ABSTRACT
Heat stress and competition for food are two major challenges in pigs reared in intensive conditions. The aim of the present work was to study the effect of providing a double feeder for pigs reared under two different environmental temperatures. In addition, two types of flooring, of 100% slat and 30% slat 70% concrete, were also considered. A total of 256 pigs in the growing-finishing period (from 27 kg to 110 kg) were housed using two environmental temperatures: control (from 18 °C to 25 °C) and heat stress (above 30 °C six hours a day). They were housed in 32 pens of 8 pigs each, distributed into 4 rooms (16 with one feeder and 16 with two). Pigs subjected to temperatures above 30 °C up to six hours had lower body weight gains than pigs subjected to a maximum temperature of 25 °C, confirming that thermal stress negatively affects performance in pigs. In addition, heat stress affected the final product by decreasing the lean percentage of carcasses by 2.6%. A double feeder reduced the presence of negative social behavior, especially in the feeding area, but body weight was lower than when one single feeder was used. A 30% slat 70% concrete floor showed better results in the pig stress indicators and body weights than 100% slat. It is concluded that providing a double feeder in the pens, although reducing the presence of negative social interactions, negatively affected body weight, in comparison to pigs fed with just one feeder.
ABSTRACT
The aim here is to present data on the efficacy of anthelmintics in sheep flocks in Rio de Janeiro, Brazil, and to discuss the interpretation of the fecal egg count reduction test (FECRT) for each nematode genus. Fecal eggs counts and pre- and post-treatment coprocultures were performed, the former to evaluate the efficacy of and the latter to determine the overall parasite prevalence. An additional efficacy test was performed at Farm # 1 a year after the initial test. Severe anthelmintic resistance was found for the flocks, with no FECRT sensitivity at any of the 22 farms evaluated. However, an analysis of the infective larvae showed that some drugs were effective against certain parasitic genera; i.e., levamisole was more effective against Haemonchus spp. and moxidectin against Trichostrongylus spp. In the additional FECRT performed at Farm # 1, moxidectin and nitroxynil were ineffective separately, but when applied in combination they were highly effective due to their efficacy against Haemonchus (nitroxynil) and Trichostrongylus (moxidectin), respectively. The use of the FECRT targeting the parasitic nematode species prevalent on farms may make it possible to choose more effective anthelmintics.
Subject(s)
Anthelmintics/therapeutic use , Feces/parasitology , Nematoda/drug effects , Parasite Egg Count , Sheep Diseases/parasitology , Animals , Anthelmintics/pharmacology , Drug Resistance , Nematoda/classification , Nematoda/isolation & purification , Parasitic Sensitivity Tests , SheepABSTRACT
Abstract The aim here is to present data on the efficacy of anthelmintics in sheep flocks in Rio de Janeiro, Brazil, and to discuss the interpretation of the fecal egg count reduction test (FECRT) for each nematode genus. Fecal eggs counts and pre- and post-treatment coprocultures were performed, the former to evaluate the efficacy of and the latter to determine the overall parasite prevalence. An additional efficacy test was performed at Farm # 1 a year after the initial test. Severe anthelmintic resistance was found for the flocks, with no FECRT sensitivity at any of the 22 farms evaluated. However, an analysis of the infective larvae showed that some drugs were effective against certain parasitic genera; i.e., levamisole was more effective against Haemonchus spp. and moxidectin against Trichostrongylus spp. In the additional FECRT performed at Farm # 1, moxidectin and nitroxynil were ineffective separately, but when applied in combination they were highly effective due to their efficacy against Haemonchus (nitroxynil) and Trichostrongylus (moxidectin), respectively. The use of the FECRT targeting the parasitic nematode species prevalent on farms may make it possible to choose more effective anthelmintics.
Resumo O objetivo deste trabalho foi apresentar dados sobre a eficácia de anti-helmínticos em rebanhos ovinos no Rio de Janeiro, Brasil, e discutir a interpretação do teste de redução da contagem de ovos nas fezes (TRCOF) para cada gênero de nematoide. A contagem de ovos fecais (OPG) e coprocultura pré e pós-tratamento foram realizadas para avaliar a eficácia e a prevalência geral do parasito, respectivamente. Um teste de eficácia adicional foi realizado na Fazenda # 1 após um ano do teste inicial. Resistência anti-helmíntica grave foi encontrada, não havendo sensibilidade no TRCOF em nenhuma das 22 fazendas avaliadas. No entanto, na análise das larvas infectantes observou-se que algumas drogas foram eficazes contra certos gêneros parasitários; por exemplo, o levamisol foi mais eficaz contra Haemonchus spp. e a moxidectina contra Trichostrongylus spp. No TRCOF adicional realizado na Fazenda 1, a moxidectina e o nitroxinil foram ineficazes separadamente, mas quando aplicados em combinação, foram altamente eficazes devido à sua eficácia contra Haemonchus spp. (nitroxinil) e Trichostrongylus spp. (moxidectina), respectivamente. O TRCOF visando às espécies de nematoides parasitas prevalentes nas fazendas pode possibilitar a escolha de anti-helmínticos mais eficazes.