Effects of vaccination against brucellosis and clostridia on the intake,performance, feeding behavior,blood parameters,and immune responses of dairy heifers calves

The aim of this study was to identify possible effects of different vaccination strategies (concomitantly or not) against brucellosis and clostridia on intake, performance, feeding behavior, blood parameters, and immune responses of dairy heifers calves. Fifty heifers calves were enrolled [38 Gyr (Zebu, Bos taurus indicus) and 12 5/8 Holstein Gyr]. At 120 d of age, animals were randomly distributed among 3 groups: B (n = 18), vaccinated against brucellosis; C (n = 14), vaccinated against clostridia and CB (n = 18), vaccinated concomitantly for both. Rectal and thermographic temperatures were evaluated on days 1, 0, 1, 2, 3, 5, 7,10, 14, and 28 relatives to the vaccination day. Feed and water intake, body weight (BW), and feeding behavior were monitored daily by an electronic feeding system. Blood was sampled on days 0, 3, 7, 14, and 28, relative to the vaccination day for determination of glucose and -hydroxybutyrate (BHBA) concentrations. Blood sampled on day 0 (prevaccination) and on days 28 and 42 were used to evaluate the immune response against Brucella abortus and clostridia. There was an increase in rectal temperature between the first and the third day postvaccination in the 3 groups. The thermography revealed an increase of local temperature for 7 d on groups B and CB. Group C had increased local temperature for a longer period, lasting for up to 14 d. Dry mater intake was reduced for groups B and CB, but no alteration was observed for group C. No alterations regarding initial BW, final BW, average daily weight gain, and feed efficiency were observed. No differences were observed for the 3 vaccination groups for blood parameters throughout the evaluation period. The concomitant vaccination against brucellosis and clostridia led to lower neutralizing antibody titers against epsilon toxin of Clostridium perfringens and botulinum toxin type C of C. botulinum (C > CB > B). When cellular proliferation assay and serological tests to B. abortus were evaluated, no differences were observed between groups B and CB. The present results indicate that the concomitant vaccination against brucellosis and clostridia has no relevant impact on the intake, performance, and feeding behavior of dairy calves. However, the concomitant vaccination of vaccines against these 2 pathogens impacts animal immunity against clostridial infections.     

Jack beans and vetiver grass growth on iron ore tailing sediments from the Doce River dam disaster in Brazil: plant growth regulator effects under different edaphic conditions

Journal of Soils and Sediments - After the greatest environmental disaster in the history of Brazil and the deposition of the iron ore tailings in alluvial regions, the process of revegetation for...     

Detection of enzootic nasal tumor virus (ENTV) in a sheep flock in southern Brazil

Enzootic nasal tumor (ENT) is a contagious neoplasm associated with enzootic nasal tumor virus (ENTV), which may induce disease in sheep (ENTV-1) and goats (ENTV-2). This study aimed to describe the occurrence of ENT in two Texel sheep (Ovis aries) from a 75-sheep flock, located in the city of Gravataí, southern Brazil. Animals used to be purchased from different origins, and no specific tests for disease monitoring or quarantine procedure were performed. Affected animals presented respiratory distress, anorexia with severe weight loss, and mucopurulent unilateral nasal discharge. Necropsy was performed in both animals and nasal cavity masses were observed. Histopathological analysis demonstrated an epithelial neoplasm compatible with nasal adenocarcinoma. PCR using a protocol that amplifies a 591 bp sequence of 5’LTR-gag region of ENTV1 was performed followed by DNA sequencing. Both samples were positive, and the sequences obtained presented highest identity (97%) with ENTV strain TN28 (GenBank accession number MH899613) detected in a Texel sheep from Scotland. This is the first report of ENTV-1 leading to enzootic nasal tumor in sheep in Latin America, which confirms the presence of the retrovirus in sheep flocks in the Brazilian territory.

     

Agronomic comparison of six bermudagrasses from Southern United States with five tropical grasses in central Puerto Rico

The dry matter yield (DMY), in vitro organic matter digestibility (IVOMD) and crude protein (CP) content of eleven grasses were studied during the years 1992 to 1994 under mob grazing conditions. Offered and consumed dry forage do not differ significantly (P<0.05) among the highest yielding accessions Cynodon nlenfuensis PRPI 2341, Cynodon plectostachium PRPI 11487, and Cynodon dactylon cv. Tifton 85. However, the commercial Cynodon nlenfuensis PRPI 2341 was consistently the highest yielding accession both years. Among the other grasses, Digitaria eriantha showed the lowest levels of refused dry forage, thus presenting the best forage acceptability by grazing animals. Digitaria eriantha also showed the highest levels of IVOMD in both the short and the long day seasons. It is concluded that none of the evaluated Cynodon dactylon accessions from southern United Sates, nor the digitaria and brachiaria species adapted better than the commercial accession Cynodon nlenfuensis PRPI 2341. Warm‐season perennial grasses are grown extensively in the southeastern United States. Among the grasses, one of the most widely grown is from the species Cynodon dactylon, commonly named bermudagrass (Eichhorn, 1984). The choice of a bermudagrass cultivar for establishment of pastures is an important decision for cattlemen seeking high weight gains of stocker steers throughout the warm grazing season of the southern United States (Greene et al., 1989). Selection of improved bermudagrass hybrids has dramatically increased forage yield over that of common bermudagrass. Improved forage quality has also resulted in improved performance of grazing animals fed harvested hybrid bermudagrass forage (Gates et al., 1989). Reports on average daily weight gains (ADG) of yearling steers grazing different bermudagrass hybrids varied between 0.68 to 0.79 kg animal^‐1 day^‐1 during the summer season of southern Louisiana (Faw et al., 1986). Hill et al. (1993) in Tifton, GA, found yearling ADG of 0.67 and 0.65 kg animal^‐1 day^‐1 for the recent bermudagrass releases Tifton 85 and Tifton 78, respectively. Forage quality dry matter yield and grazing performance support the hypothesis that Tifton 85 will likely become an important hay and grazing forage for the southern United States. In Puerto Rico, Cynodon nlenfuensis PRPI 2341 (stargrass) is at present the grass cultivar most frequently grown on dairy farms (Ramos‐Santana and Randel, 1996). Yearly ADG of 0.59 kg animal^‐1 day^‐1 has been reported for young steers grazing stargrass in the humid tropical zone of Puerto Rico (Vicente‐Chandler et al., 1983). At Ona, FL, lower ADG of 0.54 kg has also been obtained with stargrass (Mislevy, 1989). The objective of this paper is to compare the agronomic performance (dry matter yield and quality) of six of the most outstanding bermudagrass hybrids from the southern United States, with five tropical grasses from the cynodon, brachiaria, and digitaria genera under the tropical conditions of central Puerto Rico.     

Short-term baths with essential oils of Lippia sidoides,Ocimum gratissimum and Zingiber officinale influence blood parameters and survival of tambaqui (Colossoma macropomum) after infection with Aeromonas hydrophila

This study evaluated the effect of short-term baths with the essential oils (EOs) of Lippia sidoides, Ocimum gratissimum and Zingiber officinale on the survival, haematological, biochemical and histopathological parameters of native fish tambaqui (Colossoma macropomum), challenged with Aeromonas hydrophila. After challenge, the fish infected with A. hydrophila received therapeutic baths of 60 min, for five consecutive days. Treatments were as follows: challenged and not treated; challenged and treated with 10 mg L^?1 of gentamicin; challenged and treated with EO of L. sidoides (2.5 and 5.0 mg L^?1); challenged and treated with EO of O. gratissimum (5.0 and 10.0 mg L^?1); challenged and treated with Z. officinale EO (5.0 and 10.0 mg L^?1). The highest survival rates were 89.5% (fish treated with 5.0 mg L^?1 of O. gratissimum EO) and 75.0% (fish treated with 5.0 mg L^?1 of L. sidoides EO). Reductions in the haematocrit percentage, haemoglobin and erythrocyte number were observed in fish treated with L. sidoides and Z. officinale EOs compared with control fish. Mild to moderate damage to the liver tissue of fish after challenge and EO treatments were observed. It is suggested that baths containing O. gratissimum and L. sidoides EOs consist in a viable treatment to increase survival rates of C. macropomum infected with A. hydrophila.     

Epidemiological Analysis of Leptospira spp. Infection in Equids from the Brejo Paraibano Microregion of Brazil

Leptospirosis is a zoonotic disease that occurs in humans and several animal species, including cattle, pigs, and horses, and it has a worldwide distribution. In equids, leptospirosis manifests through recurrent uveitis and abortion and other reproductive disorders. The objective of the present study was to investigate the epidemiological situation of Leptospira spp. infection in equids from the Brejo Paraibano microregion in the northeast of Brazil, that is, to assess the prevalence of and identify the major risk factors for infection. For this purpose, blood samples were taken from 257 equids (204 horses, 46 mules, and 7 donkeys), and a microscopic agglutination test (MAT) was used as serological analysis, with 24 serovars of Leptospira spp. as antigens. Antibodies were observed in 16.2% of horses, 13.0% of mules, and 28.6% of donkeys. Animals between the ages of 2.5 and 11 years had a risk of infection 0.4 times lower than those younger than 2.5 years old (odds ratio, 0.4; 95% confidence interval, 0.18-0.90). Further studies are needed to identify potential wild reservoirs and the main routes of infections.     

Genotype by environment interaction and model comparison for growth traits of Santa Ines sheep

The objectives of the present study were to compare alternative models for the genetic evaluation and assess the importance of genotype by environment interaction (G×E) in the estimation of genetic parameters and genetic evaluation of birth weight (BW), weight at 60 days of age (W60) and weight at 180 days of age (W180) of Santa Ines sheep. Data comprise 7622 BW, 4673 W60 and 2830 W180 records from animals born in 44 Brazilian herds. Four models were used for the analyses: animal model (AM) with homogeneous residual variance (1), or heterogeneous residual variance (2), hierarchical reaction norms model (HRNM) with homogeneous (1) or heterogeneous residual variance (2). The models that best fit the BW, W60 and W180 data were AM2, HRNM1 and HRNM2 respectively. Thus, models for genetic evaluation that consider heterogeneity of variances are recommended to evaluate growth traits of sheep. The correlation between intercept and slope of the HRNM was higher than 0.70 for all traits studied, indicating that animals with higher average breeding values responded better to improvement in environmental conditions, a fact characterizing the scale effect of G×E. Therefore, G×E is an important factor to be considered in the estimation of genetic parameters and genetic evaluation of growth traits of sheep.     

Characterization of Phytophthora infestans populations of southern Brazil in 2004 and 2005

The populations of Phytophthora infestans (Pi) in southern Brazil in 2004 and 2005 are characterized herein. The isolates were collected from potato and tomato plants in the states of Paraná (PR), Santa Catarina (SC), and Rio Grande do Sul (RS). The mating type of 131 potato and 32 tomato isolates was determined. Forty-nine isolates from potatoes and 11 from tomatoes were analyzed for their Gpi phenotype. A subset of 35 isolates was evaluated for mitochondrial (mtDNA) polymorphisms. A sample of 146 isolates was tested for sensitivity to the fungicide metalaxyl, and most isolates (64%) were moderately sensitive. Fifty-nine isolates were classified as A1 mating type and 103 as A2. One isolate behaved as both A1 and A2 mating type. All tomato isolates were A1 mating type and presented the 86/100 pattern for the enzyme GPI and mtDNA Ib, indicating that these isolates belong to the US-1 clonal lineage. Of the 131 potato isolates, 103 were A2, 27 were A1 and one was A1/A2 mating type. Among the potato isolates 27 exhibited the Gpi phenotype 100/100, the same as BR-1, and 20 were 86/100, the same as US-1. Potato isolates presented the mitochondrial haplotypes Ia (74%) and IIa (26%). The data suggest the presence of only the BR-1 clonal lineage on potatoes in the states of PR and SC. However, in the state of RS, more than one clonal lineage was observed infecting potatoes, and there may be sexual reproduction between the lineages.