Epidural injection of ketamine for caudal analgesia in the cow

The objective of the study was to determine the analgesic and sedative effects of epidural ketamine in the cow. Eight healthy cows weighing 350–450 kg were used. One of 3 doses of ketamine (0.5, 1 and 2.0 mg/kg) or a saline control were injected into the epidural space at the first intercoccygeal interspace in random sequence at one-week intervals. Ketamine was diluted in saline (0.9%) before the experiment, and the volume adjusted according to animal size. Analgesia was tested by applying a standard stimulus (needle insertion into the skin and deep muscle) and scored using a 3-point scale. A second voltage-based stimulus was also applied and the responses scored. Another scale was used for scoring the degree of sedation. The response and the degree of sedation were assessed before drug administration and at 2, 5, 10, 15 min, and every 15 min until 120 min after ketamine or saline administration. Ketamine produced dose-related analgesia of the tail, anus, perineum and vulva but not of the hindlimb area. The effect was dose-dependent in terms of intensity and duration. None of the doses produced analgesia when 70 or 80 volts were applied. Minimal side effects were observed. Epidural ketamine produces caudal analgesia in the cow. Further studies are required to determine whether this is sufficient for surgery.     

Aurantiochytrium sp. meal can replace fish oil in practical diets for the juvenile Pacific white shrimp

This study evaluated the use of microalgae (Aurantiochytrium sp.) meal as a substitute for fish oil in the diet of juvenile Pacific white shrimp (Litopenaeus vannamei) reared in a clear‐water system. Dietary treatments at five replacement levels (0%, 25%, 50%, 75%, 100%) were performed in triplicate. After 46 days, only a slight difference in shrimp final weight was observed among treatments (0.61 g). An increase in final weight was observed with replacement of up to 50% fish oil for microalgae meal, while the optimal percentage of replacement estimated was 44.7%. Feed conversion rate (FCR) of animals fed a diet of Aurantiochytrium sp.meal to replace up to 50% fish oil decreased, and the optimal percentage of replacement estimated was 49.3%. The fatty acids profile in shrimp muscle tissue demonstrated an increase in docosahexaenoic acid (DHA) from 10.03% to 14.28% with increased replacement of fish oil by microalgae meal in the diet. Therefore, the partial replacement of fish oil by microalgae meal resulted in improved shrimp growth and FCR, and total replacement of dietary fish oil had no negative effects on these parameters. In addition, inclusion of microalgae meal raises the level of DHA in shrimp muscle.     

Response of juvenile pacu (Piaractus mesopotamicus Holmberg, 1887) to balanced digestible protein

This 45‐day work aimed to determine the response of juvenile pacu (Piaractus mesopotamicus) to balanced digestible protein (BDP) and to use these responses to determine whether the optimum economic levels of BDP would differ depending on the form in which the fish is sold. Six isoenergetic diets containing 163, 201, 238, 272, 315 and 348 g/kg BDP (dry‐matter basis) were prepared through the serial dilutions of a high‐protein diet with the low‐protein diet. Fish (initial average body weight, 10.82 ± 0.14 g) were fed with respective experimental diets three times a day until apparent satiation. The optimum biological level of BDP was calculated as 326 g/kg (dry‐matter basis) by the quadratic regression model for maximum body weight gain of juvenile pacu. To maximize economic returns (US$/kg) for different end products, the optimum economic levels of BDP were calculated as 311, 317 and 319 g/kg (dry‐matter basis) by an economic model for whole‐body, eviscerated and sliced juvenile pacu respectively. This finding revealed that obtaining maximum biological performance of fish in the case of high feed costs or low prices of the end product in consumer market would substantially reduce the economic returns.     

Digestible protein requirements and muscle growth in juvenile tambaqui (Colossoma macropomum)

Several investigations have been carried out to improve the productivity of tambaqui, an economically important fish species in Brazil and other Latin American countries. This study determined the digestible protein (DP) requirements in juvenile tambaqui by assessing their productive performance and nutritional efficiency. It also evaluated the effects of different dietary DP levels on the morphology and cellularity of skeletal fast muscle fibres. The 1750 tambaqui tested (6.53 ± 0.43 g body weight, 7.58 ± 0.18 cm length) were randomly distributed into 35 tanks. Fish were fed one of the seven isocaloric diets, which contained 140, 170, 200, 230, 260, 290 or 320 g/kg DP. The DP requirement, calculated by segmented (broken line) regression of weight gain data, was 290 g/kg. An increase in diet DP to 290 g/kg significantly improved final weight, weight gain, feed intake, specific growth rate and crude protein gain, and changed fibre diameter in deep muscle. Muscle fibres were randomly distributed into a mosaic pattern, characterized by fibres with different diameters. Treatments with 290 and 320 g/kg DP increased the frequency of large‐diameter fibres (>50 µm), indicating hypertrophic growth of skeletal muscle during the juvenile phase, which occurred in conjunction with hyperplasia.     

Butyrate and propionate improve the growth performance of Litopenaeus vannamei

Organic salts may improvement the animal performance, increasing the efficiency of nutrient utilization and modifying the intestinal microbiota. This study aimed to evaluate the effects of sodium butyrate and sodium propionate supplementation at different levels of dietary inclusions in the growth of Litopenaeus vannamei. In total, seven diets were evaluated: a control diet (without supplementation) and three diets from each sodium salt, propionate and butyrate, in concentrations of 0.5%, 1% and 2%. We used 21 tanks of 6000 L stocked with 150 shrimps (2.53 ± 0.03 g). The shrimps fed diets supplemented with propionate and butyrate, in all concentrations, increased their final weight. The feed efficiency, nitrogen retention, protein efficiency rate, survival and yield of shrimps fed the diet containing 2% butyrate were higher in comparison with control treatment. The shrimps supplemented with butyrate also showed lower counts of Vibrio sp. in the intestine. The shrimps fed the diet supplemented with butyrate and propionate also showed higher values of serum agglutination titre. Thus, it is possible to conclude that dietary supplementation with propionate and butyrate in different dietary concentrations modify the intestinal microbiota and improves the growth of L. vannamei.     

Phytoextraction of Lead from Soil from a Battery Recycling Site: The Use of Citric Acid and NTA

Phytoextraction is a soil remediation technique involving plants that concentrate heavy metals in their shoots, which may be removed from the area by harvest. The application of synthetic chelants to soil increases metal solubility, and therefore enhances phytoextraction. However, synthetic chelants degrade poorly in soil, and metal leaching poses a threat to human and animal health. The aim of this study is to assess the use of two biodegradable chelants (citric acid and nitrilotriacetic acid (NTA)) for Pb phytoextraction by maize from a soil contaminated by battery-casing disposal. In order to assess the behavior of a non-degradable chelant, ethylenediaminetetraacetic acid (EDTA) was also included in the experiment. The chelants NTA and EDTA were applied to soil pots at rates of 0, 3, 5, 7, and 10 mmol kg^?1 of soil. The rates used to citric acid were 0, 5, 10, 15, and 30 mmol kg^?1. Maize plants were grown for 72 days and chelants were applied 9 days before harvest. Soil samples were extracted with CaCl₂ to assess the Pb solubility after chelants application. The results showed that NTA was more efficient than citric acid to solubilize Pb from soil; however, citric acid promoted higher net removal of Pb (120 mg pot^?1) than NTA (57 mg pot^?1). Thus, the use of citric acid, a biodegradable organic acid, could be feasible for enhancing the phytoextraction of Pb from the site studied with no environmental constraints.     

Secondary succession in a fragmented Atlantic Forest landscape: evidence of structural and diversity convergence along a chronosequence

Changes in physiognomy, species composition and structure, and dispersal mechanisms of canopy and subcanopy plant assemblages were investigated along a chronosequence of three ages: 12, 20, and 50+ years old (=old-growth), three replications in each, in an Atlantic Forest landscape in Northeastern Brazil. Our objective was to investigate whether there is floristic and structural convergence along secondary succession. There were significant differences between secondary and old-growth forests in density and basal area only for the subcanopy. Differences in density between forest ages were noted when the assemblage was analyzed per diameter and height classes. Richness of canopy species of both secondary ages differed from those of old-growth forests. Some dominant species in the canopy of secondary forests showed a significant decrease in density with increasing age, which indicates an ongoing process of floristic changes. The low level of shared species between secondary and old-growth forests supports the idea that species composition is one of the last components to recover during successional process. Zoochory was the most important dispersal guild in species percentage and number, irrespective of stand age. Although regenerating areas can take alternative pathways, our results indicate that secondary Atlantic Forest sites have a high potential for natural regeneration. This recovery is recorded as a physiognomic convergence of the canopy layer in as little as 12 years, and progressive introductions of later successional species into the plant assemblage that lead to convergence in terms of the diversity and richness of the subcanopy and of dispersal guilds just 20 years after abandonment.     

The effect of heat stress on GHR,IGF-I,ANT, UCP and COXIII mRNA expression in the liver and muscle of high and low feed efficiency female quail

1. A study was conducted to test the hypothesis that feed efficiency (FE) correlated with the expression of genes from the somatotropic axis and mitochondrial genes involved in energy production, and that the environment to which the birds are exposed influenced the expression of such genes.

2. Quails were divided into High-FE and low-FE groups and maintained in a comfortable or heat stress (HS) (38°C for 24 h) environment to evaluate changes in insulin-like growth factor I (IGF-I), growth hormone receptor (GHR), adenine nucleotide translocator (ANT), uncoupling protein (UCP) and cytochrome oxidase subunit III (COX III) messenger ribonucleic acid (mRNA) expression in liver and muscle tissues.

3. High-FE quails (0.28 g/g) presented a higher final body weight, greater weight gain and a better feed conversion ratio than low-FE birds (0.18 g/g). High-FE birds showed greater IGF-I mRNA expression in the liver and muscle and greater GHR mRNA expression in the muscle.

4. Environmental effects only affected GHR expression in the liver, with quails under comfortable conditions exhibiting greater GHR expression than quails subjected to HS.

5. There was a significant interaction between FE and environmental temperature on ANT mRNA expression in the liver. The greatest ANT mRNA expression was observed for high FE-birds that remained under comfortable conditions.

6. In the liver, UCP mRNA expression did not differ among the quails and was not affected by environment or efficiency. However, comparisons of the low- and high-FE birds revealed higher levels of UCP mRNA in the muscle of low-FE birds.

7. COX III mRNA expression in the liver was dependent on environmental temperature and FE. Higher COX III mRNA expression was observed in animals that remained under comfortable conditions, and high-FE birds exhibited higher expression levels compared to low-FE birds.

8. These results suggest a correlation between IGF-I, GHR, ANT, UCP and COX III gene expression and FE and that environmental temperature could affect the expression of some of these genes.     

Antiproliferative effect of Canavalia brasiliensis lectin on B16F10 cells

Lectins are proteins or glycoproteins with the ability to link to carbohydrates at the cell surface in a specific and reversible manner. Studies have showed that lectins are demonstrate immunomodulatory and antitumor agents. This study aims to evaluate the effect of lectin extracted from the seeds of Canavalia brasiliensis (ConBr) on murine melanoma B16F10 cells by analyzing cell viability, apoptosis index, cell migration, production of cytokines and nitric oxide (NO). Results showed that ConBr was able to reduce cell viability and thwart apoptosis, which could be observed by decrease in cell migration. ConBr also induced NO and IL-12 synthesis. Altogether, these data demonstrate the potential of ConBr as a therapeutic agent for melanoma.     

Anti-Neospora caninum antibody detection and vertical transmission rate in pregnant zebu beef cows (Bos indicus): Neospora caninum in pregnant beef cows (Bos indicus)

The aim of the present study was to evaluate anti-Neospora caninum antibodies and the vertical transmission rate in naturally infected pregnant zebu beef cows (Bos indicus) reared on pasture. The present study began with 200 cows from four farms (50 cows from each farm), and these animals were submitted to timed artificial insemination (TAI). After ultrasonography, 76 pregnant cows were selected, 22, 15, 22, and 17, respectively, from farms 1, 2, 3, and 4. Blood samples were taken from cows thrice during the first, second, and third trimester of gestation, and a blood sample was collected from 31 calves before colostrum milking. From 76 cows 23 (30.3%) had anti-N. caninum antibodies detected by indirect ELISA (Idexx), and 53 (69.7%) did not. Sixty-four cows that initiated the experiment were negative to N. caninum and 11 became positive either during the second or third trimester of gestation, this mean an infection incidence of 17.2% (11/64). OD for ELISA was higher (OD = 2.08) during the second and third (OD = 2.10) trimesters of pregnancy when compared with the first (OD = 1.81), however, there were no statistical differences (P = 0.45). The vertical transmission was calculated to be 29.0% (9/31), and the risk of vertical transmission of N. caninum in seropositive dams was 26.25 times higher than seronegative animals (OR = 26.25, 2.38 < OR < 289, P = 0.007). In conclusion, the rate of vertical transmission of N. caninum in pregnant zebu beef cows was 29%, and the risk was 26.25 higher in seropositive dams relative to than seronegative animals.