatty acids in milk fat. Increasing unsaturation and chain length of infused fatty acids linearly decreased proportion and yield of palmitic acid but increased proportions and yields of polyunsaturated C18 fatty acids in milk fat. Infusing fatty acids increased concentrations of NEFA and cholesterol in blood plasma. The profile of fatty acids reaching the intestine may be an important determinant of responses to supplemental fats fed to lactating dairy cows.

American Academy of Pediatrics Committee on Nutrition: The use of whole cow's milk in infancy.

The pediatrician is faced with a difficult challenge in providing recommendations for optimal nutrition in older infants. Because the milk (or formula) portion of the diet represents 35% to 100% of total daily calories and because WCM and breast milk or infant formula differ markedly in composition, the selection of a milk or formula has a great impact on nutrient intake. Infants fed WCM have low intakes of iron, linoleic acid, and vitamin E, and excessive intakes of sodium, potassium, and protein, illustrating the poor nutritional compatibility of solid foods and WCM. These nutrient intakes are not optimal and may result in altered nutritional status, with the most dramatic effect on iron status. Infants fed iron-fortified formula or breast milk for the first 12 months of life generally maintain normal iron status. No studies have concluded that the introduction of WCM into the diet at 6 months of age produces adequate iron status in later infancy; however, recent studies have demonstrated that iron status is significantly impaired when WCM is introduced into the diet of 6-month-old infants. Data from studies abroad of highly iron-deficient infant populations suggest that infants fed partially modified milk formulas with supplemental iron in a highly bioavailable form (ferrous sulfate) may maintain adequate iron status. However, these studies do not address the overall nutritional adequacy of the infant's diet. Such formulas have not been studied in the United States. Optimal nutrition of the infant involves selecting the appropriate milk source and eventually introducing infant solid foods.(ABSTRACT TRUNCATED AT 250 WORDS)

Energy balance and lactation response in Holstein cows supplemented with cottonseed with or without calcium soap.

Holstein cows (n = 58, 21 primiparous), fed corn and wilted grass silages (63:37, DM basis) for free choice consumption, were assigned to control concentrate or supplemented concentrate during wk 1 to 16 postpartum with linted whole cottonseed (15% of projected DMI) alone or with Megalac (.54 kg/d). Our objective was to examine the effects of fatty acids on energy and N balances, total tract digestibility, and milk fatty acids in wk 7 and 16 and to assess total lactation responses. During balance measurements, fatty acids constituted 4.1, 6.8, and 8.6% of DM in control, oilseed, and oilseed plus protected fatty acid diets. Fat additions reduced fiber digestion (attributed to oilseed) and, to some degree, DMI and milk yield, but enhanced fat test without affecting protein percentage. Supplementary fat increased the proportion of C18:0 in milk at the expense of short-chain fatty acids. Supplemental oilseed with or without protected fatty acids reduced total heat production by 6% and reduced heat in excess of maintenance by 8%. Best estimates of NEL in linted whole cottonseed and of fat in Megalac were 1.81 and 5.69 Mcal/kg of DM. In total lactation, primiparous cows yielded more milk and FCM when fed oilseed plus Megalac and less of each when fed oilseed alone than controls. In pluriparous cows, milk yield was reduced by 2.7 kg/d relative to other treatments when oilseed plus Megalac was fed; FCM yield increased about 2 kg/d only when oilseed was supplemented alone. Overall, data suggest that basal ration fat and oilseed supplementation were too high or that supplementation should have been delayed until feed intake was higher.

Selenium content and distribution in bovine and human milk from different regions of Poland.

Human milk and bulk cow's milk samples from 3 different areas of central Poland were analyzed for their Se content. Cow's milk specimens were also analyzed for Se distribution and GSH-Px activity. Mature human milk contained 34-68% more Se than bulk cow's milk obtained from analogous areas of central Poland. Comparison of literature values suggest, that human and cow's milk from vicinity of Warsaw and Piotrków Trubunalski were Se-adequate but milk from Siedlce area was Se-deficient. Glutathione peroxidase activity accounted for 25-31% of the total peroxidase activity of cow's milk. The majority of the Se was found in the whey fraction. It was suggested that the participation of the casein fraction in total milk selenium increased faster than milk Se content. Cow's milk obtained near Warsaw had a 2-times higher concentration of Se than in milk from Siedlce but the content of this microelement in the casein fraction (pellet) was 3-times higher.

Gangliosides in bovine milk. Changes in content and distribution of individual ganglioside levels during lactation.

Bovine milk undergoes changes in its ganglioside contents during the different stages of lactation. These contents are higher in colostrum (7.5 mg of lipid-bound NeuAc/kg) than in transitional (2.3 mg) or mature (1.4 mg) milk. The sialic acid content of milk follows a similar profile to that of gangliosides with the highest content during the first few days post partum followed by a gradual decrease towards the end of the period studied. When the individual distribution of gangliosides was examined throughout the course of lactation, several changes were also found. GD3 is the major ganglioside (about 60-70%) found; its content decreases from the first to the fifth day, increasing towards the end of the period considered. GM3, GD3 and GT3, sialyllactosylceramide-containing gangliosides account for 80-90% of the total lipid-bound NeuAc content. The most striking change in the ganglioside pattern was the gradual increase in G3.

Selenium status of Christchurch infants and the effect of diet.

OBJECT: New Zealanders, because of a soil deficiency, have a low intake of selenium. To determine the impact of this on the infant population in Christchurch. METHODS: we have measured red cell and plasma selenium and the selenoenzyme, glutathione peroxidase, in 70 infants less than 12 months old and related these to age and diet. RESULTS: the infant population as a whole had mean plasma levels of selenium and glutathione peroxidase of 33 micrograms/L and 97 U/L compared with adult values of 74 micrograms/L and 150 U/L. Infant red cell levels of 0.30 mu g selenium and 9.0 U glutathione peroxidase per g haemoglobin were similar to those in adults. The selenium status of most breast fed infants after birth remained similar to that of cord blood. Mean plasma selenium and glutathione peroxidase levels in formula fed infants were about half those of breast fed infants, and their red cell selenium was also significantly lower. These did not increase until solids were introduced into the diet. The status of the infants reflected their diet, with the concentration of selenium in formulae being 3.9-5.2 micrograms/mL compared with a mean of 13.4 micrograms/mL in breast milk. CONCLUSIONS: since infants in more replete selenium areas show a gradual rise in blood selenium parameters after birth, this study suggests that formula fed and some breast fed infants in Christchurch receive an inadequate selenium intake. Consideration should be given to supplementing infant formulae and perhaps also the diet of pregnant and/or breast feeding mothers.

Determination of selenium by inductively coupled plasma mass spectrometry utilizing a new hydride generation sample introduction system.

An inductively coupled plasma mass spectrometer with a newly designed continuous flow hydride generator was used for the determination of Se in biological materials. The design of the hydride generator was important in minimizing interference from HCl and in maximizing analytical sensitivity. Two sample preparation procedures incorporating either 3.8 or 7.2 M HCl in the final sample solutions were compared. Interference from Cu was eliminated by the addition of 0.2 M NaI to the sodium borohydride solution (3.8 M method) or by maintaining a high concentration of HCl in the sample solution (7.2 M method). The 3.8 M method had the advantage of minimizing exposure of expensive equipment to corrosive HCl fumes, whereas the 7.2 M method did not contaminate equipment with I and had no measurable sample-to-sample cross-contamination. In practice, cross-contamination from sample to sample in both methods was negligible during analysis. An important factor in minimizing cross-contamination from sample to sample was the elimination of the air bubble normally entrained between samples. Determination of isotopic tracer enrichment was linear from 0 to 320% enrichment, which provided a broad range for isotope dilution analysis. A detection limit of 6.4 pg of Se was observed under optimum conditions, whereas a detection limit of 1.3 ng of Se was found for routine analysis of 1-g samples of plant material. Selenium was accurately determined by isotope dilution analysis in a variety of biological reference materials.

Voluntary intake, milk production and plasma metabolites in nursing mares fed two different diets.

Voluntary food intake, milk yield and composition, and blood metabolites were measured during the first 2 mo of lactation in draft broodmares fed diets containing either 95% hay and 5% concentrates (Diet F) or 50% hay and 50% concentrates (Diet C). Voluntary food intake was higher for mares fed Diet C than for those fed Diet F (22.9 vs. 21.4 kg dry matter in wk 4). Both diets, especially Diet C, were eaten in amounts exceeding the energy requirements. Daily milk yield in wk 4 was 26.4 kg and 23.4 kg for mares fed Diets C and F, respectively. Milk fat and protein concentrations were higher (P less than 0.01) for mares fed Diet F than for those fed Diet C and decreased (P less than 0.01) from colostrum (48 +/- 12 h after foaling to wk 8); lactose concentration was higher (P less than 0.05) for mares fed Diet C than for those fed Diet F and increased (P less than 0.01) from colostrum to wk 8. Minerals varied mainly with lactation stage. Milk fat was higher in linolenic acid and lower in linoleic acid for mares fed Diet F than for those fed Diet C. Glucose concentration was higher in plasma of mares fed Diet C; 3-hydroxybutyrate and acetate concentrations were higher in plasma of mares fed Diet F.

Manipulation of the fatty acid composition of milk by feeding protected canola seeds.

The feeding to dairy cows of canola seed protected from ruminal metabolism by emulsification and encapsulation in a matrix of aldehyde-treated protein resulted in a 10% increase in milk fat and no change in milk yield or protein content. Feeding the protected canola supplement significantly reduced the proportions of saturated fatty acids C16:0, C14:0, and C12:0 in milk fat; there were corresponding increases in proportions of C18:0, C18:1, C18:2, and C18:3. Yield of C18 monounsaturated and polyunsaturated fatty acids increased by 54%, which is equivalent to 143 g/d. Canola seed, enriched in C18:1, can be included in the diet and can result in significant changes in the proportions of saturated and unsaturated fatty acids in milk fat.

Composition and flavor of milk and butter from cows fed unsaturated dietary fat and receiving bovine somatotropin.

Composition and flavor of milk and butter were evaluated from cows divided into four treatments including a control, control with bST, added dietary fat from sunflower seeds with bST, or added dietary fat from safflower seeds with bST. Feeding added unsaturated dietary fat resulted in lower concentrations of short-and medium-chain and higher concentrations of long-chain fatty acids in milk fat and butter. Milk fat unsaturated fatty acid concentrations were 25.0, 28.4, 39.6, and 37.9%, and butter unsaturated fatty acid concentrations were 23.0, 26.9, 37.8, and 36.2% for control, control with bST, sunflower seeds with bST, and safflower seeds with bST, respectively. Sensory evaluations indicated that butters from the bST with sunflower seed and bST with safflower seed treatments were equal or superior in flavor to the control butter. Milk from cows receiving bST or fed added unsaturated dietary fat and receiving bST was no more susceptible to oxidized off-flavors than control milk. Butters from sunflower seed and safflower seed treatments with bST contained higher concentrations of unsaturated fatty acids, were softer at 4 and 20 degrees C, and possessed acceptable flavor and processing characteristics compared with butters from control and control with bST.