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Parasitology Apr 2021A prior systematic review on the efficacy of halofuginone (HFG) treatment to prevent or treat cryptosporidiosis in bovine calves was inconclusive. We undertook an... (Meta-Analysis)
Meta-Analysis
A prior systematic review on the efficacy of halofuginone (HFG) treatment to prevent or treat cryptosporidiosis in bovine calves was inconclusive. We undertook an updated synthesis and meta-analyses on key outcomes for the treatment of calves with HFG. Evaluated outcomes were oocyst shedding, diarrhoea, mortality and weight gain. Experiments had to describe results for same age animals in contemporary arms. Most doses were 100-150 mcg kg-1 day-1. Results were subgrouped by study design, experiments with the lowest risk of bias and lack of industry funding. Eighteen articles were found that described 25 experiments. Most evidence came from randomized controlled trials in Europe. Significantly lower incidence of oocyst shedding, diarrhoea burden and mortality was reported when treatment started before calves were 5 days old. Most studies reported on outcomes for animals up to at least 28 days old. Publication bias was possible in all outcomes and seemed especially likely for diarrhoea outcomes. Beneficial results when HFG treatment was initiated in calves older than 5 days were also found. Prophylactic treatment to prevent cryptosporidiosis is effective in preventing multiple negative outcomes and is beneficial to calf health and will result in a reduction of environmental contamination by Cryptosporidium oocysts.
Topics: Animals; Cattle; Cattle Diseases; Coccidiostats; Cryptosporidiosis; Cryptosporidium parvum; Diarrhea; Feces; Oocysts; Piperidines; Quinazolinones; Weight Gain
PubMed: 33261668
DOI: 10.1017/S0031182020002267 -
Ecotoxicology and Environmental Safety Jan 2021Trichogramma pretiosum is one of the main egg parasitoids used in the control of lepidopteran pests in Brazil. This natural enemy can be negatively affected by the use... (Meta-Analysis)
Meta-Analysis
Trichogramma pretiosum is one of the main egg parasitoids used in the control of lepidopteran pests in Brazil. This natural enemy can be negatively affected by the use of insecticides, herbicides, and fungicides. The present work used a systematic review and meta-analysis to group information from multiple studies on the selectivity of pesticides (279 commercial products) in rice, corn, soybean, apple and peach crops for immature stages (egg-larva, pre-pupa, and pupa) and adult parasitoids. The selected studies used the International Organization for Biological and Integrated Control (IOBC) methodology with the same adaptations for T. pretiosum. The meta-analysis found that corn crops had the highest frequency of tests (2 0 7). The most frequently tested active ingredients (a.i.) were glyphosate, glyphosate isopropylamine salt, and sulfur at frequencies of 41, 32 and 24 tests, respectively. The pesticides registered for rice crops showed the greatest sublethal effects on T. pretiosum, with an approximately 47% reduction in parasitism (RP) or emergence (RE). The adult stage of the parasitoid showed greater sensitivity to the tested pesticides (65% RP), in comparison to the immature stages. In general, insecticides showed superior toxicity for all development stages of T. pretiosum, compared to herbicides and fungicides, regardless of the recommended dosage for the crop. The present study aggregates information related to selectivity for the four life stages of T. pretiosum, contributing significantly to the integration of biological control and chemical control in rice, corn, soybean, apple and peach crops in Brazil.
Topics: Animals; Brazil; Crops, Agricultural; Drug Resistance; Hymenoptera; Life Cycle Stages; Pest Control, Biological; Pesticides; Plant Diseases
PubMed: 33099140
DOI: 10.1016/j.ecoenv.2020.111504