Levels Of Niacin Research Articles

BIOCHEMICAL AND SENSORY QUALITY OF PHYSALIS (PHYSALIS PUBESCENS L.) JUICE

ABSTRACT Ground cherry (Physalis pubescens L.) is one of the most promising exotic fruits and some interesting functional products could be developed from these berries. The fresh juice was yellowish or orangey and had a light, sweet taste with acidic nature (pH 3.5). The titratable acidity was 1.43, polyphenols 76.6 mg/100 mL and vitamin C 38.8 mg/100 mL. Physalis juice was rich in carotenoids (70 µg/mL). The juice had a high level in minerals such as phosphorus (578 mg/100 mL), potassium (1,196 mg/100 mL), zinc (2.4 mg/100 mL) and boron (1 mg/100 mL). The essential amino acids in the juice such as isoleucine, valine and tryptophan (42.97, 39.92 and 39.83 mg/100 mL) were higher than those recommended by Food and Agriculture Organization/World Health Organization/United Nations Union (FAO/WHO/UNU). PRACTICAL APPLICATIONS Tropical pulpy juices play an important role in nutrition as an excellent base for low-calorie and dietetic products. Physalis fruit and juice are nutritious, containing particularly high levels of niacin, carotenoids and minerals. There are very little available data in the literature regarding physicochemical and sensory properties. As part of the first steps toward developing Physalis as commercial crop, the present study aimed to evaluate the nutritional and sensorial properties of fresh juice as a new product from Physalis.

Development of Food-Based Complementary Feeding Recommendations for 9- to 11-Month-Old Peri-Urban Indonesian Infants Using Linear Programming

Effective population-specific, food-based complementary feeding recommendations (CFR) are required to combat micronutrient deficiencies. To facilitate their formulation, a modeling approach was recently developed. However, it has not yet been used in practice. This study therefore aimed to use this approach to develop CFR for 9- to 11-mo-old Indonesian infants and to identify nutrients that will likely remain low in their diets. The CFR were developed using a 4-phase approach based on linear and goal programming. Model parameters were defined using dietary data collected in a cross-sectional survey of 9- to 11-mo-old infants (n = 100) living in the Bogor District, West-Java, Indonesia and a market survey of 3 local markets. Results showed theoretical iron requirements could not be achieved using local food sources (highest level achievable, 63% of recommendations) and adequate levels of iron, niacin, zinc, and calcium were difficult to achieve. Fortified foods, meatballs, chicken liver, eggs, tempe-tofu, banana, and spinach were the best local food sources to improve dietary quality. The final CFR were: breast-feed on demand, provide 3 meals/d, of which 1 is a fortified infant cereal; ≥5 servings/wk of tempe/tofu; ≥3 servings/wk of animal-source foods, of which 2 servings/wk are chicken liver; vegetables, daily; snacks, 2 times/d, including ≥2 servings/wk of banana; and ≥4 servings/wk of fortified-biscuits. Results showed that the approach can be used to objectively formulate population-specific CFR and identify key problem nutrients to strengthen nutrition program planning and policy decisions. Before recommending these CFR, their long-term acceptability, affordability, and effectiveness should be assessed.

GERMINAÇÃO DE SEMENTES ARMAZENADAS DE CUBIU SOB DIFERENTES CONDIÇÕES DE LUZ

O cubiu (Solanum sessiliflorum Dunal) é uma espécie nativa da região amazônica que tem se expandido além do seu centro de origem. A planta possui potencial para a agroindústria devido a alta produtividade de frutos e acúmulo de altos níveis de ferro, niacina e ácido cítrico. Atualmente, há grande quantidade de informações sobre suas características culinárias, nutricionais e medicinais. Por outro lado, são relativamente escassas informações sobre exigências quanto ao processo germinativo como, por exemplo, sobre a qualidade de luz, a qual tem grande influência na germinação de sementes de tamanho pequeno. Assim, o presente trabalho teve como objetivo avaliar o efeito de diferentes condições de luz sobre a germinação das sementes de S. sessiliflorum Dunal variedade ‘Santa Luzia’, acondicionadas em embalagem de papel Kraft e armazenadas em geladeira (± 4 ºC) por seis meses. Foram testadas quatro condições de luz: branca, vermelha, vermelha extrema e ausência de luz. A intensidade luminosa foi produzida por quatro lâmpadas fluorescentes (20 W) fixadas internamente na porta do germinador. As condições de luz foram obtidas através da cobertura, com papel celofane, de caixas do tipo gerbox, onde se procedeu a semeadura. Foram avaliadas as seguintes variáveis: porcentagem de germinação, índice de velocidade de germinação, comprimento e massa seca de plântulas. As sementes de cubiu germinaram em todas as condições de luz, entretanto maiores porcentagens de germinação, índice de velocidade de germinação e comprimento de plântulas ocorreram sob luz vermelha e vermelha extrema.

Levels of folate, pyridoxine, niacin and riboflavin in traditional foods of Canadian Arctic Indigenous Peoples

Traditional food resources of indigenous peoples provide a wealth of information on use of unique food species, and their harvest and preparation. In conjunction with a larger study associated with the Northern Contaminants Program, traditional food items most frequently consumed in Inuit, Dene/Metis and Yukon First Nations communities of the Canadian North, were identified following a large-scale dietary assessment that included monitoring and collection of traditional and market foods in five regions of the Canadian North. Fifty out of 200 traditional food samples, collected as eaten, were prioritized for water-soluble vitamin analysis (folate, pyridoxine, riboflavin and niacin) based upon parameters that included frequency of consumption, lack of nutrient data and expectation of nutrient content. This paper reports on contents of selected B vitamins in the prioritized food samples, as eaten and expressed per 100 g of food sample. This is the first report of the levels of these water-soluble vitamins in many of these food sources. This study strongly suggests that traditional foods have the potential to contribute significantly to the water-soluble vitamin requirements of Northern Indigenous Peoples.

National fortification of staple foods can make a significant contribution to micronutrient intake of South African adults

A national survey found that micronutrient deficiencies are prevalent in South African children, particularly calcium, iron, zinc, riboflavin, niacin, vitamin B6, folate, vitamin A, E and C. Mandatory fortification of maize meal and wheat flour were introduced in 2003 to combat some of the deficiencies found in children. To date however, there has not been a national survey on dietary intake in adults. The main objectives of this study were to evaluate the micronutrient intake of the diet consumed by the average adult South African by means of secondary data analyses and secondly to evaluate the effects of fortification on selected nutrient intakes. Secondary data analysis was carried out with numerous dietary surveys on adults to create a database that included sampling (and weighting) according to ethnic/urban-rural residence in line with the population census, of which 79% were black Africans and the majority resided in rural areas. The effect of fortification was evaluated by substituting fortified foods in the diet for the unfortified products. The combined database used in this study comprised 3229 adults. Mean calcium, iron, folate and vitamin B6 intakes were very low particularly in women. Mean intakes of most micronutrients were lower in rural areas. Fortification of maize meal and wheat flour (bread) raised mean levels of thiamine, riboflavin, niacin, vitamin B6 and folate above the recommended nutrient intakes (RNIs). In women, despite fortification, mean iron intakes remained below the RNIs, as did calcium since it was not in the fortification mix. The average dietary intake of adults was of poor nutrient density, particularly in rural areas. Fortification of maize meal and wheat flour (bread) considerably improved mean vitamin B6, thiamine, riboflavin, niacin, folate and iron intakes as well as the overall mean adequacy ratio of the diet.

Antioxidant Effects and Drug Interactions of Resveratrol Present in Wine

Resveratrol is a phytoalexin found in grapes. Epidemiological and experimental studies suggest that the consumption of wine, particularly red wine, reduces the incidence and morbidity from coronary heart diseases. People using cardiovascular drugs may also consume red wine containing resveratrol for reducing the risk of disease. Thus, a potential interaction of resveratrol with the drugs is possible. Antioxidant activity of resveratrol was compared with vitamin E. IC50 values for resveratrol and vitamin E were 1.5 × 10−5M and 1 × 10−3 M (NADPH-induced) and 1.5 × 10−4 M, 1 × 10−3 M (Ascorbate-induced), respectively. These results indicate that resveratrol has higher antioxidant effects than vitamin E. Nifedipine (antihypertensive), niacin (antilipemic) or lovastatin (antilipemic) were co-administered with a high dosage of resveratrol. Resveratrol pretreatment caused a 65% decrease in the concentration of nifedipine in both one hour and one week experiments. Niacin level in blood increased 20% in the presence of resveratrol at one hour and one week experiment. Lovastatin decreased 35% and 14.6% in both one hour experiment and one week experiment, respectively. The effects of resveratrol on rat liver microsomal drug metabolizing enzymes were also investigated. Resveratrol caused a 22% decrease in cytochrome P450 3A in enzyme activity. This decrease may explain increased niacin levels, but not the nifedipine and lovastatin. Nifedipine and lovastatin may be metabolized by different cytochrome P450 enzyme systems. High dosage of resveratrol (or products containing it) should be used with caution while other drugs are taken.

Plasma and urine pharmacokinetics of niacin and its metabolites from an extended-release niacin formulation

To characterize plasma and urine pharmacokinetics of niacin and its metabolites after oral administration of 2,000 mg of extended-release (ER) niacin in healthy male volunteers. Niacin ER was administered to 12 healthy male subjects following a low-fat snack. Plasma was collected for 12 h post dose and was analyzed for niacin, nicotinuric acid (NUA), nicotinamide (NAM) and nicotinamide-N-oxide (NNO). Urine was collected for 96 h post dose and analyzed for niacin and its metabolites, NUA, NAM, NNO, N-methylnicotinamide (MNA) and N-methyl-2-pyridone-5-carboxamide (2PY). Mean niacin Cmax and AUC(0-t) values were 9.3 microg/ml and 26.2 microg x h/ml and were the highest of all analytes measured. Peak niacin and NUA levels occurred at 4.6 h (median) while tmax for NAM and NNO were 8.6 and 11.1 h, respectively. The mean plasma terminal half-life for niacin (0.9 h) and NUA (1.3 h) was shorter as compared to NAM (4.3 h). Urine recovery of niacin and metabolites accounted for 69.5% of the administered dose; only 3.2% was excreted as niacin. The highest recovery was for 2PY (37.9%), followed by MNA (16.0%) and NUA (11.6%). Mean half-lives for 2PY and MNA calculated in urine were 12.6 and 12.8 h, respectively. Niacin was extensively metabolized following oral administration, and about 70% of the administered dose is recovered in urine in 96 h as niacin, NUA, MNA, NNO, NAM and 2PY. The plasma levels of the parent niacin were higher than its metabolites though only about 3% of the unchanged drug is recovered in urine.

Determination of Niacin in Food Materials by Liquid Chromatography Using Isotope Dilution Mass Spectrometry

The availability of deuterium-labeled nicotinic acid makes stable isotope dilution mass spectromerty (MS) coupled with liquid chromatography (LC) an attractive option for the determination of the water-soluble B-vitamin niacin in food samples. A method was developed based on acid digestion, solid-phase extraction with a strong cation exchange column, and reversed-phase chromatography with a C18 column. Detection is by positive ion electrospray MS. Analysis in selected ion recording mode is subject to interference problems similar to those found with other LC determinations of niacin, but the additional selectivity of multiple reaction monitoring mode largely eliminates interference problems. The method was applied to 6 different food matrixes and to appropriate reference materials, including milk samples with niacin levels near 1 ppm. The method exhibited good accuracy, based on levels obtained for the reference materials, and relative standard deviations in the range of 0.5-5%.

Nutritional Profile of Local and Western Fast Foods Consumed in Bahrain

The aim of this study was to determine the proximate, mineral, and vitamin content of 16 commonly consumed fast foods (local and Western-based) in Bahrain. Samples were collected from several food outlets in Manama city, the capital of Bahrain, and analyzed using standard methods. In general, the findings revealed that local fast foods had higher cholesterol and energy content (ranging from 0–118 mg and 762–1796 kJ/100 g, respectively) compared to Western fast foods (ranging from 11–34 mg/100 g and 980–1172 kJ/100 g, respectively). Protein content was higher in most of the local fast foods compared to the Western fast foods (5.8–30.4 g/100 g and 10.3–17.9 g/100 g, respectively). Most of the minerals were higher in local fast foods, but calcium (16–153 mg/100 g) and phosphorous (54–273 mg/100 g) were higher in Western fast foods. Some of these foods had considerable levels of vitamin B6 (0.03–0.25 mg/100 g), vitamin B12 (0.1–2.3 μg/100 g), folacin (9.0–106 μg/100 g), and niacin (1.0–12.1 mg/100 g), while the rest of the vitamins were present to a lesser extent. Fat, energy, and sodium levels were also higher in local fast foods. It is evident that the conception that local fast foods are healthier than Western-based fast foods is inappropriate. Hence, nutrition education programmes need to focus on the nutritional aspects of both local and Western fast foods.

The increase of breath ammonia induced by niacin ingestion quantified by selected ion flow tube mass spectrometry

The ingestion of relatively large doses of the vitamin niacin by healthy volunteers results in a reddening of the skin, a skin ‘flush’. Thus, we have carried out a study of the breath metabolites of two healthy volunteers following (i) the ingestion of 200 mg of immediate-release niacin, (ii) as (i) but preceded by the ingestion of 325 mg of aspirin that diminishes the skin ‘flush’, (iii) ingestion of 500 mg of slow-release niacin. On-line breath analysis was carried out using selected ion flow tube mass spectrometry, SIFT-MS. The interesting new observation is that the breath ammonia levels of both volunteers clearly increased following (i) and (ii), and an obvious skin flush did occur following (i) but not following (ii). The slow-release niacin (iii) did not result in a flush and the breath ammonia levels increased more slowly and did not reach the higher levels produced by (i) and (ii). The results of these experiments demonstrate that breath ammonia levels are dependent on the blood/plasma levels of niacin, but are not directly related to the flushing phenomenon, and that the observed increases in blood/breath ammonia levels are consistent with current knowledge of the metabolic pathways of niacin. The parallel measurements of breath isoprene are presented, which demonstrate the quality of breath analyses that can be achieved using SIFT-MS.

Effect of Drugs on Homocysteine Concentrations

Many studies conducted over the last two decades have shown that drug treatment for common medical conditions may have an adverse effect on plasma total homocysteine (tHcy) concentrations. The mechanism for the effects of individual drugs on tHcy concentrations is frequently unknown, as the mechanism of action of the drug may not be established, or the drug is typically administered in combination with other drugs. Some drugs are believed to alter tHcy concentrations by interfering in the metabolism of folate or vitamins B (12) or B (6) or by altering renal function, but the underlying mechanisms for the effects on tHcy concentrations of many drugs remains to be discovered. Several widely used drugs, such as lipid-lowering drugs (like fibrates and niacin) or oral hypoglycemic drugs (like metformin), insulin, drugs used in rheumatoid arthritis, and anticonvulsants cause elevated tHcy concentrations. Sex hormones have variable effects on tHcy levels, and N-acetylcysteine lowers tHcy. The mechanisms of action of drugs on tHcy concentrations and strategies to avoid tHcy elevation have been studied. Assuming that the association of tHcy with cardiovascular disease is causal, this article focuses on the adverse effect on tHcy levels of fibrates, statins and niacin, antihypertensive drugs, metformin, methotrexate and sulfasalazine, anticonvulsant drugs, and levodopa and reviews strategies to avoid such effects. The clinical significance, if any, of these adverse effects on plasma tHcy concentrations remains to be determined.

Determination of niacin in fresh and dry cured pork products by ion chromatography: experimental design approach for the optimisation of nicotinic acid separation

A simple and robust method to determine the niacin level in fresh and dry-cured pork products by ion chromatography is reported. The analytical procedure includes an acidic hydrolysis to free all the bound forms (NAD and NADP) and to convert all the niacin into nicotinic acid, after that the chromatographic separation of the acid form is performed by a cation-exchange column and UV detection (262 nm). The evidence of several interferences that did not allow a good resolution of the nicotinic acid peak in fresh meat matrix led us to improve the resolution by means of statistical optimisation. A three level factorial design and response surface methodology were applied to optimise the chromatographic conditions (mobile phases compositions) and to assess the robustness of the method. Analytical performances of the optimised method were investigated in terms of linearity, limit of detection (LOD) and precision. The complete analytical procedure to extract and determine the nicotinic acid in meat was validated by IC-MS.

Dosage Effects Between Dietary Niacin and Other B Vitamins on Larval Development of <I>Ceratitis capitata</I> (Diptera: Tephritidae)

The nutritional interaction between niacin (nicotinic acid) and a group of nine other B vitamins in the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), larval diet was evaluated. Four doses of niacin (0, 0.2, 2.0, and 20 ppm) and four doses of a mixture of nine other B vitamins (0, 7.07, 70.7, and 707 ppm) in the diet were cross-tested. The other B vitamins consisted of thiamin, riboflavin, pantothenic acid, pyridoxine, folic acid, biotin, inositol, choline chloride, and p-amino benzoic acid. Diets with high doses (≥70.7 ppm) of the other B vitamins and low doses (≤0.2 ppm) of niacin resulted in no pupal recovery. However, a delayed larval duration and reduced pupal recovery resulted when no niacin and 7.07 ppm or lower of the other B vitamins were compared with those from a complete diet that contained 20 ppm niacin and 707 ppm of the other B vitamins. With omission of the other B vitamins, larval duration was delayed but was not dose dependent on niacin. Pupal recovery was not affected if niacin levels were maintained at or >0.2 ppm and the other B vitamins were absent. With 20 ppm of niacin in the diet, the larval duration and pupal recovery were dependent on the dose of the other B vitamins. Larval durations were shortened with elevated doses of the other B vitamins, whereas pupal recoveries increased with elevated dose of the other B vitamins. Therefore, the other vitamins reduced the larval duration when niacin was maintained at ≥2 ppm. When the niacin levels decreased to ≤0.2 ppm, doses of the other vitamins has to be reduced <7.07 ppm to maintain normal larval development.

Effects of l-carnitine and niacin supplied by drinking water on fattening performance, carcass quality and plasma l-carnitine concentration of broiler chicks

The present study was initiated to determine whether dietary supplemental L-carnitine and niacin affect growth performance, carcass yield, abdominal fat and plasma L-carnitine concentration of broiler chicks. One-day-old broiler chicks (COB500) were used in the experiment. A two by two factorial arrangement was employed with two levels (0 and 50 mg/l) of supplemental L-carnitine and two levels (0 or 50 mg/l) of supplemental niacin in drinking water as main effects. Body weight gain was significantly improved by L-carnitine, or L-carnitine + niacin supplementation during the first 3 weeks. However, supplemental L-carnitine and niacin did not change body weight gain during the last 3 weeks of the experimental period. Supplemental L-carnitine significantly improved feed intake during the first 3 weeks. Supplemental L-carnitine or niacin did not influence carcass weight, carcass yield and abdominal fat weight. L-carnitine content in the plasma was significantly higher in the groups receiving supplemental L-carnitine and L-carnitine + niacin. It is concluded that dietary supplemental L-carnitine or L-carnitine + niacin could have positive effects on body weight gain and feed intake during the early stages of growing. However, supplemental L-carnitine or L-carnitine + niacin were not of benefit regarding the complete growth period.

Safety, efficacy, and effect on glucose levels of once-daily niacin on patients with dyslipidemia

Safety, efficacy, and effect on glucose levels of once-daily niacin on patients with dyslipidemia

Asia Pacific food analysis network (APFAN) training exercise: the determination of niacin in cereals by alkaline extraction and high performance liquid chromatography

Analysts from 20 laboratories, mainly from developing countries in the Asia Pacific Food Analysis Network (APFAN), were invited to participate in a training exercise for the determination of niacin (vitamin B 3) in cereals using alkaline extraction and high performance liquid chromatography (HPLC) as the determinative step. The purpose of the study was to assist these laboratories in adopting a robust HPLC method for the determination of niacin in these foods. The exercise was divided into three discrete phases. Analysts were supplied with the validated method together with all of the chemicals and solid-phase extraction columns that were necessary to complete the three phases of the exercise. Phase 1 of the study consisted of a “hands on” workshop for 10 overseas analysts conducted at the 6th APFAN workshop held at the Queensland Health Scientific Services Laboratory, Brisbane, Australia, in May 1999. In phase 1, each analyst was requested to determine the niacin content of three samples of finely ground breakfast cereal that contained a known amount of niacin. Phase 2 involved these analysts as well as analysts from 12 other laboratories in the APFAN network. The analysts were requested to determine the niacin content of a fortified reference material (American Association of Cereal Chemists VMA 195) containing niacin in the range 13.9–20.1 mg/100 g in their own laboratories. Twelve participants reported levels of niacin ranging from 10.6 to 21.7 mg/100 g. Analysts who successfully completed this phase then participated in phase 3, involving the analysis of five different cereal types of unknown niacin content. Eight sets of data were reported for phase 3. Approximately half of the data were in the expected range for the levels of niacin in the samples.

Pharmacological Intakes of Niacin Increase Bone Marrow Poly(ADP-Ribose) and the Latency of Ethylnitrosourea-Induced Carcinogenesis in Rats

Cancer chemotherapy agents cause short-term leukopenia during treatment and the development of secondary leukemias after recovery from the original disease. We reported that niacin deficiency in rats increases the severity of nitrosourea-induced leukopenia and the subsequent development of cancers. This study was designed to test the effects of supplementing an already high quality diet with pharmacologic levels of niacin. For a period of 4 wk, nontumor-bearing weanling Long-Evans rats were pair-fed AIN-93M diets that were niacin adequate (30 mg/kg diet) or pharmacologically supplemented (4 g/kg diet) with nicotinic acid (NA) or nicotinamide (Nam). One week after the initiation of niacin feeding protocols, ethylnitrosourea (ENU) treatment began (12 doses, 30 mg/kg by gavage, every other day). ENU treatment caused leukopenia, which was not prevented by niacin supplementation. At the end of ENU treatment, all rats were switched to a niacin-adequate diet and monitored. Within 36 wk after the start of treatment, all of the ENU-treated rats either lost 5% of peak body weight or had palpable tumors > 1 cm in diameter, and were necropsied. Supplementation with NA or Nam at 4.0 g/kg diet (combined analysis) increased the latency of the ENU-induced morbidity curve, relative to niacin-adequate controls. Morbidity could be attributed in almost all cases to some form of neoplasm, with leukemias the predominant form. In short-term studies, supplementation with either NA or Nam caused dramatic increases in bone marrow NAD(+) (1- to 1.5-fold), basal poly(ADP-ribose) (3- to 5-fold) and ENU-induced poly(ADP-ribose) levels (1.5-fold). These data show that supplementation of a niacin-adequate, high quality diet with pharmacologic levels of nicotinic acid or nicotinamide increases NAD(+) and poly(ADP-ribose) levels in bone marrow and may be protective against DNA damage.

Abnormal vitamin levels in patients receiving home total parenteral nutrition.

The administration of multivitamins to patients receiving home parenteral nutrition (HPN) was decreased from once daily to three times weekly during the parenteral multivitamin shortage in 1997. Blood vitamin levels were measured to examine whether the decrement in the infused vitamins affected the levels. Six patients with normal renal and liver function, receiving HPN for 6 months to 10 years, were studied 6 months after the institution of 10 mL of multivitamins thrice weekly. Two patients with renal insufficiency who required hemodialysis and HPN were also studied. Multivitamin administration was eliminated in one patient and was reduced to once weekly when elevated pyridoxine levels were found in association with possible neurotoxicity. Five of the six patients with normal renal function had low serum ascorbic acid levels. Serum riboflavin levels were found to be low in one patient, serum pyridoxine was low in one, serum retinoids were low in three, and serum niacin was low in one. There were no clinically obvious untoward effects caused by the vitamin deficiencies. Each of the dialysis patients had elevated serum pyridoxine levels and had some neurologic disturbance (peripheral neuropathy, involuntary movements). The serum pyridoxine levels fell to normal in each after the cessation or decrease of the multivitamin preparation. Ascorbic acid levels were low in one patient and fell into abnormally low levels in the other when the parenteral multivitamins were reduced, but they corrected with the separate administration of intravenous vitamin C. In conclusion, the reduced administration of multivitamins in 1997 resulted in diminished ascorbic acid levels in seven of eight patients receiving total parenteral nutrition. Less often, low levels of retinoids, niacin, pyridoxine, and riboflavin were seen. Patients with chronic renal failure receiving HPN with multivitamins may develop elevated pyridoxine levels, which might result in neurologic sequelae.

Some physiological responses of pregnant Egyptian buffalo to niacin supplementation

Eighteen pregnant buffaloes in the third and fourth parities were used in this study. The animals were divided into three equal groups, according to their body weight. Animals of the first (G1) and second (G2) groups were given daily 6 and 12 g of niacin/head, respectively. Supplementation was given 4 weeks antipartum and continued until week 12 postpartum. Animals of the third group (G3) served as controls. The results showed that buffaloes which were given niacin had an increase ( P<0.05) in plasma glucose, hemoglobin, and total protein concentrations. Plasma sodium and cholesterol concentrations decreased as a result of niacin supplementation as compared with the control group, with no difference due to the level of niacin. The results indicate that animals in G1 and G2 groups consumed more ( P<0.01) food and more ( P<0.05) metabolizable energy. They produced more ( P<0.05) fat corrected milk and tended to have a shorter ( P<0.01) interval from calving to detected estrous. They also required less ( P<0.01) services per conception and had shorter ( P<0.01) days open as compared with the control. It was concluded that supplementation of niacin at 6 g/h/day led to improvement of the productive and reproductive performance of pregnant buffaloes.

Quantifying the dietary niacin requirement of the Indian catfish, Heteropneustes fossilis (Bloch), fingerlings

A growth study was conducted to determine the dietary niacin requirement of the Indian catfish, Heteropneustes fossilis (Bloch), fingerlings (Mean weight 9.41 ± 0.18 g). Semi-purified diets with five levels (0, 5, 10, 20 and 40 mg kg−1 diet) of supplemental niacin were fed to H. fossilis for 15 weeks. Each diet was fed to three replicate groups of fish. Results indicated that the highest (P < 0.05) weight gain was for the fish fed the diet supplemented with 20 mg niacin kg−1, followed by fish fed the diets with 40, 10 and 5 mg niacin kg−1, and the lowest in fish fed the unsupplemented control diet. Patterns of specific growth rate (SGR) and protein efficiency ratio (PER) were similar to those of the weight gain. Survival of fish fed the control diet and niacin-supplemented diet was 58% and 91–100% respectively. Niacin deficiency signs such as anaemia, anorexia, lethargy and skin haemorrhage were observed in fish fed the control diet. The haematocrit values (Ht) were higher (P < 0.05) in fish fed the diets supplemented with niacin than in fish fed the control diet. The hepatosomatic indexes (HSI) of fish fed with or without niacin-supplemented diets were not significantly (P > 0.05) different from each other. Both body protein and lipid content were higher (P < 0.05) in fish fed the diet supplemented with 20 and 40 mg niacin kg−1, respectively, than those fish fed other diets. The niacin content in liver significantly (P < 0.05) reflected the supplementation level in the diet and ranged from 29.11 to 40.31 mg g−1 tissue. The associated liver niacin content for growth was about 47 μg g−1 tissue. Quadratic regression analysis showed that the dietary niacin requirement for maximal growth of H. fossilis under these experimental conditions was about 25 mg kg−1 diet.