Produção de forragem de Tifton 85 adubado com nitrogênio e submetido à lotação contínua

The present assay was conducted at the Research and Development of Adamantina, SP, of the Agência Paulista de Tecnologia dos Agronegócios (APTA) - Pólo da Alta Paulista to evaluate the effect of nitrogen fertilization on morphological composition, density of tillers, leaf area index, light interception and herbage accumulation in grazed Tifton 85 subjected to continuous stocking system. The treatments consisted of four levels of nitrogen (0; 100; 200 and 400kg/ha/year of N), arranged in a randomized complete blocks experimental design with four replications. The grasslands of Cynodon cv. Tifton 85 studied influenced the time of evaluation and of nitrogen levels with a marked effect in morphological composition of the pasture, leaf area index, light interception and population density of tillers that were instrumental in the accumulation of forage. It was found a positive linear effect of nitrogen fertilization on the density of vegetative tillers, totals and herbage accumulation nitrogen fertilization had a marked effect on the amount of total and vegetative tillers, leaf area index in light interception and herbage accumulation. The cultivar Tifton 85 has not reached the necessary conditions for crop growth rate maximum when managed under continuous stocking keeping the grass to 10cm tall.

Effect of percutaneous transthoracic lung biopsy on oxidative metabolism in sheep

This study aimed to assess the effect of percutaneous transthoracic lung biopsy on the oxidative metabolism of sheep by measuring the oxidative stress markers of superoxide dismutase (SOD), total glutathione (GSH-t), peroxidase (GSH-Px) and thiobarbituric acid reactive substances (TBARS) in the red cells of these animals. Blood samples were collected from 20 clinically healthy sheep prior to, and 30 min after, percutaneous transthoracic lung biopsy. After biopsy, there was a significant decrease (p < 0.05) in SOD and GSH-Px activity, with no significant change (p ≥ 0.05) in GSH-t and TBARS concentrations. These results showed that percutaneous transthoracic lung biopsy did not significantly affect the oxidative metabolism of sheep 30 min after the procedure, which may be used widely in this species without causing serious tissue damage. © 2012. The Authors.

Differentially transcribed genes in skeletal muscle of lambs

The objective of this study was to compare gene transcription profiles in Longissimus dorsi muscle of the following four hair sheep genetic groups, Morada Nova (MO), Brazilian Somali (SO), Santa Inĉs (SI) and 1/2 Dorper×1/2 Morada Nova (F1). These groups all display different postnatal muscle growth. The transcriptomes of the skeletal muscle of the lambs (at 200 days of age) were profiled by using oligonucleotide microarrays and reverse transcription-quantitative real-time PCR (RT-qPCR). The microarray experiment identified 262 transcripts that were differentially expressed when transcription levels were compared between the different breeds. A total of 23 transcripts among which those involved in skeletal muscle development (MyoD1 and IGFBP4), lipogenesis and adipogenesis (C/EBPδ, PPARγ and PGDS) were differentially expressed in at least in one comparison. Clustering analysis showed that there is greater similarity in gene expression between the MO and SI breeds and between F1 and SO genetic groups. The SO breed has the most distinct expression pattern. The RT-qPCR results confirmed the findings from the microarray study. A positive correlation was observed between the expression of MyoD1 and the cold carcass yield. The negative correlations between the weight and yield of cold carcass with the expression of C/EBPδ mean that the selection for adipogenesis could lead to a lower carcass weight. The GLUT3 and PYGL gene transcripts were negatively correlated with fat thickness, but ATP5G1 was positively correlated with this trait. Interestingly, many genes negatively correlated with PUFA were positively correlated with cold carcass yield. In conclusion, the present work demonstrated that there are breed-specific expression patterns in Brazilian hair sheep genetic groups. The differences in gene expression among genetic groups were consistent with their phenotypic differences. The positive correlation of the MyoD1 expression with the cold carcass yield suggests that this gene is important for tissue growth in sheep. The positive correlation of the C/EBPδ expression with PUFA provides an opportunity to select for lipid deposition in meat animals. © 2012 Elsevier B.V.

Effect of roscovitine and cycloheximide on ultrastructure of sheep oocytes

It is believed the temporary meiosis arrest with roscovitine or cycloheximide may improve the in vitro developmental competence of oocytes in different animal species. However, little is known about the effects of these inhibitors on ultrastructure of ovines cumulus-oocyte complexes (COCs). The aim of this study was to evaluate the progression of cytoplasmic maturation and the ultrastructural changes in sheep COCs exposed to roscovitine or cycloheximide, at acceptable concentrations. COCs were in vitro cultured for 24. h in maturation medium (control group) containing 100 μM roscovitine or 1 μg/mL cycloheximide (treatment groups). After this time, some COCs were cultured for further 22. h in inhibitor-free medium. The ultrastructure organization of COCs was evaluated by transmission electron microscopy before (immature group) and after in vitro culture for 24 and 46. h. As expected, signs of immaturity and maturity were observed in immature and control groups, respectively. In treatment with roscovitine, there were cumulus cells degeneration, swelling of mitochondrias, few cortical granules and many vesicles with electron-dense material. However, in cycloheximide treatment there were not signs of degeneration or cellular senescence. Metabolic units and mitochondrial pleomorphism were found in all experimental groups. These evidences demonstrate that roscovitine promoted irreversible ultrastructural changes while cycloheximide did not affect the cytoplasmic maturation. However, the implications on embryo development are still unclear. © 2012 Elsevier B.V.

Haemonchus contortus: A multiple-resistant Brazilian isolate and the costs for its characterization and maintenance for research use

The aim of this work was to determine the resistance level of Haemonchus contortus isolated from the Santa Inês flock of the Embrapa (Brazilian government's Agricultural Research Company), Southeast Livestock Unit (CPPSE), as well as to determine costs of characterizing and maintaining this isolate in host donors. Forty-two male Santa Inês lambs were experimentally infected with 4000 H. contortus infective larvae of the field isolate of CPPSE, called Embrapa2010, and divided into six treatment groups, which received triclorfon, albendazol plus cobalt sulfate, ivermectin, moxidectin, closantel and levamisole phosphate, as well as a negative control group (water). Egg per gram (EPG) counts were performed at 0, 3, 7, 10 and 14. days post treatment when the animals were slaughtered for parasite count. The data were analyzed using the RESO statistical program, considering anthelmintic resistance under 95% of efficacy. EPG and worm count presented a linear and significant relation with 94% determination coefficient. The susceptibility results obtained by RESO through both criteria (EPG and worm count) were equal, except for closantel, showing that the isolate Embrapa2010 is resistant to benzimidazoles, macrocyclic lactones and imidazothiazoles. The need of a control group did not appear to be essential since the result for susceptibility in the analyses with or without this group was the same. Suppression in egg production after treatment did not occur in the ivermectin and moxidectin groups. In the control group, the establishment percentage was just 12.5 because of the low number of third-stage larvae, resistance (innate and infection immunity) of the animals studied plus good nutrition. Drug classes presented similar efficacy between adults and immature stages. The costs for isolate characterization were calculated for 42 animals during 60. days. The total cost based on local market rates was approximately US$ 8000. The precise identification of Brazilian isolates and their establishment in host donors would be useful for laboratorial anthelmintic resistance diagnoses through in vitro tests, which has an annual cost of approximately US$ 2500 for maintenance in host donors. © 2012 Elsevier B.V.

Anthelmintic effect of plant extracts containing condensed and hydrolyzable tannins on Caenorhabditis elegans, and their antioxidant capacity

Although tannin-rich forages are known to increase protein uptake and to reduce gastrointestinal nematode infections in grazing ruminants, most published research involves forages with condensed tannins (CT), while published literature lacks information on the anthelmintic capacity, nutritional benefits, and antioxidant capacity of alternative forages containing hydrolyzable tannins (HT). We evaluated the anthelmintic activity and the antioxidant capacity of plant extracts containing either mostly CT, mostly HT, or both CT and HT. Extracts were prepared with 70% acetone, lyophilized, redissolved to doses ranging from 1.0mg/mL to 25mg/mL, and tested against adult Caenorhabditis elegans as a test model. The extract concentrations that killed 50% (LC50) or 90% (LC90) of the nematodes in 24h were determined and compared to the veterinary anthelmintic levamisole (8mg/mL). Extracts were quantified for CT by the acid butanol assay, for HT (based on gallic acid and ellagic acid) by high-performance liquid chromatography (HPLC) and total phenolics, and for their antioxidant activity by the oxygen radical absorbance capacity (ORAC) assay. Extracts with mostly CT were Lespedeza cuneata, Salix X sepulcralis, and Robinia pseudoacacia. Extracts rich in HT were Acer rubrum, Rosa multiflora, and Quercus alba, while Rhus typhina had both HT and CT. The extracts with the lowest LC50 and LC90 concentrations, respectively, in the C. elegans assay were Q. alba (0.75 and 1.06mg/mL), R. typhina collected in 2007 (0.65 and 2.74mg/mL), A. rubrum (1.03 and 5.54mg/mL), and R. multiflora (2.14 and 8.70mg/mL). At the doses of 20 and 25mg/mL, HT-rich, or both CT- and HT-rich, extracts were significantly more lethal to adult C. elegans than extracts containing only CT. All extracts were high in antioxidant capacity, with ORAC values ranging from 1800μmoles to 4651μmoles of trolox equivalents/g, but ORAC did not correlate with anthelmintic activity. The total phenolics test had a positive and highly significant (r=0.826, p≤0.01) correlation with total hydrolyzable tannins. Plants used in this research are naturalized to the Appalachian edaphoclimatic conditions, but occur in temperate climate areas worldwide. They represent a rich, renewable, and unexplored source of tannins and antioxidants for grazing ruminants, whereas conventional CT-rich forages, such as L. cuneata, may be hard to establish and adapt to areas with temperate climate. Due to their high in vitro anthelmintic activity, antioxidant capacity, and their adaptability to non-arable lands, Q. alba, R. typhina, A. rubrum, and R. multiflora have a high potential to improve the health of grazing animals and must have their anthelmintic effects confirmed in vivo in both sheep and goats. © 2012.

Performance, survivability and carcass traits of crossbred lambs from five paternal breeds with local hair breed Santa Inês ewes

The present study aimed to evaluate the performance, survivability and carcass traits of crossbred lambs. Data from 299 lambs born to 209 ewes were used. The dams were from a local hair breed (Santa Inês) and five breeds of sires were used: Dorper (DR), Ile de France (IF), Hampshire Down (HD), Texel (TX) and Santa Inês (SI). The lambs were weighed at birth, weaning and slaughter. Fasting body weight, skin thickness, hot and cold carcass weight, carcass yield and carcass length were measured at slaughter. Carcasses were separated into commercial cuts: neck, shoulder, rib, belly, loin and leg. Leg length and circumference were measured. Analyses of variances using MIXED procedure in SAS® were carried out for weights and carcass traits. Factor, discriminant and canonical analysis were carried out. Mortality data of animals from birth until slaughter was analyzed using logistic regression. The HD animals had the highest mortality rate. TX lambs had similar growth rate and survivability compared to DR and IF and had better carcass traits than these genetic groups. Therefore, this breed can be used as paternal breed to crossbreeding with Santa Inês dams. Santa Inês animals did not differ in growth from birth until slaughter compared to crossbred animals, which highlights the potential of this naturalized breed for meat production. Moreover, there is a great variability inside this breed for carcass and growth traits which may undergo great improvement through selection programs. © 2013 Elsevier B.V.

Orbifloxacin: A Review of Properties, Its Antibacterial Activities, Pharmacokinetic/Pharmacodynamic Characteristics, Therapeutic Use, and Analytical Methods

Orbifloxacin is a third generation of fluoroquinolone that exhibits increased antibacterial activity against the Enterobacteriaceae, gram-negative and gram-positive bacteria, anaerobes, and mycobacteria. This drug was synthesized in 1987 and developed as a veterinary chemotherapeutic to use for livestock and domestic pets. Orbifloxacin is labeled for the treatment of skin, soft tissue, and urinary tract infections in dogs, and skin and soft tissue infections in cats, but in some countries, orbifloxacin has been given for the treatment of gastrointestinal and respiratory infections in cattle and swine and other animals. The in vitro activity and clinical efficacy of orbifloxacin against naturally occurring bacterial infections of the skin, ear, soft tissue, udder, and gastrointestinal and respiratory systems in different animals have been evaluated and good responses have been found. The minimum inhibitory concentration of orbifloxacin has been determined in various different pathogens and the results found in the literature are shown in this work. The pharmacokinetics of orbifloxacin has been evaluated by different routes of administration in goats, horses, pigs, rabbits, dogs, cats, camels, cattle, sheep, and fish. Orbifloxacin exhibits excellent pharmacokinetic parameters that suggest that this drug may have good clinical effects on various bacterial infections in these species. All methods described in the scientific literature for determination of orbifloxacin in different matrices were collected and discussed. © 2013 Copyright Taylor and Francis Group, LLC.

Prevalência de anticorpos anti-toxoplasma gondii em búfalos (Bubalus bubalis) no estado do pará

The aim was to study the seroprevalence of Toxoplasma gondii in water buffaloes (Bubalus bubalis) from State of Pará, Brazil. Three hundred and nineteen buffaloes were randomly selected into seven municipalities of Marajó Island. For comparative purposes, 128 buffaloes of five municipalities in the state of Pará were also evaluated. The seroprevalence of T. gondii was evaluated by Indirect Enzyme Linked Immunosorbent Assay (iELISA). The samples diagnosed as positive in iELISA were subjected to Immunofluorescence Antibody Test (IFAT). We evaluated risk factors: location, breed, pregnancy and co-infection with Brucella abortus or Mycobacterium bovis. The frequency of animals positive for T. gondii in iELISA were compared by chi-square (x2) with 95% confidence. Variables with p <0.2 were subjected to logistic regression analysis; the model was built based on the odds ratios test. The prevalence of T. gondii in iELISA was 41,6% (186/447). In IFAT, 86,5% (161/186) had their positivity for T. gondii confirmed. The average prevalence in the municipalities of the Marajó Island and of the mainland was 32% (103/319) and 55% (70/128), respectively. The municipalities with the highest prevalence were Soure (53%) and Salvaterra (49%) in Marajó Island, and Castanhal (55%) and Thailândia (50%) in the Continent. The breed and co-infection with Brucella abortus or Mycobacterium bovis presented no influence on the prevalence of T. gondii. Additionally, pregnant animals were 57% more positive for T. gondii than nonpregnant animals. The presence of antibodies is an indicative of T. gondii in buffaloes in the state of Pará, and these findings represent a risk not only for farm animals, but to public health as a source of infection.

Desempenho e características de carcaça de cordeiros alimentados com fontes de carboidratos associadas ao óleo de girassol

This work was carried out with the objective to evaluate the effect of different carbohydrate sources associated with sunflower oil on performance, carcass characteristics and cuts yields of feedlot sheep. Twenty four lambs were assigned to a completely randomized design with a 2 × 2 factorial arrangement with two sources of neutral detergent soluble carbohydrate, starch or neutral detergent soluble fiber, with and without the inclusion of 4.2% sunflower oil. The treatments consisted of diets containing high content of soluble fiber (17.14% DM) without adding oil, high in soluble fiber (16.35% DM) with inclusion of 4.2% sunflower oil, high starch (30.14% DM) without adding oil and high starch (28.21% DM) with addition of 4.2% of sunflower oil. The animals were feedlot with average initial of 17.7 kg and when reached 35 kg body weight were slaughtered. The different sources of carbohydrate and oil inclusion in the diet not influence the days on feedlot in the dry matter intake and average daily weight gain, but higher feed conversion was observed for the diet with a high percentage of neutral detergent soluble fiber compared to diet high in starch. The carcass weights and yields as well as the commercial cuts were not affected by diets. The performance and quantitative characteristics and carcass cuts of lamb are not affected by different carbohydrate sources and their association with 4.2% sunflower oil.

Sexual transmission of Toxoplasma gondii in sheep

Male sheep of reproductive age were distributed into three groups: GI, a sheep inoculated (oral) with 2.0×105 oocysts of the P strain of Toxoplasma gondii; GII, a sheep infected (subcutaneous) with 1.0×106 tachyzoites of the RH strain of T. gondii; and GIII, a sheep kept as a control (not infected). After the inoculation of the males, 12 breeding ewes, which were not pregnant and which were serologically negative for reproductive diseases (particularly toxoplasmosis), were distributed into three groups, synchronized, and subsequently exposed to natural mating with previously inoculated males. The distribution was as follows: five ewes that underwent natural mating with the GI male, five ewes that were exposed to natural mating with the GII male, and two ewes that were mated with the non-infected male (control). Serum samples of all the ewes were collected on days -30, -14, -7, -1, and 0 (days before natural mating) and on days 1, 3, 5, 7, 11, 14, and weekly until birth; the presence of serum antibodies against T. gondii was assessed by IFAT. Using a bioassay and PCR, T. gondii was isolated from the semen of the infected reproducing sheep before mating. Following natural mating, 5 of the 12 females displayed antibodies specific for T. gondii; of these animals, two of the ewes underwent natural mating with the male inoculated with oocysts (GI) and three with the male infected with tachyzoites (GII). One of the females that displayed antibodies specific to this coccidian and that underwent natural mating with the GII sheep had a macerated fetus on the 70th day following coverage. Using a bioassay after the birth, it was possible to isolate T. gondii from samples of the pool of tissues from the five females that seroconverted after natural mating and from their respective lambs. Using PCR, the DNA of T. gondii was isolated from the pool of tissues from one and two females exposed to natural mating with the reproductive males infected with the oocysts and tachyzoites, respectively. Using this technique, it was also possible to diagnose the presence of the parasite in the pool of tissues from the lambs of one female that underwent natural mating with the male sheep infected with oocysts. These results demonstrated the sexual transmission of T. gondii in the sheep species with consequent vertical transmission to their lambs. © 2013 Elsevier B.V.

Nursing regimens: Effects on body condition, return to postpartum ovarian cyclicity in Santa Ines ewes, and performance of lambs

The effects of nursing regimens on the body condition, onset of ovarian cyclicity postpartum and weaning weight of lambs were assessed in Santa Ines ewes. Thirty-two ewes were blocked according to parity, number of lambs, and body weight at lambing and within each block randomly allocated to treatments: continuous nursing (CN), controlled nursing (CN2) with two daily feedings for an hour after the 10th day postpartum, or early weaning (EW) with total separation from the lambs after the 10th day. The animals were evaluated from the 12th day postpartum until the first estrus or until 60th day. The dry matter and nutrients intake did not differ among treatments ( P>. 0.05) but did differ over time ( P<. 0.01). The weight, body condition score, serum concentrations of non-esterified fatty acids and prolactin, the percentages of ewes in estrus, of ewes that ovulated within 60th day and had ovulation silent, the period from lambing to estrus, ovulation and follicle with a diameter ≥5. mm and the maximum follicular diameter did not differ ( P>. 0.05) among the treatments. The percentage of ovulation until 30th day was greater ( P<. 0.05) in the EW group. The percentage of short luteal phases was higher in the CN2 and EW groups ( P=0.07) and normal luteal phases were higher in the CN group ( P=0.01). Lamb weight weaning was lower in the EW group ( P<. 0.05). It is possible to use CN to obtain lambing periods less than eight months in Santa Ines ewes, with the advantages of simpler management and higher lamb weaning weights. © 2013 Elsevier B.V.

In vitro and in vivo evaluation of the activity of pineapple (Ananas comosus) on Haemonchus contortus in Santa Inês sheep

The development of resistance to anthelmintics has prompted research into alternative methods of controlling intestinal nematodes in ruminants. This study aimed to assess the activity of Ananas comosus on Haemonchus contortus in Santa Inês sheep. The aqueous extract of pineapple skin (AEPS), bromelain from pineapple stems (B4882) and residue from pineapple processing was evaluated in in vitro and in vivo tests. The enzymatic activity of substances was analyzed by the azocasein method. The egg hatch test (EHT) and larval development test (LDT) were performed using the Embrapa2010 isolate of H. contortus. In the in vivo test, 36 sheep artificially infected with H. contortus were divided into six groups: G1: 2g/kg BW of the aqueous extract administered for three days; G2: 2g/kg BW of the industrial pineapple residue for 60 days; G3: 180mg/animal of bromelain in a single dose; G4: negative control I; G5: positive control (levamisole phosphate); and G6: negative control II. The eggs per gram (EPG) in the feces were counted till 28 days after treatment. LC50 and LC90 were obtained by the probit procedure, while the in vivo test results were analyzed by GLM. The aqueous extract in the in vitro and in vivo test, the bromelain and industrial residue presented 0.102, 0.157, 1.864 and 0.048 enzyme units/mL, respectively. In the egg hatch test, the LC50 and LC90 were respectively 31 and 81mg/mL for the aqueous extract and 0.50 and 2mg/mL for bromelain. In the larval development test, the LC50 and LC90 were respectively 1.7 and 7.3mg/mL for the aqueous extract and 0.019 and 0.086mg/mL for bromelain. In the in vivo test, the general efficacies of the treatments in relation to the negative control were 22.6%, 42.2%, 3.65% and 89% for the aqueous extract, industrial pineapple residue, bromelain and positive control respectively. The transformed EPG values were 3.19±0.59, 3.32±0.25, 2.85±0.66, 3.44±0.50, 2.28±0.93 and 2.75±0.94 for the aqueous extract, industrial residue, bromelain, negative control I, positive control and negative control II respectively. The results for all the treated groups differed significantly (p<0.05) from the positive control, and although the residue presented efficacy of 42.2%, there was no statistical difference (p>0.05) in relation to the negative control. Therefore, both the aqueous extract and bromelain were effective in vitro, but showed reduced anthelmintic efficacy in vivo. For the pineapple residue, the 42.2% in vivo efficacy in reducing the EPG and the possibility of reducing environmental contamination through reuse of industrial residue indicate it can also be useful for control of this parasite. © 2013 Elsevier B.V.

Avaliacão das técnicas de cultivo microbiológico e soroaglutinação rápida em cartão com e se 2-Mercaptoetanol da Brucelose canina

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação comparativa de duas formulações anti-helmínticas em caprinos naturalmente infectados

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)