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Florfenicol induces early embryonic death in eggs collected from treated hens.

Al-Shahrani S, Naidoo V - BMC Vet. Res. (2015)

Bottom Line: Treatment of only the cockerels had no effect on egg hatchability, while treatment of only the hens at doses of 60 and 90 mg/kg resulted in decreased hatchability of 0 % in comparison to 70 % of the control as early 24 h after treatment.In all cases, decreased hatchability was associated with embryonic death at 5 days of development.The toxic effects of florfenicol were completely reversible with comparable hatchability being present by day 4 post-treatment withdrawal.

View Article: PubMed Central - PubMed

Affiliation: Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, South Africa. SMShahrane@sfda.gov.sa.

ABSTRACT

Background: Florfenicol, a commonly used veterinary antibiotic, was reported to have caused a severe drop in egg hatchability following its off-label use on a broiler breeder farm in South Africa. According to the pharmacovigilance report, hatchability dropped by 80 % for up to a week following a five day course at 10 mg/kg (both males and females treated metaphylactically) to manage an Escherichia coli infection. While mammalian toxicity studies indicate the potential for early embryonic death in utero or testicular damage, no literature is available on the avian toxicity of florfenicol. For this study we investigated the effects of florfenicol at various doses from 10 to 90 mg/kg on the egg hatchability in a breeder flock we kept and established under controlled conditions, with the same cockerels and hens being exposed in a phased manner.

Results: Following five days of oral exposure, no toxic signs were evident in any of the cockerels or hens treated at doses up to 90 mg/kg. Treatment of only the cockerels had no effect on egg hatchability, while treatment of only the hens at doses of 60 and 90 mg/kg resulted in decreased hatchability of 0 % in comparison to 70 % of the control as early 24 h after treatment. In all cases, decreased hatchability was associated with embryonic death at 5 days of development. The toxic effects of florfenicol were completely reversible with comparable hatchability being present by day 4 post-treatment withdrawal. Toxicity correlated with total egg florfenicol concentrations with an LC50 of 1.07 μg/g.

Conclusion: Florfenicol appears to be toxic to the developing chick embryo at around day 5 of incubation, in the absence of related toxicity in the hen or cockerel.

No MeSH data available.


Related in: MedlinePlus

Fortified standard curve for the various concentrations of florfenicol spiked into egg samples
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Fig2: Fortified standard curve for the various concentrations of florfenicol spiked into egg samples

Mentions: Results were interpreted against a fortified curve in which known concentrations of florfenicol and thiamphenicol were added to eggs collected from the control birds for which were maintained strictly florfenicol free for the entire study (Fig. 2). The method was linear from 0.1 to 10 μg/g, with 0.1 μg/ml being the visual limit of the detection. The intra-day recovery (n = 2) was 91.96 and 103.02 % for the lowest and highest concentration with a corresponding relative standard deviation (RSD) of 3.8 and 1.21 % respectively. The inter-day recovery (n = 5) was 103.71 and 104.81 % for the lowest and highest concentration, with the corresponding RSD being 9.23 and 5.56 % respectively. All analysis was undertaken over a period of 5 days.Fig. 2


Florfenicol induces early embryonic death in eggs collected from treated hens.

Al-Shahrani S, Naidoo V - BMC Vet. Res. (2015)

Fortified standard curve for the various concentrations of florfenicol spiked into egg samples
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4538914&req=5

Fig2: Fortified standard curve for the various concentrations of florfenicol spiked into egg samples
Mentions: Results were interpreted against a fortified curve in which known concentrations of florfenicol and thiamphenicol were added to eggs collected from the control birds for which were maintained strictly florfenicol free for the entire study (Fig. 2). The method was linear from 0.1 to 10 μg/g, with 0.1 μg/ml being the visual limit of the detection. The intra-day recovery (n = 2) was 91.96 and 103.02 % for the lowest and highest concentration with a corresponding relative standard deviation (RSD) of 3.8 and 1.21 % respectively. The inter-day recovery (n = 5) was 103.71 and 104.81 % for the lowest and highest concentration, with the corresponding RSD being 9.23 and 5.56 % respectively. All analysis was undertaken over a period of 5 days.Fig. 2

Bottom Line: Treatment of only the cockerels had no effect on egg hatchability, while treatment of only the hens at doses of 60 and 90 mg/kg resulted in decreased hatchability of 0 % in comparison to 70 % of the control as early 24 h after treatment.In all cases, decreased hatchability was associated with embryonic death at 5 days of development.The toxic effects of florfenicol were completely reversible with comparable hatchability being present by day 4 post-treatment withdrawal.

View Article: PubMed Central - PubMed

Affiliation: Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, South Africa. SMShahrane@sfda.gov.sa.

ABSTRACT

Background: Florfenicol, a commonly used veterinary antibiotic, was reported to have caused a severe drop in egg hatchability following its off-label use on a broiler breeder farm in South Africa. According to the pharmacovigilance report, hatchability dropped by 80 % for up to a week following a five day course at 10 mg/kg (both males and females treated metaphylactically) to manage an Escherichia coli infection. While mammalian toxicity studies indicate the potential for early embryonic death in utero or testicular damage, no literature is available on the avian toxicity of florfenicol. For this study we investigated the effects of florfenicol at various doses from 10 to 90 mg/kg on the egg hatchability in a breeder flock we kept and established under controlled conditions, with the same cockerels and hens being exposed in a phased manner.

Results: Following five days of oral exposure, no toxic signs were evident in any of the cockerels or hens treated at doses up to 90 mg/kg. Treatment of only the cockerels had no effect on egg hatchability, while treatment of only the hens at doses of 60 and 90 mg/kg resulted in decreased hatchability of 0 % in comparison to 70 % of the control as early 24 h after treatment. In all cases, decreased hatchability was associated with embryonic death at 5 days of development. The toxic effects of florfenicol were completely reversible with comparable hatchability being present by day 4 post-treatment withdrawal. Toxicity correlated with total egg florfenicol concentrations with an LC50 of 1.07 μg/g.

Conclusion: Florfenicol appears to be toxic to the developing chick embryo at around day 5 of incubation, in the absence of related toxicity in the hen or cockerel.

No MeSH data available.


Related in: MedlinePlus