Effect of monensin on performance in growing ruminants reared under different environmental temperatures

To evaluate the effect of monensin on the performance of growing cattle under different environmental temperatures, 24 male calves (81.9 +/- 7.7 kg mean weight and 100 days old) were distributed in a 2 x 2 factorial arrangement, contrasting 0 or 85 mg monensin/animal per day at 24.3 or 33.2 degrees C (environmental temperatures). Monensin supplementation increased weight gain (P=0.036), improved feed efficiency (P=0.040), increased ruminal concentrations of volatile fatty acids (VFA; P=0.003) and decreased the molar proportion of butyrate (P=0.034); all effects irrespective of environmental temperatures. A temperature-dependent monensin effect was detected on nitrogen retention (P=0.018) and N retained:N absorbed ratio (P=0.012). Animals fed monensin retained higher N amounts than those of the non-supplemented ones when the environmental temperature was 33.2 degrees C. Environmental temperature and monensin supplementation showed an interaction effect on urine N concentration (P=0.003). Temperature did not affect N excretion in monensin-fed animals, but increased N excretion in the non-supplemented ones. Monensin increased the crude protein (CP) digestibility (P=0.094) for

Reactivity of Nellore steers in two feedlot housing systems and its relationship with plasmatic cortisol

To evaluate reactivity to assess the temperament of Nellore steers in two feedlot housing systems (group pen or individual pen) and its relationship with plasmatic cortisol, 36 experimental units were observed five times at 28-day intervals of weight management during a 112-day feedlot confinement. A reactivity score scale ranging from 1 to 5 was applied when an animal was in the chute system. To the calmest animal, a reactivity score of 1 was ascribed and to the most agitated, 5. Blood samples were collected for cortisol analysis. No differences were found in reactivity and feedlot system. There was a relationship noted between reactivity and feedlot time in both housing systems (P < 0.01). There was a relation between reactivity and cortisol levels for group animals (P = 0.0616) and for individual ones (P < 0.01). Cortisol levels varied among housing systems (P < 0.01). Feedlot time influenced the cortisol levels (P < 0.09 individual; P < 0.01 group) and when variable time was included, these levels changed, decreasing in the group pen and increasing in individual pens. The continuous handling reduces reactivity and plasmatic cortisol, and group pen system seems to be less stressfully than individual pens. (C) 2010 Elsevier B.V. All rights reserved.

Fluctuating abundance of humpback whales (Megaptera novaeangliae) in a calving ground off coastal Brazil

The humpback whale (Megaptera novaeangliae) population that uses Abrolhos Bank, off the east coast of Brazil as a breeding ground is increasing. To describe temporal changes in the relative abundance of humpback whales around Abrolhos, seven years (1998-2004) of whale count data were collected during July through to November. During one-hour-scans, observers determined group size within 9.3 km (5 n.m.) of a land-based observing station. A total Of 930 scans, comprising 7996 sightings of adults and 2044 calves were analysed using generalized linear models that included variables for time of day, day of the season, years and two-way interactions as possible predictors. The pattern observed was the gradual build-up and decline in whale counts within seasons. Patterns and peaks of adult and calf counts varied among years. Although fluctuation was observed, there was generally an increasing trend in adult counts among years. Calf counts increased only in 2004. These fluctuations may have been caused by some environmental conditions in humpback whales` summering grounds and also by changes in spatial-temporal concentrations in Abrolhos Bank. The general pattern observed within the study area mirrored what was observed in the whole Abrolhos Bank. Knowledge of the consistency with which humpback whales use this important nursing area should prove beneficial for designing future monitoring programmes especially related to whale watching activities around Abrolhos Archipelago.

Propagation of a Brazilian isolate of Anaplasma marginale with appendage in a tick cell line (BME26) derived from Rhipicephalus (Boophilus) microplus

Anaplasma marginale is a tick-borne pathogen of cattle responsible for the disease anaplasmosis. Data suggest that Rhipicephalus (Boophilus) microplus and R. annulatus may be the major tick vectors of A. marginale in tropical and subtropical regions of the world. In this work we demonstrated the first infection and propagation of a Brazilian isolate of A. marginale (UFMG1) in the BME26 cell line derived originally from embryos of R. (Boophilus) microplus. The establishment of A. marginale infection in a cell line derived from R. (Boophilus) microplus is relevant for studying the A. marginale/tick interface. (C) 2008 Elsevier B.V. All rights reserved.

Intraspecific sequence variation in 16S rRNA gene of Ureaplasma diversum isolates

Ureaplasma diversum infection in bulls may result in seminal vesiculitis, balanoposthitis and alterations in spermatozoids. In cows, it can cause placentitis, fetal alveolitis, abortion and the birth of weak calves. U. diversum ATCC 49782 (serogroups A), ATCC 49783 (serogroup C) and 34 field isolates were used for this study. These microorganisms were submitted to Polymerase Chain Reaction for 16S gene sequence determination using Tact High Fidelity and the products were purified and bi-directionally sequenced. Using the sequence obtained, a fragment containing four hypervariable regions was selected and nucleotide polymorphisms were identified based on their position within the 16S rRNA gene. Forty-four single nucleotide polymorphisms (SNP) were detected. The genotypic variability of the 16S rRNA gene of U. diversum isolates shows that the taxonomy classification of these organisms is likely much more complex than previously described and that 16S rRNA gene sequencing may be used to suggest an epidemiologic pattern of different origin strains. (c) 2011 Elsevier B.V. All rights reserved.

Emplacement mechanism of the main granite pluton of the Lavras do Sul intrusive complex, South Brazil, determined by magnetic anisotropies

Magnetic fabric and rock magnetism studies were performed on apparently isotropic granite facies from the main intrusion of the Lavras do Sul Intrusive Complex pluton (LSIC, Rio Grande do Sul, South Brazil). This intrusion is roughly circular (similar to 12 x 13.5 km), composed of alkali-calcic and alkaline granitoids, with the latter occupying the margin of the pluton. Magnetic fabrics were determined by applying both anisotropy of low-field magnetic susceptibility (AMS) and anisotropy of anhysteretic remanent magnetization (AARM). The two fabrics are coaxial. The parallelism between AMS and AARM tensors excludes the presence of a single domain (SD) effect on the AMS fabric of the granites. Several rock-magnetism experiments performed in one specimen from each sampled site show that for all sites the magnetic susceptibility is dominantly carried by ferromagnetic minerals, while mainly magnetite carries the magnetic fabrics. Lineations and foliations in the granite facies were successful determined by applying magnetic methods. Magnetic lineations are gently plunging and roughly parallel to the boundaries of the pluton facies, except at the few sites in the central facies which have a radial orientation pattern. In contrast, the magnetic foliations tend to follow the contacts between the different granite facies. They are gently outerward-dipping inside the pluton, and become either steeply southwesterly dipping or vertical towards its margin. The lack of solid-state and subsolidus deformations at outcrop scale and in thin sections precludes deformation after full crystallization of the pluton. This evidence allows us to interpret the observed magnetic fabrics as primary in origin (magmatic) acquired when the rocks were solidified as a result of processes reflecting magma flow. The foliation pattern displays a dome-shaped form for the main LSIC-pluton. However, the alkaline granites which outcrop in the southern part of the studied area have an inward-dipping foliation, and the steeply plunging magnetic lineation suggests that this area could be part of a feeder zone. The magma ascent probably occurred due to ring-diking. (C) 2008 Elsevier B.V. All rights reserved.

Manejo reprodutivo pós-parto de vacas primíparas e desenvolvimento de terneiros

O trabalho teve por objetivo avaliar os efeitos de cargas animais de 240 e 320 kg PV/ha em campo nativo (T1 e T2, respectivamente), de 400 kg PV/ha em pastagem melhorada com azevém (Lolium multiflorum L.) por 80 dias pós-parto e, após, carga animal igual a T2 em campo nativo (T3), e do desmame dos terneiros aos 100 dias (DP) ou aos 180 dias (DC) de idade sobre o desempenho reprodutivo de vacas de corte primíparas Hereford e Braford, e sobre o desenvolvimento de seus terneiros. A taxa de prenhez (TP) não foi influenciada (P>0,05) pelos tratamentos (T1 = 93,8%; T2= 90,6%; T3= 100%), nem pela idade de desmame (DP= 97,8%; DC= 91,3%). Houve efeito significativo dos tratamentos (P<0,05) sobre a TP aos 21 dias (T1= 15,6%; T2= 0,0%; T3= 17,9%) e aos 42 dias (T1= 46,9%; T2= 37,5%; T3= 71,4%) após iniciada a estação de acasalamento. O intervalo entre partos (IEP) e o intervalo parto-concepção (IPC) foram influenciados (P<0,01) pelos tratamentos. O IEP e o IPC para T1, T2 e T3 foram 390,9; 399,0 e 386,8 dias e 105,9; 114,0 e 101,8 dias, respectivamente Terneiros filhos de vacas Braford no T2 foram mais pesados ao desmame (P<0,05) do que terneiros filhos de vacas da mesma raça no T1 e filhos de vacas Hereford no T2. Os terneiros do DP tiveram pesos ajustados aos 180 dias menores (P<0,01) do que os do DC (174,6 kg vs. 197,2 kg, respectivamente). Não houve efeito (P>0,05) dos tratamentos, nem da idade de desmame sobre o peso dos terneiros aos 365 dias de idade. Os novilhos do DP tiveram pesos de abate e de carcaça, aos 14 meses, inferiores (P<0,01) aos novilhos do DC. Entretanto, o ganho de peso e o rendimento de carcaça dos novilhos do DP foram superiores (P<0,01) aos novilhos do DC. Não houve efeito (P>0,05) da idade de desmame sobre a espessura de gordura subcutânea.

Desenvolvimento de uma unidade pirolítica com reator de cilindro rotativo: obtenção de bio-óleo

The demand for alternative sources of energy drives the technological development so that many fuels and energy conversion processes before judged as inadequate or even non-viable, are now competing fuels and so-called traditional processes. Thus, biomass plays an important role and is considered one of the sources of renewable energy most important of our planet. Biomass accounts for 29.2% of all renewable energy sources. The share of biomass energy from Brazil in the OIE is 13.6%, well above the world average of participation. Various types of pyrolysis processes have been studied in recent years, highlighting the process of fast pyrolysis of biomass to obtain bio-oil. The continuous fast pyrolysis, the most investigated and improved are the fluidized bed and ablative, but is being studied and developed other types in order to obtain Bio-oil a better quality, higher productivity, lower energy consumption, increased stability and process reliability and lower production cost. The stability of the product bio-oil is fundamental to designing consumer devices such as burners, engines and turbines. This study was motivated to produce Bio-oil, through the conversion of plant biomass or the use of its industrial and agricultural waste, presenting an alternative proposal for thermochemical pyrolysis process, taking advantage of particle dynamics in the rotating bed that favors the right gas-solid contact and heat transfer and mass. The pyrolyser designed to operate in a continuous process, a feeder containing two stages, a divisive system of biomass integrated with a tab of coal fines and a system of condensing steam pyrolytic. The prototype has been tested with sawdust, using a complete experimental design on two levels to investigate the sensitivity of factors: the process temperature, gas flow drag and spin speed compared to the mass yield of bio-oil. The best result was obtained in the condition of 570 oC, 25 Hz and 200 cm3/min, temperature being the parameter of greatest significance. The mass balance of the elementary stages presented in the order of 20% and 37% liquid pyrolytic carbon. We determined the properties of liquid and solid products of pyrolysis as density, viscosity, pH, PCI, and the composition characterized by chemical analysis, revealing the composition and properties of a Bio-oil.

Desenvolvimento ponderal de bubalinos da raça Murrah criados em pastagem de Brachiaria brizantha no Centro-Oeste do Estado de São Paulo, Brasil

Foram analisados os dados de desempenho ponderal de bubalinos Murrah do Sistema de Produção de Leite da Universidade Estadual Paulista, Faculdade de Medicina Veterinária e Zootecnia, campus de Botucatu. Os pesos foram corrigidos às diversas idades-padrão e o modelo incluiu os efeitos de sexo (S), mês (M) e ano (A) de nascimento, classe de idade da búfala ao parto (C) e as interações S x M, S x A, S x C e M x A. As médias ajustadas e respectivos erros-padrão estimados para as características estudadas foram: Peso ao Nascer (PN): 37,71 ± 8,25kg; Peso aos 120 dias (P120): 102,08 ± 16,27kg; Peso aos 240 dias (P240): 169,84 ± 22,83kg; Peso aos 365 dias (P365): 250,59 ± 25,12kg; Peso aos 550 dias (P550): 326,13 ± 39,27kg e Peso aos 730 dias (P730): 389,80 ± 31,26kg. O efeito de sexo (S) foi significativo somente para PN e P365, sendo que machos tenderam a nascer mais pesados que fêmeas. O mês de nascimento (M) exerceu efeito sobre o PN, P120 e P730 sendo que animais nascidos em maio foram os mais pesados ao nascer, enquanto os nascidos em janeiro e maio, foram os mais pesados aos 120 e 730 dias, respectivamente. O efeito de ano de foi significativo sobre o PN, P120, P240 e P730. Os filhos de búfalas das classes de idade 1 (3 anos ou menos) e da classe 6 (10,11 e 12 anos) foram os mais leves e mais pesados ao nascer, respectivamente. O fato de a classe de idade da búfala não exercer efeito sobre os P365, P550 e P730 sugere que, em rebanhos comerciais possa ser feita a substituição de búfalas não gestantes por novilhas prenhes, apesar de esta prática reduzir a média de idade do rebanho de cria. Bubalinos da raça Murrah oriundos de rebanhos leiteiros podem ser utilizados para a produção de carne.

Anthelmintic efficacy of oral trichlorfon solution against ivermectin resistant nematode strains in cattle

Infected calves from two different rural estates in Brazil were studied to assess the anthelmintic efficacy of oral trichlorfon against naturally occurring ivermectin resistant parasitic nematode strains. In experiment 1, infected animals were from a region where ivermectin resistant populations of Haemoncus placei, Cooperia punctata,Cooperia spatulata and Trichuris discolor have recently been identified. Six calves with natural gastrointestinal nematode infections were treated with 48.5 mg/kg aqueous trichlorfon administered orally and six calves acted as a non-treated control group. In experiment 11 24 naturally infected calves were selected to enter one of four treatment groups, six animals each received: 48.5 mg/kg oral trichlorfon; 200 mu g/kg subcutaneous 1% ivermectin; 630 mu g/kg subcutaneous 3.15% ivermectin; or no treatment (control group). Gastrointestinal helminths were counted and identified post-mortem at 7 days (trichlorfon and 1% ivermectin treated and untreated animals) or 14 days (3.15% ivermectin treated and untreated animals) after administration of the test agents. Experiment I identified a high level efficacy for oral trichlorfon against four helminth species that have previously been shown to be ivermectin resistant in this geographical region: percentage efficacy was 99.82% against adult H. placei, 99.18% against C. punctata, 99.33% against C. spatulata, 81.06% against T. axei, 98.46% against Oesophagostomum radiatum and 100% against T. discolor. Trichlorfon also showed activity against the ivermectin (1% and 3.15%) resistant helminth species identified in experiment 11, attaining efficacy levels of 99.17% against H. placei, 98.46% against C punctata and 100.00% against T. discolor. These findings indicate that oral trichlorfon is an effective treatment option in the management of cattle infected with ivermectin resistant helminths. (C) 2009 Elsevier B.V. All rights reserved.

Toxoplasma gondii: Infection natural congenital in cattle and an experimental inoculation of gestating cows with oocysts

Two studies, of a natural infection and an experimental infection, were performed in order to study congenital transmission of Toxoplasma gondii in cattle. In the first study, 50 fetuses were harvested from gestating cows that were eutanasied at a municipal slaughterhouse in Jaboticabal, São Paulo state, Brazil. In the second study, 11 gestating cows were divided into four groups for inoculation with T. gondii: GI consisted of three cows inoculated with 1.0 x 10(5) oocysts during their first trimester of gestation; GII consisted of three cows inoculated with 1.0 x 10(5) oocysts during their second trimester of gestation; GIII consisted of three cows inoculated with 1.0 x 10(5) oocysts during their last trimester of gestation; and GIV consisted of two control cows, one during its first and the other during its second trimester of gestation. In both studies, the presence of T. gondii was confirmed both indirectly by immunofluorescence assay (IFAT). In the natural infection experiment, 18% (9/50) of the gestating cows were confirmed to have specific antibodies (IFAT - 1:64) against T. gondii. The bioassay was able to diagnose the presence of T. gondii in the tissue samples from three calves. In the second experiment, the nine cows from groups I, II and III presented with specific antibodies (IFAT) against T. gondii. In contrast, T. gondii could not be detected by IFAT, histopathological examination or the bioassay in any of the nine calves born to cows experimentally infected with T. gondii oocysts. Based on the results from both studies, we conclude that congenital infection of T. gondii in cattle, while infrequent, does occur naturally. The pathogenicity of the strain of T. gondii may influence the likelihood of this route of transmission. (C) 2010 Elsevier B.V. All rights reserved.

Índices de seleção para um rebanho Caracu de duplo propósito

Neste trabalho, objetivou-se determinar índices de seleção para um rebanho da raça Caracu de duplo propósito, cujo objetivo de seleção (H) incluiu a venda de bezerros desmamados e a produção de leite. As características que compuseram H foram: produção total de leite, idade ao primeiro parto, período de serviço, peso à desmama e duração da vida produtiva. Foram propostos dois índices de seleção para H. Os critérios de seleção adotados no índice 1 foram: produção de leite na primeira lactação, primeiro período de serviço, peso à desmama (PD) e perímetro escrotal. No índice 2, foram consideradas as mesmas características, sendo, entretanto, o ganho médio diário do nascimento à desmama empregado como critério de seleção para PD. As análises estatísticas para a obtenção dos componentes de (co)variâncias e das estimativas dos parâmetros genéticos e fenotípicos foram realizadas pelo método da máxima verossimilhança restrita livre de derivada, por um modelo animal (uni e bi-característica). As informações zootécnicas e genealógicas, os preços e as quantidades dos insumos e dos produtos foram obtidos no escritório da empresa estudada. Os custos de produção e as receitas da atividade pecuária foram determinados para o período de 1994 a 2000. A equação de lucro foi tomada em base anual, usando-se valores médios para número de animais por categoria, características biológicas e preços..¹ O valor econômico para cada característica foi obtido pela derivada parcial da função de lucro em relação à característica em questão. Os dois índices econômicos de seleção trariam considerável resposta para o objetivo proposto. Entretanto, o índice 1, que incluiu PD, seria um pouco mais eficiente em termos de resposta à seleção total.

Genetic associations between accumulated productivity, and reproductive and growth traits in Nelore cattle

The total meat yield in a beef cattle production cycle is economically very important and depends on the number of calves born per year or birth season, being directly related to reproductive potential. Accumulated Productivity (ACP) is an index that expresses a cow's capacity to give birth regularly at a young age and to wean animals of greater body weight. Using data from cattle participating in the "Program for Genetic Improvement of the Nelore Breed" (PMGRN - Nelore Brasil), bi-trait analyses were performed using the Restricted Maximum Likelihood method based on an ACP animal model and the following traits: age at first calving (AFC), female body weight adjusted for 365 (BW365) and 450 (BW450) days of age, and male scrotal circumference adjusted for 365 (SC365), 450 (SC450), 550 (SC550) and 730 (SC730) days of age. Median estimated ACP heritability was 0.19 and the genetic correlations with AFC, BW365, BW450, SC365, SC450, SC550 and SC730 were 0.33, 0.70, 0.65, 0.08, 0.07, 0.12 and 0.16, respectively. ACP increased and AFC decreased over time, revealing that the selection criteria genetically improved these traits. Selection based on ACP appears to favor the heaviest females at 365 and 450 days of age who showed better reproductive performance as regards AFC. Scrotal circumference was not genetically associated with ACP. (C) 2007 Elsevier B.V. All rights reserved.

Efeito de sementes oleaginosas inteiras e óleo de soja sobre a digestibilidade in vitro e os padrões ruminais de bezerros holandeses

Este trabalho foi realizado para comparar os efeitos da adição de sementes inteiras de soja e algodão e de óleo de soja sobre os padrões ruminais e a digestibilidade in vitro, em bezerros Holandeses fistulados. Dois bezerros fistulados no rúmen foram alimentados com dieta basal com 2,5% de extrato etéreo (EE), o qual foi comparado com dietas com 5,0% de EE, em que as sementes de soja e algodão inteira ou o óleo de soja foram fontes de EE adicional. A adição de sementes de soja e de algodão resultou em decréscimo na digestibilidade in vitro da matéria seca e da fibra em detergente neutro (FDN), porém não houve alterações na digestibilidade in vitro da fibra em detergente ácido (FDA) em relação à dieta controle. A adição de semente algodão provocou decréscimo na digestibilidade in vitro da proteína bruta em comparação à dieta controle. A concentração de ácido propiônico nas dietas com adição de óleo de soja foi 16% mais elevada que a proporcionada pelas demais dietas. O uso de óleo de soja pareceu ser a mais adequada em relação à digestibilidade da matéria seca, FDA e FDN e à manutenção de pH, quando comparado a outros tipos de adição lipídica, porém menos eficiente que a semente de soja em relação à digestibilidade in vitro da proteína bruta. O número de protozoários apresentou grande variação entre dietas, mas nenhum efeito com adição de óleo foi observado. A maior concentração de N-NH3 ruminal foi obtida na dieta com óleo de soja, quando comparada às outras dietas.