Calcium‐enriched goat milk,in comparison with similarly enriched cow milk,favours magnesium bioavailability in rats with nutritional ferropenic anaemia

BACKGROUND: The effects of dietary consumption of goat or cow milk, normal or enriched with calcium (Ca), on magnesium (Mg) bioavailability was evaluated in rats with nutritional ferropenic anaemia. Control and iron‐deficient rats were fed for 14 days with iron‐normal diets containing either normal (5000 mg kg^?1 diet) or high (10 000 mg kg^?1 diet) Ca content. RESULTS: The results shown that the goat milk diet gave the best results for digestive and metabolic utilization of Mg, both among the anaemic and the control group, with respect to the cow milk and standard diets. The most noteworthy result of Ca enrichment on the nutritive utilization of Mg is that it is less prejudicial in this respect when supplemented via goat milk than with cow milk or the standard diet. CONCLUSION: The results demonstrate the beneficial effects of the goat milk, normal or with double Ca, on the nutritional utilization of Mg; therefore the consumption of this type of milk for people with nutritional ferropenic anaemia can be recommended. Copyright © 2007 Society of Chemical Industry     

Beneficial effect of goat milk on nutritive utilization of iron and copper in malabsorption syndrome

The search for diets that improve the digestive and metabolic use of iron and copper in malabsorption syndrome led us to study goat milk for particular nutritional characteristics and compare it with cow milk, which is usually supplied. We studied the metabolism of iron and copper in transected rats (control) and in resected rats (resection of 50% of the distal small intestine). The diets used were the standard diet recommended by the American Institute of Nutrition and diets based on goat or cow milk. Intestinal resection reduced the apparent digestibility coefficient (ADC) of iron in the three diets tested. In the transected and resected rats, the ADC of iron was highest with the goat milk diet, followed by the standard diet and lowest with the cow milk diet. The ADC of copper was not affected by intestinal resection in the animals fed the goat milk diet, and was higher than that in the two groups of animals fed the other diets. Intestinal resection reduced the ADC of copper with the standard diet and the cow milk diet. When both groups of animals were fed the goat milk diet, the deposit of iron in the organs was greater than with those fed the cow milk diet and similar to that in those animals given the standard diet. The copper content in the kidneys was lower in the resected than in the transected animals, except in the case of those fed the goat milk diet, in which it was similar to that of the control (transected) rats. This study shows the beneficial effect of goat milk, with respect to cow milk, on the metabolism of iron and copper in control rats, especially those with malabsorption syndrome.     

Calcium-enriched goats' milk aids recovery of iron status better than calcium-enriched cows' milk, in rats with nutritional ferropenic anaemia

Ca-Fe interactions are known, but no studies are available about the effects of Ca-enriched goat or cow milk on Fe status in nutritional ferropenic anaemia (NFA). To examine this matter, control and Fe-deficient rats were fed for 14 d with goat or cow milk diets containing either normal or high Ca content (5000 or 10,000 mg/kg diet), and different indices and parameters related to iron status were measured. The apparent digestibility coefficient (ADC) and the Fe retention/intake (R/I) ratio were higher in control and anaemic rats fed goat milk diet (G diet), despite high-Ca content. Ca enrichment decreased Fe stores in liver and sternum in anaemic rats fed cow milk diet (C diet), however G diet did not modify Fe content in the organs studied in control and anaemic rats. In anaemic rats, Ca-supplementation decreased haematocrit, but platelets and serum Fe were not affected, however, in control rats platelets increased except for Ca-enriched G diet, this fact reveals that Ca-Fe interaction is minimized with G diet. Serum ferritin was always higher in rats fed G vs. C diet, both in control and anaemic rats fed either normal or Ca-enriched diets. Ca-supplementation decreased ferritin levels in control and anaemic rats fed C diet and also, though to a lesser extent, in those given the G diet. This indicates that with this G diet there is a better recovery of body Fe stores in anaemic rats, despite Ca-supplementation. In this study it is noteworthy that despite high Ca content, a goat milk diet resulted in minimal Ca-Fe interactions and did not adversely affect Fe status in rats with NFA.     

Bioavailability of Iron in Iron-Fortified Fluid Milk

The bioavailability of iron in pasteurized and homogenized cow's milk was determined by the hemoglobin depletion-repletion technique using rats. A water soluble citrate phosphate iron complex (iron, 16.67%) was used to fortify milk (iron, 38 ppm). Results showed that iron in milk was as well available as that in ferrous sulfate (99% vs 100%); the same was true when the iron complex was tested as such (not added to milk). Thus, milk or milk components appear not to adversely affect the bioavailability of added iron under the conditions of this experiment.     

Relative Bioavailability of Dietary Iron from Three Processed Soy Products

The relative bioavailability of iron from soy flour (SF), freeze-dried soy beverage (SB) and soy concentrate (SC) was determined utilizing a hemoglobin repletion bioassay. Weanling male rats were fed a low iron depletion diet (3.5 ppm Fe) for 4 wk. For the next 2 wk groups of rats were fed repletion diets containing 0, 6, 12, or 18 ppm added iron from ferrous sulfate, SF, SB, or SC. Slope ratio analysis revealed that the relative iron bioavailabilities from SC (92%) and SF (81%) were not different from the reference standard, ferrous sulfate added to a casein-based diet, whereas that from SB (66%) was significantly less (P<0.01) than the inorganic source of iron. Analysis of results at individual iron levels suggested an iron bioavailability of SC>SF>SB.     

Calcium-supplemented goat milk does not interfere with iron absorption in rats with anaemia induced by dietary iron depletion

The short-term effects of Ca-supplemented goat or cow milk on the nutritive utilization of Fe were evaluated in a metabolic balance study of rats with nutritional ferropenic anaemia (NFA). Control and Fe-deficient rats were fed for 14 d with goat or cow milk diets containing high-Ca content (10,000 mg/kg diet). The consumption of diets containing high levels of Ca for 14 d had no adverse effects on Fe absorption when the goat milk-based diet was provided, whereas for the cow milk-based diet, there was a significant fall in the apparent digestibility coefficient (ADC) of Fe. Moreover, the ADC and Fe retention/intake ratio (R/I) were higher in the anaemic rats fed the goat milk diet than among those fed the cow milk diet. These results suggest that despite a high dietary Ca content, goat milk minimizes Ca–Fe interactions and has no adverse effects on Fe absorption in rats with NFA.     

Mineral retention in three-week-old piglets fed goat and cow milk infant formulas

Goat milk and cow milk are commonly used in infant formula preparations and, as such, understanding the nutritional characteristics of infant formulas made from these milks is important. In this study, a goat milk infant formula was compared with an adapted (whey-enhanced) cow milk infant formula with respect to mineral absorption and deposition using the 3-wk-old piglet as a model for the 3-mo-old infant. Equal numbers of piglets (n = 8) were fed either the goat milk formula or the cow milk formula. The mineral composition of the prepared goat milk formula was higher than that of the prepared cow milk formula for most minerals, including calcium (75.1 vs. 56.7 mg/100 mL) but excluding iron, which was higher in the prepared cow milk formula (0.92 vs. 0.74 mg/100 mL). The amounts of calcium, phosphorus, and manganese absorbed by the piglets were significantly higher for the goat milk formula, whereas the amounts of zinc, iron, and magnesium absorbed were significantly higher for the cow milk formula. Apparent mineral absorption, relative to intake, was statistically higher in the cow milk formula for calcium and phosphorus, although the actual differences were very small (less than 1.3%). For copper, zinc, iron, and magnesium there was no significant difference between treatments in apparent mineral absorption, whereas for manganese, absorption was higher for the goat milk infant formula. The absolute mineral deposition was higher in piglets fed the goat milk formula for calcium, phosphorus, and manganese, whereas iron deposition was higher in the piglets fed cow milk formula. For all other minerals tested, there were no significant differences between treatments. The goat milk infant formula provided a pattern of mineral retention in the 3-wk-old piglet very similar to that of the adapted cow milk infant formula. The minor differences observed between the 2 appeared to be due to the different mineral contents of the 2 formulas.     

Effect of dietary inclusion of goat milk on the bioavailability of zinc and selenium in rats

The effects of dietary inclusion of freeze-dried goat and cow milk on the utilization of zinc and selenium, and on the metabolic fate of zinc, were studied in transected (control) and resected rats (resection of 50% of the distal small intestine). Intestinal resection reduced the apparent digestibility coefficient and zinc retention in the cow milk diet, whereas these biological indices were similar in transected (control) and resected rats with standard (without milk) and goat milk diets. The apparent digestibility coefficient and retention of selenium were not affected by intestinal resection in the animals fed with the three diets studied. In transected (control) and resected rats, the apparent digestibility coefficient and retention of zinc and selenium were higher for the goat milk diet than for the other two diets. Zinc deposits in the organs, expressed as microg/g dry weight were in order of decreasing concentrations: femur, testes, sternum, liver, kidney, heart, spleen, longissimus dorsi muscle and brain. Deposits were greatest with the goat milk diet, followed by the standard diet and were lowest for the rats given the cow milk diet, both for transected (control) and resected animals. We conclude that consumption of the goat milk diet produces a greater bioavailability of zinc and selenium and a greater deposit of zinc in key organs, for both the transected (control) and the resected rats, with respect to the standard diet and the cow milk diet.     

Study of nutritive utilization of protein and magnesium in rats with resection of the distal small intestine. Beneficial effect of goat milk

The search for diets to improve the nutritive utilization of protein and magnesium in malabsorption syndrome led us to study goat milk, because of its particular nutritional characteristics, and to compare it with cow milk, which is most commonly consumed. We studied the nutritive utilization of protein and magnesium in transected rats (control) and in rats with resection of 50% of the distal small intestine. The diets used were the standard diet recommended by the American Institute of Nutrition and diets based on lyophilized goat or cow milk. The consumption of goat milk produces better protein efficiency ratio and food conversion efficiency values, particularly in rats with intestinal resection, together with a higher nutritive utilization of protein. Magnesium apparent digestibility coefficient is not modified by intestinal resection in rats fed with goat milk-based diet, on the contrary to the standard and cow milk diets. Magnesium apparent digestibility coefficient is greater for the goat milk group, which is reflected in the greater quantity of this mineral stored in bone. These results demonstrate the beneficial effect of goat milk on the nutritive utilization of protein and on magnesium bioavailability, especially in animals with resection of the distal small intestine.     

Structural changes in cow,goat, and sheep skim milk during dynamic in vitro gastric digestion

Coagulation of milk in the stomach is the first crucial step in its digestion. Using a human gastric simulator, the dynamic gastric digestion of goat and sheep skim milk were compared with that of cow skim milk, focusing particularly on their physical characteristics. The gastric contents were analyzed for changes in dry matter and microstructure, and the extent of protein digestion. The study revealed that the skim milk from all species formed a curd within the first 15 min of gastric digestion, at which time the pH was ~6.1 to 6.3. Compared with cow skim milk, the dry matter contents of the clots formed from goat and sheep skim milk were lower and higher, respectively, which was due to the differences in their total solids and protein contents. Microstructural analysis showed that, as digestion progressed, the clot structure became more cohesive, along with a decrease in moisture content, which in turn affected the breakdown and hydrolysis of caseins by pepsin; this phenomenon was similar for milk from all species. However, the extent of moisture retained in the sheep skim milk clot appeared to be lower than those of the cow and goat skim milk clots. In addition, the relative firmness of the sheep milk clot was higher than those of the cow and goat milk clots at the end of gastric digestion. The pattern of protein hydrolysis by pepsin was similar for the milk of all species, despite the differences in the proportions of different proteins. The study provided insight into the coagulation kinetics of goat and sheep skim milk under in vitro gastric digestion conditions.     

Extrusion and iron bioavailability in chickpea (Cicer arietinum L.)

The effect of extrusion cooking (14% moisture and 130°C processing temperature) and of home-cooking on chickpea iron bioavailability was studied by the hemoglobin regeneration method in anemic rats. The iron pool was calculated from hemoglobin concentration and animal weight, and iron bioavailability from the relationship between iron pool gain (Δ pool) and mg of ingested iron. Iron bioavailability relative to ferrous sulfate was calculated by the following equation: Y=63.989 e^−0.0458X [Y= % absorbed; X=ingested Fe (mg)] on the basis of the results of control groups. The results showed that there was no significant difference between groups (extruded and cooked) in terms of mean percentage of iron bioavailability relative to Fe₂SO₄. We conclude that chickpea is a good source of iron and extrusion cooking is a process comparable to home-cooking in terms of iron bioavailability.     

Effect of Heat Treatment on Bioavailability of Meat and Hemoglobin Iron Fed to Anemic Rats

Efficiency of converting dietary iron from meat, bovine hemoglobin (HB) and ferrous sulfate into hemoglobin was investigated in anemic rats. Raw or autoclaved HB, and raw, autoclaved, boiled, or baked beef round, and ferrous sulfate were mixed into diets to give 36 mg Fe/kg diet. Heat treatments increased the efficiency of converting both HB and meat iron into hemoglobin by the anemic rats. Efficiencies of conversion were 23, 30, 33, 37, 37, 36 or 60 (LSD 0.05/0.01 = 4/6), respectively, for raw HB, autoclaved HB, raw meat, autoclaved meat, boiled meat, baked meat or ferrous sulfate. An in vitro measurement of iron availability in meat correlated poorly with bioavailability determined in rats. Cooking did not significantly affect the bioavailability of meat iron.     

Dietary goat milk improves iron bioavailability in rats with induced ferropenic anaemia in comparison with cow milk

Using rats with induced iron (Fe)-deficiency anaemia, this study investigated the effects of diets based on goat milk (GM) or cow milk (CM) lyophilates on the nutritive utilization of Fe, its deposit in target organs and haematic parameters involved in Fe metabolism. GM improved Fe metabolism, especially in Fe-deficient rats, leading to a higher Fe content in the spleen, liver, sternum and femur in comparison with CM. After feeding the rats for 2 weeks with the different diets, the anaemia had decreased, especially with GM, as assessed by higher haemoglobin regeneration efficiency (HRE), serum Fe, red blood cells (RBC) and packed cellular volume (PCV) levels and lower platelet count. We conclude that dietary GM improves Fe bioavailability in both control and anaemic rats, increasing Fe deposits in target organs and favouring the recovery of haematological parameters after ferropenic nutritional anaemia.     

Effect of processing on iron bioavailability of extruded bovine lung

The iron bioavailability of extruded and non-extruded lung products was compared with that of ferrous sulfate by the haemoglobin regeneration method. Extrusion was performed in a laboratory extruder (L/D 20:1) at several processing temperatures and moisture contents of the feed (115–160 °C; 16–30% moisture) with screw (4:1 compression ratio) speed fixed at 200 rpm. These conditions included the optimum observed for lung texturization. Bioavailability of iron was determined as efficiency of haemoglobin regeneration in rats fed bovine extruded lung-based diets, compared with non-extruded lung and casein standard diets. The results showed that iron bioavailability was high and comparable with ferrous sulfate standard, irrespective of the extrusion conditions adopted. These results showed that extruded lung can be used as a good iron source, even if processed in conditions deleterious for other nutrients.     

蛋氨酸螯合铁对大鼠肝脏物质代谢相关基因表达的影响

研究缺铁日粮中补充蛋氨酸螯合铁与硫酸亚铁对大鼠铁利用及肝基因表达的影响。20只SD断奶大鼠,建立缺铁大鼠模型,然后均分成两组,分别饲喂加入等量铁(35mg/kg)的蛋氨酸螯合铁和硫酸亚铁日粮,补铁后4、7d后测定体重、血红蛋白,组织器官铁含量及血清总铁结合力;并提取大鼠肝组织总RNA,用Afymetrix基因芯片进行基因表达分析,研究硫酸亚铁与蛋氨酸螯合铁对缺铁大鼠物质代谢基因表达的差异。结果表明,蛋氨酸螯合铁组大鼠增重明显高于硫酸亚铁组,血红蛋白、总铁结合力含量有升高趋势。与硫酸亚铁组比较,蛋氨酸螯合铁组肝组织珠蛋白与转铁蛋白合成相关基因,以及胆固醇合成,脂肪代谢、ATP合成相关基因明显上调。补充蛋氨酸螯合铁动物铁代谢和物质代谢存在显著差异。     

Influence of high dietary iron as ferrous carbonate and ferrous sulfate on iron metabolism in young calves

Twelve intact male Holstein calves averaging 90 kg and 12 wk of age were fed one of three dietary treatments for 28 d. The diets were A) control, B) control plus 1000 ppm iron as ferrous carbonate, and C) control plus 1000 ppm iron as ferrous sulfate monohydrate. Calves were dosed orally on d 15 of the treatment period with 1 mCi of iron-59. Neither source of added iron had a significant effect on weight gains, feed consumption, hemoglobin, packed cell volume, serum total iron, serum total iron-binding capacity, unbound iron-binding capacity, serum copper, tissue copper, fecal dry matter, or a consistent effect on fecal pH. The ferrous carbonate had no significant effect on stable zinc or stable iron in any tissue studied. Calves fed ferrous sulfate had higher average stable iron in most tissues and significantly more in the small intestine. Tissue zinc was lower in spleen and pancreas of ferrous sulfate-fed calves. Both sources of added iron sharply reduced iron-59 in serum, whole blood, and body tissues. The reduction was substantially greater in calves fed the ferrous sulfate iron. Iron in ferrous sulfate had a higher biological availability than that in the ferrous carbonate; however, bioavailability of the ferrous carbonate iron appeared to be substantial and considerably more than that noted in previous studies in which a different source of ferrous carbonate was used. The maximum safe level of dietary iron is materially influenced by the source of iron with a higher tolerance indicated for ferrous carbonated than ferrous sulfate monohydrate.     

Dietary fibers and supplementary iron in a milk replacer for veal calves

Thirty 1-wk-old male Holstein calves were allotted randomly to six groups into a 3 X 2 factorial design. The control diet was skim milk, whey, tallow, vitamins, and minerals. Either Alpha-Floc or pectin was added at 5% dry matter. Supplementary iron was added at 30 and 50 ppm (dry basis). The six diets were fed for 14 wk. Calves without supplementary iron were mildly anemic at 6 wk and severely at 14 wk (7 and 5 g/dl hemoglobin). At 14 wk, both fibers had decreased blood hemoglobin in calves given supplementary iron. Feed refusal began at 8 wk with the appearance of anemia for calves unsupplemented with iron, but both Alpha-Floc and pectin decreased feed refusal. Supplementary iron practically eliminated feed refusal. Supplementary iron improved average daily gain and feed conversion, but dietary fibers had no effect. Adding Alpha-Floc and pectin to the diets reduced frequency of diarrheic feces. Mean carcass weight of calves fed supplementary iron was 11.6% higher than that of unsupplemented calves. Supplementary iron decreased liver lipids and increased glutamic oxaloacetic transaminase activity in blood plasma.     

Effect of dry matter intake from whole goat milk and calf milk replacer on performance of Nubian goat kids

The dry matter in calf milk replacer was compared with dry matter in goat milk for Nubian goat kids. Kids were fed the following diets from 4 days of age for 6 wk: 1) whole goat milk (14.0% dry matter), 2) calf milk replacer (13.5% dry matter), and 3) calf milk replacer (18.0% dry matter). Body weight of kids fed whole milk and 18.0% dry matter milk replacer increased each week. Kids fed the 13.5% dry matter milk replacer increased in weight to the 3rd wk but steadily declined thereafter. Total weight gain was more for kids fed whole milk (3.89 kg) than for kids fed milk replacer diets with 13.5 or 18.0% dry matter (.79 and 3.06 kg, respectively). For the first 3 wk, average daily gain was lowest for kids fed 18.0% milk replacer diet, but highest for wk 4 to 6. These data indicate that 3-week-old goat kids can utilize large amounts of dry matter from milk replacer to sustain a rate of growth similar to that of kids fed whole milk; however, high amounts of dry matter from milk replacer are poorly utilized by kids during the first 3 wk of life.     

Iron absorption and haemoglobin status of rats fed a ferrous bisglycinate‐fortified growing‐up milk

BACKGROUND: Infants and toddlers aged 6–24 months constitute one of the groups at highest risk of iron deficiency. A promising alternative for ferrous sulfate (FS) might be ferrous bisglycinate (FeAAC), which is less likely to cause sensory changes in the food vehicle. This work aims to compare the effect of FeAAC with that of FS, when added to a growing‐up milk, on the iron and haemoglobin status in weanling rats using a depletion–repletion model. RESULTS: After the repletion period no significant differences were found in iron absorption, Hb concentration, Hb iron, Hb regeneration efficiency (HRE), mean corpuscular volume (MCV), mean corpuscular Hb (MCH), mean corpuscular Hb concentration (MCHC), serum iron, total iron binding capacity (TIBC), transferrin saturation (TS), and ferritin between the group fed a growing‐up milk fortified with FS and the group fed one fortified with FeAAC. Furthermore, iron absorption, HRE, MCV, MCH, serum iron, and TS were significantly (P < 0.05) higher in groups fed either type of iron‐fortified growing‐up milk compared to the control group (AIN‐93G diet). CONCLUSION: A growing‐up milk supplemented with FeAAC showed an improvement in the iron absorption and haemoglobin status at the same level as those of FS. Copyright © 2009 Society of Chemical Industry     

山羊奶与牛奶和人奶营养成分的比较

对山羊奶、牛奶和人奶中蛋白质、脂肪、维生素、矿物质等主要营养成分进行了比较,分析了3种奶中主要营养成分的差别。通过比较发现,山羊奶在总体营养成分方面优于牛奶,更接近人奶。但山羊奶存在铁、叶酸和维生素B12含量较低以及羊奶膻味的问题,应在营养上对这方面加以重视。