Tolerance evaluation of overdosed dietary levels of 25-hydroxyvitamin D3 in growing piglets.

Forty-eight, cross-bred (GL × LW × P) piglets were used in a 42-day tolerance trial to assess the effects of feeding diets supplemented with vitamin D or increasing levels of 25-hydroxyvitamin D3 (25-OH-D3 ). Six-week-old piglets (24 castrate males, 24 females) were used. Two replicate groups of 6 piglets were randomized by weight and allocated to four dietary treatments. The control group (T1) was supplemented with 50 µg vitamin D3 /kg feed. The experimental groups received 25-OH-D3 at the recommended dose (T2: 50 µg/kg = 1x), at 250 µg/kg (T3: 5x) or at 500 µg/kg (T4: 10x) respectively. Feed intake and daily weight gain were measured weekly, and the animals were examined by a veterinarian daily. After 42 days, body mass, blood, urine, bone and tissue samples were analysed and a pathology examination conducted. Dietary treatments had no significant effect on final body mass or daily weight gain. The 25-OH-D3 plasma concentration in T1 was 17 ± 3 ng/ml (mean ± SD) while the respective values of the experimental groups were significantly increased in T2, T3 and T4. Tissue concentrations of 25-OH-D3 were higher in liver and muscle for T3 and T4 and in skin for T4 than in T1. However, neither gross pathology nor histology, nor blood and urine characteristics, nor bone parameters were affected by dietary treatments. Weight of organs as well as dry matter, ash and calcium content of kidneys remained unaffected by dietary 25-OH-D3 intake. Furthermore, no changes were observed for general indicators of health. The results of this study demonstrated that feeding piglets with 25-OH-D3 at 5 or 10 times the recommended level had no adverse effects on any of the biological parameters measured. It was concluded that 25-OH-D3 can be regarded as a supplement with a very high safety margin when used at the recommended level.

Effect of low doses of dietary rare earth elements on growth performance of broilers.

The present study was designed to investigate effect of dietary rare earth elements (REE), including both organic and inorganic compounds, on growth performance of broilers. In experiment 1, a total of 180 male Ross broiler chicks were allocated to 72 pens with different assignment: four chicks per pen or individually. The following three treatment diets were applied: control, REE-chlorides at a dose of 40 mg/kg and REE-citrate at a dose of 70 mg/kg. Each treatment group had 24 pens containing both assignments (12 pens each). In experiment 2, a total of 72 male 3-day-old Ross broiler chicks were separated to four groups: control, REE-chlorides at a dose of 70 mg/kg and REE-citrate at doses of 70 mg/kg and 100 mg/kg. In experiment 1, dietary REE-citrate improved body weight gain during the overall period by 5.0% (p < 0.05) while the increase with REE-chloride was not significant. In experiment 2, growth effects (p < 0.05) were only found in the period from day 21 to slaughter with all REE forms, and feed conversion ratio was improved by 3.4% (p < 0.05) with REE-citrate. No significant effects of REE were found on chill weight, percentages of breast meat, thigh weight, drumstick weight and wing weight. Concentrations of La and Ce in the liver and muscles were very low, accounting for 0.11-0.76 and 0.02-0.30 mg/kg respectively. There was weak tendency for a dose-response relationship especially in the groups supplemented with REE-chlorides. The main blood serum biochemical parameters were not significantly affected by REE in the diets. The results suggest that dietary supplementation of low doses of REE-citrates might improve growth performance of broilers without affecting carcass composition and health of the broilers.

[Biochemical bone resorption markers during the healing of osteoporotic fractures]. / Biochemische Knochenresorptionsmarker in der Heilungsphase osteoporotischer Frakturen.

BACKGROUND: This study investigated the progression and clinical relevance of biochemical resorption marker values during fracture healing in osteoporosis. PATIENTS AND METHODS: In 44 patients with distal radius fractures and 29 patients without fractures, the blood and urine concentrations of pyridinoline (PYD), deoxypyridinoline (DPD), N-telopeptides (NTx), and bone sialoprotein (BSP) were recorded on the day of trauma as well as during further progression. All postmenopausal patients underwent bone density measurement. Accordingly, patients were divided into premenopausal, postmenopausal osteoporotic, and postmenopausal nonosteoporotic groups. RESULTS: Between the groups, PYD, DPD, and NTx showed significant differences in their initial values. However, their further relative progression was primarily affected by the chosen therapy. CONCLUSION: Bone resorption markers can diagnostically point to osteoporosis and are significant parameters in fracture healing.

Biochemical bone markers are useful to monitor fracture repair.

UNLABELLED: Biochemical bone markers reflect bone metabolism but little is known regarding their usefulness during fracture repair. Reduced bone mineral density may influence fracture healing. We hypothesized that low bone mineral density results in decreased levels of bone markers during the acute phase of fracture healing, especially in women who are postmenopausal. We also addressed the question of different fracture types and locations resulting in different levels of bone markers. Urinary levels of N-terminal cross-linked telopeptide, deoxypyridinoline, and pyridinoline were measured preoperatively and postoperatively in patients with hip fractures, distal forearm fractures, and in 25 control subjects. Bone mineral density was determined using quantitative computed tomography of the spine. Patients with low bone mineral density, especially women who were postmenopausal, had greater concentrations of N-terminal cross-linked telopeptide when compared with patients with normal bone mineral density or men. Patients with pertrochanteric fractures had greater concentrations than patients with femoral neck fractures, as did patients with hip fractures compared with patients with fractures of the distal forearm. These results suggest that levels of bone markers increase during fracture healing despite low bone mineral density and that different fracture types and locations result in different levels of bone markers. LEVEL OF EVIDENCE: Prognostic study, Level I (high quality prospective study-all patients were enrolled at the same time with > or = 80% of followup of enrolled patients). See the Guidelines for Authors for a complete description of levels of evidence.

[Biochemical bone marrow markers and their significance in postmenopausal osteoporosis--a new method in the diagnosis of osteoporosis?]. / Biochemische Knochenmarker und deren Bedeutung bei der postmenopausalen Osteoporose--Eine neue Methode in der Osteoporosediagnostik?

This study analyzes the qualification of biochemical markers in the diagnosis of osteoporosis and evaluates the potential of a multiparametric classification of premenopausal and non-osteoporotic as well as osteoporotic postmenopausal women, which is based on biochemical marker profiles. For this evaluation data of 29 women in the age between 28-74 years were used. The classification of osteoporosis was done by the trabecular density of the lumbar spine using qCT-measurements. The biochemical markers of formation and resorption AP, bAP, OC, ucOC, PICP, PYD, DPD, NTX, BSP and vitamin K were analyzed on day 1 and 42 in all patients. For vitamin K we found significant distribution differences between non-osteoporotic and osteoporotic women (p<0.005). The crosslinks PYD and DPD showed weakly significant differences. All other parameters exhibited non-significant results. Vitamin K acted with a sensitivity of 64% and a specificity of 82%. The used multiparameter classification process improved sensitivity and specificity considerably. The parameter profiles of OC/PYD, vitamin K/PYD and vitamin K/bAP revealed the highest sensitivities with specificities of more than 82%.

Effect of dietary rare earth elements on growth performance and blood parameters of rats.

Rare earth elements (REE) have been shown to influence growth performance in animal production, especially in pigs. In the present study, the effect of oral administration of rare earth elements on growing rats was investigated. Pure LaCl3 or an REE mixture containing 38% of LaCl3, 52% of CeCl3, 3% of PrCl3 and 7% of chlorides of other REE were used at two different concentrations as supplements to the diets. Fifty male Wistar rats at 4 weeks of age were allotted to five experimental groups: a control group; a La-low group and a La-high group with 75 and 150 mg/kg LaCl3.6H2O, respectively; a REE-low and an REE-high group with 75 and 150 mg/kg REE mixture, respectively. The animals were housed in individual pens. Feed and water were provided ad libitum. After 18 days the oral supplementation of LaCl3.6H2O or of the REE mixture improved daily body weight gain (BWG) by up to 5 or 9% (p > 0.05), respectively. LaCl3.6H2O as well as the REE mixture had positive effects (p < 0.05) on feed conversion ratio (FCR) with a decreased ratio by up to 8 and 11%, respectively. Supplementation of REE also had clear effects on blood serum parameters. The activities of alkaline phosphatase (AP) and alanine amino transferase (ALT) increased significantly (p < 0.05). At the same time, blood glucose level decreased and blood creatine level increased significantly (p < 0.05). There was no significant difference in cholesterol, total protein, albumin and urea nitrogen among the groups. There was no significant difference in triglyceride level between the control and those REE groups, however, a significantly lower (p < 0.01) triglyceride level was found in the 150 mg/kg REE mixture group compared with that in 75 mg/kg REE mixture group and the 150 mg/kg LaCl3.6H2O group. The results suggest that oral supplementation of REE improves growth performance in rats as in pigs. In this respect, concentration and type of REE supplemented to the diets are two important factors herein.

Supplementation of algae to the diet of pigs: a new possibility to improve the iodine content in the meat.

Meat products with a higher iodine content can be produced through feeding animals with a diet supplemented with inorganic iodine salts or with algae containing high iodine. This may help to improve daily iodine intake and to control iodine deficiency disorders (IDD) in man. In the present study a total of 40 crossbred pigs (Deutsche Landrasse x Piétrain) with an average body weight of 17 kg were allotted to either a control group, to two groups receiving potassium iodide (KI) at different concentrations (5 or 8 mg iodine per kg of feed) or to two groups receiving the algae Laminaria digitata containing the same amount of iodine. After pigs were fed with iodine-supplemented diets for 3 months, it was found that compared to the control group the iodine content increased by up to 45% in fresh muscle, by 213% in adipose tissue, by 124% in the heart, by 207% in the liver and by 127% in the kidneys. There was a significant (p < 0.01) higher concentration of serum thyroxine (T4) and a lower concentration of serum triiodothyronine (T3) in those iodine-supplemented groups. The iodine content of urine from all iodine-supplemented groups was also greatly increased. Furthermore, it was shown that the supplementation of algae into feed could increase daily body weight gain by 10% (p > 0.05). It is suggested that the carry-over of iodine through feeding pigs with an algae-supplemented feed could be beneficial to both the control of IDD and the improvement of pig production.

[The effectiveness of rare earth elements as a possible alternative growth promoter for pigs and poultry]. / Untersuchungen zur Wirkung Seltener Erden als mögliche Alternative zu Leistungsförderern bei Schweinen und Geflügel.

Mixtures of Rare Earth Elements (REE) have been used as animal growth-promoters on a large scale in China during the last 20 years. Numerous studies carried out in China claim it produces quite sensational growth-promoting effects in all categories of farm animals. To explore the question of whether REE's might prove suitable as a growth-promoter under western keeping conditions, feeding experiments were performed on pigs and poultry. The animals received a typical diet, supplemented with REE salts in concentrations between 75 and 300 mg/kg feed. Weight-gain, feed-intake, feed-conversion and (where applicable) laying parameters were observed. It was shown that in pigs receiving feed supplemented with REEs, an increase in daily weight gain of up to 19% and an improvement in feed-conversion of up to 11% can be achieved, whereas, for poultry, no positive effects on growth or productivity of the animals could be observed. Testing of important organs via Neutron Activating Analysis (NAA) showed a minute accumulation of REE, principally in liver and bones. Analysis of the poultry gut-flora, using selective media, showed that the main microorganism populations of the alimentary canal were unaffected by feed-supplementation with REE.

Study on the performance enhancing effect of rare earth elements in growing and fattening pigs.

A feeding study was performed to investigate possible performance enhancing effects of rare earth elements (REE) in growing and fattening pigs, as well as their influence on the blood serum biochemical changes and the accumulation of REE in the organs of pigs treated with a REE diet for a longer time period. Fourteen crossbred piglets (Deutsche Landrasse x Piétrain) were allotted to two dietary treatments: a control group and the REE-treated group which was supplemented with 300 mg of an REE mixture per kg feed. The REE mixture contained mainly chlorides of lanthanum (La), cerium (Ce) and praseodymium (Pr). The whole feeding period consisted of a 2 months ad libitum feeding period M-I and a 1 month restricted feeding period M-II. It was found that in comparison with the control group, the REE group had a better daily body weight gain of 19% (p < 0.05) in the period M-I and 12% in the period M-II; the REE group also had a better feed conversion ratio of 11% in period M-I and 3% (p > 0.05) in the period M-II. The REE had no significant (p > 0.05) influence on blood serum thyroxine (T(4)), aspartate-amino-transferase (AST), alanine-amino-transferase (ALT), alkaline-phosphatase (AP), total cholesterol, triglyceride, total protein, albumin, glucose, Ca, P, Na, K and Cl. However, serum triiodothyronine (T(3)) in the REE group was significantly (p < 0.01) lower than that in the control group. The accumulation rate of La and Ce in the muscle, liver and kidneys was very low after feeding the REE diet for 3 months. The study indicates the possibility of using rare earth elements as safe and inexpensive alternative performance enhancers for pig production.

Rare earth elements--a new generation of growth promoters for pigs?

The present study which includes two feeding experiments was performed to investigate a possible performance enhancing effect of rare earth elements (REF) in piglets. This performance enhancing effect has been described in the Chinese literature for a long time, however, it was never tested under "western conditions". In the first feeding experiment 72 piglets at a mean BW of 7.3 kg were allotted to a control and to 4 REE groups at different levels of lanthanum chloride or an REE mixture containing mainly chlorides of lanthanum, cerium and praseodymium. The experimental period lasted 5 weeks. Positive effects of REE were found on body weight gain as well as on feed conversion ratio of the piglets. Compared to the control group, the daily weight gain was improved by 2 to 5% and feed conversion was better by up to 7%. These effects were, however, not significant. In the second feeding experiment, piglets (mean BW 17.3 kg) were fed for 8 weeks with a similar REE mixture. Significant positive effects of REE were found on both body weight gain and on feed conversion ratio by 19% and 10%, respectively. This is the first time that a performance enhancing effect of REE in pigs under western feeding conditions has been shown. Since the use of antibiotics as growth promoters in animal feed has been restricted in the European Union recently, rare earth elements might be of interest as new, safe and inexpensive alternative performance enhancers.

Prevention of osteoporosis after cardiac transplantation: a prospective, longitudinal, randomized, double-blind trial with calcitriol.

BACKGROUND: Accelerated bone loss is a well-recognized complication after cardiac transplantation (HTx) due to immunosuppressive therapy. The purpose of this prospective, longitudinal, randomized, placebo-controlled, double-blind study was to investigate the effect of calcitriol (1,25-dihydroxyvitamin D3) in the prevention of bone loss and fracture rate after HTx. METHODS: Basic therapy included 1000 mg of calcium daily and sex hormone replacement in hypogonadal patients. A total of 132 patients (111 male, 21 female; mean age: 51+/-10 years; 35+/-25 months after HTx) were randomized to 0.25 microg of calcitriol or placebo. Bone mineral density (BMD, g/cm2; T score, %) of the lumbar spine and x-rays for the assessment of vertebral fractures were performed at baseline and after 12, 24, and 36 months. Biochemical indexes of mineral metabolism were measured every 3 months. RESULTS: Overall BMD was significantly decreased after HTx (T score 87+/-13%). BMD increased continuously within the study period in the calcitriol group (1 year: 2.2+/-4.8%; 2 years: 3.9+/-5.4%; 3 years: 5.7+/-4.4%) as well as in the placebo group (1 year: 1.8+/-4.9%; 2 years: 3.7+/-6.5%; 3 years: 6.1+/-7.8%) without statistical difference between the groups. Fracture incidence was low during the study interval (1 year: 2.0%; 2 years: 3.4%; 3 years: 0%). Hypogonadism (20%) was associated with a lower BMD (78+/-12% vs. 88+/-12%; P<0.01) and a higher increase (35%) after hormone replacement in comparison to normogonadal patients. Increased intact parathyroid hormone and bone resorption markers decreased significantly during therapy. CONCLUSIONS: Calcium supplementation and sex hormone replacement in hypogonadism proved a sufficient long-term prevention therapy to improve decreased BMD and to prevent fractures after HTx. Besides immunosuppression, both concomitant hypogonadism and secondary hyperparathyroidism play a major role in the long-term bone loss and should therefore be monitored and treated adequately. Low-dose calcitriol demonstrated no significant extra benefit regarding BMD and fracture rate in the long-term period after HTx.

[Occurrence of struma in cattle in the Czech Republic]. / Strumavorkommen bei Kälbern in der Tschechischen Republik.

In the years 1988 to 1995 among 1355 cattle examined in the frame of iodine deficiency studies in the Czech Republic 404 animals (30%) showed congenital struma. Clinical and postmortal findings are described. A monitoring of iodine content in milk showed lower values in herds with struma prevalence. The insufficient supply of iodine in these animals results from low iodine content of feed or from the goitrogenic influence of nitrate in drinking water or high content of crucifera in feed or other stress factors. An increased iodination of mineral mix in feed is highly recommended.

Iodine supplementation of laying hen feed: a supplementary measure to eliminate iodine deficiency in humans?

Iodine deficiency still exists in many countries worldwide, to a certain degree this is also true for Germany. Food of animal origin can be a good source for iodine depending on the feed. To investigate the possible use of laying hen feed enriched with iodine, we conducted a feeding experiment with 40 laying hens receiving feed with different amounts of iodine either as KIO3 or in the form of seaweed. Iodine concentration in eggs increased significantly depending on iodine intake after a 2 week period. Seaweed could also be used as an iodine source by the hens. A subsequent consumption study with 24 volunteers showed that eggs enriched with iodine can increase human's iodine excretion and therefore improve human's iodine supply. This new strategy is thought to accompany salt iodization programs, not to replace them.

[Improving the human iodine supply by iodination of swine feed]. / Verbesserung der Jodversorgung des Menschen durch Jodierung von Schweinefutter.

Germany and several other countries are areas of severe iodine deficiency. In addition to iodized salt additional strategies to fight iodine deficiency exist. A promising possibility is the supplementation of feed with iodine, in order to increase its content in food of animal origin. In a feeding experiment 24 male castrated and female piglets of the cross breed Deutsche Landrasse x Pietrain were fed a high iodine supplemented diet. At a body weight of 100 kg the animals were slaughtered and the effect of the iodine supplementation on iodine content in the organs was studied. Animals receiving 30 mg iodine/kg feed showed significantly higher iodine contents in muscle, heart, kidney, liver, serum, fat and in the thyroidea than animals receiving no iodine supplementation. The iodine content in muscle and organs increased by a factor three to seven. Concerning meat quality and other slaughter parameters there was no difference between the two groups. This demonstrates that this strategy is in addition to iodized salt a possibility to reduce iodine deficiency.

[Bioavailability of cadmium: effect of vitamin C and phytase in broiler chickens]. / Zur Bioverfügbarkeit von Kadmium: Einfluss von Vitamin C und Phytase beim Hühnerküken.

Though the application of the toxic heavy metal cadmium is reduced, its concentration in soil and in feed still increases. Especially smoking habits and unbalanced diets cause cadmium intake in humans beyond the limits suggested by WHO. One possibility to reduce cadmium burden is to influence the bioavailability of cadmium in the feed by certain vitamins, trace elements and other feed components and thus to lower its content in food from animal origin. In the present study the influence of vitamin C and phytase on the bioavailability of cadmium was investigated in broiler chicken. It was shown that 1 g vitamin C per kg of feed lowered cadmium accumulation in kidney and in liver by up to 40%. Addition of phytase, a new feeding enzyme, licensed in 1992 in Germany for improving phosphate utilization from phytate, lowered cadmium accumulation by up to 60%. Therefore the addition of these two components to the feed lowers the cadmium burden in food from animal origin and thus increases its quality.

Plasma transport and tissue distribution of [14C] beta-carotene and [3H]retinol administered orally to pigs.

The absorption, plasma transport, and tissue distribution of beta-carotene and vitamin A were studied in pigs after the oral administration of radiolabeled beta-carotene and retinol. Plasma radioactivity as well as retinol and beta-carotene were measured over a 24-h period, after which the pigs were killed. Plasma radioactivity increased within 4 h and 5 h for beta-carotene and retinol, respectively. The administration of radiolabeled retinol resulted in highest levels in the liver (83016 +/- 17614 dpm/g of tissue), followed by the kidney (5598 +/- 1309 dpm/g), the duodenum (2783 +/- 300 dpm/g), the colon (835 +/- 117 dpm/g), and the lung (756 +/- 68 dpm/g). Twenty-four hours after beta-carotene administration, tissue radioactivity distribution showed highest accumulation in the lung (22772 +/- 11997 dpm/g) and the liver (2328 +/- 694 dpm/g). The identification of the radioactive component 14C in the lung and colon indicated that the radioactivity was associated with beta-carotene only. This indicates that pigs may absorb intact beta-carotene. In other tissues such as liver, kidney, and intestine, only retinol-associated radioactivity was found after saponification of retinyl esters. The physiological importance of the unique accumulation of beta-carotene in lung tissue remains speculative.

[The effect of vitamin C and zinc on the copper-induced increase of cadmium residues in swine]. / Der Einfluss von Vitamin C und Zink auf die durch Kupfer erhöte Rückstandsbildung von Cadmium beim Schwein.

In commercial pig fattening, copper is added to the feed in amounts that greatly exceed the requirements of the animals. On the one hand, this improves weight gain, but on the other, as we were able to recently prove, the retention of the heavy metal cadmium rises in the kidney, in the liver and in muscle. In a feeding experiment with female and male castrated piglets, we tried to counter the copper-induced rise in cadmium (175 mg Cu/kg feed) by adding zinc or vitamin C to the diet. While addition of 100 or 200 mg zinc per kg of diet had no influence, the addition of 1000 mg vitamin C reduced the elevated cadmium values in the kidneys and livers to values only determined with a low copper supplementation of 35 mg copper per kg of feed. This positive vitamin C effect not only occurs in cases of high copper supplementation (175 mg Cu/kg feed); when the pigs were given only 35 mg copper per kg of feed, vitamin C also reduced the cadmium content in the organs by 35 to 40%. This indicates that vitamin C improves the quality of food gained from animals for human consumption in both conditions.

Vitamin D metabolites prevent vertebral osteopenia in ovariectomized rats.

The present study investigated the prophylactic effects of vitamin D metabolites and vitamin D metabolite combinations on static and dynamic, tetracycline-based, histomorphometric parameters in the axial skeleton of ovariectomized rats. Forty-three Fischer-344 rats (10 weeks old, 130 g each body weight, BW) were either bilaterally ovariectomized (OVX) or sham-operated (SHAM). The rats were allocated into the following groups: SHAM; OVX; OVX + 7.5 ng 1 alpha,25-dihydroxyvitamin D3 [1,25(OH)2D3]/rat/day; OVX + 15 ng 1 alpha,24R,25-trihydroxyvitamin D3 [1,24,25-(OH)3D3]/rat/day; OVX + 75 ng 24R,25-dihydroxyvitamin D3 [24,25(OH)2D3]/rat/day; OVX + 7.5 ng 1,25(OH)2D3/rat/day + 15 ng 1,24,25(OH)3D3/rat/day; OVX + 7.5 ng 1,25(OH)2D3/rat/day + 75 ng 24,25(OH)2D3/rat/day. The vitamin D metabolites were fed orally starting 4 weeks after surgery. Urine and blood samples were collected 12 and 16 weeks postovariectomy, respectively. Sixteen weeks after surgery, all rats were sacrificed, and the first lumbar vertebrae were processed undecalcified for histomorphometric analysis. Ovariectomy induced a highly significant reduction (P less than 0.001) of cancellous bone mass in the secondary spongiosa of the lumbar vertebral body. The bone loss in OVX rats was accompanied by a distinct elevation of all histomorphometric parameters of bone formation and resorption. 1,25(OH)2D3 and both vitamin D metabolite combinations significantly raised serum calcium levels and prevented the bone loss by inhibiting the increased bone resorption in OVX rats. In the applied dosage, 1,24,25(OH)3D3 and 24,25(OH)2D3 alone were ineffective in preserving the cancellous bone of the lumbar vertebra in OVX rats.(ABSTRACT TRUNCATED AT 250 WORDS)

[The effect of increased copper supplements in feed on the development of cadmium residues in swine]. / Der Einfluss erhöhter Kupferzulagen zum Futter auf die Rückstandsbildung von Cadmium beim Schwein.

In commercial pig fattening copper is added to the feed at a concentration exceeding the requirement by a factor of more than ten. This improves the weight gain of the pigs during the first three months remarkably. In order to study the influence of copper supplementation on cadmium retention, 4 groups of male castrated weanling crossbred pigs (Deutsche Landrasse x Pietrain) received for 3 months a diet containing 1 mg Cd per kg feed, given as CdCl2, as well as 0, 50, 100 or 200 mg Cu per kg feed, given as CuSO4. The liver, kidney, spleen, pancreas, brain, heart, diaphragm, bile and duodenal mucosa were submitted to wet ashing and analyzed by atomic absorption spectroscopy for cadmium. The Cd retention in all tissues increased in correlation to the Cu content of the feed. When 200 mg Cu per kg were added, Cd rose in the muscle from 10 to 15 micrograms per kg, in the liver from 770 to 1720 micrograms per kg and in the kidney, where the highest Cd concentration occurred, from 4620 to 9320 micrograms per kg. This indicates that in pigs the retention of cadmium in kidney and in liver is promoted by Cu supplementation as used in commercial pig fattening.