Genotype-dependent impact of dietary vitamin D3 on laying hens.

Vitamin D3 has an integral part in calcium and phosphorus homoeostasis, which in turn plays a key role in egg production of hens. The present study aimed to investigate whether an additional vitamin D3 supplementation improves the laying performance and egg quality of hens according to their genetic potential. For this purpose, four layer lines (low performing: R11 and L68; high performing: WLA and BLA) supplemented either with 300 or 3000 IU vitamin D3 per kg feed were compared concerning serum 25-hydroxyvitamin D3 (25-OHD3), calcium, phosphorus and alkaline phosphatase (ALP), laying performance and egg quality. The higher supplementation of vitamin D3 increased 25-OHD3 serum concentrations in all genotypes, except for R11 and WLA hens in week 49, and also elevated vitamin D3 and 25-OHD3 content in the egg yolk (p < 0.05). In week 29, 3000 IU vitamin D3 decreased pooled least squares means (LSMeans) of serum calcium concentrations considering all genotypes and increased the ALP concentrations in BLA hens (p < 0.05). Considering the whole experimental period daily egg mass of R11 hens was increased by an additional vitamin D3 supplementation (p < 0.001). Regarding all genotypes and the whole experimental period the pooled LSMeans of breaking strength of eggs from hens fed 3000 IU vitamin D3 were higher than those of hens fed 300 IU (p = 0.044). In conclusion, present results give evidence that the higher vitamin D3 supplementation might have genotype-dependently beneficial effects on calcium and phosphorus homoeostasis of hens, which might improve feed efficiency in the early laying period and promote the persistence of the laying period irrespectively of genotype. The increase of serum 25-OHD3 by the higher vitamin D supplementation supported the higher transfer of vitamin D in the egg yolk and improved genotype-dependently the breaking strength of the eggshell.

Genotypic and Dietary Effects on Egg Quality of Local Chicken Breeds and Their Crosses Fed with Faba Beans.

The quality of chicken eggs is an important criterion for food safety and the consumers' choice at the point of sale. Several studies have shown that egg quality can be influenced by the chickens' genotype and by the composition of the diet. The present study aimed to evaluate the effect of faba beans as a substitute for soybeans in the diet of chickens originating from traditional low-performance breeds in comparison with high-performing laying type hens and their crosses on egg quality parameters. Chickens of six different genotypes were fed either with a feed mix containing 20% faba beans with high or low vicin contents or, as a control, a feed mix containing soybeans. The genotypes studied were the local breeds Vorwerkhuhn and Bresse Gauloise, as well as commercial White Rock parent hens and their crosses. Yolk weight, Haugh units, yolk and shell color, the frequency of blood and meat spots and the composition of the eggs were significantly influenced by the genotype. The feeding of faba beans had an effect on yolk and shell color, Haugh units and shell portion, while there was no significant influence on the frequency of blood and meat spots.

Correction: Jansen, S., et al. Relationship between Bone Stability and Egg Production in Genetically Divergent Chicken Layer Lines. Animals 2020, 10, 850.

The authors wish to make the following corrections to this paper [...].

Bone Health or Performance? Adaptation Response of Genetically Divergent Chicken Layer Lines to a Nutritive Calcium Depletion.

In modern laying hybrids, calcium (Ca) homeostasis is immensely challenged by daily eggshell calcification. However, excessive mobilization of Ca from bones may lead to osteoporosis, which then manifests in a high incidence of poor bone quality. The aim of this study was to characterize the hens' adaptation response to an alternating dietary Ca restriction. The animal model consisted of four purebred layer lines, differing in laying performance (high vs. moderately performing lines) and phylogenetic origin (white- vs. brown-egg lines). According to the resource allocation theory, hens selected for high egg production were assumed to show a different response pattern to cope with this nutritive challenge compared to moderately performing lines. Data collected included egg number, egg quality traits, body weight and bone characteristics. The Ca depletion led to a temporary drop in egg production and shell quality and a loss of bone stability due to Ca mobilization. The white-egg lines response was more pronounced, whereas the brown-egg lines were less sensitive towards reduced Ca supply. Our study shows that the hens' responsiveness to coping with a nutritive Ca depletion is not ultimately linked to genetic selection for increased egg production but rather to phylogenetic origin.

Egg Production and Bone Stability of Local Chicken Breeds and Their Crosses Fed with Faba Beans.

Poultry production is raising concerns within the public regarding the practice of culling day-old chicks and the importation of soy from overseas for feedstuff. Therefore, an alternative approach to poultry production was tested. In two consecutive experiments, two traditional chicken breeds, Vorwerkhuhn and Bresse Gauloise, and White Rock as a commercial layer genotype as well as crossbreds thereof were fed diets containing either 20% vicin-rich or vicin-poor faba beans, though addressing both subjects of debate. Hen performance traits and bone stability were recorded. All parameters were considerably influenced by the genotype with White Rock showing the significantly highest (p < 0.05) laying performance (99.4% peak production) and mean egg weights (56.6 g) of the purebreds, but the lowest bone breaking strength (tibiotarsus 197.2 N, humerus 230.2 N). Regarding crossbreds, the Bresse Gauloise × White Rock cross performed best (peak production 98.1%, mean egg weight 58.0 g). However, only limited dietary effects were found as only the feeding of 20% vicin-rich faba beans led to a significant reduction of egg weights of at most 1.1 g (p < 0.05) and to a significant reduction of the shell stability in the crossbred genotypes. In terms of dual-purpose usage, crossing of Bresse Gauloise with White Rock seems to be the most promising variant studied here.

Meat Quality Parameters and Sensory Properties of One High-Performing and Two Local Chicken Breeds Fed with Vicia faba.

The current practices of the poultry industry have raised concerns among consumers. Among these is the culling of day-old male chicks of laying hybrids; a suitable alternative for this could be the use of dual-purpose breeds where both sexes are used. Another practice that causes concern is the import of large quantities of soybeans for feedstuff production. Substitutes for these soybean-based products are regional protein crops, such as faba beans (Vicia faba L.; FBs). The objective of this study was to test the suitability of FB as a locally produced soybean meal replacement for two local dual-purpose chicken breeds and one high-performing layer line. The breast and leg meat of male Bresse Gauloise (BG), Vorwerkhuhn (VH), and White Rock (WR) animals was evaluated for different meat quality parameters: pH, color, water holding capacity, and tenderness. Sensory properties of the samples were evaluated by a trained panel with a conventional descriptive analysis. Results show different effects of FB diets on meat quality parameters in the different breeds. The attributes mostly affected by the diet are related to aroma, flavor, and texture, particularly in VH and WR. Overall, faba beans appear to be an acceptable dietary protein source for rearing these breeds for meat production.

Relationship between Bone Stability and Egg Production in Genetically Divergent Chicken Layer Lines.

Impaired animal welfare due to skeletal disorders is likely one of the greatest issues currently facing the egg production industry. Reduced bone stability in laying hens is frequently attributed to long-term selection for increased egg production. The present study sought to analyse the relationship between bone stability traits and egg production. The study comprised four purebred layer lines, differing in their phylogenetic origin and performance level, providing extended insight into the phenotypic variability in bone characteristics in laying hens. Data collection included basic production parameters, bone morphometry, bone mineral density (BMD) and bone breaking strength (BBS) of the tibiotarsus and humerus. Using a multifactorial model and regression analyses, BMD proved to be of outstanding importance for bone stability. Only for the tibiotarsus were morphometric parameters and the bone weight associated with BBS. Within the chicken lines, no effect of total eggshell production on BBS or BMD could be detected, suggesting that a high egg yield itself is not necessarily a risk for poor bone health. Considering the complexity of osteoporosis, the estimated genetic parameters confirmed the importance of genetics in addressing the challenge of improving bone strength in layers.

Growth Performance of Local Chicken Breeds, a High-Performance Genotype and Their Crosses Fed with Regional Faba Beans to Replace Soy.

The faba bean (Vicia faba L.) is a native protein crop and considered a promising alternative to soybeans. Due to its anti-nutritive substances such as vicin and convicin (VC) its use in animal nutrition has been restricted. In the present study, two consecutive experiments were conducted to analyse the effects of feeding 20% faba beans, which differ in their VC content on fattening performance and slaughter traits of different chicken genotypes. In a first trial, purebred male chickens of the local breeds Bresse Gauloise and Vorwerkhuhn as well as of a high-performance White Rock line were tested. In a second trial, crossbreds of them were evaluated: Vorwerkhuhn x Bresse Gauloise, Vorwerkhuhn x White Rock, Bresse Gauloise x White Rock. Daily weight gain and feed intake were recorded until slaughter at approximately 2100 g. At slaughter the final live weight, carcass yield and the weights of the valuable parts (breasts and legs) were measured. For the genotypes studied, no adverse or undesirable effects of both VC-rich and VC-poor faba beans in the feedstuff were detected regarding body weight development, carcass quality, and fattening parameters. Furthermore, there was no indication that the birds' health was impaired.

Kinetic studies on clinical and immunological modulations by intramuscular injection of Escherichia coli LPS in laying hens.

The present study investigated clinical and immunological modulations due to intramuscular injection of Escherichia coli LPS in 49-wk-old laying hens over 48 h post injection (p.i.). LPS induced characteristic sickness behavior but no significant body temperature alterations ( P > 0.05). During experimental period decreases in blood albumin, calcium, phosphorus and tryptophan concentrations, hyperglycemia, increased plasma nitrite concentrations, leucopenia, decreased thrombocyte counts, lymphopenia, heterophilia and an increased heterophilic granulocyte/lymphocyte (H/L) ratio were observed after LPS administration. Time-dependent effects were shown on T and B cell subsets in caecal tonsils (CT) and on splenic CD3+/CD4+/CD8+ proportions, on IL-1ß and -10 and inducible NO synthase mRNA expression in peripheral blood lymphocytes (PBL), liver, spleen and CT, and on the mRNA expression of the TLR4 in PBL, liver and spleen p.i. ( P < 0.05). The main responding period of mentioned alterations due to LPS appears to include the period from 2 until 8 h p.i. According to the H/L ratio, the most stressful phase was 5 h p.i. T and B cell subsets in CT, the IL-1ß and TLR4 mRNA expression in liver and plasma nitrite concentrations seemed to be affected for a longer period.

Safety and efficacy of Deccox® (decoquinate) for chickens for fattening.

Deccox®, containing decoquinate as the active substance, is a feed additive intended to be used for the prevention of coccidiosis in chickens for fattening at a dose range of 20-40 mg/kg complete feed. Decoquinate from Deccox® is safe for chickens for fattening at the highest applied concentration in complete feed of 40 mg/kg. No practically relevant interactions with other additives or veterinary drugs exist except with bentonite. Decoquinate does not have antibacterial action. Decoquinate is not genotoxic and not carcinogenic. Deccox® is safe for the consumer under the proposed conditions of use. No withdrawal period is required to ensure consumer safety. No maximum residue limits are considered necessary. The inhalation risk for users is considered negligible since inhalation toxicity and exposure are very low. Deccox® is not an irritant to skin and eyes and has no sensitisation potential. The ratios predicted environmental concentration/predicted no effect concentration (PEC/PNEC) for terrestrial, aquatic compartment and sediment are below 1, indicating that decoquinate used in chickens for fattening up to the highest proposed dose, does not pose a risk for these compartments; as well, no risk is expected neither for secondary poisoning nor for groundwater contamination. Due to insufficient evidence, the potential of decoquinate to prevent coccidiosis in chickens for fattening cannot be established.

Safety and efficacy of Robenz® 66G (robenidine hydrochloride) for chickens for fattening and turkeys for fattening.

Following a request from European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of Robenz® 66G (robenidine hydrochloride (HCl)) when used as a feed additive for chickens for fattening and turkeys for fattening. The coccidiostat Robenz® 66G is considered safe for chickens for fattening at the highest proposed level of 36 mg robenidine HCl/kg complete feed with a margin of safety of approximately 2.5. This conclusion is extrapolated to turkeys for fattening. Robenidine HCl is active against Gram-positive but not against Gram-negative bacteria. It is not expected that the use of robenidine HCl as a feed additive would induce resistance or cross-resistance to antimicrobials used in human and animal therapy. The use of robenidine HCl from Robenz® 66G at the highest proposed level of 36 mg/kg complete feed in chickens and turkeys for fattening is considered safe for the consumer. The existing maximum residues limits for both avian species are confirmed. Robenidine HCl is not a skin or eye irritant and not a skin sensitiser. The risk via inhalation is considered negligible. The use of robenidine HCl from Robenz® in feed for chickens for fattening and turkeys for fattening up to 36 mg/kg complete feed does not pose a risk to either the terrestrial or the aquatic compartment. A risk for bioaccumulation cannot be excluded. The risk for secondary poisoning is not likely to occur. The FEEDAP Panel concludes that 36 mg robenidine HCl/kg complete feed from Robenz® 66G has the potential to effectively control coccidiosis of chickens for fattening under field conditions but cannot conclude on the efficacy of robenidine HCl in turkeys for fattening. The existing 5-day withdrawal period to avoid off-flavours in edible tissues should be maintained.

Safety and efficacy of Monimax® (monensin sodium and nicarbazin) for chickens for fattening and chickens reared for laying.

The coccidiostat Monimax® (monensin sodium and nicarbazin) is considered safe for chickens for fattening and chickens reared for laying at the highest use level of 50 mg monensin and 50 mg nicarbazin/kg complete feed. This conclusion is extended to chickens reared for laying. For both active substances, the metabolic pathways in the chicken are similar to those in the turkey and rat. Nicarbazin, when ingested, is rapidly split in its two components dinitrocarbanilide (DNC) and 2-hydroxy-4,6-dimethylpyrimidine (HDP) which behave independently. Monimax® does not represent a genotoxic risk. No safety concerns would arise from the nicarbazin impurities p-nitroaniline and methyl(4-nitrophenyl) carbamate. The lowest no observed effect level (NOEL) identified for monensin sodium in a developmental study in rabbits is 0.3 mg monensin sodium/kg body weight (bw) per day for maternal toxicity in rabbits. The lowest no observed adverse effect level (NOAEL) identified in a 52-week study in rat using DNC + HDP was 20 mg DNC + 8 mg HDP/kg bw per day based on the absence of microcrystals in urine and related microscopic renal observations. No significant interaction between monensin sodium and nicarbazin is expected from toxicological studies. The use of Monimax® at the highest proposed dose will not pose a risk to persons consuming animal products from treated chickens for fattening. This conclusion is extended to chickens reared for laying. No withdrawal time is required for Monimax® in chickens for fattening. Residue data comply with the established maximum residue limits (MRLs) for monensin and DNC. Based on the available data, the FEEDAP Panel cannot conclude on the safety of Monimax® for the environment. Monimax® has the potential to control coccidiosis in chickens for fattening at a minimum concentration of 40 mg monensin and 40 mg nicarbazin/kg complete feed.

Safety and efficacy of Monteban® G100 (narasin) for chickens for fattening.

The feed additive Monteban® G100, containing the active substance narasin, an ionophore anticoccidial, is intended to control coccidiosis in chickens for fattening at a dose of 60-70 mg/kg complete feed. Narasin is produced by fermentation. Limited data on the taxonomic identification of the production strain did not allow the proper identification of strain NRRL 8092 as Streptomyces aureofaciens. The FEEDAP Panel cannot conclude on the absence of genetic determinants for antimicrobial resistance in Streptomyces spp. under assessment. Based on the available data set, the FEEDAP Panel cannot conclude on the safety of Monteban® G100 for chickens for fattening. The simultaneous use of Monteban® G100 and certain antibiotic drugs (e.g. tiamulin) is contraindicated. Narasin is not genotoxic. No indication of carcinogenicity or developmental toxicity was found at the doses tested in the mouse, rat and rabbit. The lowest no observed effect level (NOEL) identified in the oral toxicity studies was 0.5 mg/kg body weight (bw) per day for the neuropathy seen in a one-year dog study. The acceptable daily intake (ADI) derived from this NOEL is 0.005 mg narasin/kg bw applying a uncertainty factor of 100. Monteban® G100 is safe for the consumer. Maximum residue limits (MRLs) of 50 µg narasin/kg for all wet tissues ensure consumer safety. Monteban® G100 is irritatant to the eyes but not to the skin. It has the potential to induce skin sensitisation. Inhalation exposure would pose a risk to persons handling the additive. Narasin, when used as a feed additive for chickens for fattening at 70 mg/kg feed, is not expected to pose a risk to the environment. The risk for sediment compartment cannot be assessed. The FEEDAP Panel cannot conclude on the efficacy of Monteban® at the minimum applied dose of 60 mg narasin/kg complete feed for chickens for fattening.

Safety and efficacy of Monteban® G100 (narasin) for ducks for fattening.

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of Monteban® G100 for ducks. Monteban® G100, containing narasin, is intended for the prevention of coccidiosis in ducks for fattening at a dose range of 60-70 mg/kg of complete feed. Narasin from Monteban® G100 is safe for ducks for fattening at a level of 70 mg/kg complete feed with a margin of safety of about 4. The FEEDAP Panel assumes that the residues in duck tissues would be of the same magnitude as those measured in the physiologically similar major species, chickens for fattening. The use of Monteban® G100 at a maximum concentration of 70 mg/kg complete feed for ducks for fattening is safe for the consumer without applying a withdrawal period, provided the maximum residue limit (MRL) of 50 µg narasin/kg for all wet tissues would not be exceeded. Monteban® G100 is irritant to the eyes but not to the skin. It has the potential to induce skin sensitisation. The acute systemic toxicity following dermal application is low. Inhalation exposure would pose a risk to persons handling the additive. Narasin, when used as feed additive for ducks for fattening at 70 mg/kg feed, is not expected to pose a risk to the environment. The risk for sediment compartment cannot be assessed. Narasin is not considered to have a bioaccumulation potential. Insufficient data were provided to allow a conclusion on the efficacy of Monteban® G100 in ducks.

Safety and efficacy of Coxiril® (diclazuril) for chickens reared for laying.

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of Coxiril® (diclazuril) for chickens reared for laying. Coxiril®, containing 0.5% diclazuril, is intended for the prevention of coccidiosis in chickens reared for laying at a dose range of 0.8-1.2 mg diclazuril/kg of complete feed up to a maximum age of 12 weeks. Derived from data already assessed for chickens and turkeys for fattening, diclazuril from Coxiril® is safe for chickens reared for laying up to 1.2 mg/kg complete feed when applied until 12 weeks of age. The FEEDAP Panel extended its previous assessment of consumer safety for the use of diclazuril from Coxiril® in chickens for fattening to chickens reared for laying. No measurable diclazuril residues were found in the first eggs laid from chickens reared for laying fed diclazuril from Coxiril® at 1.2 mg/kg complete feed until 12 weeks of age. Coxiril® was considered as a non-irritant to eyes and skin. It is not a potential skin sensitiser. User inhalation exposure to Coxiril®, as a result of normal handling, is unlikely to cause respiratory or systemic toxicity. The use of diclazuril from Coxiril® in chickens reared for laying at the highest proposed feed concentration would not pose a risk to the environment for neutral/alkaline soils (pH ≥ 7). A final conclusion on the risk resulting from the use of diclazuril in acid soil from Coxiril® cannot be done due to the high uncertainties related to potential accumulation of diclazuril over time. Derived from data already assessed for chickens for fattening, diclazuril from Coxiril® has the potential to control coccidiosis in chickens reared for laying at a minimum concentration of 0.8 mg/kg complete feed.

Safety and efficacy of Coxiril® (diclazuril) for pheasants.

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of Coxiril® for pheasants. Coxiril®, containing 0.5% diclazuril, is intended for the prevention of coccidiosis in pheasants at a dose range of 1.0-1.2 mg/kg of complete feed. Diclazuril from Coxiril® is considered safe for pheasants at a level of 1.2 mg/kg complete feed. The conclusion was made by extrapolating the results of a tolerance study with turkeys for fattening. The FEEDAP Panel considered that the residues in pheasant tissues and eggs would be of the same magnitude as those measured in the physiologically similar major species chickens and turkeys for fattening. The use of diclazuril at a maximum concentration of 1.2 mg/kg complete fed for pheasants would be safe for the consumer, provided that the maximum residue limits (MRLs) established for poultry would not be exceeded. The conclusions on the safety of the additive for the target species and the consumer are made under the provision that Coxiril® is not fed to laying birds. Coxiril® is considered as a non-irritant to eyes and skin. It is not a potential skin sensitiser. User inhalation exposure to Coxiril®, as a result of normal handling, is unlikely to cause respiratory or systemic toxicity. The use of diclazuril from Coxiril® in pheasants does not pose a risk to the environment for neutral/alkaline soils (pH ≥ 7). A final conclusion on the risk resulting from the use of the additive in acid soil cannot be done due to the high uncertainties related to potential accumulation of diclazuril over time. The FEEDAP Panel concluded that diclazuril from Coxiril® at a minimum dose of 1 mg/kg complete feed has the potential to control coccidiosis in pheasants.

Safety and efficacy of Sacox® microGranulate (salinomycin sodium) for rabbits for fattening.

Sacox ® microGranulates, containing salinomycin sodium (SAL-Na), for chickens for fattening and chickens reared for laying have been recently re-evaluated by Panel on Additives and Products or Substances used in Animal Feed. Following an urgent request from the European Commission, the safety and efficacy of the product when fed to rabbits for fattening was assessed based on the available data submitted by the applicant at the beginning of the assessment. SAL-Na is largely absorbed and metabolised. Metabolites have a reduced ionophoric activity. SAL is the marker residue. SAL-Na is not genotoxic and not a carcinogen. A no observed adverse effect level (NOAEL) of 0.5 mg/kg body weight (bw) per day is derived from a study in dogs. Only data on feed intake and body weight were available to conclude on the safety of SAL for rabbits. Levels of 35 mg SAL/kg feed and higher were not tolerated by growing rabbits. The Panel considers the available data indicate that the additive is tolerated by rabbits for fattening up to 25 mg/kg. The safety of SAL in rabbits for fattening needs to be established by a tolerance study compliant with the current standards. Adverse effects on breeding does cannot be excluded. The simultaneous use of SAL-Na with certain medicinal substances (e.g. tiamulin and valnemulin) and bentonite is contraindicated. Consumer exposure to residues of toxicological concern complies with the acceptable daily intake (ADI) of 0.005 mg/kg bw, after 1-day withdrawal. A provisional maximum residue limit (MRL) of 0.01 mg/kg liver would ensure consumer safety. A 5-day withdrawal period as proposed by the applicant is supported. SAL-Na in feed for rabbits will not pose a risk for the aquatic environment. A risk for the terrestrial ecosystem is considered unlikely. Efficacy and effective dose of SAL-Na under present farming conditions could not be established.

Safety and efficacy of Coxar® (nicarbazin) for turkeys for fattening.

The coccidiostat Coxar® is safe for turkeys for fattening at the use level of 100 mg nicarbazin/kg complete feed, with a margin of safety of about 1.25. Nicarbazin, when ingested, is rapidly split in its two components 2-hydroxy-4,6-dimethylpyrimidine (HDP) and dinitrocarbanilide (DNC), which behave independently. HDP-related residues are much lower than those of DNC. DNC is the marker residue. Liver is the target tissue. Nicarbazin is not genotoxic. The primary toxicity resulting from the oral use of nicarbazin is renal toxicity. The lowest no observed adverse effect level (NOAEL) identified in a 52-week study in rat using DNC+HDP is 20 mg DNC + 8 mg HDP/kg body weight (bw) per day based on the absence of microcrystals in urine and related microscopic renal observations. The use of 100 mg nicarbazin from Coxar®/kg complete feed for turkeys for fattening will not pose a risk to consumers, provided that maximum contents in nicarbazin of 0.1% p-nitroaniline (PNA) and 0.4% methyl(4-nitrophenyl) carbamate (M4NPC) would be respected. No withdrawal time is required. Residue data comply with the established maximum residue limits (MRLs). Nicarbazin is not a skin or eye irritant and not a skin sensitiser. These conclusions also apply to the additive Coxar®. Inhalation toxicity of nicarbazin is limited; the granulated additive has a low dusting potential. No risk for users is identified. Based on the available data, the FEEDAP Panel cannot conclude on the safety of Coxar® for the environment. The efficacy of 100 mg nicarbazin from Coxar®/kg feed was demonstrated in three anticoccidial sensitivity tests (AST), but only in one floor pen study. The floor pen study with 75 mg nicarbazin failed to demonstrate evidence of efficacy. No final conclusions on the efficacy of nicarbazin from Coxar® for turkeys for fattening can be drawn.

Safety and efficacy of COXAM® (amprolium hydrochloride) for chickens for fattening and chickens reared for laying.

The coccidiostat amprolium hydrochloride from COXAM ® is considered safe for chickens for fattening at 125 mg/kg complete feed. The margin of safety is at least 5. This conclusion is extended to chickens reared for laying. Amprolium hydrochloride does not possess any significant antibacterial activity. The applicant provided no information on the absorption, distribution, metabolism and excretion (ADME) and on the toxicology of the additive or active substance. Reference was made to the Committee for Medicinal Products for Veterinary Use (CVMP) summary reports from 1999 and 2001 citing studies used for the establishment of maximum residue limits (MRLs) for amprolium. However, the original data used in these assessments were not provided and the literature review covering the subsequent period was not made. Thus, the FEEDAP Panel cannot independently evaluate all data relevant to the current application and is therefore unable to conclude on the safety for the consumer of amprolium when used as a feed additive in chickens for fattening and chickens reared for laying. COXAM ® is considered to be a skin and respiratory sensitiser. Inhalation exposure to dust from COXAM ® may present a risk for the user. The use of amprolium hydrochloride from COXAM ® in feed for chickens for fattening up to 125 mg/kg complete feed does not pose a risk for the environment. This conclusion can be extended to chickens reared for laying because of the lower predicted concentration in soil. COXAM ® was effective as a coccidiostat in three floor pen studies and in two anticoccidial sensitivity tests. Since three anticoccidial sensitivity tests showing positive effects of the treatment are required, the FEEDAP Panel is not in the position to conclude on the efficacy of COXAM ® for chickens for fattening under EU farming conditions. Consequently, a conclusion on the efficacy for chickens reared for laying is also not possible.

Scientific Opinion on the safety and efficacy of Aviax 5% (semduramicin sodium) for chickens for fattening.

The feed additive Aviax 5%, containing the active substance semduramicin sodium, an ionophore anticoccidial, is intended to control coccidiosis in chickens for fattening at a dose of 20-25 mg/kg complete feed. Semduramicin sodium is present in Aviax 5% in its mycelial form and is produced by fermentation of Actinomadura spp. (ATCC 53664). Semduramicin sodium is active against certain Gram-positive bacteria, while Gram-negative bacteria are resistant; its use as a feed additive is unlikely to increase shedding of Salmonella, Escherichia coli and Campylobacter and to induce resistance and cross-resistance to antimicrobials used of human and animal relevance. In the absence of a tolerance study in chickens for fattening performed according to the current EU standards, the FEEDAP Panel cannot conclude on the safety of Aviax 5%, containing semduramicin mycelium. Semduramicin sodium in the feed is not compatible with the concurrent use of tiamulin. Mycelial semduramicin sodium is not genotoxic. There is no evidence that the mycelial semduramicin is more toxic than the crystalline by oral administration. The acceptable daily intake (ADI) of 0.00125 mg/kg set for the crystalline semduramicin is applicable to mycelial semduramicin. The use of semduramicin sodium is safe for the consumer provided a withdrawal time of 24 h is respected. No conclusions can be made on the irritancy of Aviax 5% to skin and eye and on the potential for dermal and respiratory sensitisation. Model calculations on inhalation exposure of persons handling the additive indicate a serious risk. Aviax 5% used in feed for chickens for fattening up to 25 mg/kg complete feed does not pose a risk for the terrestrial compartment. A risk for the aquatic compartment and for groundwater pollution cannot be excluded. Aviax 5% at a minimum dose of 20 mg/kg feed has the potential to effectively control coccidiosis in chickens for fattening.