Literatur / Sicherheit
Greifvögel und andere Wildtiere/Tiere:
Hier einige Literatur über die Sicherheit von Ovistop bei Greifvögeln. Ovistop hat keine toxische Wirkung auf Greife und hat auch keinen negativen Einfluss auf die Schlupfrate. Das hat man bei mehreren Pärchen gesehen, die in unmittelbarer Umgebung von einer Ovistop Fütterungsstelle brüten. Hier ein Link zu einem Wanderfalken Pärchen in Gevaert (Belgien) mit genauer Dokumentation über die Eiablage und die Entwicklung der Küken: Webcam – Slechtvalken (agfa.be). Es zeigt deutlich, dass Ovistop nicht gefährlich nicht für Greifvögel.
Weitere Literatur aus dem Ausland:
Safety of Nicarbazin in Raptors in Relation to Pigeon Eradication Programs
"the risk of adverse effects on nontarget birds of prey is extraordinarily low, and any potential exposure is estimated to be well below the dosage necessary to have any toxicological or pharmacological effects. There are thus no risk from secondary exposure to NCZ in raptors in relation to pigeon eradication programs."
Offizielle Website der kanadischen Regierung zur Zulassung von Nicarbazin/OvoControl
"Nicarbazin is not acutely toxic to birds or other terrestrial and aquatic organisms. Effects on birds are limited to the reduction of egg hatch caused by DNC and the effects are reversible. Daily exposure to non-target birds from bait pellets is not expected, because the bait is consumed quickly by the target pigeons. Exposure to birds of prey or scavengers is also expected to be minimal since the DNC found in pigeon tissue is not easily absorbed and no effects are expected from HDP."
Offizielle Website der Stadt Barcelona (Spanien)
"When pigeons ingest nicarbazin, they metabolise it quickly and it breaks up into two components, DCN, the active part, and HDP, which enables its absorption into bird intestines. So, when a bird of prey eats a pigeon treated with nicarbazin, it ingests the broken-up, inactive form of that product, which cannot be absorbed. Even then, the inactive nicarbazin residues that it can consume are insignificant, given the low quantity that remains in the pigeon’s tissues and organs."
Controlling urban pigeon populations humanely
"There is no risk posed to raptors that eat pigeons that have consumed nicarbazin. When pigeons ingest nicarbazin, they metabolize it rapidly and it breaks down into the two components. When a raptor eats a pigeon treated with nicarbazin, the nicarbazin exists in a dissociated form and is consequently inactive because it cannot be absorbed or the remaining inactive nicarbazin, that could be consumed, is irrelevant due to the scarce amount that remains (WHO, 1999; UN et al., 2000)"
Botstiber Institute for wildlife fertility Controle (Fact sheet)
"When pigeons ingest nicarbazin, they metabolise it quickly and it breaks up into two components, DCN, the active part, and HDP, which enables its absorption into bird intestines. So, when a bird of prey eats a pigeon treated with nicarbazin, it ingests the broken-up, inactive form of that product, which cannot be absorbed. Even then, the inactive nicarbazin residues that it can consume are insignificant, given the low quantity that remains in the pigeon’s tissues and organs."
Offizielle Website der kanadischen Regierung zur Zulassung von OvoControl (Ovistop in Amerika, aber mit einer 6-fach höheren Dosierung)
"Nicarbazin is not acutely toxic to birds or other terrestrial and aquatic organisms. Effects on birds are limited to the reduction of egg hatch caused by DNC and the effects are reversible. Daily exposure to non-target birds from bait pellets is not expected, because the bait is consumed quickly by the target pigeons. Exposure to birds of prey or scavengers is also expected to be minimal since the DNC found in pigeon tissue is not easily absorbed and no effects are expected from HDP."
EPA Nicarbazin Fact Sheet
"The potential for human exposure and mammals (e.g. dogs) is anticipated to be low from the use of nicarbazin fed to
resident Canada geese. The WHO studies indicate that non-target mammals (including humans) would have to consume
prohibitively large amounts of the product to produce any toxic effects. Based on the rat acute oral LD50 toxicology data, an
acute single ingestion for a child (15kg or 33lbs) would have to exceed 60 kilograms (132 pounds) of bait and for a dog (10kg
or 23lb.) 40kg (88lbs) of bait to cause lethal effects in 50% of the population"
The Secondary Toxicity of OvoControl® (nicarbazin) in Birds
„Likewise, the consumption of OvoControl bait through undigested prey gut contents could also be considered a means of exposure. However, unlike a toxicant, the consumption of one pigeon with undigested bait does not constitute even a single dose for a raptor. OvoControl requires both an adequate dose and adequate duration to achieve a contraceptive effect. Therefore, a 1500 gram Peregrine falcon requires 5x the dose of a 300 gram pigeon and would have to consume 5 pigeons/day. Furthermore, the dose must be provided daily, for a minimum of 5 days to achieve a contraceptive blood level. In other words, the falcon would have to consume the undigested OvoControl containing gut contents of 25 pigeons over 5 days to achieve the contraceptive blood level. This scenario is extremely remote, if not impossible.“
Offizielle Website der kanadischen Regierung zur Zulassung von Nicarbazin/OvoControl
"Nicarbazin is not acutely toxic to birds or other terrestrial and aquatic organisms. Effects on birds are limited to the reduction of egg hatch caused by DNC and the effects are reversible. Daily exposure to non-target birds from bait pellets is not expected, because the bait is consumed quickly by the target pigeons. Exposure to birds of prey or scavengers is also expected to be minimal since the DNC found in pigeon tissue is not easily absorbed and no effects are expected from HDP."
Offizielle Website der Stadt Barcelona (Spanien)
"When pigeons ingest nicarbazin, they metabolise it quickly and it breaks up into two components, DCN, the active part, and HDP, which enables its absorption into bird intestines. So, when a bird of prey eats a pigeon treated with nicarbazin, it ingests the broken-up, inactive form of that product, which cannot be absorbed. Even then, the inactive nicarbazin residues that it can consume are insignificant, given the low quantity that remains in the pigeon’s tissues and organs."
Controlling urban pigeon populations humanely
"There is no risk posed to raptors that eat pigeons that have consumed nicarbazin. When pigeons ingest nicarbazin, they metabolize it rapidly and it breaks down into the two components. When a raptor eats a pigeon treated with nicarbazin, the nicarbazin exists in a dissociated form and is consequently inactive because it cannot be absorbed or the remaining inactive nicarbazin, that could be consumed, is irrelevant due to the scarce amount that remains (WHO, 1999; UN et al., 2000)"
Botstiber Institute for wildlife fertility Controle (Fact sheet)
"When pigeons ingest nicarbazin, they metabolise it quickly and it breaks up into two components, DCN, the active part, and HDP, which enables its absorption into bird intestines. So, when a bird of prey eats a pigeon treated with nicarbazin, it ingests the broken-up, inactive form of that product, which cannot be absorbed. Even then, the inactive nicarbazin residues that it can consume are insignificant, given the low quantity that remains in the pigeon’s tissues and organs."
"Nicarbazin is not acutely toxic to birds or other terrestrial and aquatic organisms. Effects on birds are limited to the reduction of egg hatch caused by DNC and the effects are reversible. Daily exposure to non-target birds from bait pellets is not expected, because the bait is consumed quickly by the target pigeons. Exposure to birds of prey or scavengers is also expected to be minimal since the DNC found in pigeon tissue is not easily absorbed and no effects are expected from HDP."
EPA Nicarbazin Fact Sheet
"The potential for human exposure and mammals (e.g. dogs) is anticipated to be low from the use of nicarbazin fed to
resident Canada geese. The WHO studies indicate that non-target mammals (including humans) would have to consume
prohibitively large amounts of the product to produce any toxic effects. Based on the rat acute oral LD50 toxicology data, an
acute single ingestion for a child (15kg or 33lbs) would have to exceed 60 kilograms (132 pounds) of bait and for a dog (10kg
or 23lb.) 40kg (88lbs) of bait to cause lethal effects in 50% of the population"
The Secondary Toxicity of OvoControl® (nicarbazin) in Birds
„Likewise, the consumption of OvoControl bait through undigested prey gut contents could also be considered a means of exposure. However, unlike a toxicant, the consumption of one pigeon with undigested bait does not constitute even a single dose for a raptor. OvoControl requires both an adequate dose and adequate duration to achieve a contraceptive effect. Therefore, a 1500 gram Peregrine falcon requires 5x the dose of a 300 gram pigeon and would have to consume 5 pigeons/day. Furthermore, the dose must be provided daily, for a minimum of 5 days to achieve a contraceptive blood level. In other words, the falcon would have to consume the undigested OvoControl containing gut contents of 25 pigeons over 5 days to achieve the contraceptive blood level. This scenario is extremely remote, if not impossible.“
Wirkungsmechanismus und Feldversuche:
Nicarbazin wurde schon 1950 in der Geflügelindustrie angewendet. Wenn die Tauben Ovistop (mit 0,8mg Nicarbazin/kg) aufnehmen, wird dieses sofort in seine 2 Bauteile (DNC und HDP) zerlegt. Diese beiden Bausteine können sich danach nicht mehr zusammenschließen. Die Vitellin Membran im Ei, welche Dotter und Eiweiß trennt wird beschädigt. Eine Entwicklung vom Embryo ist nicht möglich. Hier finden Sie noch weitere Literatur:
Feldversuch aus Genoa (Italien)
„From the analysis of the superimposable trend over the years, 2 reduction phases were observed during the treatment period. The first one was observed in the first 2 or 3 years and led to a significant reduction of about 40%; the second phase was observed in subsequent years with a further reduction of up to 65% with respect to the original dimension of the population.“
National wildlife research center, Colorado
"Metabolic studies show that HDP is cleared within 24 h in the urine, whereas DNC remains in the blood for approximately 4 d before clearing in the feces “
Merck Institute of Therapeutic research, New Jersey
„…. 4,4′-dinitrocarbanilide (DNC) and 2-hydroxy4,6-dimethylpyrimidine (HDP). The function of HDP is to increase absorption of the material in the gut, whereas DNC is the active anticoccidial drug“
US Department of Agriculture/Animal and Planet health
„Nicarbazin (NCZ) is a compound approved by the FDA for control of coccidiosis in broiler chickens; if accidentally fed to breeder or layer hens, NCZ causes reduction in hatchability and egg laying due to increased permeability of the membrane between the egg white and egg yolk, which destroys the conditions necessary for development of the embryo“
„Advantages of nicarbazin are that it is specific to egg layers, it is cleared from the body within approximately 48 h and the infertility effect is reversible“
„Nicarbazin has been used by the poultry industry in numerous countries for 45 years. It has no effects in mammal species and is safe for both target and non-target bird species, even when administered at much higher doses than needed to cause the contraceptive effect“
Merck Institute of Therapeutic research, New Jersey
„…. 4,4′-dinitrocarbanilide (DNC) and 2-hydroxy4,6-dimethylpyrimidine (HDP). The function of HDP is to increase absorption of the material in the gut, whereas DNC is the active anticoccidial drug“
Umwelt:
Mehrere Studien belegen, dass Ovistop keinen negativen Einfluss auf die Umwelt hat. Hier weitere Literatur:
EFSA Journal, Monimax (registriertes Tierarzneimittel für Hühner) mit Nicarbazin und Monensin
"DNC does not bioaccumulate in the environment and the risk for secondary poisoning is not likely to occur."
EFSA Journal, a. Koffogran (registriertes Tierarzneimittel für Hühner) mit 25% Nicarbazin:
„Ingested nicarbazin is rapidly split into its components 2-hydroxy-4,6-dimethylpyrimidine (HDP) and 4,4’-dinitrocarbanilide (DNC). DNC is the marker residue, liver the target tissue. HDP-related residues are much lower than those derived from DNC. Nicarbazin is not genotoxic.“
„No safety concern for the soil compartment, groundwater or by secondary poisoning was identified, the risk for surface water could however not be assessed.“