Effect of fulvic and humic acids on performance, immune response and thyroid function in rats.

Effect of humic acid (HA) and fulvic acid (FA) on production parameters, immune response and thyroid function of rats were investigated in two experiments. First experiment: control or 0.1%, 0.2%, 0.4%, 0.8% HA- or FA-supplemented diets. Second experiment: control and 0.4% HA- or FA-supplemented diets. The feeding period lasted 26 days in both trials. No significant changes were observed in production parameters. Ovalbumine antibody titre of rats on HA- or FA-supplemented diets showed dose-dependent (at 0.4% supplementation) and significant (p < 0.05) increase (350 and 418% respectively) over the control (100%). Dose-related increase of plasma TSH (r = 0.99), and decrease of the T(4)/T(3) ratio (r = -0.97) was observed in FA-supplemented rats. Second experiment: both FA and HA stimulated the immune response by the 14th day (mean values: control: 685.79; FA: 1131.37; HA: 1055.6099) and 26th day (control: 544.31; FA: 1969.83; HA: 1600.00). No significant differences were noted with lymphocyte stimulation test. Diameter of the 'B'-dependent lymphoid tissues in the ileum and spleen were significantly (p < 0.05) larger in both the FA- and HA-treated animals. Humic acid and FA supplementation resulted in strong humoral immune stimulation. Our data also indicate that FA content is responsible for the mild hypothyroid effect of humic substances.

Effects of oral L-carnitine, L-lysine administration and exercise on body composition and histological and biochemical parameters in pigeons.

The purpose of this study was to examine whether L-carnitine and its precursor L-lysine could have any beneficial effect in racing pigeons, and if so, whether this effect is influenced by the extent of exercise (short-distance flight: 135 km vs. long-distance flight: 580 km). Birds were divided into seven groups of animals. Group 1: negative control, no flight, no treatment, Group 2: positive control, placebo treatment before the short-distance flight, Group 3: 200 mg/day L-carnitine treatment before the short-distance flight, Group 4: 400 mg/day L-lysine treatment before the short-distance flight, Group 5: positive control, placebo treatment before the long-distance flight, Group 6: 200 mg/day L-carnitine treatment before the long-distance flight, Group 7: 400 mg/day L-lysine treatment before the long-distance flight. L-carnitine, L-lysine and distilled water (placebo) were orally administered (tube feeding) for 7 days before flight. Just after returning home, blood samples were collected and analyzed for glucose, fructosamine, cholesterol, triglycerides and thiobarbituric acid reactive substances. Pigeons were euthanized using carbon dioxide as an inhalation agent, and the whole body was subjected to proximate analysis. The status at arrival was referred to as a basis for comparison. Sex did not affect the measured parameters. As a result of the L-carnitine and L-lysine administrations, the body fat mobilization was higher during the 580 km flight, whereas no changes were noted during the 135 km flight. The main changes in the measured blood parameters were caused by the extent of exercise. This experiment considered the extent of exercise as a factor potentially modulating L-carnitine supplementation effects. In conclusion, flight distance affected several parameters but the supplements of L-carnitine and L-lysine were not effective in the tested situations.

Study of the energy and protein balance of pregnant rabbit does using two comparative methods.

The total body composition of 4 x 10 female, 5-month-old New Zealand White rabbits was determined, using direct chemical analysis and computerised tomography (CT). Ten non-pregnant rabbits (control) and 3 x 10 pregnant rabbits at days 14, 21 and 28 of gestation, respectively, were included in the study. With the advancement of pregnancy, the body weight (BW) of does significantly (P < 0.05) increased (control: 3255 g, day 28: 3938 g), while the dry matter, DM (control: 43.02%, day 28: 40.94%), ether extract, EE (control: 20.15%, day 28: 18.13%), crude protein, CP (control: 20.15%, day 28: 18.13%), and energy concentration decreased (control: 12.41 MJ/kg BW, day 28: 11.81 MJ/kg BW). During pregnancy the protein content of uteri (control: 12.24%, day 28: 49.45% of DM) and the retained energy in the form of uterus with fetuses (day 14: 0.824 MJ, day 28: 2.189 MJ) increased, while the dry matter (control: 82.39%, day 28: 28.96%) and ether extract content (control: 86.05%, day 28: 45.92% of DM) of uteri decreased. With the advancement of pregnancy the dry matter (day 14: 39.70%, day 28: 18.65%) and crude protein (day 14: 75.74%; day 28: 63.63% of DM) content and the number of fetuses (day 14: 8.8; day 28: 6.4) decreased, while their fat concentration (day 14: 10.13%, day 28: 24.34% of DM) increased. According to the equations created from the CT pictures, body fat (R2 = 0.871) and energy (R2 = 0.926) content can be predicted with high accuracy. The accuracy of predicting body protein content is much lower (R2 = 0.356), which can be improved by introducing the body weight as a new dependent variable (R2 = 0.797). It can also be concluded that, in contrast to other animal species, rabbit fetuses show considerable development not only in the last trimester of gestation but already from the second half of pregnancy.

Effect of different fibre types on the digestibility of nutrients in cats.

In this study the effect of different fibre types was investigated on the acceptance of foods (in a short-term study) and on the nutrients' digestibility by using 10 adult, castrated cats. Peanut hull (PH, source of lignin), dried sugar beet pulp (SBP, source of hemicelluloses and pectin) and alfalfa meal (ALF, source of cellulose) were mixed to a poultry meat based cat food in 10% on dry matter (DM) basis. The average DM intake did only slightly differ according to the type of fibre added. Supplementation of basal food by dried SBP did not influence the digestibility of DM and crude protein (CP) significantly. Using ALF as a fibre source decreased the digestibility of DM (85.8% vs. 78.6%) and CP (93.8% vs. 92.0%) significantly. More severe decline could be observed in the digestibility of DM (85.8% vs. 63.4%) and CP (93.8% vs. 83.7%) when using PH as a fibre source. Fibre sources also influenced the stool DM content significantly. While application of PH increased the DM content of the faeces (45.0% vs. 49.6%), the use of dried sugar beet or ALF reduced the faecal DM content (45.0% vs. 24.1% and 39.0%, respectively). According to these results the less digestible fibre source (PH) increased the DM content of the faeces while by improving the digestibility of the fibre sources the DM content of the faeces decreased. It can be concluded, that not only the absolute fibre content of the food but also the type of fibre must be taken into account when evaluating its possible role as a component of weight loss products.

Reduction of the energy density of cat foods by increasing their fibre content with a view to nutrients' digestibility.

Indigestible compounds are useful for reducing the energy density of food for obese cats, but the acceptance and digestibility of such components must also be taken into consideration. In this trial, dried apple pomace was investigated as a compound having sweet taste, aromatic flavour and high fibre content (207 g/kg dry matter). It was mixed in a meat-based diet at a ratio of 10, 20, and 40%. These diets were fed to adult cats in digestibility trials. As could be predicted, by increasing the percentage of apple pomace in the mixtures the digestibility of nutrients significantly decreased (p < 0.01; p < 0.001). However, the digestibility of ether extract decreased much less than that of the other nutrients. The addition of apple pomace to the diets at an inclusion rate of 10 or 20% reduced their energy density but only slightly changed the digestibility of fat. However, the digestibility of crude protein decreased considerably. According to the present findings, the energy density of mixed diets decreases proportionally to the percentage of apple pomace added. However, due to the much lower digestibility, the protein supply to the cat will be worse. It was concluded that the addition of palatable fibrous components is the best method for reducing the energy content of food for obese cats, as it maintains a normal level of food intake. When calculating the required protein content of a diet supplemented with a fibrous component, in addition to the degree of dilution the reduced protein digestibility must be taken into account.

Factors influencing the food preference of cats.

Four individual preference tests were carried out using the same 10 castrated adult cats. The main questions investigated were: (i) do the cats prefer diets having one dominant taste or diets made from a relatively wide range of compounds of animal origin and (ii) can the preference be connected to one taste? In test 1 a dry diet (K) made by a world-renowned company having a beef taste was compared with four others (I, II, III, IV) dry foods prepared at the authors' institute in order to prevent any one of the mixtures having a predominant taste. In test 2 diets I, II, III and IV were compared with each other in the absence of diet K. In test 3 another four diets with different dominant tastes (fish, liver, poultry with fat addition and poultry without fat addition) were investigated. In test 4 the same three tastes (beef, fish and poultry) were compared with each other by using diets of three world-renowned companies. From the results the following conclusions can be drawn. Cats undoubtedly use smell in the detection and selection of food. If cats find the odour of a certain food is significantly more attractive than that of the other, they will consume it exclusively and without tasting the less attractive food. If none of the diets are especially attractive, according to smell, cats will also taste the foods and make their decision on the basis of both senses. Diets having one dominant taste result in a higher feed intake than that reached by diets without a dominant taste. If a diet is manufactured well, its dominant taste may have less effect on diet consumption. Food preference does not seem to be connected to one exclusive taste but is significantly influenced by other factors connected to the manufacturing of the diets.

Retarded myelination in the lumbar spinal cord of piglets born with spread-leg syndrome.

Piglets born with spread-leg syndrome, a congenital weakness of the hindlimb adductors, were investigated to determine the site of lesion leading to limb impairment. Histological and immunohistochemical studies of the motor neuron unit showed no alterations but quantitative analysis revealed a reduction of axonal diameter and myelin sheath-thickness of the fibres innervating the adductors of the affected limbs. In the lumbar spinal cord a lack of myelination was observed in the tracts descending to the lower motor neurons. Recovery from the syndrome was accompanied by a catching-up of myelination with that of the controls. The spread-leg syndrome is due to a nutritional deficiency in the sow; thus it is assumed that the deficient maternal substances, mainly choline and methionine, are essential for the normal myelin production by spinal white matter oligodendrocytes of the fetus.

Ovarian consequences of low dose peroral Fusarium (T-2) toxin in a ewe and heifer model.

The effect of low dose peroral Fusarium produced T-2 toxin intake upon the ovarian function was evaluated in ewes (n = 30; Trial 1) and heifers (n = 7; Trial 2). Half of the ewes and all of the heifers were fed rich, acidosis-inducing concentrate. The 30 ewes were divided into 6 groups of 5 animals each. They were given 0, 0.3 or 0.9 mg/day (0, 5 or 15 ug/kg) purified T-2 toxin per os for 21 days (3x2 factorial design). Four of the 7 heifers were fed 9 mg/day (25 ug/kg) of the same purified T-2 toxin for 20 days while 3 remained untreated. The estrus cycles in all animals were synchronized prior to the trials and the T-2 exposure was started in the mid-luteal phase. The acidic condition in the rumen was estimated by the determination of urinary net acid-base excretion. The ovarian activity was followed with blood sampling for progesterone on alternate days (Trial 1) or with ultrasonography and sampling for progesterone daily (Trial 2). All of the heifers and concentrate-fed ewes showed a compensated acidosis, during first two thirds of T-2 exposure. In Trial 1, ovarian malfunction manifested as lower P4 peak concentration in the midluteal phase, shortening of the CL lifespan and prolonged follicular phases. These malfunctions were detected in 3 and 3 ewes fed concentrate and 0.3 mg and 0.9 mg T-2 toxin. Lower P4 peak concentration was observed in 1 ewe fed regular diet and 0.9 mg T-2 toxin. None of the control and acidotic groups (0 mg T-2), or ewes fed regular diet with 0.3 mg T-2 showed any ovarian malfunction. In Trial 2, after PGF2, administration the ovulation occured later and the plasma progesterone level remained low (< 3 nmol/l) for a longer period in T-2 treated heifers, than their untreated control mates (5.0+/-0.7 vs 3.7+/-0.5 d, P<0.05 and 8.3+/-0.4 vs 6.3+/-0.9 d, P<0.01, respectively). These results show that the peroral T-2 intake can significantly retard the folliculus maturation and ovulation and perhaps the subsequent luteinisation also in ruminants kept on concentrate-rich diet.

Study of the soil-plant (carrot)-animal cycle of nutritive and hazardous minerals in a rabbit model.

Carrots were grown on soils polluted by heavy metal salts. Each particular microelement reached a high concentration [molybdenum (Mo) 39.00, cadmium (Cd) 2.30, lead (Pb) 4.01, mercury (Hg) 30.00, and selenium (Se) 36.20 mg/kg dry matter] in the carrot. In a metabolic balance trial conducted with 15 male and 15 female New Zealand White rabbits, the control animals (n = 5) were fed ad libitum with concentrate as basal diet, while the other rabbits received the basal diet and carrots containing the particular microelement. Blood samples were taken to determine the activity of serum enzymes. To investigate the metabolism of Mo, Cd, Pb, Hg and Se, samples were taken from the heart, liver, lungs, kidneys, spleen, ovaries/testicles, entire digestive tract, adipose tissue, femur, hair, faeces and urine. Carrot had significantly higher digestibility for all nutrients than the rabbit concentrate. Carrot samples of high Pb content had the lowest digestibility of crude protein. The microelements differed in their rate of accumulation in the organs examined: Mo and Cd accumulated in the kidneys, Pb in the kidneys, liver, bones and lungs, Hg in the kidneys and liver, while Se in the liver, kidneys and heart. The proportions of microelements eliminated from the body either via the faeces and urine (Mo 80.18% and Se 47.41%) or via the faeces (Cd 37.86%, Pb 66.39%, Hg 64.65%) were determined. Pathohistological examination revealed that the rate of spermatogenesis was reduced in the Mo, Cd, Pb and Hg groups compared to the control. Lead, Cd and Hg intake resulted in a considerable decrease in gamma-glutamyltransferase (GGT) and in an increase of alkaline phosphatase (ALP) activity because of damages to the kidneys and bones. All experimental treatments decreased the activity of cholinesterase (CHE) because of lesions in the liver.

Studies on the energy content of pigeon feeds II. Determination of the incorporated energy.

The effect of breed and sex on adult body composition of four pigeon breeds: Texan (TEX), Mondain (MON), Szeged Tumbler (SZT), and homing (HOM) and on the digestibility coefficients (DC) and metabolizable energy (ME) content of their feeds was studied. A total of eight groups, each comprising five males and five females of each breed, were used. All birds were fed the same pelleted pigeon feed (17.27% CP) ad libitum. After the metabolic study, the whole body was analyzed for dry matter (DM), ash, CP, and ether extract (EE) contents. The DC of DM, TEX, MON, and HOM pigeons did not differ significantly, whereas DC for the SZT breed were consistently lower. In the majority of cases, the DC values obtained for males were higher, irrespective of the breed. The body composition of the two sexes was first compared within a given breed, and no major differences were detected. Interbreed differences were greater. The DM content of the body of HOM pigeons exceeded that of the other three breeds for both sexes. For ash and CP content of the body, the reverse was found, i.e., the values of both parameters were lower in HOM pigeons. The HOM pigeons had significantly (P < 0.05) higher body fat (EE) content as compared with the other three breeds except TEX females. The NFE value for HOM also tend to be higher than in the other three breeds.

Studies on the energy content of pigeon feeds I. Determination of digestibility and metabolizable energy content.

The digestibility coefficient and metabolizable energy (ME) content of the most important pigeon feeds (corn, wheat, barley, red and white millet, sorghum, canary seed, peas, lentils, sunflower, and hemp) were determined. The experiment was carried out using 10 adult male homing pigeons. All feeds were fed alone, in a whole-grain form, ad libitum. Drinking water and grit were offered to the birds on a continuous basis. Each feedstuff was fed to five pigeons in 1-wk cycles. There was no significant difference between the values determined in pigeons and those reported in the literature for chickens among the digestibilities of the CP of the various feeds. For pigeons, the digestibility of carbohydrates (N-free extracts, NFE) was lower (e.g., 62.37 vs 83.00% for barley and 63.45 vs 77.00% for peas), whereas the ether extract (EE) was higher (e.g., 75.58 vs 61.00% for barley and 82.59 vs 80.00% for peas) in pigeons compared with chickens. As a result, the AMEn values determined in pigeons did not differ significantly from those reported for chickens but tended to be slightly higher. For feeds of high-oil content, that difference may be somewhat larger. The correlation between the CP, EE, crude fiber (CF), and NFE contents of the feeds and the ME values determined in this experiment were calculated by multivariate linear regression. It was concluded that it was more accurate to determine and tabulate the ME contents of other potential pigeon feeds directly by experimental methods rather than using an equation.

Effect of methionine and its derivatives on the weight gain and protein utilisation of growing rats.

Methionine and its derivatives are used as feed supplements. The objective of this study was to compare the effectiveness of DL-methionine (MET), DL-methionine-hydroxy-analogue (2-hydroxy-4-methylthio-butyric acid, MHA), and DL-S methyl-methionine-sulphonium-chloride (SMM) in rats using low- (10 g/100g, BD10), medium-(15g/100g, BD15) and high-protein (20 g/100 g, BD20) diets. In a 10-day growth assay with weaning male rats (Wistar, SPF, LATI, Gödöllo, Hungary, 6 rats/group) methionine-deficient basic diets (BD10, BD15, BD20) were supplemented with 0, 1.5 ad 3.0 g/kg MET, MHA OR SMM. Extracted soybean meal was used as sole protein source. A protein-free diet was used for determining net protein ratio (NPR) indices. The weight gain of rats fed test diets fortified with 1.5 and 3.0 g/kg MET, MHA, or SMM was significantly higher (p < 0.05) than that obtained with the unfortified diets. The NPR index of the diets was increased by MET, MHA or SMM supplementation, which increase was significant (p < 0.05) at 3.0 g/kg fortification level. However, there were no significant differences between the efficiencies of methionine derivatives on the same dietary protein levels. The weight gains of the rats were higher and the NPR indices of the diets were lower at a higher dietary protein level.

Body composition of mice of different body condition score and sex.

After a critical review of recent research on the whole body chemical composition of laboratory animals, especially that of the mouse, the authors present data on the body composition of a mouse line of different body condition score, varying from normal to double-muscled ("culard", "compact") type. One hundred male and 100 female mice of different compact categories were measured in vivo, using total body electrical conductivity (TOBEC method), then by direct chemical analysis performed on day 77 of life. In male mice, body weight and protein content were found to increase while fat content decreased parallel to the increase in phenotypic condition score. Female mice showed a rather constant fat, protein and ash content in the dry matter of the body. The precision and validity of TOBEC data under 40 grams of body weight proved to be insufficient.

Nutritional factors affecting milk quality, with special regard to milk protein: a review.

This paper reviews some of the recent scientific literature that relates nutritional management to protein concentration in the milk of dairy cows. Nutritional management of the dairy cattle was organized under the headings of nutrition and body condition before calving, forage to concentrate ratio, type and treatments of forage, dietary fibre, dietary protein, dietary amino acid supplementation, dietary fat, dietary carbohydrates, concentrate composition, vitamins, feed additives, and feeding frequency. The level of feeding and rate of liveweight change prior to calving within "normal" limits seems to have relatively little effect on milk yield and composition. Cows which are thin at calving, are biologically more efficient because they produce more milk directly from food rather than from mobilization of body reserves. Increasing the forage content of the diet leads to increased milk fat and depressed milk protein as well as milk yield, and vice versa. Modification of forage type and the treatments of forage seem to exert a relatively weak effect on milk composition. Increasing neutral detergent fibre (NDF) concentration of the diet from 25% to 37% on dry matter (DM) basis corresponds to a linear decrease in milk production, milk protein and a linear increase in the fat content of milk. When data were analysed by the source of roughage, a significant interaction of effects was found between NDF content of the diet on milk yield. Increasing the protein concentration of the diet up to 22% was found to raise milk yield and milk fat concentration, but an increase beyond that level had no consistent effect. A moderate amount of undegradable protein, however, can improve the milk yield and milk protein content of high-lactating cows. Milk protein concentration may be improved by various combinations of ruminally protected methionine and lysine if these amino acids are limiting in the diet. The inclusion of free lipids in diets generally increases the milk yield, but decreases milk protein concentration. By-pass lipids improve milk yield. Levels of dietary fat above 6-7 per cent lead to a depression of both total milk yields and fat and protein content. The source of carbohydrate in the concentrate has little effect on milk production when the concentrates are of similar metabolizable energy (ME) content. Dietary beta carotene has no significant effects on milk production or milk components, while vitamin A may be more effective. Niacin supplementation may correct a milk protein depression induced by dietary oil.(ABSTRACT TRUNCATED AT 400 WORDS)

The effect of animal fat and vegetable oil supplementation of feeds of different energy concentration upon the digestibility of nutrients and some blood parameters in rabbits.

The effect of mixed animal fat and sunflower oil supplementation (5%) of a feed of medium (12.02 MJ DE/kg) and low (8.54 MJ DE/kg) energy concentration upon the digestibility of nutrients and on some blood parameters was investigated. The ether-extractable content of feed and faecal samples was determined by diethyl ether extraction (after Soxhlet) and the total (true) fat level was measured by the method of Stoldt (1952), viz. petroleum ether extraction of samples pretreated with 4 N HCl. In the majority of cases the voluntary feed intake decreased after the addition of animal fat or vegetable oil. Mixed animal fat supplementation significantly (by 5 and 11 units) improved the digestibility of the ether extract if added to either of the basal diets. The digestibility of crude fibre and N-free extract increased only in the case of the basal diet of low energy concentration (by 4 and 7 units, respectively). Sunflower oil addition produced changes of the same tendency (9, 9, 28 and 5 units). The digestibility of the crude protein was practically not altered by either supplementation. The total fat content of feed and faecal samples proved to be higher than that of the ether extract, on an average by 27 and 100%, respectively. Consequently, the digestibility coefficients of the total fat are by 10 units lower than those of the ether extract. The DE concentrations, calculated by means of the digestible ether extract or the total fat content, differed significantly only between the basal diets. The addition of mixed animal fat to either of the basal diets increased the blood concentration of total lipids (by 18 and 32%, respectively), while that of sunflower oil did not cause such an alteration. Neither fat nor oil supplementation had an effect on the cholesterol level of the blood plasma. Both the animal fat and the vegetable oil surplus modified the fatty acid composition of blood lipids. It was characteristic of each treatment that the proportion of polyunsaturated fatty acids increased.