Relação lisina digestível: proteína digestível em rações para tilápias-do-nilo

This study was carried out to determine the best digestible protein/digestible lysine ratio that should be present in feed fed to Nile tilapias. Two hundred and sixteen tilapias (11.0 +/- 0.43g) were distributed in 36 fish tanks (205 L) at a density of 6 fish/tank. Twelve feeds were formulated with three different digestible protein (DP) levels 22.0; 26.0 and 30.0% (based on digestible amino acids) and four different lysine percentages of 4.5; 6.0; 7.5 or 9.0% in relation to digestible protein. The fish were fed ad libtum during a 60-day period. There was significant effect of the digestible protein and digestible lysine ratio on weight gain, because the increase in lysine levels in feeds with 26 and 30% DP promoted linear increase in this parameter. The best values for feed conversion were obtained at the levels 26 and 30% DP that increased the daily consumption of digestible protein. The lysine level caused a linear reduction in feed conversion and linear increase in the protein efficiency rate. The results suggested that the 26% DP level might be used in ration to feed Nile tilapia juveniles; however, these should contain digestible amino acids and the digestible lysine/digestible protein ratio should be 6.0%. However, for levels higher than 26% DP, a maximum digestible lysine level of 7.5% DP improved weight gain for the species.

Fibrous Osteodystrophy in a Captive Common Eland Antelope (Taurotragus oryx).

Fibrous osteodystrophy (FO) is a common condition described mainly in domestic species, with only few cases described in wild ones kept in captivity. Herein we report a case of FO in a 2 yr-old female common eland antelope (Taurotragus oryx) maintained in captivity and fed with a horse pelleted ration plus hays. The animal showed a firm bilateral symmetrical enlargement of upper maxillary bones which was submitted to histological evaluation. Microscopic findings were those related to extensive bone resorption and fibroplasia.

Níveis de proteína digestível e energia digestível em dietas para tilápias-do-nilo formuladas com base no conceito de proteína ideal

This study was carried out to determine the best digestible energy and digestible protein ratio in feeds for Nile tilapia (Oreochromis niloticus) juveniles 30.0 +/- 4.21 g) based on digestible amino acids and the ideal protein concept). Twelve rations were formulated with protein levels 22.0; 26.0; 30.0 and 34.0% of digestible protein and levels 3,000, 3,300 and 3,600 kcal/kg digestible energy. The digestible energy/digestible protein ratio was between 8.94 and 15.19 kcal/g. Three hundred and twenty four tilapias were randomly distributed in thirty six 250 L circular tanks at a density of 9 fish/tank, a total of 12 treatments with three replications. After 60 days, there was no significant difference in weight gain, daily weight gain and feed conversion ratio among the studied treatments. A linear increase was observed in fillet yield with increasing digestible protein. With respect to feed cost/kg weight gain, the treatment with 30.0% DP and 3,000 kcal/kg DE presented low cost and better cost effectiveness index. Therefore, it was concluded that digestible energy did not influence the productive performance parameters and that effective feeds can be formulated with DP levels lower than 34% when feeding juvenile tilapias. The ration should be formulated based on the concept of ideal protein.

Selênio orgânico na alimentação de matrizes de tilápia-do-Nilo (Oreochromis niloticus)

Organic selenium in the diet of Nile tilapia (Oreochromis niloticus) broodstock. The aim of this study to test the effect of organic selenium supplementation in the diets of Nile tilapia broodstock. Growth, reproductive performance and performance of fingerlings were evaluated. Eighty adult fish were used, with average weight of 121.7 g and divided into groups of four animals (3 female and 1 male) stocked in 20 tanks with 1.5 cubic meters. The fish were fed five diets containing different levels of organic selenium (0.0, 0.25, 0.50, 0.75, and 1.0 mg kg-1 ration). In the experimental period, females from all tanks were captured and the eggs collected. The experimental design was entirely randomized, with five treatments and four replicates. To evaluate progeny performance, the fingerlings were shared in four aquariums and fed during 30 days with commercial diet (45% CP). The supplementation with organic selenium did not affect the productive performance as with the reproductive parameters of the broodstock (p > 0.05). on the other hand, the broodstock fed with 0.50 mg of organic selenium produced fingerlings that presented improved weight gain (p < 0.05) compared to fish fed the control diet.

Matéria seca, cálcio e fósforo em rações para ovinos, contendo farelo de algodão, levedura e uréia

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Utilização do colágeno cromatado como indicador em estudos de digestão com caprinos

The objective of this research was to study the feasibility of utilizing chromated collagen as an external indicator of digestibility by comparing it to acid insoluble ash (AIA) and indigestible acid detergent fiber (IADF) as internal markers, and to the total collection method. Six castrated Alpine breed kid goats with an average weight of 33,4 kg were used. They were housed in metabolism cages. Feeding was based on 60 g/kg PV 0,75 of a pelleted ration per animal, supplied daily in two meals (7 am and 4 pm). The experimental design was completely randomized with four treatments and six replications. The results permitted the conclusion that the chromated collagen was the best of the indicators studied, and therefore, is one more indicator which can be used. The AIA and IADF were less efficient and underestimated the digestibility of the feed.

Níveis de proteínas nas dietas de faisões em crescimento

The experiment with pheasants in initial growth phase (1 to 35 days of age), which had as its objective evaluating the nutritional needs of pheasants in the growth phase as to protein levels in the diets, was conducted on a pheasant farm located at Ribeirão Preto, SP, Brazil. Small pheasants were used, which were submitted to isocaloric diets containing 26%, 28% and 30% of crude protein. The experimental design was totally random with four repetitions of 30 birds per parcel, totaling 360 birds. The results showed that a 30% crude protein level should be recommended for pheasants in the growth phase (1 to 35 days of age).

Estabilidade física de péletes protegidos por diferentes produtos impermeabilizantes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ultrastructural study of the lateral lobe of the prostate of Wistar rats submitted to experimental chronic alcohol ingestion

Alcoholism is considered today one of the most serious social and medical problems. Different investigators have demonstrated that chronic exposure to alcohol causes morphological and physiological changes in the testes and in the accessory sex glands, in the prostate in particular. In the present study, experimental rats were divided into groups receiving sugar cane brandy diluted to 30° G.L. (30%, v/v) and Purina ration ad libitum for 60, 120, 180, 240 and 300 days, respectively. At the end of each period the animals were sacrificed and the lateral lobe of the prostate was collected for histological examination. The results showed atrophied epithelium, accumulation of lipidic droplets and rupture of the microvilli that line the cell surface facing the lumen of cells of the secretory epithelium of the lateral lobe of the prostate.

Acao antioxidante de extratos de alecrim (Rosmarinus officinalis L.) em files de peixes da especie pacu (Piaractus mesopotamicus Holmberg)

The antioxidant effect of plant extract has been an interesting issue for many researchers in past few years. Spices have been identified as products with large amounts of antioxidants, and rosemary is one the most studied spice. Studies have shown evidences that population with high intake of these substances have less incidence of coronary heart disease. The objective of this work was verify the antioxidant action of the commercial rosemary oleoresin Herbalox® (used to feed the pacu (Piaractus mesopotamicus) fish. The juveniles pacu were fed with isocaloric and isoproteic diets, for two groups the lipid source was soybean oil and for the another it was corn oil. For each group of the different lipid sources, rosemary extract Herbalox® (were added in one lot and on the other which was used as control. The results showed that the addition of rosemary extracts to the ration protected them against peroxidation, when compared with the control, the lipid source also have influence on these protection.

Effects of food quality on growth and biochemical composition of a calanoid copepod, Argyrodiaptomus furcatus, and its importance as a natural food source for larvae of two tropical fishes

Growth, reproduction and biochemical composition were analyzed for the copepod Argyrodiaptomus furcatus fed on the alga Ankistrodesmus gracilis grown in different media. The ingestion of this copepod by larvae of two species of tropical fishes was also evaluated. The mean peak density of the copepod population was 1369 individuals 1-1 for all four diets used, and the highest was 1387 individuals 1-1 on diet ARV (algae + ration + vitamins). A small copepod, A. furcatus tends to have a short life span. The smallest females did not attain maturity in the shortest time on all diets used. Food quality may play a major role in the dynamics of the biochemical composition of this copepod. Argyrodiaptomus furcatus was a more important food item for larvae of tambaqui (Colossoma macropomum) than of pacu (Piaractus mesopotamicus). However, it made up a large part of the gut contents of larvae of both species.

Phytochrome and light influence on germination and vigor of ocimum gratissimum L. (Lamiaceae) seeds under high irradiance conditions

Ocimum gratissimum seed germination (% germination and vigor) has been found as phytochrome dependent, having a typical High Irradiant Response (HIR). Seven treatments were tested: daylight (DL), red (R), far-red (FR), blue (B), green (G), dark (DK), and reversible (RVB). No statistical difference among the DL, R, FR, B, and G were found. DK and RVB were statistically equal and presented the lowest results. The germination also occurred in the DK treatment but in non-useful rates, and it was nonreversible in the RVB treatment. It allows these seeds to be classified as positively photoblastic. The minimum energy need to initiate the germination was evaluated by a fluency-response curve. It plotted four different exposition times to R light (1 second, 60 seconds, 1 hour, and 13 hours) against percent germination. Useful germination occurred only after 1 hour, confirming the high energy needed to incite the process. The germination rate increased with the raise of the photoequilibrium (j). The high positive correlation index found confirms the phytochrome influence in this process. Facing all the results presented here, it is suggested to sow these seeds under direct and highly intense sunlight. It is preferable to avoid places exposed to variations in the shading, because inhibition induced by dense shade effects (low R/FR ration and consequently low j established) were demonstrated irreversible, and it can lead to undesirable loss of the germination power.

Valor nutritivo de macrófitas aquáticas flutuantes (Eichhornia crassipes, Pistia stratiotes e Salvinia molesta) utilizadas no tratamento de efluentes de aqüicultura

The aim of this study was to evaluate the nutritive value of free-floating aquatic macrophytes, Eichhornia crassipes (Mart.) Solms (Pontederiaceae), Pistia stratiotes (L.) (Araceae) and Salvinia molesta (Mitchell) (Salviniaceae) used in a Nile tilapia (Oreochromis niloticus) waste treatment, and these species biomass potential uses. The vegetal biomass samples were collected from 0.25 m 2 floating squares and divided in aerial and submerse parts, to determine the concentrations of cell wall fraction, soluble carbohydrates, polyphenols, lipids, crude protein and total phosphorus. The higher nutritive value was observed in E. crassipes and S. molesta aerial parts, and in P. stratiotes total biomass, due to their lower cell wall fraction mean rates (60.7; 64.2 and 56.9 % dry mass, respectively) and to the higher rates of: crude protein (10.1; 9.1 and 8.8 % dry mass, respectively), soluble carbohydrates (26.6; 18.7 and 12.4 mg.g -1 dry mass, respectively) and lipids (7.6; 4.5 and 4.4% dry mass, respectively). It may be concluded that P. stratiotes total biomass, and E. crassipes and S. molesta aerial biomass have nutritive values with potential use for ruminant feeding or as ration ingredients.

Acute reduction in serum progesterone concentrations after feed intake in dairy cows

This study tested the hypothesis that high feed consumption will acutely decrease circulating progesterone concentrations. In the first experiment, a Latin Square design was used to test whether feeding pattern would alter circulating progesterone in pregnant lactating Holstein cows (n = 12). Feed was removed for 12 h before the experiment and cows were then either fed 100% of the total mixed ration (TMR), 50% of TMR every 12 h, 25% of TMR every 6 h, or left unfed for an additional 12 h. Blood samples were taken every hour for 24 h. Provision of 100 or 50% of TMR decreased circulating progesterone by 1 h after feeding and progesterone remained depressed until 8-9 h after feeding. Feeding 25% of TMR did not reduce circulating progesterone concentrations. Experiment 2 used a crossover design to measure the effect of acute feeding on circulating progesterone and LH concentrations during delivery of a constant amount of exogenous progesterone (Eazi-Breed CIDRs) in lactating Holstein cows (n = 8) and nonpregnant dry Holstein cows (n = 6). Blood samples were taken every 15 min for 8 h. There was no change in serum progesterone during the 8 h treatment period in unfed cows; however, feeding decreased (P < 0.05) circulating progesterone between 2 and 6 h after feeding. In lactating cows, feeding increased mean LH (P < 0.05). There were more LH pulses (P = 0.01) in lactating than nonlactating cows. Thus, acute feeding reduced circulating progesterone in pregnant lactating cows apparently due to an increase in progesterone metabolism. Interestingly, feeding multiple smaller meals eliminated the acute effect of feeding on circulating progesterone. © 2003 Published by Elsevier B.V.

Long-term creatine supplementation improves the aerobic capacity of horses

The aim of the present study was to investigate the effect of long-term oral supplementation of creatine on the physiological responses to aerobic training. Twelve purebred Arabian horses were submitted to aerobic training for 90 days, with and without creatine supplementation which consisted of the daily administration of 75g of creatine monohydrate mixed into the ration for 90 days of training. Physical conditioning was conducted on a high performance treadmill and training intensity was stipulated by calculating the V 4 (velocity at which blood lactate reaches 4mmol L -1) determined monthly for each animal. The individual intensity of physical force at 80% of aerobic threshold was established. An incremental exercise test was used to set the individual V4. After a warm up period of 4 min at 4m s -1), the speed was increased at 2min intervals to 6, 8 and 10m s -1). The blood samples were collected 15s before the end of each step to determine the concentration of lactate, packed cell volume, hemoglobin and red cell values. The results demonstrated a significant increase (P<0.05) in V4 in the groups that received creatine supplementation for 60 days or more when compared to the animals without creatine supplememntation. The other hematological variables were similar to all groups. The results showed that the prolonged creatine supplementation may have a beneficial al effect on the equine athletic performance.