An immunohistochemical study of the distribution of biotin in tissues of pigs and chickens.

An optimised indirect peroxidase-anti-peroxidase immunohistochemical technique was used to detect endogenous biotin in frozen tissue sections from biotin-supplemented and biotin-depleted pigs and chickens. A monoclonal anti-biotin antibody was used as primary antibody in this technique. Immunoreactive biotin was detected in many tissues of both species including liver, kidney, pancreas, adipose tissue, adrenal gland, testis, brain, choroid plexus, cardiac and skeletal muscle, epithelium of the respiratory and digestive systems, skin and lymphoid tissues.

Tissue content of alpha-tocopherol and oxidative stability of broilers receiving dietary alpha-tocopheryl acetate supplement for various periods pre-slaughter.

1. The effects of dietary alpha-tocopheryl acetate on the alpha-tocopherol status of chicken plasma and tissues were investigated. The rate of iron-ascorbate-induced lipid peroxidation was also studied.

Effects of vitamin E on mammary and blood leukocyte function, with emphasis on chemotaxis, in periparturient dairy cows.

Objective: To determine the effect of vitamin E supplementation on the immune system of dairy cows.

Design: The following immune parameters were followed: production of chemotactic factors and superoxide by mammary macrophages and chemotactic responsiveness of blood neutrophils.

Animals: 16 healthy Holstein dairy cows.

Color coordinates for assessment of dietary vitamin E effects on beef color stability.

Color stability was investigated in longissimus lumborum (LL), semimembranosus (SM), and gluteus medius (GM) muscles from Holstein steers fed diets including doses of alpha-tocopheryl acetate that were 0 (EO), 250 (E250), 500 (E500), and 2,000 (E2000) mg.steer-1.d-1 for 42 or 126 d.

Rapid determination of alpha-tocopherol in muscle and adipose tissues of pork.

A fast, sensitive and reproducible method for the analysis of alpha-tocopherol in pork tissues is presented. It combines saponification of the tissue and alpha-tocopherol extraction in a single vessel, followed by HPLC separation and fluorescence detection. Added alpha-tocopherol was recovered quantitatively.

Folic acid requirements of broilers.

1. Dietary folic acid requirements of broilers were studied in three experiments using wheat- and maize-based practical diets. Requirements were assessed on the basis of performance and metabolic criteria.

Modulatory effects of dietary beta-carotene on blood and mammary leukocyte function in periparturient dairy cows.

Beginning 4 wk prior to predicted calving, 14 Holstein cows per treatment were fed diets 1) unsupplemented (control) or supplemented daily with 2) 300 mg of beta-carotene, 3) 600 mg of beta-carotene, or 4) 120,000 IU of vitamin A. Blood was collected around calving on wk -4, -2, -1, 0 (within 24 h postcalving), 1, 2, and 4 for isolation of lymphocytes and neutrophils and for the analysis of plasma vitamins. Lacteal secretions were collected on wk 0, 1, 2, and 4 for the isolation of phagocytes.

Biotin kinetics in serum of cattle after intravenous and oral dosing.

Single oral (p.o.) or intravenous (i.

The bioavailability of supplemental biotin in cattle.

A trial using 12 yearling heifers was carried out to test whether biotin metabolism and bioavailability are influenced by continuous dietary supplementation with biotin. Six of these heifers received no biotin supplementation (controls), while six received a daily dietary supplement of 20 mg biotin over the whole experimental period of four months. During each of three test periods (on days 14 and 21, 56 and 63, and 118 and 124), single test dosages of 40 mg (oral) and 5 mg (intravenous) biotin were given to each animal in a crossover test design.

Effect of high concentrations of dietary vitamin E during various age periods on performance, plasma vitamin E and meat stability of broiler chicks at 7 weeks of age.

1. The effect of high concentrations of vitamin E (alpha-tocopheryl acetate) fed during various age periods on the performance and the oxidative stability (thiobarbituric acid [TBA] values) of the drumstick meat of 7-week-old broiler chicks was determined. The basal diets (for the age periods 0 to 3, 3 to 6 and 6 to 7 weeks) contained 60 g soyabean oil and 24 mg vitamin E/kg.

Effects of dietary retinol on hepatic retinol storage and on plasma and tissue alpha-tocopherol in pigs.

A feeding experiment was carried out with pigs to investigate the effects of graded dietary retinol supplements on hepatic and plasma retinol and on alpha-tocopherol in plasma and selected tissues. Four groups of twelve weanling pigs each with a mean body weight of 7 kg were fed a complete ration containing 54 IU vitamin E/kg and supplemented with 5, 10, 20 or 40 x 10(3) IU retinol/kg for Treatments 1 to 4, respectively. The feed was fed in restricted amounts for 150 days when the pigs were slaughtered at 105 kg body weight.

Bioavailability of ascorbic acid in horses.

The bioavailability of ascorbic acid administered to thoroughbreds by intramuscular injection was investigated. For intramuscular injection two preparations were studied, and the percentage bioavailability up to 24 h of 10 g of ascorbic acid was 95% +/- 22 in four horses and 60% in two horses with preparations A and B, respectively. Bioavailability at 24 h in three horses injected subcutaneously with 10 g of preparation B was 82%.

Biotin supply by large bowel bacteria in minipigs: evidence from intracaecal avidin.

The influence of a change of colonic availability of biotin on biotin status was studied. This was done by inhibition of biotin absorption by intracaecal avidin infusion. Five adult minipigs with a permanent caecal 'T' cannula were fed on a semi-synthetic, biotin-deficient diet for 4 months.

Clinical study on the effect of biotin on skin conditions in dogs.

In a collaborative study with small-animal veterinary surgeons, dogs with fur and skin conditions were treated with biotin (approximately 5 mg biotin/10 kg body weight/day) for 3 to 5 weeks. In total 119 cases could be treated which were reported to show symptoms such as dull coat, brittle hair, loss of hair, scaly skin, pruritus or dermatitis. Cases requiring other treatments with e.

Dietary biotin requirements of young rainbow trout (Salmo gairdneri) determined by weight gain, hepatic biotin concentration and maximal biotin-dependent enzyme activities in liver and white muscle.

The objective of the present work was to determine the dietary biotin requirements of young, rapidly growing rainbow trout according to independently measured parameters. Two experiments were conducted with a purified diet which had a basal biotin level of 0.01-0.

Incompatibility between lasalocid and chloramphenicol in broiler chicks after a long-term simultaneous administration.

Two growth experiments were conducted to evaluate in broiler chicks the compatibility between lasalocid medication in the feed (at 90 or 125 ppm) and a long-term administration of chloramphenicol either via the feed (500 ppm) or via the drinking water (500 mg/liter). The simultaneous administration of lasalocid and chloramphenicol generally caused severe growth depression, decreased feed intake and impaired feed conversion. Several chicks showed evident symptoms of intoxication, such as ataxia, leg weakness and paralysis.

Available biotin content of various feed ingredients.

The availability to the chick of the microbiologically determined biotin in various feed ingredients was assayed using a standard curve methodology. The chicks were grown up to 28 days of age. Ingredients of the standard diet were partially replaced by the test ingredient.

Relationships between vitamin A and vitamin E in the chick.

Plasma levels of vitamins A and E were analysed during the dietary administration of two levels of vitamin A (10 000 or 50 000 IU/kg) in combination with four levels of supplemental vitamin E (0, 50, 100, or 150 mg/kg) and with or without a supplement of oil to the diet. Tocopherol levels in plasma were markedly decreased by the higher vitamin A supplementation. In contrast, the various vitamin E intakes had no influence on plasma retinol levels.

Autoradiographic localisation of 3H-biotin in chick tissues.

In an autoradiographic study with a 243 days' exposure time of the autoradiographs, the tissue distribution of 3H-labelled biotin was investigated. Label being always related to cytoplasma, no label was found in the nucleus in cells suitable for such an observation. High labelling was found in differentiated cells, e.

Histological and cytological alterations in the skin of biotin-deficient chicks.

A basal diet with practically no natural biotin was supplemented with 10, 19, 34, 62, 111 or 200 microgram of biotin per kg. Chicks receiving these graded levels of biotin were used for histological investigations of skin samples of the foot pad and the under and upper side of the middle toe. Where there was biotin deficiency, epidermal hyperplasia, papillary growth, acanthosis and hyperkeratosis were observed on the foot pad and the under side of the toe.

Pyruvate carboxylase activities in red blood cells and liver of chicks and their dependency on biotin status. First results with activation assays.

Pyruvate carboxylase activities of erythrocytes and liver preparations and their in vitro stimulation by biotin were used for the determination of the biotin status of chicks. Reasonable stability of the enzyme in erythrocytes was achieved when storing the erythrocytes deep-frozen in a glycerol-containing medium. Results of the activation assays in erythrocytes and liver are compared with biotin levels in feed, plasma and liver.

Acetyl-CoA carboxylase activities in blood and liver of chicks and their dependency on biotin status.

Acetyl-CoA carboxylase activities from whole blood and, in some of the experiments, from liver were found to be lower in biotin-deficient chicks compared with controls. In vitro stimulation of liver acetyl-CoA carboxylase activity by biotin appeared to be a better index for the evaluation of the biotin status than measuring the enzyme activity alone.

Stereological composition of the liver of biotin deficient and control chicks.

In an ultrastructural and stereological study the livers of 28-day-old chicks, fed either a biotin-deficient or a supplemented diet, were investigated. The biotin-deficient chicks showed the known dermal lesions and were significantly retarded in growth. About 30% less hepatocytic nuclei per unit volume liver were found in the deficient chicks than in the controls.