Parasitism level by helminths and weight gain of calves kept in organic and conventional grazing

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito do barbatimão verdadeiro (Stryphnodendron adstringens Mart.) Coville, na dieta de frango de corte

Pós-graduação em Zootecnia - FCAV

Eimeria species in young and adult sheep raised under intensive and/or semi-intensive systems of a herd from Umuarama city, Parana State, Brazil

The present study aimed to identify Eimeria species in young and adult sheep raised under intensive and / or semi-intensive systems of a herd from Umuarama city, Parana State, Brazil using the traditional diagnostic methods and to correlate the infection level/types of infection in the different age/system in this herd. Fecal samples were collected from the rectum of 210 sheep and were subjected to laboratory analysis to differentiate the species. Furthermore, animals were observed to determine the occurrences of the clinical or subclinical forms of eimeriosis. Out of the 210 collected fecal samples, 147 (70%) were positive for Eimeria oocysts, and 101 (47.86%) belonged to young animals that were raised under intensive and / or semi-intensive farming systems. Oocysts from 9 species of Eimeria parasites were identified in the sheep at the following prevalence rates: E. crandallis, 50.0%; E. parva, 21.6%; E. faurei, 8.1%; E. ahsata, 8.1%; E. intricata, 5.4%; E. granulosa, 2.7%; E. ovinoidalis, 2.0%; E. ovina, 1.3%; and E. bakuensis, 0.6%. There were no differences regarding the more frequent Eimeria species among the different ages of animals or between the different farming management systems. Based on these data, E. crandallis was the most prevalent, followed by E. parva and E. faurei species, regardless of the age. Higher parasitism was diagnosed in the young animals that were raised in a confinement regime, and the disease found in the herd was classified as subclinical. Further studies should be conducted in this herd, to verify if the eimeriosis subclinical can cause damage especially in young animals with a high level of infection.

Efficacy of sulfadoxine plus trimethoprim compared to management measures for the control of Eimeria parasitism in naturally infected and clinically asymptomatic sheep that were maintained in a feedlot

The efficacy of sulfadoxine + trimethoprim in comparison to management measures for the control of Eimeria parasitism was studied in naturally infected sheep that were raised in a feedlot and were clinically asymptomatic for eimeriosis. Weight gain was also evaluated in these animals. The following groups were formed with 15 animals/group: TO!, control animals that received saline solution and maintenance of the same management measures that were performed before the study; T02, animals that received two intramuscular doses of sulfadoxine (20 mg/kg) + trimethoprim (4 mg/kg) with a 14-day interval; T03, sheep that received two intramuscular doses of sulfadoxine (20 mg/kg) + trimethoprim (4 mg/kg) with a 14-day interval plus management measures (wood shaving bedding was changed every Monday, and 30g of ammonium sulfate were applied to the bedding and other facilities were performed every Thursday, 10 mL/20 L of water); and T04, animals that received only the management measures described for the previous group. The highest efficacy rates (arithmetic mean) for the T02 group (sulfadoxine + trimethoprim at days 0 and 14) were 21.04% and 21.98% on the 14th and 28th days after the first treatment (DAFT), respectively. However, the treatment showed efficacy rates below 17% and was totally ineffective from the 70th DAFT to the end of the study. In both the T03 (chemical treatment+ management) and T04 (management only) groups, a significant (P <= 0.05) reduction of oocyst shedding per gram of feces was observed in the animals from the 14th DAFT in comparison to the control group; however, an efficacy rate above 90% was observed from the 28th DAFT. Animals belonging to the T02, T03 and T04 groups presented with alterations in weight gain of 0.57 kg, 4.30 kg and 4.53 kg, respectively, in comparison with the control animals (T01) throughout the 91-day study period. Thus, it is possible to conclude that the two-dose sulfadoxine + trimethoprim treatment, given with a 14-day interval, had little no effect on the oocyst shedding. Moreover, the adopted management measures were enough to cause a significant decrease in the animal parasite loads. (C) 2013 Published by Elsevier B.V.