Szervetlen és szerves humát kötésben lévő mikroelemek (Cr, V, B) hatásának összehasonlító vizsgálata = Investigations on the mechanism of effects of humates and organic micro elements (Cr, V, B)

Három kísérletben vizsgáltuk a fulvosavnak és a huminsavnak valamint a szervetlen és szerves (humát- illetve fulvát-) kötésben lévő mikroelemek (Cr, B, V) hatását patkányokon. A fulvát, a humát illetve ezek kötéseiben lévő mikroelemek etetése nem idézett elő szignifikáns eltérést a kontrollállatokhoz képest a takarmányfogyasztásban, a súlygyarapodásban és a fajlagos takarmányhasznosításban. A kísérleti anyagok nem befolyásolták a plazma antioxidáns kapacitását. Nem volt kimutatható májkárosító hatás a fulvosav és a huminsav valamint szerves kötéseikben lévő mikroelemek esetében sem. Vizsgálati adataink arra utalnak, hogy a huminanyagok hypothyreoid hatásáért a fulvosav felelős korrelációban a dózissal (r=0,954). A humorális immunválaszt a 0,4%-ban alkalmazott fulvosav szignifikánsan erősíti (P<0,05) és az ellenanyagok vérben való perzisztálását is megnyújtja. A fulvosav és a huminsav szignifikánsan csökkentette (P<0,05) a vastagbéltartalom réztartalmát, a fulvosav növelte a vastartalmát, a huminsav csökkentette a mangántartalmát. A huminsav csökkentette (P<0,05) a réz- és vaskoncentrációt a májban. A vesében a fulvosav növelte a vas-, csökkentette a cinktartalmat, a huminsav csökkentette a vas- tartalmat (P<0,05). A szerves kötésben lévő mikroelemek esetében a vizsgálati mintákban nem tudtunk kimutatni szignifikáns eltérést a kontrollhoz képest. Sem az in vivo, sem az in vitro vizsgálatokkal nem volt bizonyítható a bakteriosztatikus hatás. | In this project the effect of fulvic acid (FA), humic acid (HA), Cr-, B- and V-fulvate or humate were investigated in rats. There were no significant effects of the above mentioned dietary supplementations on the feed consumption, weight gain, feed conversion ratio, antioxidant capacity of plasma, blood glucose level, activity of hydrolases in pancreas and small intestinal content. We could not observe any adverse effect on the liver function in either dietary treatments. Mild dose related (r=0.954) hypothyreoid effect of FA has been observed. There was a dose related (r=0.704) immune stimulatory effect of FA, with significant difference compared to the control, at 0.4% (P<0.05) level. Also the persistence of antibodies was longer. The effect of FA and HA on the micro elements were not always identical. Both FA and HA significantly decreased (P<0.05) the copper level of large intestinal content. FA increased the Fe, HA decreased the Mn concentration of the large intestinal content (P<0.05). HA decreased (P<0.05) the Cu and Fe content of liver. FA increased, HA decreased the Fe level, FA also decreased the Zn concentration of kidney (P<0.05). There was no significant difference between the effect of inorganic form and fulvate or humate form of Cr, B and V on the microelement concentrations of large intestinal content, liver, kidney, bone and hair. Bacteriostatic effect could not be proven either in vivo or in vitro experiments

Effect of arginine or glutamine supplementation on production, organ weights, interferon gamma, interleukin 6 and antibody titre of broilers

The objective of this study was designed to test whether supplementation of the diet with arginine (Arg) or glutamine (Gln) or their combination influences the production, organ weights and humoral immune response of broilers. A total of 432 one-day-old male Ross 308 broiler chickens were divided into 6 treatment groups: control, Arg-0.5%, Arg-1%, Gln-0.5%, Gln-1% and Arg-0.5%+Gln-0.5%. Drinking water and feed were provided ad libitum. On day 18 of the experiment 50% of chickens in each treatment group were immunised with bovine serum albumin. Ten and 21 days after immunisation blood samples were collected to determine the anti-albumin IgY titre, interleukin 6 (IL6) and interferon gamma (IFNG) and to measure the weight of the liver, spleen, bursa of Fabricius and thymus. Arg or Gln supplementation of the diets influenced neither the production nor the organ weights until 18 days of age. Between 18 and 39 days of age both Arg (0.5% and 1%) and Arg + Gln supplementation improved the feed conversion ratio (FCR) by 3.7%, 6.3% and 4.9%, respectively, while Gln-1% worsened it by 15%. Immunisation slightly (−0.79%) depressed the body weight gain of broilers fed the control diet, which was significantly improved by both Arg (0.5 or 1%) and Arg + Gln supplementation. Immunisation increased the weight of the spleen, bursa and thymus and decreased that of the liver. Supplementation with 1% Gln depressed (−5.13%) the body weight gain of the immunised chickens but strongly stimulated the immune response. Supplementations with Arg and Gln did not influence the IL6 and IFNG level of the blood; however, on day 10 after immunisation these two parameters showed a negative correlation with each other. Regarding production, organ weights and immunity, Arg supplementation should be recommended in the grower phase, while Gln supplementation can be useful in pullets raised for egg production, where a good immune response to vaccinations is an important factor

Effect of fulvic and humic acids on iron and manganese homeostasis in rats

The objective of this study was to investigate the effects of fulvic acid (FA) and humic acid (HA) as the two main compounds of humic substances, separately on Fe and Mn homeostasis. Seventy-two male Wistar rats were randomly divided into 9 experimental groups. The control diet (AIN-93G formula) and diets supplemented with 0.1%, 0.2%, 0.4% and 0.8% HA or FA were fed for 26 days. Fe and Mn concentrations of the large intestinal content, liver, kidney, femur and hair were determined. No significant differences were observed in the production parameters. The effects of FA and HA on iron homeostasis were significantly different. FA proved to be a good iron source, and slightly increased the iron content of liver and kidney, but — up to a dietary iron level of 52.7 mg/kg — it did not influence the efficiency of iron absorption. Above a dietary iron level of 52.7 mg/kg down-regulation of Fe absorption can be assumed. HA significantly stimulated the iron uptake and there was no down-regulation of Fe absorption up to 0.8% dietary HA supplementation level (61.5 mg Fe/kg diet). In the HA groups the iron content of the liver and kidney decreased significantly, suggesting that in spite of the better Fe absorption, the HA—Fe complex does not provide iron to the investigated organs. Neither FA nor HA supplementation influenced the Fe content of the femur and hair and slightly decreased the Mn concentration in the large intestinal content. This effect was significant (with a 22.7% Mn concentration decrease) only at the HA supplementation rate of 0.8%. Neither FA nor HA influenced significantly the Mn concentrations of the liver, kidney and femur. The Mn concentration of the hair in rats receiving FA- or HA-supplemented diets was higher than in the control rats; however, this result needs further confirmation

Effect of fulvic and humic acids on copper and zinc homeostasis in rats

The objective of this study was to investigate the effects of fulvic acid (FA) and humic acid (HA), the two main compounds of humic substances (HSs), on copper (Cu) and zinc (Zn) homeostasis. Seventy-two male Wistar rats were randomly divided into nine experimental groups. The control diet (AIN-93G formula) and the diets supplemented with 0.1%, 0.2%, 0.4% and 0.8% FA or HA were fed for 26 days. Cu and Zn concentrations of the large intestinal content (LIC), liver, kidney, femur and hair were determined. FA and HA did not influence significantly the Cu or Zn contents of the experimental diets, the rats’ feed intake, weight gain and the feed to gain ratio. Both FA and HA decreased the Cu concentrations of the LIC significantly and in a dose-related manner; however the absorption-stimulating effect of HA was more pronounced. FA increased the Cu content of the liver, but neither FA nor HA had a dose-dependent effect on it. FA or HA supplementations had no significant effect on the Cu concentration of the kidney. At the concentrations used, dietary FA or HA supplementations are not promising growth promoters. FA influences the Cu homeostasis unlike HA, because FA not only stimulates Cu absorption, but the extra quantity of absorbed Cu is retained in the organism. The stimulatory effect of HA on Zn absorption may not be manifested in Cu and Zn homeostasis, because of the tight connection of these microelements to FA and HA, which prevents the transmission of Zn from the ZnHA complex to the organs. As regards the effect of FA and HA on Cu and Zn homeostasis, both FA and HA stimulated the absorption of these microelements, but only FA increased the retention of Cu (in the liver) and Zn (in the kidney)

Fructose, glucose and fat interrelationships with metabolic pathway regulation and effects on the gut microbiota

The purpose of this 30-day feeding study was to elucidate the changes, correlations, and mechanisms caused by the replacement of the starch content of the AIN-93G diet (St) with glucose (G), fructose (F) or lard (L) in body and organ weights, metabolic changes and caecal microbiota composition in rats (Wistar, SPF). The body weight gain of rats on the F diet was 12% less (P = 0.12) than in the St group. Rats on the L diet consumed 18.6% less feed, 31% more energy and gained 58.4% more than the animals on the St diet, indicating that, in addition to higher energy intake, better feed utilisation is a key factor in the obesogenic effect of diets of high nutrient and energy density. The G, F and L diets significantly increased the lipid content of the liver (St: 7.01 +/- 1.48; G: 14.53 +/- 8.77; F: 16.73 +/- 8.77; L: 19.86 +/- 4.92% of DM), suggesting that lipid accumulation in the liver is not a fructose-specific process. Relative to the St control, specific glucose effects were the decreasing serum glucagon (-41%) concentrations and glucagon/leptin ratio and the increasing serum leptin concentrations (+26%); specific fructose effects were the increased weights of the kidney, spleen, epididymal fat and the decreased weight of retroperitoneal fat and the lower immune response, as well as the increased insulin (+26%), glucagon (+26%) and decreased leptin (-25%) levels. This suggests a mild insulin resistance and catabolic metabolism in F rats. Specific lard effects were the decreased insulin (-9.14%) and increased glucagon (+40.44%) and leptin (+44.92%) levels. Relative to St, all diets increased the operational taxonomic units of the phylum Bacteroidetes. G and L decreased, while F increased the proportion of Firmicutes. F and L diets decreased the proportions of Actinobacteria, Proteobacteria and Verrucomicrobia. Correlation and centrality analyses were conducted to ascertain the positive and negative correlations and relative weights of the 32 parameters studied in the metabolic network. These correlations and the underlying potential mechanisms are discussed

Alteration of body composition in rats: Effect of organic chromium and L-carnitine

A growth trial was carried out to test the effect of organic, trivalent chromium and L-carnitine on the body composition of growing rats. At the same time, an evaluation of different measurement methods (weight of epididymal fat pad, adipocyte morphometry, total body electrical conductivity) was performed. Outbred Wistar rats of 30 days of age were fed diets of different (0, 10 and 20%) protein level. The diets were supplemented with 4 mg/kg Cr as chromium nicotinate, and 100 mg/kg L-carnitine. The experimental feeding lasted 15 days, after a 5-day-long adjustment period. It was found that Cr addition increased feed intake. Both treatments caused changes in body composition, increasing fat and protein deposition. Organic chromium had no effect at either protein level, while L-carnitine improved the protein retention only at an optimum (20%) protein supply. No statistically significant correlation was found between total body electrical conductivity (TOBEC) and body composition, which could be attributed to the great individual differences. A close correlation was found among total body fat percentage, weight of epididymal fat pad and the adipocyte surface. The data suggest that there is an interaction between dietary protein supply and the effect of repartitioning agents

Influence of feeding intensity on corporeal development, body composition and sexual maturity in female rabbits

Twenty-six 6-week old female New Zealand White rabbits were divided into two groups: ad libitum (AL) and 70% restricted (RS) feeding. At the beginning of the experiment the liveweights were practically the same: 0.99 ± 0.08 vs. 1.01 ± 0.08 kg in group AL and RS, respectively. At 18 weeks of age the body weight of Group RS rabbits was 84.7% (3.14 ± 0.24 kg) of the group AL (3.71 ± 0.31 kg). The apparent digestibility of crude protein was significantly (p < 0.001) higher in Group RS than in Group AL (76.5 ± 1.4 vs. 73.0 ± 2.7%). The daily water consumption was significantly (p < 0.05) higher (3.5 ml/g DM intake) in Group RS as compared to Group AL (1.9 ml/g DM). Since the average body weight in Group RS at 18 weeks was the same as that of Group AL at 14 weeks of age (3.14 kg), the comparison of the live body measures and indices was based on these ages. Animals fed ad libitum or restricted show no differences at the defined age in most live body measurements except in heart girth and rump width, which were significantly (p < 0.05) shorter in Group AL than in Group RS (29.3 ± 0.8, 5.7 ± 0.5 and 30.7 ± 1.0, 6.2 ± 0.3 cm, respectively). Body capacity was significantly (p < 0.05) smaller in Group AL, as the head capacity-body capacity proportion was significantly (p < 0.05) higher in Group AL than in Group RS (1653.1 ± 134.5, 22.0 ± 2.5 and 1913.7 ± 168.7, 17.7 ± 1.9, respectively). Due to restricted feeding the growth of the head proved to be less intensive than that of the body at the same body weight. The body in these does tended to be wider. Since the head in comparison to length or capacity of the body was smaller in does fed 70% of ad libitum, it could be concluded that the development of body parts of restricted-fed does was unequal (allometric growth). The effect of feed restriction reflected in lower dry matter and fat, and a higher ash and protein content both in total body and in dry matter composition of rabbits at 18 weeks of age. Restricted feeding delayed sexual maturity (69 vs. 92% of rabbits) with later starting ovarian activity, weaker ovarian responsiveness, and a smaller number of tertiary follicles on the ovarian surface

Investigations concerning the voluntary dry matter intake, passage time, and the nutrients’ digestibility in Hermann’s tortoises (Testudo hermanni)

SUMMARY Information on the voluntary dry matter (DM) intake, gut passage time and digestibility of nutrients may help the adequate feeding of tortoises and may also help to prevent fast growth rate due to overfeeding of the animals. The aim of the study was to determine the voluntary DM intake and gut transit time in Hermann’s tortoises (Testudo hermanni) and also to investigate whether it is possible to determine digestibility with the method of total collection. The twelve male tortoises were placed individually in plastic terrariums. Three different foods (slicing cucumber, lettuce, dandelion) were tested for voluntary DM intake. The DM intake in percentage of the body weight was much higher in case of lettuce than in slicing cucumber or dandelion. Gut transit time was much lower in case of slicing cucumber than in the two other foods. Most of the animals (in all three diets) partially or totally consumed the faeces, so the digestibility could not be determined. According to the results of the study ad libitum feeding of lettuce is not advised. The method of total collection cannot be reliably applied in tortoises

Pathological changes induced by rancid feed in rats and effects on growth and protein utilisation

The objective of this trial was to study the effect of rancid feeds on the health status and growth of rats and to determine the pathological changes induced by dietary rancidity. Forty-two weaned male rats (body weight: 69.3 ± 1.0 g) were divided into seven experimental groups (n = 6 each). Rats in the different groups were fed diets containing meat-and-bone meal at an inclusion rate of 19 to 22%, low or high in peroxides and high in organic acids, with or without antioxidant. The diets were isoproteic (10%) and isolipidic (6%). During the 26-day-long trial (5 days for adjustment and 21 days for the main period) the body weight gain and the feed consumption were recorded. At the end of the trial detailed gross and histopathological examinations were performed. Feeding high-peroxide feed mixtures for 21 days significantly (P < 0.05) decreased feed intake and liveweight gain, while high organic acid concentration had only slight negative effects. Antioxidant supplementation alleviated the harmful effects, especially in the high-peroxide group. The ingestion of rancid feed mixtures and the subsequent decreased feed intake caused a decrease of glycogen content in the hepatocytes, accompanied by a slight centrolobular fatty infiltration. Peroxides caused lymphocyte depletion in the spleen, decreased the size of Malpighian bodies and the number of lymphoblasts, and altered the spermatogenesis. The protective effect of the antioxidant mixture seemed to be negligible in this respect

Effect of dietary catmint (Nepata cataria) on the behaviour, feed preference and digestibility of nutrients in cats

SUMMARY Catnip (syn. catmint) is known to be irresistible for most cats. The effect of inhaled catnip smell was investigated on the general clinical state and behaviour, as well as on the feed preference and nutrients’ digestibility if added to the canned petfood. Nutrients’ digestibility of catmint meal was determined by an indirect digestibility trial using 10 castrated, adult cats. In the preference test the pure canned wet petfood was supplemented by 1% of catmint on dry matter basis. Punched plastic balls filled up with catmint were also tested for possible attractability of catmint for cats. Catmint meal is poor in protein (6.74%), but it is rich in fibre (41.05%) and in aromatic compounds. There were changes in the behaviour: catnip-filled plastic play balls only half of the cats showed different kind of interest. In the preference test cats ate less from the catmint-supplemented diet (78.4 g/animal/day) than from the control (278.6 g/animal/day). The digestibility of the dry matter (34.78%) and crude protein (42.39%) content of the catnip meal is low. If added to canned petfood, it really improved the consistency of the faeces. Taken together, the use of catnip can be proposed for environmental enrichment, both in case of laboratory and pet cats, but not added to the feed, but in form assuring the possibility of inhalation