|De Almeida, Gustavo|
Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/20/2011
Publication Date: 5/25/2012
Citation: De Almeida, G.F., Horsted, K., Thamsborg, S.M., Kyvsgaard, N.C., Ferreira, J.F., Hermansen, J.E. 2012. Use of Artemisia annua as a natural coccidiostat in free-range broilers and its effects on infection dynamics and performance. Veterinary Parasitology. 186:178-187. Interpretive Summary: Although coccidiosis is a major cause of economic losses in the poultry industry, and consumers are fast opposing to the use of synthetic coccidiostats, due to possible residuals on its end products like meat and eggs, there is no natural alternative to these synthetic drugs. Natural anti-parasitic compounds that can have a short life and be absent of consumed animal products and that are safe for animal consumption would be a plus for organic and non-organic poultry production systems. This work tested the use of sweet Annie leaves (a natural source of an anti-parasitic compound used to fight malaria), added as 3% of the chicken daily feed intake, on the control of coccidia in two genotypes of chickens used in free range and organic systems. White Bresse L40 (a slow growing breed) and Kosmos 8 Ross (a cross-breed with medium growing potential) were naturally infected with the coccidia microorganism (a protozoan parasite similar to the malarial agent). The birds from both genotypes were monitored for 30 days after infection and each treatment (with or without sweet Annie in the diet) was replicated three times, using a total of 120 chickens of mixed sex. Birds were monitored for parasite excretion in feces and other clinical symptoms caused by the mixed coccidia infection. Broiler chickens supplemented with 3% sweet Annie leaves showed a significant reduction in parasite egg excretion in feces, independent of the genotype of chicken used. Birds also had an increase in body weight gain once the infection was subdued due to the effect of the sweet Annie herbal feed additive. The herbal additive provided better control of coccidia on White Bresse chickens and female from Kosmos 8 Ross chickens than on the male Kosmos 8 Ross chickens. That difference was attributed to behavioral feeding pattern between female and male Kosmos chickens because females were more interactive socially and active in leeding on the ground. This research indicates that adding sweet Annie leaves to the feed can substantially reduce parasite fecal excretion of infected animals (consequently reducing the paddock contamination levels), and leads to weight gain due to both the reduction of coccidia infection and clinical symptoms. Farmers can benefit from this natural anti-coccidia treatment, reduce their use of sythetic anti-parasitic drugs, and produce a safer and more acceptable poultry product to the consumer. This natural control of parasites also helps to meet the demands for food safety, while decreasing the environmental pollution by synthetic, inorganic, anti-parasitic drugs.
Technical Abstract: This work investigated the preventive effect of Artemisia annua L. dried leaves supplied as a botanical coccidiostat to two broiler genotypes reared in a Danish free-range system in a factorial experiment (two genotypes and +/- supplement of dried A. annua leaves). The genotypes White Bresse L40, a pure slow-growing line, and Kosmos 8 Ross, a hybrid genotype with medium growing characteristics, were used. Broilers were raised indoor until 29-days-old and kept free of parasites. Twelve groups of 30 randomly selected broilers were placed in the range forming 3 replicates for each treatment combination. The paddocks were cultivated with a mix of grass and clover. A separate group of broilers were naturally infected with Eimeria spp. oocysts and five animals nominated as “seeders” were introduced to the above mentioned 12 groups 10 days after its formation, with each group consisting of 35 animals per plot. This infection strategy was meant to imitate the transmission pathway observed at farm level. Ten individual birds from each of the 12 groups, in total 120 animals of mixed sex, were monitored twice weekly for 30 days for oocysts excretion. PCR of pooled faecal samples and localization upon necropsy were used to identify the Eimeria species involved in the infection. In general, broilers from both genotypes in the range coped well with a mixed coccidia infection caused by E. maxima and E. acervulina as no clinical symptoms or deaths were reported during the experiment. In general, broilers supplemented with A. annua dried leaves showed a significant (p<0.05) reduced number of oocysts during the infection with no interaction to genotype. In general, females showed a significantly higher shedding of oocysts than males (P < 0.05). The overall body weight gain and the weight gain when infection was subdued showed a three way interaction between genotype, sex and treatment – the main reason being that Kosmos female responded positively to the Artemisia treatment while Kosmos male responded negatively and only minor treatment differences were found between sex for the White Bresse line. In conclusion, sex effect on oocyst shedding is assumed to be related to the behavioural feeding pattern and the preventive supply of A. annua as a botanical coccidiostat increased productivity and reduced infection level of females from the hybrid Kosmos genotype. This research indicates that A. annua supplementation substantially limit oocyst excretion and may form part of a strategy to prevent commercial losses.