Hasil untuk "Cattle"

Evan A. Mihalakakos, Victor Ssempijja, Ruy M. Ribeiro et al.

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne disease endemic to many regions of Africa, the Middle East, Southeast Asia and the Balkans. Caused by the CCHF virus (CCHFV), CCHF has been a recognized cause of illness in Uganda since the 1950s and recently, more intensive surveillance suggests CCHFV is widely endemic within the country. Most surveillance has been focused on the Ugandan cattle corridor due to the risk of CCHFV exposure associated with livestock practices. Here we evaluated the seroprevalence of CCHFV in several Southern Ugandan communities outside the cattle corridor combined with longitudinal sample sets to measure the immune response to CCHFV for up to a decade. Interestingly, across three community types, agrarian, trading and fishing, we detected CCHFV seroprevalence in all three but found the highest seroprevalence in fishing communities. We also measured consistent CCHFV-specific antibody responses for up to a decade. Our findings support the conclusion that CCHFV is widely endemic in Uganda and highlight that additional communities may be at risk for CCHFV exposure.

Sonoko Watanuki, Kazuyuki Shoji, Masaki Izawa et al.

Bovine leukemia virus (BLV) is prevalent worldwide, causing serious problems in the cattle industry. The BLV proviral load (PVL) is a useful index for estimating disease progression and transmission risk. We previously developed a quantitative real-time PCR (qPCR) assay to measure the PVL using the coordination of common motif (CoCoMo) degenerate primers. Here, we constructed a novel duplex BLV-CoCoMo qPCR assay that can amplify two genes simultaneously using a FAM-labeled MGB probe for the BLV LTR gene and a VIC-labeled MGB probe for the <i>BoLA-DRA</i> gene. This liquid duplex assay maintained its original sensitivity and reproducibility in field samples. Furthermore, we developed a dry duplex assay composed of PCR reagents necessary for the optimized liquid duplex assay. We observed a strong positive correlation between the PVLs measured using the dry and liquid duplex assays. Validation analyses showed that the sensitivity of the dry duplex assay was slightly lower than that of the other methods for the detection of a BLV molecular clone, but it showed similar sensitivity to the singleplex assay and slightly higher sensitivity than the liquid duplex assay for the PVL quantification of 82 field samples. Thus, our liquid and dry duplex assays are useful for measuring the BLV PVL in field samples, similar to the original singleplex assay.

Hani Boshra, Graham A. D. Blyth, Thang Truong et al.

Capripoxviruses are the causative agents of sheeppox, goatpox, and lumpy skin disease (LSD) in cattle, which cause economic losses to the livestock industry in Africa and Asia. Capripoxviruses are currently controlled using several live attenuated vaccines. It was previously demonstrated that a lumpy skin disease virus (LSDV) field isolate from Warmbaths (WB) South Africa, ORF 005 (IL-10) gene-deleted virus (LSDV WB005KO), was able to protect sheep and goats against sheeppox and goatpox. Subsequently, genes encoding the protective antigens for peste des petits ruminants (PPR) and Rift Valley fever (RVF) viruses have been inserted in the LSDV WB005KO construct in three different antigen forms (native, secreted, and fusion). These three multivalent vaccine candidates were evaluated for protection against PPR using a single immunization of 10⁴ TCID₅₀ in sheep. The vaccine candidates with the native and secreted antigens protected sheep against PPR clinical disease and decreased viral shedding, as detected using real-time RT-PCR in oral and nasal swabs. An anamnestic antibody response, measured using PPR virus-neutralizing antibody response production, was observed in sheep following infection. The vaccine candidates with the antigens expressed in their native form were evaluated for protection against RVF using a single immunization with doses of 10⁴ or 10⁵ TCID₅₀ in sheep and goats. Following RVF virus infection, sheep and goats were protected against clinical disease and no viremia was detected in serum compared to control animals, where viremia was detected one day following infection. Sheep and goats developed RVFV-neutralizing antibodies prior to infection, and the antibody responses increased following infection. These results demonstrate that an LSD virus-vectored vaccine candidate can be used in sheep and goats to protect against multiple viral infections.

Andreas W. Oehm, Andrea Springer, Daniela Jordan et al.

Fasciola hepatica and Ostertagia ostertagi are internal parasites of cattle compromising physiology, productivity, and well-being. Parasites are complex in their effect on hosts, sometimes making it difficult to identify clear directions of associations between infection and production parameters. Therefore, unsupervised approaches not assuming a structure reduce the risk of introducing bias to the analysis. They may provide insights which cannot be obtained with conventional, supervised methodology. An unsupervised, exploratory cluster analysis approach using the k–mode algorithm and partitioning around medoids detected two distinct clusters in a cross-sectional data set of milk yield, milk fat content, milk protein content as well as F. hepatica or O. ostertagi bulk tank milk antibody status from 606 dairy farms in three structurally different dairying regions in Germany. Parasite–positive farms grouped together with their respective production parameters to form separate clusters. A random forests algorithm characterised clusters with regard to external variables. Across all study regions, co–infections with F. hepatica or O. ostertagi, respectively, farming type, and pasture access appeared to be the most important factors discriminating clusters (i.e. farms). Furthermore, farm level lameness prevalence, herd size, BCS, stage of lactation, and somatic cell count were relevant criteria distinguishing clusters. This study is among the first to apply a cluster analysis approach in this context and potentially the first to implement a k–medoids algorithm and partitioning around medoids in the veterinary field. The results demonstrated that biologically relevant patterns of parasite status and milk parameters exist between farms positive for F. hepatica or O. ostertagi, respectively, and negative farms. Moreover, the machine learning approach confirmed results of previous work and shed further light on the complex setting of associations a between parasitic diseases, milk yield and milk constituents, and management practices.

Matthew A. Scott, Amelia R. Woolums, Brandi B. Karisch et al.

The impact of preweaning vaccination for bovine respiratory viruses on cattle health and subsequent bovine respiratory disease morbidity has been widely studied yet questions remain regarding the impact of these vaccines on host response and gene expression. Six randomly selected calves were vaccinated twice preweaning (T1 and T3) with a modified live vaccine for respiratory pathogens and 6 randomly selected calves were left unvaccinated. Whole blood samples were taken at first vaccination (T1), seven days later (T2), at revaccination and castration (T3), and at weaning (T4), and utilized for RNA isolation and sequencing. Serum from T3 and T4 was analyzed for antibodies to BRSV, BVDV1a, and BHV1. Sequenced RNA for all 48 samples was bioinformatically processed with a HISAT2/StringTie pipeline, utilizing reference guided assembly with the ARS-UCD1.2 bovine genome. Differentially expressed genes were identified through analyzing the impact of time across all calves, influence of vaccination across treatment groups at each timepoint, and the interaction of time and vaccination. Calves, regardless of vaccine administration, demonstrated an increase in gene expression over time related to specialized proresolving mediator production, lipid metabolism, and stimulation of immunoregulatory T-cells. Vaccination was associated with gene expression related to natural killer cell activity and helper T-cell differentiation, enriching for an upregulation in Th17-related gene expression, and downregulated genes involved in complement system activity and coagulation mechanisms. Type-1 interferon production was unaffected by the influence of vaccination nor time. To our knowledge, this is the first study to evaluate mechanisms of vaccination and development in healthy calves through RNA sequencing analysis.

Pedro Augusto Cordeiro Borges, Danilo Conrado Silva, Nivan Antônio Alves da Silva et al.

The aim of this study was to compare three methods of processing thermographic images for the evaluation of carpal temperature in healthy calves. Additionally, we sought to evaluate the thermal symmetry between the contralateral carpi of these calves. Thermographic images were obtained from both carpi of eight healthy calves aged between 20 and 45 days with a mean weight of 38.65 ± 2.27 kg. Using GRAYESS® IRT Analyzer 7 software, the total temperature (Ttot), region-of-interest temperature (Troi), and maximum mean temperature (Tmax) were determined. There was no difference between the temperatures obtained by the Ttot and Troi methods. Tmax showed higher temperatures (p < 0.01) than the other methods. The three image processing methods showed high and significant positive correlations for the temperature of the right and left carpi of healthy calves. Tmax presented a higher correlation coefficient (r = 0.99) than the two other methods, which suggests a greater sensitivity for identifying thermal variations among the contralateral carpi. The 99% confidence interval for the difference between the temperatures of the right and left carpi (Δr-l) was between 0.03 and 0.26°C; thus, a temperature variation within that range does not refer to pathologic processes. Key words: cattle; joint; thermal symmetry; thermography

PRAJWALITA PATHAK, ANUPAMA MUKHERJEE, VIVEK KUMAR NAYAK et al.

The present study explored the association between single nucleotide polymorphisms (SNPs) in leptin gene with various economic traits (body weight at different age, first lactation reproduction and production traits) in Sahiwal cows. PCR-RFLP of 522 bp fragment comprising partial intron 2 and exon 3 of leptin gene, carried out using BsaAI restriction endonuclease, revealed three genotypes (GG, AG and AA) at position G93263736A in chromosome 4 with genotypic frequencies of 0.39, 0.52 and 0.09 respectively. The allele frequencies were 0.65 for the G allele and 0.35 for the A allele. General Linear Model (GLM) analysis revealed significant association of SNP G93263736A with growth and first lactation production traits. The present study supports that SNP in leptin gene could be used as an aid to selection for improving different economic traits in Sahiwal cows.

Juan Bidart, Juan Bidart, Claudia Kornuta et al.

Foot-and-Mouth Disease (FMD) is an acute viral disease that causes important economy losses. Vaccines with new low-cost adjuvants that stimulate protective immune responses are needed and can be assayed in a mouse model to predict their effectiveness in cattle. Immunostimulant Particle Adjuvant (ISPA), also known as cage-like particle adjuvant, consisting of lipid boxes of dipalmitoyl-phosphatidylcholine, cholesterol, sterylamine, alpha-tocopherol, and QuilA saponin, was shown to enhance protection of a recombinant vaccine against Trypanosoma cruzi in a mouse model. Thus, in the present work, we studied the effects on the magnitude and type of immunity elicited in mice and cattle in response to a vaccine based on inactivated FMD virus (iFMDV) formulated with ISPA. It was demonstrated that iFMDV–ISPA induced protection in mice against challenge and elicited a specific antibody response in sera, characterized by a balanced Th1/Th2 profile. In cattle, the antibody titers reached corresponded to an expected percentage of protection (EPP) higher than 80%. EPP calculates the probability that livestock would be protected against a 10,000 bovine infectious doses challenge after vaccination. Moreover, in comparison with the non-adjuvanted iFMDV vaccine, iFMDV–ISPA elicited an increased specific T-cell response against the virus, including higher interferon gamma (IFNγ)+/CD8+ lymphocyte production in cattle. In this work, we report for first time that an inactivated FMDV serotype A vaccine adjuvanted with ISPA is capable of inducing protection against challenge in a murine model and of improving the specific immune responses against the virus in cattle.

Michelle M. Halstead, Colin Kern, Perot Saelao et al.

Abstract Background Although considerable progress has been made towards annotating the noncoding portion of the human and mouse genomes, regulatory elements in other species, such as livestock, remain poorly characterized. This lack of functional annotation poses a substantial roadblock to agricultural research and diminishes the value of these species as model organisms. As active regulatory elements are typically characterized by chromatin accessibility, we implemented the Assay for Transposase Accessible Chromatin (ATAC-seq) to annotate and characterize regulatory elements in pigs and cattle, given a set of eight adult tissues. Results Overall, 306,304 and 273,594 active regulatory elements were identified in pig and cattle, respectively. 71,478 porcine and 47,454 bovine regulatory elements were highly tissue-specific and were correspondingly enriched for binding motifs of known tissue-specific transcription factors. However, in every tissue the most prevalent accessible motif corresponded to the insulator CTCF, suggesting pervasive involvement in 3-D chromatin organization. Taking advantage of a similar dataset in mouse, open chromatin in pig, cattle, and mice were compared, revealing that the conservation of regulatory elements, in terms of sequence identity and accessibility, was consistent with evolutionary distance; whereas pig and cattle shared about 20% of accessible sites, mice and ungulates only had about 10% of accessible sites in common. Furthermore, conservation of accessibility was more prevalent at promoters than at intergenic regions. Conclusions The lack of conserved accessibility at distal elements is consistent with rapid evolution of enhancers, and further emphasizes the need to annotate regulatory elements in individual species, rather than inferring elements based on homology. This atlas of chromatin accessibility in cattle and pig constitutes a substantial step towards annotating livestock genomes and dissecting the regulatory link between genome and phenome.

Toru Ogata, Hiroki Makino, Naoki Ishizuka et al.

To increase intramuscular fat accumulation, Japanese Black cattle are commonly fed a high-grain diet from 10 to 30 months of age although it can result in the abnormal accumulation of organic acids in the rumen. We explored the effect of long-term high-concentrate diet feeding on ruminal pH and fermentation, and its effect on the rumen bacterial community in Japanese Black beef cattle during a 20-month fattening period. Nine castrated and fistulated Japanese Black beef cattle were housed with free access to food and water throughout the study period (10-30 months of age). The fattening stages included Early, Middle, and Late stages (10-14, 15-22, and 23-30 months of age, respectively). Cattle were fed high-concentrate diets for the experimental cattle during fattening. The body weight of the cattle was 439 ± 7.6, 561 ± 11.6, and 712 ± 18.5 kg (mean ± SE) during the Early, Middle, and Late stages, respectively. Ruminal pH was measured continuously during the final 7 days of each stage, and rumen fluid and blood samples were collected on day 4 (fourth day during the final 7 days of the pH measurements). The 24-h mean ruminal pH during the Late stage was significantly lower than that during the Early stage. Total volatile fatty acid (VFA) during the Late stage was significantly lower than during the Early and Middle stages, but no changes were noted in individual VFA components. The lactic acid concentration during the Late stage was significantly higher than that during the Early and Middle stages. The bacterial richness indices decreased significantly during the Late stage in accordance with the 24-h mean ruminal pH. Among the 35 bacterial operational taxonomic units (OTUs) shared by all samples, the relative abundances of OTU8 (Family Ruminococcaceae) and OTU26 (Genus Butyrivibrio) were positively correlated with the 24-h mean ruminal pH. Total VFA concentration was negatively correlated with OTU167 (Genus Intestinimonas), and lactic acid concentration was correlated positively with OTU167 and OTU238 (Family Lachnospiraceae). These results suggested that long-term high-grain diet feeding gradually lowers ruminal pH and total VFA production during the Late fattening stage. However, the ruminal bacterial community adapted to feeding management and the lower pH during the Late stage by preserving their diversity or altering their richness, composition, and function, to enhance lactic acid production in Japanese Black beef cattle.

Patric Brandt, Martin Herold, Mariana C Rufino

Reducing greenhouse gas (GHG) emissions from agriculture has become a critical target in national climate change policies. More than 80% of the countries in Sub-Saharan Africa (SSA) refer to the reduction of agricultural emissions, including livestock, in their nationally determined contribution (NDC) to mitigate climate change. The livestock sector in Kenya contributes largely to the gross domestic product and to GHG emissions from the land use sector. The government has recently pledged in its NDC to curb total GHG emissions by 30% by 2030. Quantifying and linking the mitigation potential of farm practices to national targets is required to support realistically the implementation of NDCs. Improvements in feed and manure management represent promising mitigation options for dairy production. This study aimed (i) to assess mitigation and food production benefits of feed and manure management scenarios, including land use changes covering Kenya’s entire dairy production region and (ii) to analyse the contribution of these practices to national targets on milk production and mitigation, and their biophysical feasibility given the availability of arable land. The results indicate that improving forage quality by increasing the use of Napier grass and supplementing dairy concentrates supports Kenya’s NDC target, reduces emission intensities by 26%–31%, partially achieves the national milk productivity target for 2030 by 38%–41%, and shows high feasibility given the availability of arable land. Covering manure heaps may reduce emissions from manure management by 68%. In contrast, including maize silage in cattle diets would not reduce emission intensities due to the risk of ten-fold higher emissions from the conversion of land required to grow additional maize. The shortage of arable land may render the implementation of these improved feed practices largely infeasible. This assessment provides the first quantitative estimates of the potential of feed intensification and manure management to mitigate GHG emissions and to increase milk yields at sectoral-level and at a high spatial resolution for an SSA country. The scientific evidence is tailored to support actual policy and decision-making processes at the national level, such as ‘Nationally Appropriate Mitigation Actions’. Linking feed intensification and manure management strategies with spatially-explicit estimates of mitigation and food production to national targets may help the sector to access climate financing while contributing to food security.

Marcos Paulo Gonçalves Rezende, Emanoela Aragão Souza Lisboa Conde, Ana Carla Borges et al.

The objective of this study was to evaluate the population structure of 91,579 Nellore cattle reared in the Northeast semi-arid, born between 1965 and 2011. We analyzed the pedigree and the estimation of population parameters based on the probability of gene origin. In the early years, a higher number of female births occured, tending to gender balance over the years. The number of founder animals (fe) and ancestors (fa) indicated the reduced use of animals in the genetic formation of the herd. Among 2,4676 ancestors, 450 were responsible for 50% of the genetic variability of the population. Of the 10 most important founders, 8 were among the 10 ancestors. The individual with the highest expression presented a mean coefficient of relationship (CR) of 1.31%, explaining 1.81% of the variability.72% of animals have identified fathers and mothers, revealing loss of information between generations. 100% of the herds use external bulls and 61% of them sell bulls, with no core classification or isolate. Inbreeding ranged from 0.14% in the second generation to 0.73% in the eighth, while the CR ranged from 0.8% to 0.35% between the first and fourth generations, decreasing from the fifth on. The average generation interval observed was of 8.3 years. The herd has a small number of animals in the genetic make-up, and small completeness of pedigree, making it difficult to estimate some population parameters. Keywords: generation interval; genetic variability; inbreeding; Zebu.

Adair da Silva Santos Filho, Christiano Vieira Pires, Weslley José Cardoso et al.

Cheese type cabacinha from Vale do Jequitinhonha is obtained by curd heating in a similar process made to Mozzarella, but the raw milk is unpasteurized and the final product is stored unpackaged and at room temperature. This milk derivative may contribute to the increase the income of the local population, especially the residents of the edges of roads, due to the flow of vehicles and possible buyers. The purpose of this work was to identify the physical and sanitary conditions of cheese type cabacinha market places present in three municipalities of the Vale do Jequitinhonha, MG, Brazil. Previously the investigation was detected the number of marketplaces that sell these cheese in the Medina, Cachoeira de Pajeú and Pedra Azul, municipalities of the state of Minas Gerais, Brazil, located on the surrounding area of the highways BR 251 and BR 116. Afterward as developed a physical and sanitary checklist and it were filled in loco. It was observed that most market places were not provided of masonry walls, piped water or toilet and sink. It is also common to the presence of possible contamination vectors in surroundings, such as dogs and insects. It is verified that most of these cheese is exposed in pairs held by string and unpackaged. This study demonstrated the precariousness of the physical structures and consequently the lack of adequate sanitary conditions in the cheese type cabacinha market places. Because it is an artisanal product from family farming, which generates income and employment in the field deserve more attention of competent state and municipal authorities.

Catherine E. Vrentas, Justin J. Greenlee, Gregory H. Foster et al.

Abstract Objective The most common hereditary prion disease is human Creutzfeldt-Jakob disease (CJD), associated with a mutation in the prion gene resulting in a glutamic acid to lysine substitution at position 200 (E200K) in the prion protein. Models of E200K CJD in transgenic mice have proven interesting but have limitations including inconsistencies in disease presentation, requirement for mixed species chimeric protein constructs, and the relatively short life span and time to disease onset in rodents. These factors limit research on the mechanism by which the mutation drives disease development. Therefore, our objective was to provide the first assessment of cattle carrying the homologous mutation, E211K, as a system for investigating longer-term disease mechanisms. The E211K substitution was associated with a case of bovine spongiform encephalopathy from 2006. Results We assessed the molecular properties of bovine E211K prion protein, characterized the molecular genetics of a population of cattle E211K carriers (offspring of the original EK211 cow) in relation to findings in humans, and generated preliminary evidence that the impacts of copper-induced oxidative stress may be different in cattle as compared to observations in transgenic mouse models. The cattle E211K system provides the opportunity for future analysis of physiological changes over time.

PLOS ONE Staff

[This corrects the article DOI: 10.1371/journal.pone.0154748.].

Khordadmehr, M., , Namavari, M., , Khodakaram-Tafti, A.

Neospora caninum is a coccidian protozoan parasite which is a major cause of bovine abortions and neonatal mortality in cattle, sheep, goat and horse. Occasionally, cultured cells are used for isolation and multiplication of the agent in vitro with several purposes. In this study the tachyzoite yields of N. caninum were compared in various cell cultures as the host cell lines. Among the cell cultures tested, two presented good susceptibility to the agent: cell lines Vero and MA-104. SW742 and TLI (in vitro suspension culture of lymphoid cells infected with Theileria lestoquardi) showed moderate sensitivity. No viable tachyzoite were detected in the culture of MDCK and McCoy cell lines. These results demonstrate that MA-104 and SW742 cells present adequate susceptibility to N. caninum compared to Vero cells, which have been largely used to multiply the parasite in vitro. Moreover, these have easy manipulation, fast multiplication and relatively low nutritional requirements. In addition, the result of this study showed that TLI cell line as a suspension cell culture is susceptible to Nc-1 tachyzoites infection and could be used as an alternative host cell line for tachyzoites culture in vitro studies.

Julianne Milléo, Jonathan Pena Castro, José Pedrosa-Macedo

Senecio brasiliensis (Spreng.) Less quando ingerido por bovinos e eqüinos causa uma séria intoxicação, a seneciose. Devido a significativa perda econômica para a pecuária é interessante o controle com uso de insetos. Através de coletas sistêmicas e contínuas na planta observou-se que Phaedon confinis Klug, causa sérios danos à planta apresentando grande potencial como biocontrolador. O objetivo foi ampliar a 52 plantas os testes de especificidade hospedeira com larvas de 1º instar e adultos do crisomelídeo. Os insetos foram submetidos aos testes “sem chance de escolha” e de “múltipla escolha”. Os seguintes resultados foram obtidos: “SEM CHANCE DE ESCOLHA” L1 - 52 plantas testadas: dano nulo 90,39%; exploratório 5,77%; fraco 1,92%; e normal apenas no S. brasiliensis 1,92%, onde 31,67% das larvas atingiram a fase adulta. “SEM CHANCE DE ESCOLHA” ADULTOS - 46 plantas testadas: em 82,60% o dano foi nulo; 13,04% exploratório; 2,17% fraco; 2,17% normal S. brasiliensis. O crisomelídeo ovipositou durante os dias de observação somente nas folhas de S. brasiliensis, 615 ovos com viabilidade de 73,01%. No teste “MÚLTIPLA ESCOLHA” LARVAS - Nove plantas testadas: 66,67% dano nulo; 11,11% fraco; 11,11% exploratório; e 11,11% normal S. brasiliensis. Os resultados indicam que a alimentação normal, oviposição, sobrevivência e desenvolvimento de P. confinis estão restritos ao S. brasiliensis e contribuem para confirmar o seu potencial como agente de biocontrole. Host Specificity Test of Phaedon confinis (Coleoptera, Chrysomelidae), a Potential Biocontrol Agent of Senecio brasiliensis (Asteraceae) Abstract. Senecio brasiliensis (Spreng.) Less when ingested by cattle and horses, the plant causes seneciosis, a serious poisoning. Due to the great financial losses to cattle ranchers, controlling the plant using insects has become attractive. Systematic survey efforts have revealed that Phaedon confinis Klug causes serious damage to the plant, and may be a great biocontrol agent. The object was to extend the tests of host specificity to 52 plants using 1st larval instar and adult chrysomelid bettles. The insects were submitted to “no-choice” and “multiple-choice” tests. The following results were obtained: “NO-CHOICE” L1 – 52 plants tested: null 90.39%; negligible damage 5.77%; light 1.92%; and normal in only S. brasiliensis 1.92%, where 31.67% of larvae obtained an adult phase. “NO-CHOICE” ADULTS – 46 plants. Null damage was recorded in 82.60%; 13.04% showed negligible damage; 2.17% light; 2.17% normal in S. brasiliensis. The chysomelids oviposited during observation days only on S. brasiliensis leaves. 615 eggs were oviposited with 73.01% viability. “MULTIPLE CHOICE” LARVAE – nine plants tested. 66.67% null; 11.11% weak; 11.11% negligible damage; and 11.11% normal in S. brasiliensis. The results indicate that the normal diet, oviposition, survival and development of P. confinis is restricted to S. brasiliensis and corroborates its potential as a biocontrol agent.

Marina Vranić, Mladen Knežević, Krešimir Bošnjak et al.

The objective of this study was to determine effect of additive supplementation to red clover silage on ad libitum intake of fresh silage and dry matter (DM), in vivo digestibility of DM, organic matter (OM), OM in DM (D-value), crude protein (CP) and nitrogen (N) balance. Red clover was harvested at 60% bloom stage. It was ensiled into round bales without an additive (CD) and with an additive supplementation (CDA) in the amount of 2 L t-1 fresh material. Statistically lower (P<0.001) DM content was recorded in CD (405 g kg-1 fresh sample) in comparison with CDA (665 g ST kg-1 fresh sample). Statistically higher CP content (P<0.001) was recorded in CD (127 g kg-1 ST) in comparison with CDA (110 g SP kg-1 ST). CD had lower pH (P<0.001) (4.9) in comparison with CDA (5.2). No differences were recorded in NH3 between treatments. Ad libitum intake of fresh silage and silage DM was higher (P<0.001 and P<0.01, respectively) in CD in comparison with CDA. Digestibility of DM, OM, CP, D-value and N balance were not different between treatments. It was concluded that the positive effect of additive supplementation to red clover silage on chemical composition, ad libitum intake, digestibility and N balance was not recorded due to applied ensiling technology as additive can improve feeding value of roughage, but it is not a replacement for good management practices.

Nadia A.B. Antoniassi, Eduardo V. Ferreira, Carlos E.P. dos Santos et al.

Relata-se a intoxicação espontânea por Ipomoea carnea subsp. fistulosa (canudo, algodoeiro) em bovinos no Pantanal Matogrossense. As investigações iniciaram após a morte de 12 bovinos, de um rebanho de 500 animais, criados em uma extensa área intensamente infestada por I. carnea subsp. fistulosa com escassa disponibilidade de outra forragem. As mortes ocorreram entres os meses de junho e setembro de 2006. O quadro clínico foi caracterizado por emagrecimento e sinais neurológicos com dificuldade locomotora. Um bovino foi necropsiado sem que se observassem alterações macroscópicas significativas. Histologicamente havia tumefação e vacuolização celular, em neurônios, células acinares pancreáticas, tubulares renais e foliculares da tireóide. Bovinos com quadro clínico similar foram retirados da área invadida por I. carnea subsp. fistulosa e colocadas em áreas com pastagem nativa e de Brachiaria sp. e apresentaram melhora clínica após período de 15 dias.<br>A spontaneous Ipomoea carnea subsp. fistulosa (canudo, algodoeiro) poisoning of cattle in the county of Poconé, Brazilian Pantanal, is reported. The investigation began after 12 cattle had died from a flock of 500 animals maintained in an extensive area intensely infested by I. carnea subsp. fistulosa with scarce availability of other fodder plants. The deaths occurred from June to September of 2006. Clinical signs were loss of weight and neurological deficits with hypermetry and incoordination. No significant gross lesions were observed at postmortem examination of one bovine. Histological changes comprised widespread cytoplasmic vacuolation of neurons, cells of the thyroid, kidney and pancreas. Cattle with similar clinical picture, that had been removed from the area invaded by I. carnea subsp. fistulosa and placed into areas with native and Brachiaria sp. pasture, recovered clinically within 15 days.

Meirelles Flávio V., Rosa Artur J.M., Lôbo Raysildo B. et al.

The American continent was colonized in the 16th century by Europeans who first introduced cattle of Bos taurus origin. Accounts register introduction of Bos indicus cattle into South America in the 19th and continuing through the 20th century, and most reported imports were males derived from the Indian subcontinent. In the present study we show, by using mitochondrial DNA (mtDNA) polymorphism, major participation of matrilineages of taurus origin in the American Zebu purebred origin, i.e., 79, 73 and 100% for the Nellore, Gyr and Brahman breeds, respectively. Moreover, we have created a restriction map identifying polymorphism among B. taurus and B. indicus mtDNA using three restriction enzymes. Results are discussed concerning American Zebu origins and potential use of this information for investigating the contribution of cytoplasmic genes in cattle production traits.