Occurrence and risk factors associated with gastrointestinal parasitism in horses reared in different systems.

To facilitate exploration of the immense range of gastrointestinal parasites in horses and the impact of parasitism on equine health, the present study aimed to evaluate the occurrence and risk factors associated with these infections in horses reared in different management systems in the state of Santa Catarina, Brazil. Samples were collected from 208 horses: 91 from extensive, 64 from semi-extensive, and 53 from intensive rearing systems. The identified helminths included those of the Strongylida order (80.29%), Parascaris equorum (3.36%), Oxyuris equi (4.33%), and Anoplocephala spp. (1.92%). By analyzing the coproculture results to differentiate among Strongylida order parasites, species such as Strongylus vulgaris, S. edentatus, S. equinus, Triodontophorus spp., and Trichostrongylus axei, in addition to members of the Cyathostominae subfamily, which include Gyalocephalus capitatus and Poteriostomum spp., were identified. The only positive sample of protozoa was that of Cryptosporidium spp. (13%). Regarding the rearing system, animals in the extensive system had a higher proportion of infected horses and a higher chance of infection than those in the other systems. For the variable co-grazing with cattle, only cyathostomins showed a significant difference with relatively low infection risk in co-grazing. Overall, the present study demonstrated a high occurrence of equine gastrointestinal parasites, especially those of the Strongylida order, with emphasis on small strongylids. In addition, analyzing factors associated with infection showed that management variables are important for controlling parasitism in horses.

Effect of Prepartum Maternal Supplementation with Diphenyl Diselenide on Biochemical, Immunological, and Oxidative Parameters of the Offspring.

This study aimed to assess the impact of prepartum maternal diphenyl diselenide (PhSe)2 supplementation on the development, biochemical, immune, and antioxidant parameters of calves. Eighteen Holstein breed calves were used, born to females who were or were not subjected to supplementation, at 42, 28, and 14 days prior to calving. The (PhSe)2 group (DDG) was administered 3 µmol/kg of (PhSe)2 in 4 mL of dimethyl sulfoxide (DMSO), while the DMSO and NaCl groups were administered 4 mL of DMSO and 0.9% NaCl, subcutaneously. The calves were evaluated based on their weight, withers height, body condition score 24 h post-birth (0), as well on days 14, 28, 42, 56, 70. Blood samples were also taken to determine serum variables. Calves on the DDG showed higher average levels of total protein, albumin, and globulins on day 0, and the immunoglobulin G level was significantly higher than the other groups on days 0, 14, 56, 70. Maternal supplementation showed immunomodulatory effect on calves, evidenced by the exceptional rates of passive immunity transfer, as well as the enhancement of humoral immunity. Our research offers fresh insights into the immunomodulatory potential of (PhSe)2, making it a viable alternative in facing this challenging phase, rearing dairy calves.

Effect of a phytogenic feed additives mixture on milk physico-chemical properties and biochemical parameters of Holstein cows / Efeito de uma mistura de aditivos fitogênicos alimentares nas propriedades físico-químicas do leite e parâmetros bioquímicos de vacas leiteiras da raça holandês

ABSTRACT: This study aimed to analyze the effect of phytogenic additives based on cardol, cardanol, and ricinoleic acid on the physico-chemical qualities and biochemical parameters of Holstein cow milk. Nineteen animals were divided into the control (GI) and treatment (GII) groups. Prior to the beginning of the experiment, sodium monensin was removed from the feed provided to the animals. This study consisted of two phases. In the first, animals from GI received the standard diet, without additives, while animals from GII received the standard diet supplemented with 10 g of phytogenic additives for 60 days. At the end of the first stage, the animals remained 30 days without receiving additives and in the second phase the groups were inverted, and the GII again received the phytogenic additive during the subsequent 60 days. Physical-chemical analyzes of milk were performed at moments 0, 15, 30, 45 and 60 days of the experiment and the blood parameters at times 0 and 60 days of the experiment were evaluated. There was no significant difference for the treatment x time interaction in any of the variables, but there was a trend between groups for the CCS parameter and there was a statistical difference for the protein, as well as for the AST. In this study it is observed that the addition of phytogenic additive modulating rumen fermentation based on cardol, cardanol and ricinoleic acid does not compromise, in general, the quality of milk, with positive results for some specific parameters such as protein content and aminotransferase.

RESUMO: Esse estudo teve por objetivo avaliar o efeito de um aditivo fitogênico a base de cardol, cardanol e ácido ricinoléico na qualidade físico-química do leite e perfil bioquímico de vacas da raça Holandês. Dezenove animais foram divididos em dois grupos: Grupo Controle (GI) e Grupo Tratado (GII). Previamente ao início do experimento, retirou-se a monensina sódica da ração fornecida aos animais. Este estudo consistiu de duas fases, sendo que na primeira fase, os animais do GI receberam a dieta padrão, sem aditivos, enquanto os animais do grupo GII receberam a ração padrão suplementada com 10 g dos aditivos fitogênicos durante 60 dias. Ao final da primeira etapa, os animais permaneceram 30 dias sem receber aditivos e na segunda fase os grupos foram invertidos, sendo que o GII novamente recebeu o aditivo fitogênico durante os 60 dias subsequentes. Foram realizadas análises físico-químicas do leite nos momentos 0, 15, 30, 45 e 60 dias do experimento e avaliados os parâmetros sanguíneos nos momentos 0 e 60 dias do experimento. Não se observou diferença significativa para a interação tratamento x tempo em nenhuma das variáveis, mas tendência entre grupos para o parâmetro de CCS, e houve diferença estatística para a proteína, assim como para a AST. Neste estudo observa-se que a adição de aditivo fitogênico modulador de fermentação ruminal a base de cardol, cardanol e ácido ricinoléico não compromete, de forma geral, a qualidade do leite, tendo resultados positivos para alguns parâmetros específicos como teor de proteína e aspartato aminotransferase.

Factors associated with the efficiency of acaricides on different populations of Rhipicephalus microplus / Fatores associados à eficiência de acaricidas sobre diferentes populações de Rhipicephalus microplus

Tick infestation causes major problems in cattle. Tick parasitism accounts for significant economic losses in many beef and dairy herds in the vast majority of the states in the Brazilian territory including the State of Santa Catarina in the southern region of the country. Tick resistance to several active principles occurs due to a number of factors including the indiscriminate, injudicious and inadequate use of tick insecticides. Considering the great importance of fighting off tick infestations in cattle, we evaluated the efficiency of 8 different topical active principles against the ixodid tick R. microplus and identified the main factors that contribute to the development of ticks that are resistant to acaricides in the farms and bovine herds studied. For such purpose, R. microplus telegionae were collected in 39 farms locates in different municipalities of the West of Santa Catarina, south Brazil. At the time of sample collection, information about the management, the history of the acar used in the herd, the number of annual applications of these pesticides, the frequency of acaricide rotation, and the frequency of technical monitoring for strategic tick control were retrieved. We collected this data in order determine contributing factors to the development resistant R. microplus populations. For the sensitivity profile of these ticks to a number of different acaricides tested, 10 engorged females for each principle and a control were used. The results of our study show that most associations between pyrethroids and organophosphates had an efficiency between 96.6% and 100% in the control of R. microplus except for the combination of Alfacipermetrine 15%, Ethion 16%, and Chlorpyrifos 8.5% that had 93.4% of efficiency. Among the chemicals not associated with any other type of compound, Amitraz 12.5% ​​was effective in 98.3% of the cases. In contrast, Cypermethrin 15% had an efficiency in only 25.8% of the farms/herds analyzed. Based on the results of the present study, we may infer that the methods of control and management used by producers may be related to the low indexes of resistance to topical acaricides in the different populations of ticks in the study area.

A infestação por carrapatos em bovinos gera grandes problemas, sendo esse parasito responsável por elevados prejuízos econômicos em diversos rebanhos de produção de corte e também de leite na maioria das regiões brasileiras, inclusive em Santa Catarina. A resistência dos carrapatos frente aos diversos princípios ativos pode ser decorrente de fatores como o uso indiscriminado de carrapaticidas, bem como a inadequada forma de aplicação dos mesmos. Tendo em vista a grande importância em combater essas infestações, buscou-se avaliar a eficiência de oito diferentes princípios ativos de contato contra o carrapato Rhipicephalus microplus, bem como identificar os principais fatores que possam contribuir com a seleção de carrapatos resistentes nas propriedades avaliadas. Para isso, teleóginas de R. microplus foram coletadas em 39 propriedades de diferentes municípios do Oeste de Santa Catarina. No momento da coleta também foram obtidas informações referentes ao sistema de manejo dos animais, histórico dos carrapaticidas utilizados, número de aplicações anuais, frequência de rodízios de acaricidas, e frequência de acompanhamento técnico para controle estratégico, com a finalidade de evidenciar os diferentes fatores que possam estar contribuindo para o surgimento de eventual resistência das populações do R. microplus. A avaliação de suscetibilidade foi realizada através da técnica de biocarrapaticidograma, utilizando 10 teleóginas ingurgitadas para cada princípio e mais o controle. Dentre os principais resultados obtidos, a maioria das associações entre piretróides e organofosforados demonstraram ter eficiência entre 96,6% e 100%, com exceção da associação de Alfacipermetrina 15%, Ethion 16% e Clorpirifós 8,5% com 93,4% de eficiência. Dentre as bases químicas sem nenhum tipo de associação o Amitraz 12,5% demonstrou ser eficaz em 98,3%, em contrapartida a Cipermetrina 15% teve eficiência em apenas 25,8% das propriedades analisadas. A partir dos resultados obtidos, pode se afirmar que as formas de controle e manejo adotados pelos produtores podem estar relacionadas com os baixos índices de resistência aos carrapaticidas de contato, nas diferentes populações de carrapato na região do estudo.