RESUMO

Grazing systems have great potential to promote animal welfare by allowing animals to express natural behaviours, but they also present risks to the animals. Diseases caused by gastrointestinal nematodes are some of the most important causes of poor ruminant health and welfare in grazing systems and cause important economic losses. Reduced growth, health, reproduction and fitness, and negative affective states that indicate suffering are some of the negative effects on welfare in animals infected by gastrointestinal nematode parasitism. Conventional forms of control are based on anthelmintics, but their growing inefficiency due to resistance to many drugs, their potential for contamination of soil and products, and negative public opinion indicate an urgency to seek alternatives. We can learn to deal with these challenges by observing biological aspects of the parasite and the host's behaviour to develop managements that have a multidimensional view that vary in time and space. Improving animal welfare in the context of the parasitic challenge in grazing systems should be seen as a priority to ensure the sustainability of livestock production. Among the measures to control gastrointestinal nematodes and increase animal welfare in grazing systems are the management and decontamination of pastures, offering multispecies pastures, and grazing strategies such as co-grazing with other species that have different grazing behaviours, rotational grazing with short grazing periods, and improved nutrition. Genetic selection to improve herd or flock parasite resistance to gastrointestinal nematode infection may also be incorporated into a holistic control plan, aiming at a substantial reduction in the use of anthelmintics and endectocides to make grazing systems more sustainable.

RESUMO

The objective of this study was to evaluate the predatory activity of the nematophagous fungus Duddingtonia flagrans on infective larvae of gastrointestinal nematodes from dairy heifers in different conditions (shaded and sunny) of a silvopastoral system (SPS) on an agroecological farm. Ten Jersey heifers were divided into two groups: treated (received pellets containing fungus); and control (received pellets without fungus). Twelve hours after fungus administration, faeces samples were collected for in vitro efficacy tests. The animals then remained for 8 h in the experimental pasture area. At the end of this period, 20 faecal pads (10 treated and 10 control) were selected. Pasture, faecal pad and soil collections occurred at intervals of seven days (d), totalling four assessments over 28 d. To evaluate the influence of the conditions shaded and sunny, we registered the condition of the location of each faecal pad per hour. After 12 h of gastrointestinal transit in dairy heifers, a reduction of 65% was obtained through the in vitro test. The treated group presented a lower number of infective larvae (L3) in the faecal pad and upper pasture. Differences in numbers of L3 were observed between the conditions (sunny and shaded) in the faecal pad of the control group; while in the treated group there were no differences between the conditions. The predatory activity of the fungus was efficient over time in the shaded and sunny conditions of an SPS, decreasing the parasite contamination during the pasture recovery time in a subtropical climate.

Assuntos

RESUMO

The resistance of gastrointestinal nematodes (GIN) of sheep to anthelmintic treatment has motivated researchers to seek alternatives to reduce the use of these drugs in sheep farming and decontaminate pastureland based on knowledge about the survival dynamics of larvae. The aim of this work was to evaluate the migration of the infective larvae (L3) of Haemonchus contortus at different times of the day, strata, and sward heights, with and without shade after the deposition of contaminated sheep feces. The grass species used here was Cynodon dactylon cv. Tifton 85 in four treatments: low sward height shade; low sward height sunshine; high sward height shade; and high sward height sunshine. The number of L3 recovered from the pasture at different times of the day did not differ. The highest number of L3 recovered was in shade. The number of L3 at different times and strata occurred uniformly, confirming that L3 remain in the same place after migrating from dung at the hottest times of the day. Infective larvae of H. contortus were able to migrate across all the strata regardless of the time of day in the summer season in humid subtropical climate.

Assuntos

RESUMO

Biological control is a strategy to decrease parasitic populations, and the action takes place through natural antagonists in the environment. We studied the predatory activity of the fungus Duddingtonia flagrans in infective larvae (L3) of gastrointestinal nematodes after gastrointestinal transit. Ten heifers were divided into two groups: treated (animals received pellets containing fungus) and control (animals received pellets without fungus). Twelve hours after administration, faeces samples were collected for in vitro efficacy tests. The animals then remained for 7 h in the experimental pasture area. At the end of this period, 20 faecal pads (ten treated and ten control) were selected at random. Pasture, faecal pad and soil collections occurred with an interval of 7 days, totalling four assessments. In vitro activity demonstrated that fungi effectively preyed on L3, achieving a reduction percentage of 88%. In the faecal pad of the pasture area, there was a difference (P < 0.05) between collections 3 and 4 for both groups; in the treated group a reduction of 65% was obtained, while in the control group there was an increase of 217% in the number of L3. The recovery of L3 in the soil and in the pasture was similar in both groups. There was no influence (P = 0.87) of the passage time on the fungus predatory activity. Duddingtonia flagrans demonstrated the ability to survive gastrointestinal transit in the animals, reducing the number of L3 in the faeces, indicating that this biological control has great potential in the control of worm infections.

Assuntos

RESUMO

Abstract The resistance of gastrointestinal nematodes (GIN) of sheep to anthelmintic treatment has motivated researchers to seek alternatives to reduce the use of these drugs in sheep farming and decontaminate pastureland based on knowledge about the survival dynamics of larvae. The aim of this work was to evaluate the migration of the infective larvae (L3) of Haemonchus contortus at different times of the day, strata, and sward heights, with and without shade after the deposition of contaminated sheep feces. The grass species used here was Cynodon dactylon cv. Tifton 85 in four treatments: low sward height shade; low sward height sunshine; high sward height shade; and high sward height sunshine. The number of L3 recovered from the pasture at different times of the day did not differ. The highest number of L3 recovered was in shade. The number of L3 at different times and strata occurred uniformly, confirming that L3 remain in the same place after migrating from dung at the hottest times of the day. Infective larvae of H. contortus were able to migrate across all the strata regardless of the time of day in the summer season in humid subtropical climate.

Resumo A resistência dos nematódeos gastrintestinais (NGI) de ovinos aos tratamentos com anti-helmíntico tem estimulado os pesquisadores a buscar alternativas para reduzir o uso desses medicamentos na ovinocultura e descontaminar pastagens com base no conhecimento sobre a dinâmica de sobrevivência das larvas. O objetivo do trabalho foi avaliar a migração das larvas infectantes (L3) de Haemonchus contortus em diferentes horários do dia, estratos, e alturas do pasto, com e sem sombra, após a deposição de fezes de ovinos contaminadas. A espécie forrageira utilizada foi Cynodon dactylon cv. Tifton 85 em quatros tratamentos: pasto baixo sombra; pasto baixo sol; pasto alto sombra; e pasto alto sol. Não houve diferença na recuperação de L3 no pasto nos diferentes horários. As maiores recuperações foram encontradas na sombra. O número de larvas recuperadas nos diferentes horários e estratos ocorreu de forma uniforme, confirmando que as L3 podem permanecer no mesmo local, após migrar do bolo fecal, nos horários mais quentes do dia. Larvas infectantes de H. contortus foram capazes de migrar por todos os estratos, independentemente da hora do dia no verão em clima subtropical úmido.

Assuntos

RESUMO

The objective of the study was to evaluate the resistance of Purunã heifers to nematode infection in two different production systems. In this study, 29 heifers were divided into eight pickets, four in an integrated livestock forest system (ILF) and four in a conventional pasture system (CPS). Feces were collected monthly to perform the fecal egg count (FEC), evaluate the degree of infection caused by gastrointestinal nematodes in cattle, and carry out coproculture, to identify the genus of the parasites. In addition, animal body weight was determined to evaluate performance. On the same day as the measurements, forage samples were collected to determine the number of infective larvae per kilogram of dry matter (L3/kg DM) in each picket. There were no statistical differences in FECs between the treatments. Although no significant differences were observed in the recovery of L3/kg DM, the contamination was higher in the ILF compared to CPS in December (344 and 37.7 L3/kg DM, respectively) and January (312 and 0 L3/kg DM, respectively). In March, the CPS (321 L3/kg DM) presented higher contamination than the ILF (80.7 L3/kg DM), but with no statistical difference. The weight of the animals was higher for the CPS compared to the ILF treatment throughout the whole experimental period, with a significant difference in December (343.30 kg and 314.08 kg, respectively). The present study demonstrated numerically that greater numbers of L3 were recovered from pasture of the ILF, which could have resulted in higher contamination and lower performance of the animals.

O objetivo do estudo foi avaliar a resistência de novilhas Purunã às infecções por nematódeos gastrintestinais em diferentes sistemas de produção. Neste estudo, 29 novilhas foram divididas em oito piquetes, quatro no sistema integrado pecuária-floresta(ILPF) e quatro no sistema convencional de pastagem (SCP). Mensalmente, as fezes eram coletadas para realizar a contagem de ovos por grama de fezes (OPG), com o objetivo de avaliar o grau de infecção causada por nematódeos gastrintestinais em bovinos; e coprocultura, para identificar o gênero dos parasitas. Além disso, o peso corporal dos animais foi determinado para avaliar o desempenho. No mesmo dia das medições, amostras de forragem foram coletadas para determinar o número de larvas infectantes por quilograma de matéria seca (L3 / kg MS) em cada piquete. Não houve diferença estatística no OPG entre os tratamentos. Também não houve diferença significativa na recuperação de L3 / kg de MS, porém a contaminação foi maior na ILPF em comparação com a SCP em dezembro (344 e 37,7 L3/kg MS, respectivamente) e janeiro (312 e 0 L3/kg MS respectivamente), em março, o SCP (321 L3 / kg MS) apresentou maior contaminação que o ILPF (80,7 L3/kg MS). O peso dos animais foi maior para o SCP comparado ao tratamento com ILPF durante todo o período experimental, com diferença significativa em dezembro (343,30 kg e 314,08 kg, respectivamente). O presente estudo mostrou numericamente que o ILPF apresentou maior recuperação de L3 no pasto, o que poderia resultar em maior contaminação dos animais e menor desempenho.

Assuntos

RESUMO

The objective of the study was to evaluate the resistance of Purunã heifers to nematode infection in two different production systems. In this study, 29 heifers were divided into eight pickets, four in an integrated livestock forest system (ILF) and four in a conventional pasture system (CPS). Feces were collected monthly to perform the fecal egg count (FEC), evaluate the degree of infection caused by gastrointestinal nematodes in cattle, and carry out coproculture, to identify the genus of the parasites. In addition, animal body weight was determined to evaluate performance. On the same day as the measurements, forage samples were collected to determine the number of infective larvae per kilogram of dry matter (L3/kg DM) in each picket. There were no statistical differences in FECs between the treatments. Although no significant differences were observed in the recovery of L3/kg DM, the contamination was higher in the ILF compared to CPS in December (344 and 37.7 L3/kg DM, respectively) and January (312 and 0 L3/kg DM, respectively). In March, the CPS (321 L3/kg DM) presented higher contamination than the ILF (80.7 L3/kg DM), but with no statistical difference. The weight of the animals was higher for the CPS compared to the ILF treatment throughout the whole experimental period, with a significant difference in December (343.30 kg and 314.08 kg, respectively). The present study demonstrated numerically that greater numbers of L3 were recovered from pasture of the ILF, which could have resulted in higher contamination and lower performance of the animals.(AU)

O objetivo do estudo foi avaliar a resistência de novilhas Purunã às infecções por nematódeos gastrintestinais em diferentes sistemas de produção. Neste estudo, 29 novilhas foram divididas em oito piquetes, quatro no sistema integrado pecuária-floresta(ILPF) e quatro no sistema convencional de pastagem (SCP). Mensalmente, as fezes eram coletadas para realizar a contagem de ovos por grama de fezes (OPG), com o objetivo de avaliar o grau de infecção causada por nematódeos gastrintestinais em bovinos; e coprocultura, para identificar o gênero dos parasitas. Além disso, o peso corporal dos animais foi determinado para avaliar o desempenho. No mesmo dia das medições, amostras de forragem foram coletadas para determinar o número de larvas infectantes por quilograma de matéria seca (L3 / kg MS) em cada piquete. Não houve diferença estatística no OPG entre os tratamentos. Também não houve diferença significativa na recuperação de L3 / kg de MS, porém a contaminação foi maior na ILPF em comparação com a SCP em dezembro (344 e 37,7 L3/kg MS, respectivamente) e janeiro (312 e 0 L3/kg MS respectivamente), em março, o SCP (321 L3 / kg MS) apresentou maior contaminação que o ILPF (80,7 L3/kg MS). O peso dos animais foi maior para o SCP comparado ao tratamento com ILPF durante todo o período experimental, com diferença significativa em dezembro (343,30 kg e 314,08 kg, respectivamente). O presente estudo mostrou numericamente que o ILPF apresentou maior recuperação de L3 no pasto, o que poderia resultar em maior contaminação dos animais e menor desempenho.(AU)

Assuntos

RESUMO

This study aimed to evaluate the resistance of Texel (Tx) and Ile de France (IF) sheep to gastrointestinal nematode infections in the periparturient period and after weaning, and the performance of their lambs. Fecal samples were collected from 19 IF and 17 Texel ewes to determine fecal egg counts (FEC) and larval cultures were prepared to determine the prevalence of nematodes. The ewes were weighed to determine body weight (BW) and blood samples were taken to determine the packed cell volume (PCV) and plasm protein values (PPV). The ewes were classified into two groups by FEC (heavy and moderate infection). The IF presented higher FECs than Tx 28 and 14 days before parturition; 14, 28, and 56 days after parturition; and 28 days after weaning (P<0.05). In the weaning and dry periods, the IF presented higher PCVs than Tx (P<0.05). The PPV did not differ between the groups (P>0.05). The IF presented a higher BW than Tx 14, 28, and 42 days after parturition, and in the weaning and dry periods (P<0.05). The ewes of both breeds classified as moderately infected had the highest BW at weaning (P<0.05). IF ewes with a moderate infection produced weaning lambs that were heavier than those of Tx with the same level of infection (P<0.05). Overall, Tx ewes presented a better ability to withstand infections during the periparturient period and after weaning. Although the IF ewes presented the highest FEC and more intense periparturient rise, they managed to maintain their level of production.(AU)

Objetivou-se avaliar a resistência de ovelhas Texel (Tx) e Ile de France (IF) às infecções naturais por nematódeos gastrintestinais no periparto e após a desmama e o desempenho de cordeiros. Foram utilizadas 19 ovelhas IF e 17 Tx, nas quais coletou-se fezes para a contagem de ovos por grama de fezes (OPG) e coproculturas. As ovelhas foram pesadas para determinar o peso vivo (PV) e sangue foi coletado para determinar volume globular (VG) e proteína plasmática total (PPT). As ovelhas foram classificadas em dois grupos através do OPG (infecção pesada e moderada). As IF apresentaram OPG superior aos das Tx nos seguintes períodos: 28 e 14 dias antes do parto, 14, 28 e 56 dias após o parto e 28 dias após a desmama (P<0,05). Na desmama e no período seco as IF apresentaram VG superiores aos das Tx (P<0,05). PPT não diferiu entre as raças avaliadas (P>0,05). As IF apresentaram PV superior aos das Tx nos dias 14, 28 e 42 após o parto, na desmama e no período seco (P<0,05). As ovelhas classificadas como infecção moderada de ambas as raças apresentaram maior PV a desmama (P<0,05). Ovelhas IF infecção moderada desmamaram cordeiros mais pesados do que as Tx, com o mesmo nível de infecção (P<0,05). No geral, ovelhas Tx apresentaram melhor habilidade para suportar as infecções durante o periparto e após a desmama. No entanto, apesar das IF apresentarem maior OPG e fenômeno do periparto (FP) mais intenso conseguiram manter seu nível de produção.(AU)

Assuntos

RESUMO

The purpose of this work was to identify, critically assess, and summarize available data from primary research about the anthelmintic resistance of injectable macrocyclic lactones in cattle. Meta-analysis was performed to estimate the pooled Odds Ratio and 95% Confidence Intervals. Of the 1504 abstracts screened for eligibility, 80 were deemed relevant for full publication review. Thirteen publications were included in the qualitative synthesis and assessed for systematic bias. Only five studies were included in the quantitative analysis because they showed a low risk of producing biased results in all the parameters. The forest plot indicated four studies that discuss anthelmintic resistance (P<0.05), while only one study did not discuss anthelmintic resistance (P<0.05). The pooled estimate showed 0.59 (95% Confidence intervals: 0.08, 0.47) times higher odds for studies that report anthelmintic resistance than for studies reporting efficacious anthelmintic treatment, with significant and substantially low heterogeneity (I2=25%). Anthelmintic resistance to injectable macrocyclic lactones is a reality. There are need to improve methodological reporting in studies, which is a problem for investigations that involves systematic review and meta-analysis (SR-MA).

Assuntos

RESUMO

Abstract The purpose of this work was to identify, critically assess, and summarize available data from primary research about the anthelmintic resistance of injectable macrocyclic lactones in cattle. Meta-analysis was performed to estimate the pooled Odds Ratio and 95% Confidence Intervals. Of the 1504 abstracts screened for eligibility, 80 were deemed relevant for full publication review. Thirteen publications were included in the qualitative synthesis and assessed for systematic bias. Only five studies were included in the quantitative analysis because they showed a low risk of producing biased results in all the parameters. The forest plot indicated four studies that discuss anthelmintic resistance (P<0.05), while only one study did not discuss anthelmintic resistance (P<0.05). The pooled estimate showed 0.59 (95% Confidence intervals: 0.08, 0.47) times higher odds for studies that report anthelmintic resistance than for studies reporting efficacious anthelmintic treatment, with significant and substantially low heterogeneity (I2=25%). Anthelmintic resistance to injectable macrocyclic lactones is a reality. There are need to improve methodological reporting in studies, which is a problem for investigations that involves systematic review and meta-analysis (SR-MA).

Resumo O objetivo deste trabalho foi identificar, avaliar criticamente e resumir os dados disponíveis da literatura primária sobre resistência anti-helmíntica a lactonas macrocíclicas injetáveis em bovinos. Uma meta-análise foi realizada para estimar o "Odds Ratio" e Intervalos de Confiança (95%). Dos 1504 resumos selecionados para elegibilidade, 80 foram considerados relevantes para a revisão completa da publicação. Treze publicações foram incluídas na síntese qualitativa, as quais foram avaliadas quanto ao viés sistemático. Apenas cinco estudos foram incluídos na análise quantitativa porque apresentaram um baixo risco de produzir resultados tendenciosos em todos os parâmetros. O gráfico de floresta indicou quatro estudos que apresentaram resistência anti-helmíntica (P <0,05), enquanto um não apresentou (P <0,05). A estimativa combinada mostrou uma maior probabilidade de publicações de estudos que relatam resistência anti-helmíntica no valor de 0,59 (95%: 0,8, 0,47) do que estudos relatando tratamento anti-helmíntico eficaz. Os dados apresentaram baixa heterogeneidade (I2 = 25%). A resistência anti-helmíntica a lactonas macrocíclicas é uma realidade. Há a necessidade de melhorar a metodologia dos estudos, pois é um problema para os trabalhos que envolvem revisões sistemáticas e meta-análises (RS-MA).

Assuntos

RESUMO

This study aimed to evaluate the resistance of Texel (Tx) and Ile de France (IF) sheep to gastrointestinal nematode infections in the periparturient period and after weaning, and the performance of their lambs. Fecal samples were collected from 19 IF and 17 Texel ewes to determine fecal egg counts (FEC) and larval cultures were prepared to determine the prevalence of nematodes. The ewes were weighed to determine body weight (BW) and blood samples were taken to determine the packed cell volume (PCV) and plasm protein values (PPV). The ewes were classified into two groups by FEC (heavy and moderate infection). The IF presented higher FECs than Tx 28 and 14 days before parturition; 14, 28, and 56 days after parturition; and 28 days after weaning (P0.05). The IF presented a higher BW than Tx 14, 28, and 42 days after parturition, and in the weaning and dry periods (P<0.05). The ewes of both breeds classified as moderately infected had the highest BW at weaning (P<0.05). IF ewes with a moderate infection produced weaning lambs that were heavier than those of Tx with the same level of infection (P<0.05). Overall, Tx ewes presented a better ability to withstand infections during the periparturient period and after weaning. Although the IF ewes presented the highest FEC and more intense periparturient rise, they managed to maintain their level of production.

Objetivou-se avaliar a resistência de ovelhas Texel (Tx) e Ile de France (IF) às infecções naturais por nematódeos gastrintestinais no periparto e após a desmama e o desempenho de cordeiros. Foram utilizadas 19 ovelhas IF e 17 Tx, nas quais coletou-se fezes para a contagem de ovos por grama de fezes (OPG) e coproculturas. As ovelhas foram pesadas para determinar o peso vivo (PV) e sangue foi coletado para determinar volume globular (VG) e proteína plasmática total (PPT). As ovelhas foram classificadas em dois grupos através do OPG (infecção pesada e moderada). As IF apresentaram OPG superior aos das Tx nos seguintes períodos: 28 e 14 dias antes do parto, 14, 28 e 56 dias após o parto e 28 dias após a desmama (P0,05). As IF apresentaram PV superior aos das Tx nos dias 14, 28 e 42 após o parto, na desmama e no período seco (P<0,05). As ovelhas classificadas como infecção moderada de ambas as raças apresentaram maior PV a desmama (P<0,05). Ovelhas IF infecção moderada desmamaram cordeiros mais pesados do que as Tx, com o mesmo nível de infecção (P<0,05). No geral, ovelhas Tx apresentaram melhor habilidade para suportar as infecções durante o periparto e após a desmama. No entanto, apesar das IF apresentarem maior OPG e fenômeno do periparto (FP) mais intenso conseguiram manter seu nível de produção.

Assuntos

RESUMO

A inclusão de aditivos na alimentação animal tem se tornado uma preocupação dos consumidores devido os riscos à saúde humana, portanto, os aditivos extraídos de plantas podem ser uma alternativa para substituir os antibióticos melhorando a produtividade. O presente trabalho teve por objetivo avaliar o desempenho produtivo, composição do leite e carga parasitária de vacas Holandesas lactantes suplementadas com aditivo rico em ácidos graxos essenciais e tocoferol. Utilizou-se 16 vacas em lactação, divididas em dois grupos, animais tratados com o aditivo (10/g/animal/dia) e animais do grupo controle. A cada 15 dias foi realizado o Califórnia mastite teste e o controle leiteiro, para análise dos seguintes parâmetros: produção de leite; proteína, gordura; lactose; sólidos totais e contagem de células somáticas. A cada 14 dias foram realizados a contagem de ovos por grama de fezes, e a contagem de moscas (Haematobia irritans) e carrapatos (Rhiphicephalus Boophilus microplus). Não houve diferença na qualidade e produção de leite, assim como na carga parasitária dos animais, verificando que a administração do aditivo não melhorou o desempenho produtivo e não diminuiu a carga parasitária de vacas holandesas. (AU)

The inclusion of additives in animal feed has become a concern of consumers due to the risks to human health, therefore the additives extracted from plants can be an alternative to replace the antibiotics improving productivity. The objective of this study was to evaluate the productive performance, milk composition and worm burden of lactating Holstein cows supplemented with essential fatty acid and tocopherol. Sixteen lactating cows were divided in two groups, animals treated with the additive (10 μg/animal/day) and animals from the control group. Every 15 days, the California mastitis test and evaluation of milk were made to analyze the following parameters: milk production; protein, fat; lactose; total solids and somatic cell counts. The counting of eggs per gram of feces and counting of flies (Haematobia irritans) and ticks (Rhiphicephalus Boophilus microplus) were performed every 14 days. There was no difference in the quality and milk yield, as well as in the worm burden of the animals, verifying that the administration of the additive did not improve the productive performance and did not decrease the worm burden of the Holstein cows.(AU)

Assuntos

RESUMO

A inclusão de aditivos na alimentação animal tem se tornado uma preocupação dos consumidores devido os riscos à saúde humana, portanto, os aditivos extraídos de plantas podem ser uma alternativa para substituir os antibióticos melhorando a produtividade. O presente trabalho teve por objetivo avaliar o desempenho produtivo, composição do leite e carga parasitária de vacas Holandesas lactantes suplementadas com aditivo rico em ácidos graxos essenciais e tocoferol. Utilizou-se 16 vacas em lactação, divididas em dois grupos, animais tratados com o aditivo (10/g/animal/dia) e animais do grupo controle. A cada 15 dias foi realizado o Califórnia mastite teste e o controle leiteiro, para análise dos seguintes parâmetros: produção de leite; proteína, gordura; lactose; sólidos totais e contagem de células somáticas. A cada 14 dias foram realizados a contagem de ovos por grama de fezes, e a contagem de moscas (Haematobia irritans) e carrapatos (Rhiphicephalus Boophilus microplus). Não houve diferença na qualidade e produção de leite, assim como na carga parasitária dos animais, verificando que a administração do aditivo não melhorou o desempenho produtivo e não diminuiu a carga parasitária de vacas holandesas.

The inclusion of additives in animal feed has become a concern of consumers due to the risks to human health, therefore the additives extracted from plants can be an alternative to replace the antibiotics improving productivity. The objective of this study was to evaluate the productive performance, milk composition and worm burden of lactating Holstein cows supplemented with essential fatty acid and tocopherol. Sixteen lactating cows were divided in two groups, animals treated with the additive (10 μg/animal/day) and animals from the control group. Every 15 days, the California mastitis test and evaluation of milk were made to analyze the following parameters: milk production; protein, fat; lactose; total solids and somatic cell counts. The counting of eggs per gram of feces and counting of flies (Haematobia irritans) and ticks (Rhiphicephalus Boophilus microplus) were performed every 14 days. There was no difference in the quality and milk yield, as well as in the worm burden of the animals, verifying that the administration of the additive did not improve the productive performance and did not decrease the worm burden of the Holstein cows.

Assuntos

RESUMO

The purpose of this work was to identify, critically assess, and summarize available data from primary research about the anthelmintic resistance of injectable macrocyclic lactones in cattle. Meta-analysis was performed to estimate the pooled Odds Ratio and 95% Confidence Intervals. Of the 1504 abstracts screened for eligibility, 80 were deemed relevant for full publication review. Thirteen publications were included in the qualitative synthesis and assessed for systematic bias. Only five studies were included in the quantitative analysis because they showed a low risk of producing biased results in all the parameters. The forest plot indicated four studies that discuss anthelmintic resistance (P 0.05), while only one study did not discuss anthelmintic resistance (P 0.05). The pooled estimate showed 0.59 (95% Confidence intervals: 0.08, 0.47) times higher odds for studies that report anthelmintic resistance than for studies reporting efficacious anthelmintic treatment, with significant and substantially low heterogeneity (I2=25%). Anthelmintic resistance to injectable macrocyclic lactones is a reality. There are need to improve methodological reporting in studies, which is a problem for investigations that involves systematic review and meta-analysis (SR-MA).(AU)

O objetivo deste trabalho foi identificar, avaliar criticamente e resumir os dados disponíveis da literatura primária sobre resistência anti-helmíntica a lactonas macrocíclicas injetáveis em bovinos. Uma meta-análise foi realizada para estimar o Odds Ratio e Intervalos de Confiança (95%). Dos 1504 resumos selecionados para elegibilidade, 80 foram considerados relevantes para a revisão completa da publicação. Treze publicações foram incluídas na síntese qualitativa, as quais foram avaliadas quanto ao viés sistemático. Apenas cinco estudos foram incluídos na análise quantitativa porque apresentaram um baixo risco de produzir resultados tendenciosos em todos os parâmetros. O gráfico de floresta indicou quatro estudos que apresentaram resistência anti-helmíntica (P 0,05), enquanto um não apresentou (P 0,05). A estimativa combinada mostrou uma maior probabilidade de publicações de estudos que relatam resistência anti-helmíntica no valor de 0,59 (95%: 0,8, 0,47) do que estudos relatando tratamento anti-helmíntico eficaz. Os dados apresentaram baixa heterogeneidade (I2 = 25%). A resistência anti-helmíntica a lactonas macrocíclicas é uma realidade. Há a necessidade de melhorar a metodologia dos estudos, pois é um problema para os trabalhos que envolvem revisões sistemáticas e meta-análises (RS-MA).(AU)

Assuntos

RESUMO

Verificou-se a resistência de ovelhas Santa Inês nos períodos de gestação, parto, lactação e desmama. Fezes e pastagem foram colhidas a cada 21 dias, assim como a aferição do peso e avaliação do escore de condição corporal (ECC). Não houve diferença na contagem de OPG em relação aos períodos avaliados (P>0,05). Médias de peso corporal durante o período da gestação e parto foram maiores do que as médias da lactação e desmama (P<0,05). ECC foi maior no período da gestação (P<0,05). Haemonchus spp. e Trichostrongylus spp. foram encontrados nas coproculturas, respectivamente, assim como nas pastagens durante todo o período experimental.

An evaluation was made of the resistance of Santa Ines ewes to gastrointestinal nematode infections during the periods of gestation, parturition, lactation and weaning. Feces and pasture grass were collected every 21 days, and the animals weight was checked and their body condition score (BCS) evaluated. No differences were found in EPG counts during the periods of evaluation (P>0.05). The average body weight during gestation and parturition was higher than during lactation and weaning (P<0.05). The highest BCS was recorded during gestation (P<0.05). Throughout the experimental period, Haemonchus spp. and Trichostrongylus spp. were found in fecal cultures and in the pastures.

Assuntos

RESUMO

Verificou-se a resistência de ovelhas Santa Inês nos períodos de gestação, parto, lactação e desmama. Fezes e pastagem foram colhidas a cada 21 dias, assim como a aferição do peso e avaliação do escore de condição corporal (ECC). Não houve diferença na contagem de OPG em relação aos períodos avaliados (P>0,05). Médias de peso corporal durante o período da gestação e parto foram maiores do que as médias da lactação e desmama (P<0,05). ECC foi maior no período da gestação (P<0,05). Haemonchus spp. e Trichostrongylus spp. foram encontrados nas coproculturas, respectivamente, assim como nas pastagens durante todo o período experimental. (AU)

An evaluation was made of the resistance of Santa Ines ewes to gastrointestinal nematode infections during the periods of gestation, parturition, lactation and weaning. Feces and pasture grass were collected every 21 days, and the animals weight was checked and their body condition score (BCS) evaluated. No differences were found in EPG counts during the periods of evaluation (P>0.05). The average body weight during gestation and parturition was higher than during lactation and weaning (P<0.05). The highest BCS was recorded during gestation (P<0.05). Throughout the experimental period, Haemonchus spp. and Trichostrongylus spp. were found in fecal cultures and in the pastures. (AU)

Assuntos

RESUMO

Infecções por nematódeos gastrintestinais são responsáveis por prejuízos à criação de bovinos de corte. O controle destas infecções é imprescindível para o sucesso dos sistemas de produção de ruminantes. Além da observação de animais suscetíveis a parasitos, deve-se destacar a seleção de parasitos adultos resistentes a princípios ativos. Neste caso, as práticas de manejo equivocadas que diminuem a população de parasitos em refugia. Verifica-se a importância da profilaxia das endoparasitoses em bovinos visando uma menor perda produtiva dos mesmos. Animais infectados mesmo quando não apresentam a sintomatologia clínica da doença deixa de produzir consideravelmente, afetando negativamente o sistema de produção.

Gastrointestinal nematode infections are responsible for beef cattle production losses. The success of ruminant production systems is known to be closely tied to the control of these infections. Indeed, as important as the detection of animals susceptible to parasites is the identification of adult parasites resistant to active ingredients, given that unsound management practices fail to reduce the population of parasites in refugia. Therefore, prophylaxis of endoparasites in cattle is essential in order to reduce production losses, because even when infected animals exhibit no clinical symptoms of the disease, their production diminishes considerably, thus negatively affecting the production system.

Assuntos

RESUMO

Infecções por nematódeos gastrintestinais são responsáveis por prejuízos à criação de bovinos de corte. O controle destas infecções é imprescindível para o sucesso dos sistemas de produção de ruminantes. Além da observação de animais suscetíveis a parasitos, deve-se destacar a seleção de parasitos adultos resistentes a princípios ativos. Neste caso, as práticas de manejo equivocadas que diminuem a população de parasitos em refugia. Verifica-se a importância da profilaxia das endoparasitoses em bovinos visando uma menor perda produtiva dos mesmos. Animais infectados mesmo quando não apresentam a sintomatologia clínica da doença deixa de produzir consideravelmente, afetando negativamente o sistema de produção. (AU)

Gastrointestinal nematode infections are responsible for beef cattle production losses. The success of ruminant production systems is known to be closely tied to the control of these infections. Indeed, as important as the detection of animals susceptible to parasites is the identification of adult parasites resistant to active ingredients, given that unsound management practices fail to reduce the population of parasites in refugia. Therefore, prophylaxis of endoparasites in cattle is essential in order to reduce production losses, because even when infected animals exhibit no clinical symptoms of the disease, their production diminishes considerably, thus negatively affecting the production system. (AU)

Assuntos

RESUMO

The survival of infective larvae (L3) of Trichostrongylus colubriformis was evaluated on Brachiaria, Coast-cross and Aruana forage grasses. Feces of sheep parasitized exclusively by T. colubriformis were deposited in winter and spring on experimental plots whose grasses were cut at two heights: 5 cm and 30 cm. One, two, four, eight, 12 and 16 weeks after depositing the feces, fecal and forage samples were collected for the retrieval and quantification of L3. Retrieval of L3 from feces and forage was negligible in winter due to the dry weather, although a few larvae were retrieved in the last larval collections. However, L3 retrieval from fecal samples was greater in spring, especially two weeks after feces were deposited on 30 cm high grasses. At this time, the L3 retrieval rate from the three forage grasses differed significantly (P <0.05), with Aruana grass showing the highest average L3 retrieval rate, followed by Coast-cross and Brachiaria. In conclusion, the winter drought proved very unfavorable for the presence of L3 in the environment, and the microclimate of Aruana pastureland was generally the most favorable for the retrieval of infective larvae.

Assuntos

RESUMO

The survival of infective larvae (L3) of Trichostrongylus colubriformis was evaluated on Brachiaria, Coast-cross and Aruana forage grasses. Feces of sheep parasitized exclusively by T. colubriformis were deposited in winter and spring on experimental plots whose grasses were cut at two heights: 5 cm and 30 cm. One, two, four, eight, 12 and 16 weeks after depositing the feces, fecal and forage samples were collected for the retrieval and quantification of L3. Retrieval of L3 from feces and forage was negligible in winter due to the dry weather, although a few larvae were retrieved in the last larval collections. However, L3 retrieval from fecal samples was greater in spring, especially two weeks after feces were deposited on 30 cm high grasses. At this time, the L3 retrieval rate from the three forage grasses differed significantly (P <0.05), with Aruana grass showing the highest average L3 retrieval rate, followed by Coast-cross and Brachiaria. In conclusion, the winter drought proved very unfavorable for the presence of L3 in the environment, and the microclimate of Aruana pastureland was generally the most favorable for the retrieval of infective larvae.

A sobrevivência de larvas infectantes (L3) de Trichostrongylus colubriformis foi avaliada em pastagem de Braquiária, Coast-cross e Aruana. Fezes de ovinos parasitados exclusivamente por T. colubriformis foram depositadas no inverno e na primavera em parcelas experimentais com duas alturas de corte da forragem, 5 cm e 30 cm. Uma, duas, quatro, oito, 12 e 16 semanas após o depósito, amostras de fezes e de forragem foram coletadas para a recuperação e quantificação de L3. Devido à seca no inverno, a recuperação de L3 das fezes e da forragem foi ínfima, embora tenha havido recuperação de algumas larvas nas últimas coletas. Por outro lado, na primavera houve maior recuperação de L3 das amostras, especialmente duas semanas após a deposição das fezes em meio às pastagens com 30 cm de altura. Nesse momento, houve diferença significativa (P<0,05) entre as três forrageiras, com maior média de L3 no capim Aruana, seguido de Coast-cross e Braquiária. Em conclusão, a seca registrada no período de inverno se mostrou bastante desfavorável à presença de L3 no ambiente e, de forma geral, o microclima da pastagem de Aruana foi o que mais favoreceu a recuperação de larvas infectantes.

Assuntos