Transfer of dietary selenium to milk.

Twenty-five lactating cows were used in groups of five to study the amounts of dietary selenium transferred to milk. Amounts of dietary selenium varied from deficient to five times the adequate concentration and ranged between 41 ppb and 828 ppb. Sodium selenite and brewers grains, a rich naturally occurring source of selenium, supplied supplemental selenium. Selenium in milk and plasma were related to the amount consumed, but the response was nonlinear since 4.8% of the added selenium was transferred to milk with a deficient diet but only .9% of the amount of added selenium was in milk of cows consuming diets adequate in selenium. Nineteen percent of the selenium furnished in brewers grains appeared in the milk when the ration was deficient in selenium. The small amounts of selenite selenium transferred from the diet to milk were too little (5.5 micrograms/kg) to be a potential hazard to human health when a diet containing .1 to .2 ppm of selenium was fed to dairy cows, an amount sufficient to meet the cow's dietary needs.     

Studies of bioavailability of different food sources of selenium in experiment

The selenium bioavailability in selenium enriched Spirulina (Arthrospira platensis), phycocyanin containing (Se-PC) protein isolate, separated from this micro algae and in sodium selenite was studied and compared in rats. The daily dose of selenium per one animal was 5 microgram in all experimental groups. The average selenium levels in blood serum and liver of animals that received sodium selenite during 14 days were the highest. The average selenium level in blood serum of animals fed with selenium enriched Spirulina platensis after 14 days of receiving was the same with the control group, but the average concentration of selenium in their liver was rather high and close to this parameter of sodium selenite animal group. The animals which were fed with Se-PC showed better results. Their average selenium level in blood serum was higher than in Spirulina group, but lower than in sodium selenite group. The average concentration of selenium in the liver of these animals was the same with sodium selenite animal group. As regards to animals that were fed with selenium enriched Spirulina, Se-PC and sodium selenite for 21 days, the average selenium levels ratio in their blood serum and liver was higher than in control group, but these results were not significantly different among each other. The concentrations of selenium in seminal glands in all groups of animals including control group both after 14 and 21 days feeding were close to each other.     

Dietary energy regulation during gestation on subsequent lactational response to soybean meal or dried brewers grains

Forty-two Holstein cows were paired by body condition and mature equivalent milk production and fed either a high or low energy diet for the last 16 to 18 wk of lactation. Cows fed the high energy diet produced more milk (21.6 versus 17.6 kg/d), gained more body condition, and were heavier after calving (641 versus 591 kg) than cows fed the low energy diet. Beginning wk 3 postpartum, half the cows in each prepartum energy group were fed supplemental dried brewers grains or soybean meal. During wk 1 to 15 of lactation, cows from the high energy group produced more 3.5% fat-corrected milk (33.8 versus 31.3 kg/d), consumed less dry matter (23.2 versus 24.4 kg/d), and lost more body weight (-2.7 versus .9 kg/wk) compared with cows from the low energy group. Milk production, feed intake, and body weight change were not affected by protein source. The high amount of bound nitrogen in dried brewers grains resulting in decreased intestinal digestibility of escape protein may have been responsible for the lack of production response to this protein source.     

牦牛骨营养粉对大鼠骨密度及血清生化指标的影响

目的：研究牦牛超微骨粉配以菊粉和酪蛋白磷酸肽后对大鼠骨密度及血清生化指标的影响。方法：雌性Wistar大鼠50只,体重90±10g,随机分为5组,各组饲料钙含量均为10±1g Ca /kg。结果：与对照组比较试验组大鼠股骨密度分别增加23.48%、20.0%、21.74%、18.26%。血清碱性磷酸酶、甘油三酯含量均没有统计学差异(p＞0.05),血清胆固醇含量试验组二显著低于对照组(p＜0.05),降低了9.82%。血清中钾、钠含量在各组之间无统计学差异(p＞0.05),但血清钙含量试验组较对照组分别降低了47.1%、12%、14.49%、8.29%,血清氯含量试验组二显著低于对照组和其他试验组(p＜0.05)。结论：牦牛骨营养粉能显著改善大鼠骨质,且不会对血清生化指标产生不良影响。     

Milk production response to diets supplemented with dried brewers grains, wet brewers grains, or soybean meal

Forty four multiparous Holsteins, 114 +/- 28 days in milk (32 kg/day, 3.4% fat), were fed a basal diet of 12% crude protein and 20% acid detergent fiber for 10 days, then stratified by milk production into four groups. Cows were randomized to one of nine diets in a 3 X 3 factorial in which basal was supplemented with dried brewers grains, wet brewers grains, or soybean meal to supply in the diet 14.5, 16.0, and 17.5% crude protein. Eight cows remained on basal during the 50-day trial. Basal contained: 14% alfalfa silage, 27% ensiled ground-corn, 53% corn silage, and 6% vitamin-mineral mix. Milk production (kg/day) for cows fed dried brewers grains (29.4) and wet brewers grains (28.9) was higher than soybean meal (26.2) and basal (23.1). Milk production was different for diets with high (29.6) vs. low (27.8) and medium (27.2) protein. Dry matter intake (as percent of body weight) was 3.7, 3.5, 3.3, and 2.9 for dried brewers, wet brewers, soybean meal, and basal, respectively. Milk protein percent and milk fat percent differed for protein source. Rumen fluid ammonia nitrogen for combined 2, 4, and 6 h post-feeding, was (mg/100 ml) 10.4 for dried brewers, 14.9 for wet brewers, and 18.0 for soybean meal and increased from 13.2 to 15.4 with increased protein. Plasma urea tended to follow patterns of rumen ammonia. Dried brewers grains had lower apparent nitrogen digestibility but equal nitrogen balance, indicating more efficient metabolic use than soybean meal.     

Effect of prepartum energy intake and postpartum protein source on plasma somatotropin and insulin in lactating cows

Forty-two Holstein cows were fed a high or low energy diet during the last third of lactation, then fed soybean meal or dried brewers grains in the subsequent lactation. Responses of plasma somatotropin and insulin to arginine were measured at 6 and 15 wk postpartum. Basal somatotropin, response area, and peak value were greater at 6 versus 15 wk of lactation. Insulation responses were greater at 15 wk of lactation. At 6 wk, basal somatotropin was higher (6.1 versus 4.1 ng/ml) in cows fed the low energy diet prepartum. Shape of somatotropin response curves at 6 wk differed between prepartum energy intakes, but response areas were similar. Plasma insulin at 6 wk tended to be higher (1.0 versus .7 ng/ml) in cows fed dried brewers grains. At 15 wk, both insulin and somatotropin response areas tended to be smaller for cows fed dried brewers grains, and shape of insulin response curves differed between protein sources. Of the observed hormonal responses to diet, only 6-wk plasma somatotropin was associated with differences in production parameters. Somatotropin secretion during early lactation appears to respond to prepartum changes in the energy status.     

Evaluation of the physical structure of fodder beets, potatoes, pressed beet pulp, brewers grains, and corn cob silage

The physical structure of fodder beets, raw potatoes, ensiled pressed sugar beet pulp, ensiled brewers grains, and corn cob silage was evaluated in diets containing concentrates and either corn silage or grass silage as the roughage source. In one series of experiments, the chewing activity of eight cows was measured over 4 d. The beet pulp and fodder beets were added to the two roughage sources at two ratios [20:80 and 35:65, dry matter (DM) basis]. Potatoes, brewers grains, and corn cob silage were fed in a fixed amount (5 to 6 kg of DM) with corn silage. The chewing indexes (eating and ruminating time per kilogram of DM ingested) for fodder beets and beet pulp averaged 34.3 and 32.3 min/kg of DM, respectively, and were hardly affected by the nature of the roughage or by the inclusion ratio. The chewing indexes for potatoes, brewers grains, and corn cob silage were 23.7, 56.6, and 41.6 min/kg of DM, respectively. In another series of experiments using 8 to 11 cows, the ratio of roughage to concentrates was lowered weekly by 5 percentage units, and the critical rough-age portion of the diet was determined (i.e., the amount just before a lack of physical structure was observed). The roughage source was either fed alone or supplemented with about 4 kg of DM of the experimental feed. The critical roughage portion of the diet decreased when the experimental feeds were added; the decrease was greatest with ensiled pressed beet pulp and was lowest with corn cob silage.     

Glutathione-related enzymic activities in rats receiving high cholesterol or standard diets supplemented with two forms of selenium

Selenium deficiency was produced in rats fed a high cholesterol diet for 57 days (Group 1). It was characterized by an increase in malondialdehyde (MDA) an end product of lipid peroxidation and by the dramatic collapse of selenium-dependent glutathione peroxidase activity (GSHPx) in plasma, erythrocytes and in homogenate supernatant fraction of liver, kidney and heart compared with rats fed a standard diet containing sodium selenite (Group 3). A compensatory rise in the activity of liver glutathione S-transferase (GST) activity and also in glutathione reductase (GSSGR) activity was accompanied by an increase in NADPH-generating enzymes glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase. Adequate dietary selenium supplementation by Se-rich Spirulina corrected all the selenium deficiency effects (Group 2), then, GSHPx and NADPH-consuming enzymes activities were of the same magnitude as those exhibited by rats fed a standard diet containing adequate selenium in the form of sodium selenite. Based on this study, it is concluded that Se-enriched Spirulina behave as an excellent selenium carrier.     

Influence of dietary selenium and vitamin E on quality of veal

Three groups of six calves each were fed a milk replacer and a starter concentrate for 15weeks. Calves of the first group received the basal diet containing selenium (Se) and vitamin E at 0.095-0.128mg and 30-33mg per kg of total solids, respectively. Calves of the second group received the basal diet supplemented with Se-enriched yeast to increase dietary Se concentration to 0.50mg/kg. The third group of calves received the latter diet supplemented with vitamin E to increase its concentration to 100mg/kg. There was no effect of diet on growth rate, digestibility of dry matter and Se, chemical composition of meat (M. Longissimus thoracis et lumborum), meat colour and fatty acid profile of meat lipids. The Se supplementation significantly increased Se concentration in muscle from 0.21 to 0.43mg/kg. The activity of glutathione peroxidase (GSH-Px) in muscle and liver tissue of Se-supplemented animals was increased by 56% and 67%, respectively, compared to the control. The combined supplementation of vitamin E and Se significantly improved the lipid stability of meat compared to the control diet, but not compared to the Se-supplemented diet. It can be concluded that dietary Se supplementation increases the concentration of Se and the GSH-Px activity in meat, but has limited potential for improving meat oxidative stability.     

CHLORINATED HYDROCARBON TISSUE RESIDUES FROM BOVINE FEED SUPPLEMENTS: APPLE POMACE AND FISH MEAL

Beef cattle were fed corn silage with or without apple pomace andlor fish meal. Trace levels of dicofol, an acaricide used on apples, were found in tissues of animals fed apple pomace. Detectable levels of p, p'-DDE were also found in tissues of these cattle since dicofol, as formulated, contains about 2.5% p, p'-DDT. The addition of fish meal containing traces of p,p'-DDE to the ration did not consistently increase p, p'-DDE concentrations since this supplement only comprised 3% of the diet. The corn silage and fish meal each contained trace concentrations of polychlorinated biphenyls (PCBs) but PCBs were not detectable in tissues of any of the cattle.     

Influence of dietary vitamin E and selenium on muscle fatty acid composition in pigs

A total of 28 female pigs were fed a basal diet containing a low amount of α-tocopherol (10.3 mg/kg; control), and diets supplemented with 0.3 mg selenium/kg (group Se) or with 200 mg α-tocopherol/kg (group V) at the growing-finishing period. Increasing dietary level of vitamin E resulted in higher concentration of α-tocopherol in plasma and muscle immediately after slaughter and 4 h later (P⩽0.05). The fatty acid composition of muscle microsomes and mitochondria was slightly affected by the diet. Corresponding to the minor changes of the membrane fatty acid composition the fluidity was unaffected by the diet. A positive relationship was observed between the resistance to in vitro stimulation of peroxidation and the vitamin E content of the muscle samples. Supplementation with selenium did not reduce the lipid oxidation after stimulation. In conclusion, even though the effect was minor, vitamin E improved the antioxidative status in pork.     

Selenium enriched spirulina and phycocyanin are sources of bioavailable selenium

Rats were fed for two weeks low-selenium semi-synthetic diet supplemented with different sources of selenium: sodium selenite (selenium concentration 96 and 350 mcg/kg diet), selenium-enriched Spirulina (selenium concentration 350 mcg/kg diet) and selenium-enriched Phycocyanin (selenium concentration 96 mcg/kg diet). Selenium bioavailability was evaluated in terms of selenium accumulation in blood and liver as well as glutathione peroxidase activity. It was shown that selenium from selenium-enriched Spirulina and selenium-enriched phycocyanin was high bioavailable in rats.     

酵母硒对肉鸡组织硒含量及抗氧化能力的影响

试验选择108只1日龄健康AA肉仔鸡(公母混合),随机分为3组,每组3个重复,每重复12只鸡,对照组饲喂基础日粮,试验组A在对照组日粮基础上添加0.3mg/kg硒(亚硒酸钠),试验组B在对照组日粮基础上添加0.3mg/kg硒(酵母硒),饲养35d。通过检测试验鸡组织中硒含量和超氧化物酶活性及丙二醛含量,来研究酵母硒对肉鸡组织硒含量和抗氧化能力的影响。结果表明:酵母硒组鸡群的肌肉组织中硒含量显著高于对照组;与对照组相比,酵母硒和亚硒酸钠均可显著提高鸡群血液和组织中超氧化物歧化酶活性,显著降低丙二醛含量。     

Effects of sodium carbonate on milk yield, milk composition, and blood components of dairy cows in early lactation

Eighteen multiparous Friesian cows were paired according to lactation number and expected calving date and assigned randomly to one of two diets in a crossover design experiment to study effects of sodium carbonate on milk yield, milk composition, blood metabolites plus Na, and K in early lactation. Diets were concentrate containing either 0 or 1.2% sodium carbonate (as fed) for ad libitum intake plus 7.0 kg of wet brewers grains and 5.5 kg of long-stemmed alfalfa hay per cow daily. Dry matter intake, milk yield, milk protein percentage and yield, and percentages of milk lactose and milk SNF were not significantly affected. Compared with the control diet, the sodium carbonate treatment increased milk fat percentage (3.98 vs. 3.53%) and yield (1.23 vs. 1.07 kg/d), 4% FCM yield (30.9 vs. 28.2 kg/d) and milk total solids (12.47 vs. 12.04%). No significant differences were observed in blood plasma concentrations of glucose, CP, urea, acetate, beta-hydroxybutyrate, triglycerides, FFA, Na, or K when sodium carbonate was added to diets for early lactation cows.     

Dietary selenium intake influences Cx43 dephosphorylation, TNF-α expression and cardiac remodeling after reperfused infarction

Scope : Post‐infarct left ventricular dysfunction and cardiac remodeling are the primary causes of chronic heart failure in industrialized countries. In the present study, we examined the influence of dietary selenium intake on cardiac remodeling after reperfused myocardial infarction and explored one of the possible mechanisms. Methods and results : Rats were fed a diet containing either 0.05 mg/kg (Low‐Se, group of rats receiving the low‐selenium diet) or 1.50 mg/kg (group of rats receiving the high‐selenium diet) selenium. At the end of the 5th week of the diet, rats were subjected to transient (1 h) coronary ligation followed by 8 days of reperfusion. Infarct size and cardiac passive compliance were increased in the Low‐Se group compared with group of rats receiving the high‐selenium diet. Similarly, indices of cardiac remodeling (thinning index and expansion index) were more altered in Low‐Se hearts. These adverse effects of the Low‐Se diet on cardiac remodeling were accompanied by an increase in cardiac TNF‐α content, a decreased activity of antioxidant seleno‐enzymes and an increase in connexin‐43 dephosphorylation. Conclusion : Dietary selenium intake influences post‐infarct cardiac remodeling even when provided within the range of physiological values. Our data suggest that the cardioprotective effect of selenium might be mediated by a reduced oxidative stress, a lower connexin‐43 dephosphorylation, and a decreased TNF‐α expression.     

Effects of feedborne Fusarium mycotoxins on the performance, metabolism, and immunity of dairy cows

Little is known about the effects of feedborne Fusarium mycotoxins on the performance, metabolism, and immunity of dairy cattle. A total mixed ration (TMR) containing a blend of feedstuffs naturally contaminated with Fusarium mycotoxins was fed for 56 d to 18 midlactation Holstein cows (average milk production, 33 kg/d) in a completely randomized design with repeated measures that included 3 treatments: 1) a control diet, 2) a contaminated diet, and 3) a contaminated diet + 0.2% polymeric glucomannan mycotoxin adsorbent (GMA). Wheat, corn, and hay were the contaminated feedstuffs used in the study. Deoxynivalenol was the major contaminant and was found in the TMR at levels of up to 3.6 μg/g of dry matter. Body weight, body condition score, dry matter intake, net energy balance, milk production, milk composition, somatic cell count, blood serum chemistry, hematology, serum Ig concentrations, and coagulation profile were measured. Dry matter intake and body weight, as well as milk production, milk composition, and SCC, were not affected by diet. Total serum protein and globulin levels increased significantly in cows fed the contaminated TMR compared with cows fed the control diet at 42 d, whereas the albumin:globulin ratio decreased. Serum urea concentrations were significantly elevated throughout the experiment in cows fed the contaminated diet compared with those fed the control diet. Serum IgA concentrations decreased significantly in cows fed the contaminated TMR at 36 d of feeding. Feeding GMA prevented these effects. Serum sodium concentration and osmolality levels were increased throughout the experiment in all cows fed the contaminated diets. We concluded that feed naturally contaminated with Fusarium mycotoxins can affect the metabolic parameters and immunity of dairy cows and that GMA can prevent some of these effects.     

Effects of dietary microalgae,other lipid sources,inorganic selenium and iodine on yolk n‐3 fatty acid composition,selenium content and quality of eggs in laying hens

BACKGROUND: This aim of this study was to investigate the effects of supplementing laying hen diets with different n‐3 fatty acid sources (linseed oil, fish oil and microalgae) on egg quality and fatty acid profile. The addition of inorganic selenium (Se) and iodine (I) and their effects on egg characteristics and Se concentration were also evaluated. RESULTS: A significantly lower egg weight was found in the control group and in groups fed a diet containing fish oil or a diet containing microalgae plus Se and I. Yolks from all supplemented diet groups exhibited a significant reduction in n‐6 fatty acid content compared with the control group. The docosahexaenoic acid (DHA) content of yolks was higher (P < 0.01) in all supplemented diet groups. Selenium supplementation increased the Se concentration (P < 0.001) in eggs. CONCLUSION: The results of this study provide evidence that an improvement in egg weight and in the DHA content of yolks can be achieved by feeding hens a microalgae‐rich diet, which avoids the unpleasant flavours associated with fish oil supplementation. Dietary inorganic Se, especially in combination with I, can enhance the concentration of Se in eggs. Copyright © 2009 Society of Chemical Industry     

酵母硒和枣粉对鸡肉成熟过程中肉品质及氧化特性的影响

研究酵母硒和枣粉对肉鸡生长性能、肉品质和抗氧化性能的变化.选取240只1日龄白羽肉鸡,随机分为4组,每组3个重复,每个重复20只.分别为CK组(基础日粮)、J组(基础日粮+8％枣粉替换8％玉米,质量分数)、0.3S组(基础日粮+0.3 mg/kg酵母硒)和0.3S+J组(基础日粮+0.3 mg/kg酵母硒+8％枣粉替换...     

Influence of cation-anion balance on feed intake, body weight gain, and humoral response of dairy calves.

The objective of this study was to examine the influence of diets with varying cation-anion balance on performance and humoral responses in young, growing dairy calves. Twenty-eight Holstein and 4 Jersey female calves were blocked at 56 to 70 d after birth according to breed and age and assigned randomly to dietary treatments of 0, 21, 37, and 52 meq(Na + K) - Cl/100 g of dietary DM. Diets were based on cracked corn, dried brewers grains, and oats and were fed for 8 wk. Feed intake and average daily gain tended to increase quadratically, being highest for calves fed the +37-meq diet and lowest for those fed the 0-meq diet. Blood and urine pH increased linearly with increasing dietary cation-anion balance. Plasma Ca increased linearly, and Mg and Cl decreased linearly with increasing cation-anion balance. Plasma Na and P were unaffected by dietary treatments. Urinary Ca, Mg, and Cl excretions decreased linearly; urinary P, Na, and K excretion increased linearly with increasing dietary cation-anion balance. Blood pH increased linearly with increasing dietary cation-anion balance. Blood partial pressure of CO2 and HCO3 increased concurrently with increasing dietary cation-anion balance. Results indicate that altering cation-anion balance may impact DMI and average daily gain in the young ruminant.     

Effect of dietary high-oleic sunflower oil on pork carcass traits and fatty acid profiles of raw tissues

Ten gilts were randomly assigned to either a control sorghum-soybean diet or a similar diet containing 12% high-oleic sunflower oil (HOSO). No significant differences between the two groups were found in feedlot performance, carcass muscling and marbling score, but animals fed the HOSO diet had softer carcass fat and oilier carcasses than those fed the control diet. The ratio of monounsaturated fatty acids to saturated fatty acids (M/S) for subcutaneous fat increased from 1·58 in the control group to 3·76 in the HOSO group (138% increase); the M/S ratio for muscles (longissimus dorsi, semimembranosus and semitendinosus) increased from 0·96–1·19 to 1·84–1·88 (73% increase on an average). The percentage of polyunsaturated fatty acids in both adipose or muscle tissue was generally similar between the two diet treatments.