Successful lactation induction in non-pregnant gilts.

A protocol to induce lactation was applied to non-pregnant gilts. In Experiment I, five gilts with oestrus synchronized through oral supplementation of 20 mg altrenogest for 18 days received: 10 mg oestradiol cypionate (EC) on the last day of oestrous expression (D0); 10 mg EC and 300 mg long-acting progesterone (P4) on D26; and two 0.53 mg doses of a prostaglandin F2α analogue (PGF) 12 h apart on D36. Blood was collected on D12, D19, D26 and D33. Milk secretion started in all gilts 24 h after PGF administration and lasted at least 8 days. Milk samples were collected from D37 to D45. The serum P4 concentration was lower on D12 than subsequently (p < .05), but the oestradiol concentration was unaltered (p > .05). The milk produced during the induced lactation was generally richer in protein and poorer in fat compared to the milk from the lactation of a reference sow. In Experiment II, the same protocol induced lactation in two gilts, which nursed fostered piglets for 22 days. Thus, lactation was induced in all treated gilts and the milk produced was capable to nurture fostered piglets.

A rare case of heteropaternal twin calves after natural mating in Brazil.

Twin birth is a complex condition observed in most livestock animals, when the female gives birth to two or more offspring, generally out of the same mating. In cattle, it is a rare condition (3 to 5%) and depends on the genetic background and environmental factors. Twin birth is a result of multiple ovulations, being more common in dairy rather than in beef cattle. Calves could be monozygous or dizygous, with the same or of different sexes. When twins are born with different sexes, a sexual condition called Freemartinism occurs in between 90 to 97% of pregnancies, causing infertility in the female calf. Knowing that the twin rate is rare in commercial beef cattle, here we present an even rarer case of twin birth from two different sires after natural mating, also called heteropaternal superfecundation.

Chemoprophylaxis for babesiosis and anaplasmosis in cattle: case report.

Cattle tick fever (CTF) causes significant economic losses in the livestock sector. The pathogenic action of the hemoparasites is associated with anemia, weight loss, abortion and reduced productivity, which result with animal death. Programs to prevent CTF involve several procedures, including immunization, chemoprophylaxis and use of ectoparasiticides, together with the vector control in the environment. The objective of this study was to report an acute outbreak of CTF in a group of 157 Hereford cattle from a farm without presence of the vector, that were moved to a farm in the same state with a high tick infestation (Rhipicephalus microplus). On the day before the transportation, the animals received a chemoprophylaxis with imidocarb dipropionate (3 mg/kg, SC), which was repeated 21 days after the first application. After 42 days, some animals showed signs compatible with CTF, which was confirmed through clinical examination, necropsy, histopathological and hemoparasitological analyses. The morbidity rate was 37.6% and the mortality rate was 24.8%. Calves that were recently weaned were the group most affected with the tick fever, morbidity (100% and mortality (73%). Chemoprophylaxis in association with use of ectoparasiticides was not sufficient to control the outbreak of the disease.

Study of vaginal microbiota of Holstein cows submitted to an estrus synchronization protocol with the use of intravaginal progesterone device.

The characterization of vaginal microbiota will help to understand some of the reproductive problems and mechanisms to improve cattle reproduction. The objective of this study was to characterize the vaginal microbiota of cyclical Holstein cows with different parturition orders using 16S rDNA sequencing. Animals were submitted to an estrus synchronization protocol with the use of intravaginal progesterone (P4) implants and were treated or not with ceftiofur hydrochloride. DNA samples were extracted from vaginal swabs on day 0 and 10 of the synchronization, and sequenced with the Illumina MiSeq platform with an average coverage rate of 10.000 reads per samples using a Single-End library for fragments of 300 bp. The main bacterial phyla found in the vaginal tract of Holstein cows, were Firmicutes (37.61%), Tenericutes (29.45%), Proteobacteria (17.47%) and Bacteriodetes (13.73%), followed by Actinobacteria (0.82%) and Spirochaetae (0.45%). The use of intravaginal P4 devices has increased the relative abundance of the genera Family XIII AD3011 and Family XIII unclassified (p < .049). We have also observed an effect of the number of calving on the vaginal microbiota composition, showing that multiparous cows have a greater bacterial diversity than primiparous animals (p < .05). The use of ceftiofur hydrochloride was effective to reduce the vaginal bacteria proliferation. This study describes for the first time the vaginal microbiota of cows synchronized with intravaginal progesterone devices, different from the traditional methods such as microbiological culture and biochemical tests. We have identified a large number of microorganisms commonly found in the gastrointestinal tract of cows, colonizing the vaginal microbiota.

Chemoprophylaxis for babesiosis and anaplasmosis in cattle: case report / Quimioprofilaxia para babesiose e anaplasmose em bovinos: relato de caso

Abstract Cattle tick fever (CTF) causes significant economic losses in the livestock sector. The pathogenic action of the hemoparasites is associated with anemia, weight loss, abortion and reduced productivity, which result with animal death. Programs to prevent CTF involve several procedures, including immunization, chemoprophylaxis and use of ectoparasiticides, together with the vector control in the environment. The objective of this study was to report an acute outbreak of CTF in a group of 157 Hereford cattle from a farm without presence of the vector, that were moved to a farm in the same state with a high tick infestation (Rhipicephalus microplus). On the day before the transportation, the animals received a chemoprophylaxis with imidocarb dipropionate (3 mg/kg, SC), which was repeated 21 days after the first application. After 42 days, some animals showed signs compatible with CTF, which was confirmed through clinical examination, necropsy, histopathological and hemoparasitological analyses. The morbidity rate was 37.6% and the mortality rate was 24.8%. Calves that were recently weaned were the group most affected with the tick fever, morbidity (100% and mortality (73%). Chemoprophylaxis in association with use of ectoparasiticides was not sufficient to control the outbreak of the disease.

Resumo A "tristeza parasitária bovina" (TPB) gera importantes perdas econômicas na bovinocultura mundial. A ação patogênica dos hemoparasitas resulta em anemia, perda de peso, abortos e diminuição da produtividade, culminando, muitas vezes, em óbito dos animais. Um programa de prevenção para TPB necessita de medidas integradas, como a imunização, quimioprofilaxia e utilização de ectoparasiticidas, em conjunto com ações que visem ao controle ambiental dos vetores. Este artigo tem em vista o relato de um surto de TPB em uma fazenda de produção de bovinos de corte e com alta infestação do carrapato (Rhipicephalus microplus). A fazenda adquiriu 157 animais puros de origem, da raça Hereford, proveniente de uma fazenda sem presença do vetor. No dia anterior ao transporte, os animais receberam quimioprofilaxia com dipropionato de imidocarb (3mg/Kg/SC), repetindo-se 21 dias após a primeira aplicação. Aos 42 dias, alguns bezerros manifestaram sinais clínicos compatíveis com TPB, sendo confirmado pelo exame clínico, necropsia, análises histopatológicas e hemoparasitológicas. A morbidade foi de 37,6% (59/157), e a letalidade de 24,8% (39/157). A categoria de bezerros recém desmamados foi a mais acometida, com morbidade de 100% (52/52) e letalidade de 73% (38/52). A quimioprofilaxia associada à utilização de ectoparasiticidas foram insuficientes para evitar a ocorrência do surto da enfermidade.

Effects of different concentrations of sodium azide and chloramphenicol on the preservation of raw milk samples / Efeitos de diferentes concentrações de azida sódica e cloranfenicol na preservação de amostras de leite cru

ABSTRACT: The preservation of milk samples for microbiological analyses by the Brazilian Network of Milk Quality Control Laboratories requires the addition of preservatives to maintain the microbiota from the time of sample collection to the moment of analysis. The number of microorganisms can change as a result of the active ingredients and concentration of the preservative, as well as due to interactions between the preservatives, incubation time, and packaging temperature. The objective of this research was to evaluate the conservation potential of different concentrations of sodium azide and chloramphenicol on the analytical shelf life of milk samples. Two farms were selected, one with a low bacterial count and one with a high bacterial count. The milk was dispensed into sterile vials and tested after the addition of the usual concentrations of sodium azide and chloramphenicol, doubled concentrations, tripled concentrations, and as a control, without preservatives. The samples were incubated at 3 ± 1 °C, 6 ± 1 °C, and 9 ± 1 °C for 14 days and analyzed daily for their bacterial count by flow cytometry. The tripled preservative concentrations improved conservation, increasing the timespan of the analytical viability of the samples without altering the results.

RESUMO: A conservação das amostras de leite destinadas para análises microbiológicas pela Rede Brasileira de Laboratórios de Controle da Qualidade do Leite requer adição de conservantes para a preservação da microbiota existente desde o momento da coleta até as análises. O número de microrganismos pode apresentar alterações decorrentes do princípio ativo e concentração do conservante, e ainda entre as interações conservante, tempo de incubação e temperatura de acondicionamento. O objetivo deste trabalho foi avaliar o potencial de conservação de diferentes concentrações de azida sódica e cloranfenicol sobre a vida útil analítica de amostras de leite. Foram selecionadas duas fazendas, sendo uma com baixa contagem bacteriana e outra com alta contagem bacteriana. O leite foi fracionado em frascos estéreis e testado nas seguintes condições: pastilhas com a concentração usual de azida sódica e cloranfenicol, com dupla concentração, com tripla concentração e sem a adição do conservante. As amostras foram incubadas por quatorze dias a 3 ± 1 °C, 6 ± 1 °C e 9 ± 1 °C, e analisadas diariamente por citometria de fluxo para a determinação da contagem bacteriana. A tripla concentração do conservante demonstrou maior conservação, possibilitando o aumento da viabilidade analítica das amostras sem alteração nos resultados.

Variation of cow's milk composition across different daily milking sessions and feasibility of using a composite sampling / Variação da composição do leite de vaca em diferentes turnos diários de ordenha e viabilidade de usar uma amostragem composta

ABSTRACT: This study vised to detect possible changes in chemical and cellular composition of cow's milk at different milking sessions and to test if proportional or composite milk sampling can be used instead of separate milk analysis. Two experiments were conducted: one in cows milked thrice daily and the other one in cows milked twice daily. In both experiments, three milk samples were collected from each cow in each milking session in order to determine milk composition at each milking; to have a composite sample, i.e., a single sample from the same aliquots of milk from each milking session; and to have a proportional sample, i.e., a single sample from each milking session in a volume proportional to milk volume yielded. Fat content and fat to protein ratio were higher in the afternoon on both experiments. Protein content was larger in the afternoon on cows milked twice daily, but not on cows milked thrice daily. Lactose level was not different across the milking sessions in any of the experiments. The urea level was higher in the afternoon and evening milking on cows milked thrice daily, and in the morning milking on cows milked twice daily. Somatic cell count did not differ between milking in any experiment. No difference in milk composition was noted between proportional and composite samples on cows milked thrice or twice daily. The collection of proportional and composite samples is recommended in twice or thrice daily milking sessions so that the analysis of milk components becomes more easy and cheap.

RESUMO: Este estudo visou detectar possíveis mudanças na composição química e celular do leite de vaca em diferentes sessões de ordenha, e testar se a amostragem de leite proporcional ou composta pode ser usada em vez de uma análise separada do leite. Dois experimentos foram conduzidos: um em vacas ordenhadas três vezes ao dia e outro em vacas ordenhadas duas vezes ao dia. Em ambos os experimentos, três amostras de leite foram coletadas de cada vaca em cada ordenha: para determinar a composição do leite em cada ordenha; ter uma amostra composta, isto é, uma única amostra das mesmas alíquotas de leite de cada sessão de ordenha; e ter uma amostra proporcional, ou seja, uma única amostra de cada sessão de ordenha em um volume proporcional ao volume de leite produzido. O conteúdo de gordura e a relação gordura:proteína foram maiores no período da tarde nos dois experimentos. O conteúdo de proteína foi maior à tarde nas vacas ordenhadas duas vezes ao dia, mas não nas vacas ordenhadas três vezes ao dia. O nível de lactose não foi diferente nas sessões de ordenha em nenhum dos experimentos. O nível de ureia foi maior à tarde e à noite, nas vacas ordenhadas três vezes ao dia e, pela manhã, nas vacas ordenhadas duas vezes ao dia. A contagem de células somáticas não diferiu entre as ordenhas em nenhum experimento. Não houve diferença na composição do leite entre as amostras proporcionais e compostas em vacas ordenhadas três vezes ao dia. Recomenda-se a coleta de amostras proporcionais e compostas em duas ou três sessões diárias de ordenha, para que a análise dos componentes do leite se torne mais fácil e barata.

Milk composition of Holstein cows: a retrospective study / Caracterização da composição do leite de vacas Holandesas: estudo retrospectivo

ABSTRACT: Worldwide, milk analysis is an satisfactory measurement of milk quality on dairy farms. Milk composition is the base for payment systems, so knowledge of its characteristics at different periods is essential for modern dairy producer. The aim of the study was to evaluate the effects of year, season, stage of lactation, and lactation number on variations in milk yield and composition of Holstein cows (n=148,604). Milk yield estimated by multiple regression was 25,50L/cow/day. Winter was the season with the highest milk yield and the highest protein and lactose content. Milk fat was highest in the fall, in cows in late lactation and also in primiparous cows. Lactating cows from 6 to 60 days in lactation and those in 2nd or 3rd lactation showed the highest milk yield. Lactose concentration was positively correlated with milk yield. Somatic cell score was negatively correlated with milk yield and with lactose concentration. Most important variations in milk characteristics occur among seasons, lactation stages and parities. Mammary gland health is yet the greatest challenge to be overcome.

RESUMO: A determinação da qualidade do leite nas fazendas é um parâmetro mundialmente aceito e utilizado como base para os sistemas de pagamento. Os produtores modernos utilizam o conhecimento das características do leite para adotar medidas que visam melhorar produtividade e qualidade. O objetivo do estudo foi avaliar os efeitos do ano, estação, estágio de lactação e número de lactação sobre as variáveis produção e composição do leite de vacas Holandesas (n=148,604). A produção de leite estimada por regressão múltipla foi de 25,50L/vaca/dia. O inverno foi à estação com a maior produtividade e os maiores teores de proteína e lactose. A gordura de leite foi maior no outono em vacas primíparas e no final da lactação. As vacas com estágio de lactação entre 6 a 60 dias e aquelas que se encontram na segunda ou terceira lactação apresentaram a maior produtividade. A concentração de lactose correlacionou-se positivamente com a produção de leite. O escore das células somáticas correlacionou-se negativamente com a produtividade e com a concentração de lactose. As variações mais importantes nas características do leite ocorrem entre estações, estágios de lactação e número de partos. A saúde da glândula mamária ainda é o maior desafio a superar.

Random regression models using different functions to estimate genetic parameters for milk production in Holstein Friesians / Modelos de regressão aleatória usando diferentes funções para estimar parâmetros genéticos para produção de leite na raça Holandesa

ABSTRACT: The objective of this study was to compare the functions of Wilmink and Ali and Schaeffer with Legendre polynomials in random regression models using heterogeneous residual variances for modeling genetic parameters during the first lactation in the Holstein Friesian breed. Five thousand eight hundred and eighty biweekly records of test-day milk production were used. The models included the fixed effects of group of contemporaries and cow age at calving as covariable. Statistical criteria indicated that the WF.33_HE2, LEG.33_HE2, and LEG.55_HE4 functions best described the changes in the variances that occur throughout lactation. Heritability estimates using WF.33_HE2 and LEG.33_HE2 models were similar, ranging from 0.31 to 0.50. The LEG.55_HE4 model diverged from these models, with higher estimates at the beginning of lactation and lower estimates after the 16th fortnight. The LEG55_HE4, among the three better models indicated by the index, is the one with highest number of parameters (14 vs 34) and resulted in lower estimation of residual variance at the beginning and at the end of lactation, but overestimated heritability in the first fortnight and presented a greater difficulty to model genetic and permanent environment correlations among controls. Random regression models that used the Wilmink and Legendre polynomials functions with two residual variance classes appropriately described the genetic variation during lactation of Holstein Friesians reared in Rio Grande do Sul.

RESUMO: Objetivou-se comparar as funções de Wilmink e Ali e Schaeffer com polinômios de Legendre em modelos de regressão aleatória, utilizando variâncias residuais heterogêneas, para modelar parâmetros genéticos ao longo da primeira lactação na raça Holandesa. Foram utilizados cinco mil oitocentos e oitenta registros quinzenais de produção de leite no dia do controle. Os modelos incluíram os efeitos fixos de grupo de contemporâneos e a idade da vaca ao parto como covariável. Os critérios estatísticos apontaram as funções WF.33_HE2, LEG.33_HE2 e a LEG.55_HE4 como as melhores em descrever as mudanças nas variâncias que ocorrem ao longo da lactação. As herdabilidades estimadas pelos modelos WF.33_HE2 e LEG.33_HE2 foram semelhantes, variando de 0,31 a 0,50. O LEG.55_HE4 divergiu destes, no início da lactação, com estimativas superiores e, a partir da 16ª quinzena, com estimativas inferiores. O LEG55_HE4, entre os três melhores modelos indicados pelo índice, é o mais parametrizado (14 vs 34) e resultou em menores estimativas de variância residual no início e no final da lactação, mas superestimou a herdabilidade na primeira quinzena e apresentou maior dificuldade em modelar as correlações genéticas e de ambiente permanente entre os controles. Os modelos de regressão aleatória que usaram a função de Wilmink e Polinômios de Legendre com duas classes de variâncias residuais descreveram adequadamente a variação genética ao longo da lactação de vacas da raça Holandesa, criadas no Rio Grande do Sul.

Milk production and percentages of fat and protein in Holstein breed cows raised in Rio Grande do Sul, Brazil / Produção de leite e porcentagens de gordura e proteína de bovinos da raça Holandesa criados no Rio Grande do Sul, Brasil

ABSTRACT: The objective of this study was to identify a nonlinear regression model that better describes the milk production and the percentages of fat and protein curves, and to identify the season and age of calving that result in higher productions. For the analysis, 8,047 records of milk production and percentages of fat and protein obtained from 1,330 Holstein breed cows raised in Rio Grande do Sul, born from 1989 to 2011, were used. After determining the most appropriate nonlinear regression model, the identity of models and the equality of parameter tests for the different classes of season and age of calving were performed. Residual mean square, mean absolute deviation, mean squared prediction error and percentage of estimated curves per animal, indicated the Linear Hyperbolic Function (LHF) as the most appropriate to describe the milk production and the levels of fat and protein curves. Cows calving in the autumn and winter seasons yield higher quantities of milk and lower fat and protein content than those calved in the spring and summer seasons. Cows aged between 46 and 93 months at calving yield higher milk quantities, and those with calving age between 94 and 118 months produced more fat.

RESUMO: Objetivou-se identificar o modelo de regressão não linear que melhor descreve as curvas de produção de leite e de porcentagens de gordura e proteína; a estação e idade ao parto que resultam em maiores produções. Nas análises, foram utilizados 8047 registros de produção de leite e porcentagens de gordura e proteína provenientes de 1330 vacas da raça Holandesa, criadas no Rio Grande do Sul, nascidas de 1989 a 2011. Após a definição do modelo de regressão não linear mais adequado, procedeu-se à realização do teste de identidade de modelos e de igualdade de parâmetros para as diferentes classes de estação e idade da vaca ao parto. O quadrado médio do resíduo, desvio médio absoluto, erro quadrático médio de predição e a porcentagem de curvas estimadas por animal apontaram a Função Linear Hiperbólica (FLH) como a mais adequada para descrever as curvas de produção de leite e teores de gordura e proteína. Vacas com ocorrência de partos nas estações de outono e inverno produzem maior quantidade de leite e menor teor de gordura e proteína do leite do que aquelas que parem nas estações de primavera e verão. Vacas com idades ao parto entre 46 e 93 meses produzem maior quantidade de leite e as com 94 a 118 meses, maior teor de gordura do leite.

Parâmetros genéticos para produção de leite no dia do controle de vacas da raça Holandesa utilizando modelos de análises de fatores e componentes principais / Genetic parameters for test day milk production of Holstein cows using factors and principal components analysis

Objetivou-se comparar um modelo multi-característica padrão com modelos de análise de fatores (AF) e de componentes principais (CP) para estimar parâmetros genéticos para a produção de leite no dia do controle (PLDC) de vacas da raça Holandesa. O arquivo de trabalho constituiu-se de 4.616 registros mensais de PLDC de primeiras lactações de vacas da raça Holandesa. As PLDC foram agrupadas em dez classes mensais, entre o 5o e 305o dia da lactação (PLDC1 a PLDC10). Foram realizadas análises considerando 11 modelos diferentes, como segue: multi-característica padrão (MC); cinco modelos de posto reduzido, para a matriz de covariância genética, ajustando um a cinco (CP1 ... CP5) componentes principais; e dois modelos utilizando análise de fatores (F1, F2, F3, F4 e F5). Para todos os modelos, foram considerados como aleatórios os efeitos genético aditivo e o residual e como fixos os de grupo de contemporâneos, da idade da vaca ao parto (linear e quadrático) e dias em lactação (linear). Os valores de Log L, AIC e BIC melhoraram com o aumento do número de parâmetros até CP4 e AF4. Comparando CP4 e AF4, observa-se que CP4 resultou em melhores valores de Log L, AIC e BIC. As estimativas de herdabilidade e correlações genéticas utilizando os modelos MC, CP4 e AF4 foram similares, variando de 0,06 (PL6) a 0,65 (PL10) e de 0,05 (PL4xPL10) a 0,94 (PL2xPL3), respectivamente, indicando que a estrutura de covariâncias genéticas entre as produções de leite no dia do controle pode ser ajustada utilizando um modelo de posto reduzido, contendo quatro componentes principais ou quatro fatores.

The objective was to compare a standard multi-trait (MT) analysis model with factor (FA) and principal components (PC) analyses models to estimated genetic parameters for Holstein cows test day milk production (TD). The data file was composed by 4.616 TD at first lactation registers. The TD was grouped into ten monthly classes of lactation, from the 5th and the 305th day of lactation (TD1 to TD10). Analyses were performed considering 11 different models: standard multi-traits (MT), five reduced rank models to genetic covariance matrix adjusting one (PC1), two (PC2), three (PC3), four (PC4) and five (PD5) principal components and five models using factor analyses (F1, F2, F3, F4 and F5). To all the models the effects additive genetic and residual were considered as random and the effects of contemporary group, age of cow at parturition (linear and quadratic) and days in lactation (linear) were considered as fixed. The values of Log L, AIC e BIC improved with the augment of the number of parameters until CP4 and AF4. Comparing CP4 and AF4 is possible to verify that CP4 proportioned better values to Log L, AIC e BIC. The heritabilities and genetic correlations estimated to the ten test day milk production using MC, CP4 and AF4 models were similar ranging from 0.06 (PL6) to 0.65 (PL10) and from 0.05 (PL4xPL10) to 0.94 (PL2xPL3), respectively, indicating that the structure of the genetic covariance between the TD milk productions can be adjusted using a reduced rank model with four principal components or four factors.

Perfil proteico e metabolismo oxidativo de cordeiros experimentalmente infectados pelo Haemonchus contortus e suplementados com selênio e vitamina E / Protein Profile and oxidative metabolism of lambs experimentally infected with Haemonchus contortus and supplemented with selenium and vitamin E

Para avaliar a influência da suplementação com selênio e vitamina E sobre o perfil proteico e metabolismo oxidativo de cordeiros infectados experimentalmente pelo Haemonchus contortus, trinta cordeiros fêmeas foram distribuídos em quatro grupos: G1 (n=10): animais infectados; G2 (n=10): infectados e suplementados; G3 (n=5): controle; e G4 (n=5): não infectados e suplementados. Os grupos 1 e 2 receberam 500 larvas de H. contortus (L3), via oral, por um período de 20 dias, com intervalo de dois dias entre as doses. A suplementação nos grupos 2 e 4 foi realizada no dia zero, com 0,1mg kg-1 de Selenito de sódio (1,67 por cento) e com 2.000UI de vitamina E por via intramuscular (IM). Somente a vitamina E foi reaplicada no dia 30. As coletas de sangue para determinação do perfil proteico (proteína total, albumina, alfa, beta e gamaglobulina) e metabolismo oxidativo (espécies reativas ao ácido tiobarbitúrico-TBARS e a enzima glutationa peroxidase (GSPX) foram realizadas nos dias zero, 20, 30, 45, 60 e 80. OPG foi quantificado nos dias 0, 20 ,45 e 80. Em relação aos valores de proteínas totais, albumina, betaglobulina e gamaglobulina, as principais diferenças foram observadas quando os grupos parasitados foram comparados com o grupo somente suplementado; e este manteve valores mais elevados. Conclui-se que não há influência da suplementação com selênio e vitamina E no perfil proteico e metabolismo oxidativo quando os cordeiros se encontram severamente parasitados por H.contortus.

The objective of the present study was to describe the influence of supplementation with selenium and vitamin E on the protein and oxidative profiles of lambs experimentally infected with Haemonchus contortus. Thirty female lambs were divided into four groups as follows: G1 (n=10): infected animals; G2 (n=10): infected and supplemented; G3 (n=5): control; G4 (n=5): non-infected and supplemented. Groups 1 and 2 received 500 H. contortus larvae (L3) orally for a period of 20 days, with 2-day intervals between doses. Supplementation in groups 2 and 4 was performed on day zero by injecting 0.1mg kg-1 of sodium selenite solution (1.67 percent) and 2,000IU vitamin E through the intramuscular (IM) route. Vitamin E alone was injected once again on day thirty. The blood samples to determine the protein profile (total protein, albumin, alpha, beta and gamma) and oxidative metabolism (species reactive to thiobarbituric acid and glutathione peroxidase (GSPX) were performed on days zero, 20, 30, 45, 60 and 80. The OPG was quantified on days 0, 20, 45 and 80. Regarding the values of total proteins, albumin, beta and gamma globulins, the main differences were observed when the parasitized groups were compared to the supplemented, non-infected group, the latter exhibiting higher values. It is concluded that there is no influence of supplementation with vitamin E and selenium in the protein profile and oxidative metabolism when the lambs are severely parasitized with H. contortus.

Qualidade seminal e histomorfometria dos órgãos reprodutivos de ovinos tratados com fluoreto de sódio / Seminal quality and reproductive histomorphometry of ram lambs treated with sodium fluoride

O presente estudo objetivou avaliar as características espermáticas, os indicadores do metabolismo oxidativo do sêmen, o diâmetro dos túbulos seminíferos e a altura do epitélio testicular, do epididimário e do canal deferente de ovinos tratados com fluoreto de sódio. Foram utilizados 12 ovinos, com idade aproximada de cinco meses. Os animais foram divididos em grupo controle, o qual recebeu diariamente sal iodado (5g de NaCl animal-1 + 0,2mg I kg-1 matéria seca), e tratado, que recebeu sal iodado adicionado de fluoreto de sódio (4,7mg F kg-1 de peso corporal). Aos 150 dias de tratamento, foram realizadas coletas de sêmen e, em seguida, os animais foram eutanasiados. Na comparação entre o grupo controle e o tratado, não foram observadas diferenças no percentual de motilidade, vivos : mortos e morfologia espermática, na concentração da glutationa reduzida seminal, no teor de zinco seminal, no peso testicular, na morfometria e na histologia do testículo, na cauda do epidídimo e no canal deferente. A concentração de substâncias reativas ao ácido tiobarbitúrico (TBARs) e o teor de cobre no sêmen foram menores (P<0,05) no grupo tratado. Conclui-se que a administração crônica de flúor para ovinos jovens não afeta a capacidade reprodutiva de uma forma geral. Entretanto, os dados sugerem que o flúor pode reduzir a lipoperoxidação e os teores de cobre que são essenciais para a capacitação espermática e a fertilização.

The objective of the present study was to evaluate different reproductive parameters of ram lambs treated with sodium fluoride. Spermogram, indicators of seminal oxidative profile, seminiferous tubules diameter and cell height of the testicular epithelium, epididimus and vas deferens were analyzed. Twelve 5-month-old ram lambs were used. They were allocated into one of two experimental groups: The control, which received daily iodized salt (5g NaCl animal-1 + 0.2mg I kg-1 DM); and the treated, which received (5g NaCl animal-1 + 0.2mg I kg-1 DM + 4.7mg F kg-1 BW). After 150 days of treatment, animals went through a complete andrological exam, and were euthanized on the next day. No differences were observed in sperm motility, dead: alive ratio and morphology between the control and treated group. Also, seminal concentration of reduced glutathione and zinc, as well as, testicular weight, histology and morphometry of testicles, caudal portion of epididimus and vas deferens did not differ between groups. The seminal concentration of thiobarbituric acid reactive substances (TBARs) and seminal copper levels were lower (P<0.05) in the treated group. We conclude that chronic fluoride administration to lambs does not affect reproductive capacity as a whole. However, the data suggest that fluoride can induce a reduction in seminal lipoperoxidation and copper levels with are essential for sperm capacitation and fertilization.

[Ovine abortion associated with toxoplasmosis: serological, anatomo-pathological and immunohistochemistry characterization]. / Aborto em ovinos associado à toxoplasmose: caracterização sorológica, anátomo-patológica e imunoistoquímica.

Ovine toxoplasmosis is a major cause of abortion and placentitis. Lambs with congenital infection are born with encephalitis. Abortions occurred between May and August 2006 in an estate in Três Palmeiras, southern Brazil. This study aimed to assess the frequency of abortion associated with toxoplasmosis among ewes in southern Brazil using indirect hemagglutination and pathoanatomical and immunohistochemical analyses. Blood samples were collected from nine animals for indirect hemagglutination. One fetus underwent necropsy and histopathological and immunohistochemical analyses. Three samples, one of which belonged to the necropsied animals mother, were positive on the serological test. The necropsy revealed pale foci in the liver, lungs with a marbled appearance, heart with severe pallor and brain and cerebellar congestion. Fragments of all organs were collected, fixed in 10% buffered formalin, processed, and stained with hematoxylin-eosin. Microscopically, there were cysts and tachyzoites in the brain in areas of malacia with microgliosis and lymphoplasmacytic infiltration, suggesting toxoplasmic encephalitis. There was also interstitial pneumonia, centrolobular necrosis with structures compatible with tachyzoites, focal lymphocytic myocarditis and acute tubular nephrosis. The immunohistochemical test was positive for Toxoplasma gondii. The results allowed diagnosing the ovine toxoplasmosis.

Dextran iron in anemic lambs: effects on reticulocytosis and free radical production

Anemia due to worm infection is a major cause of loss in the sheep industry, due to deaths, drop in average daily gains and long recovery time following treatment. The present experiment was aimed at evaluating the oxidative status and the recovery of red blood cell (RBC) profile in lambs with induced anemia by bleeding, treated or not with dextran iron. Ten ram lambs 5 to 7 months old were used. Blood samples were drawn every other day and when reached packed cell volume (PCV) of 15 percent were randomly allocated (day zero) to one of the experimental groups. Treated group received a single dose of 25mg per kg body weight of a commercial formulation of dextran iron, the control group received no treatment. Blood samples were taken on days 0, 7, 14, and 21 after treatment. On days 7 an 21 treated animals presented higher thyobarbituric acid reactive species (TBARS) values, reduced non-protein thiol groups (NPTH) levels were found in the treated group on days 7, 14 and 21. Erythrocyte membrane resistance to osmotic challenge was improved on day 7 in treated animals. Recovery to normal values for the RBC profile was faster in the treated group with significant differences starting on day 7. It was conclude that althouth the iron treatment increased the oxidative stress, it also accelerated recovery of the hematological profile. Moreover, it did not increase hemolysis in anemic blood by the action of oxygen reactive species upon biological membranes.

A anemia verminótica é a principal causa de perdas na ovinocultura, incluindo diminuição no ganho médio diário, demora no tempo de recuperação pós-tratamento e óbito. O objetivo deste trabalho foi avaliar o status oxidativo e a recuperação do quadro hematológico de cordeiros com anemia induzida por flebotomia e suplementados ou não com ferro dextrano. Foram utilizados dez cordeiros machos entre cinco e sete meses de idade. O dia zero do experimento foi considerado quando cada animal atingiu o hematócrito 15 por cento após a indução da anemia, sendo alocado em um dos grupos experimentais. O grupo tratado recebeu uma dose única de 25mg-1 kg-1 de peso vivo de uma formulação comercial de ferro dextrano intramuscular e o grupo controle não foi tratado. As coletas de sangue foram feitas nos dias zero, 7, 14 e 21 pós-tratamento. Nos dias sete e 21, os animais do grupo tratado tiveram aumento nos valores de espécies reativas ao ácido tiobarbitúrico (TBARS) e diminuição nos valores dos grupamentos tióis não-protéicos (NPTH) nos dias 7, 14 e 21. No dia sete, o teste de fragilidade osmótica eritrocitária indicou um aumento na resistência da membrana dos eritrócitos dos animais do grupo tratado quando comparado aos animais do grupo controle. A recuperação da série vermelha do sangue (número de eritrócitos, hematócrito e hemoglobina) foi mais rápida no grupo tratado. A suplementação de ferro, apesar de aumentar o estresse oxidativo, acelerou a recuperação do quadro hemático, não aumentando a porcentagem de hemólise pela ação das espécies reativas de oxigênio sobre a membrana eritrocitária.

Oxidative stress in the erythrocytes of cattle intoxicated with Senecio sp.

BACKGROUND: Intoxication caused by Senecio sp is characterized by irreversible damage to liver cells and may be associated with oxidative stress. OBJECTIVES: The aim of this study was to evaluate the effects of intoxication by Senecio sp on lipoperoxidation, antioxidant defenses, and the osmotic resistance of erythrocytes in cattle. METHODS: Blood samples from 30 intoxicated animals (group 1) and 30 healthy animals (group 2) were analyzed. The diagnosis of poisoning by Senecio sp was based on histopathologic lesions verified through hepatic biopsy. The following biochemical parameters of oxidative stress in the erythrocytes were determined: thiobarbituric acid-reactive substances (TBARS), copper-zinc superoxide dismutase (CuZnSOD) activity, and nonprotein sulfhydryl (NPSH) groups. Erythrocyte osmotic fragility also was evaluated. RESULTS: TBARS concentration and CuZnSOD activity were significantly (P <.001) higher in group 1 when compared with group 2. The concentration of erythrocyte NPSH groups was significantly (P <.03) lower in group 1 when compared with group 2. Osmotic fragility was more pronounced in the erythrocytes of group 1 when compared with group 2 (P < .001). CONCLUSIONS: The results of this study indicate that poisoning by Senecio sp causes an increase in lipoperoxidation, oxidation of NPSH groups, and consequently, oxidative stress in bovine erythrocytes that may contribute to hemolysis. These findings may contribute to a better understanding of the mechanisms involved in cell damage in animals intoxicated by Senecio sp.