The EFSA Journal (2005) 231, 1-6

Transcription

1 The EFSA Journal (2005) 231, 1-6 Opinion of the Scientific Panel on Additives and Products or Substances used in Animal Feed on the safety of the enzyme preparation Econase Wheat Plus for use as feed additive for chickens for fattening (Question No EFSA-Q ) Adopted on 15 June 2005 SUMMARY The product Econase Wheat Plus is a preparation of endo-1,4-beta-xylanase produced by Trichoderma reesei (CBS ), and endo-1,3(4)-beta-glucanase produced by Trichoderma reesei (CBS ) intended for use in wheat based poultry diets. The safety evaluation (consumer, user and environment) of Econase Wheat has been done previously by the Scientific Committee on Animal Nutrition (SCAN) (16 October 2002). In a further safety assessment of Econase Wheat Plus, limited to the target animals (chickens for fattening and turkeys for fattening), SCAN concluded that, due to the inadequate experimental design, another tolerance test in chickens for fattening was necessary in order to assess the safety of the product. The European Food Safety Authority received a request to assess the safety for chickens for fattening. A new tolerance test was provided by the petitioner. This test carried out with 3360 chickens for fattening over a 35-day period, at the recommended highest dose of xylanase (analysed in-feed value) and at an intended 10 times the recommended highest dose of glucanase (analysed in-feed value), demonstrated no adverse effects on performance, mortality rate and carcass characteristics. Incidence of dyschondroplasia like tibial aberrations was not affected. Consequently, the FEEDAP Panel is of the opinion that the safety of Econase Wheat Plus for chickens for fattening has been demonstrated. Keywords: feed additive, tolerance, xylanase, glucanase, safety, chickens for fattening

2 Opinion on Econase Wheat Plus for chickens for fattening 2/6 BACKGROUND Council Directive 70/524/EEC establishes rules governing the Community authorisation of additives for animal nutrition and in particular defines the conditions that a substance/product should meet to get authorisation. The company AB Enzymes is seeking provisional Community authorisation of its enzyme product with the trade name ECONASE Wheat Plus L and P, as a feed additive intended for use in chickens for fattening under the category "Enzyme" (Table 1). Table 1. Description of the product: Product category: Enzyme Trade name: ECONASE Wheat Plus L and P Preparation of endo-1, 4-beta-xylanase (IUB ) from Description: Trichoderma reesei CBS and endo-1, 3(4)-betaglucanase (IUB ) from Trichoderma reesei CBS (in ratio of 4:1) Target animal category: Chickens for fattening Applicant: AB Enzymes Member State Rapporteur: FI Type of request: Provisional authorisation In accordance with the above legislation, the Commission received a request from this company, through FI, the Member State rapporteur chosen by the company, to authorise its product under the conditions set out in Table 2. Supporting data produced by the company were compiled in a dossier and accompanied that application. All Member States received the dossier. This dossier was made available to the European Food Safety Authority directly by the company, via its Member State rapporteur. The safety of the product Econase Wheat had been evaluated by the SCAN in its opinion on the use of certain enzymes in animal feedingstuffs adopted on 4 June 1998, updated on 16 October 2002 (available on and in its opinion on the safety of the enzymatic product Econase Wheat Plus for use as feed additive in chickens and turkeys for fattening, adopted on 22 January 2003 (available on TERMS OF REFERENCE In view of the above, the Commission asks the European Food Safety Authority to deliver an opinion on the safety of the enzyme preparation "Econase Wheat Plus L and P", which is a preparation of endo-1, 4-beta-xylanase (IUB ) from Trichoderma reesei CBS and endo-1, 3(4)-beta-glucanase (IUB ) from Trichoderma reesei CBS , for the chickens for fattening, when used under the conditions set out in Table 2 below, taking into account the background and the information submitted by the applicant in the dossier.

3 Opinion on Econase Wheat Plus for chickens for fattening 3/6 Table 2. Annex entry Endo-1,4- Additive beta-xylanase EC Endo-1,3(4)- beta-glucanase EC Chemical formula, description Preparation of endo-1,4 -betaxylanase produced by Trichoderma reesei (CBS ) and endo- 1,3(4)-beta-glucanase produced by Trichoderma reesei (CBS ) having minimum activities of: Solid form: BXU 1 g BU 2 g -1 Species or category of animal Chickens for fattening Maximum age Minimum content Maximum content Units of activity kg -1 of complete feedingstuff BXU BU - Other provisions 1. In the directions for use of the additive and pre-mixture, indicate the storage temperature, storage life, and stability to pelleting. 2. Recommended dose per kg of complete feedingstuff: BXU BU Liquid form: BXU 1 g BU 2 g For use in compound feed rich in non-starch polysaccharides (mainly arabinoxylans and glucans), e.g. containing more than 53.5% wheat 1 1 BXU is the amount of enzyme which liberates 0.06 micromoles of reducing sugars (xylose equivalents) from birch xylan per minute at ph 5.3 and 50 C 2 1 BU is the amount enzyme which liberates 0.06 micromoles of reducing sugars (glucose equivalents) from barley beta-glucan per minute at ph 4.8 and 50 C.

4 Opinion on Econase Wheat Plus for chickens for fattening 4/6 ASSESSMENT 1. Introduction The product Econase Wheat Plus is a preparation of endo-1,4-beta-xylanase produced by Trichoderma reesei (CBS ), and endo-1,3(4)-beta-glucanase produced by Trichoderma reesei (CBS ) with a minimum activity of, for solid form: BXU g - 1 and BU g -1 and for liquid form: BXU g -1 and BU g -1, intended for use in wheat-based poultry diets. The safety evaluation (consumer, user, and environment) of Econase Wheat has been done previously by the SCAN 3 (16 October 2002). In a further safety assessment of Econase Wheat Plus, limited to the target animals (chickens for fattening and turkeys for fattening), SCAN 4 (22 January 2003) concluded that another tolerance test in broilers was necessary in order to assess and demonstrate the safety, due to the weak experimental design (only 40 animals) and to the fact that besides the occurrence of many leg disorders, enlargement of duodenum and jejunum was noted. Therefore, in the present dossier a new tolerance test with broilers was included by the petitioner. 2. Safety for the chickens for fattening The 35 day tolerance test for Econase Wheat Plus was conducted as part of a study including several xylanase preparations and 5600 chickens for fattening. Only the relevant treatments are reported here one-day old chickens for fattening (Ross breed) were housed on floor pens and randomly distributed over three dietary treatments: control, Econase Wheat Plus BXU kg -1 (highest recommended dose) and Econase Wheat Plus BXU kg -1 (10 times highest recommended dose), with eight pens per treatment and 70 chicks of each sex per pen. Analyses of the original enzyme preparation confirmed the xylanase activity ( BXU kg -1 ). For the first two weeks birds were fed a starter diet; thereafter a grower diet until 5 days before slaughter. For the last 5 days a finisher diet without a coccidiostat was used. The solid form of Econase Wheat Plus was used in the all-mash diets. Feed consumption was recorded during grower and finisher period and body weight of groups on day 0, 14 and 35. Mortality was checked daily. At day 35, all animals were slaughtered, carcass and abdominal fat weighed and livers collected. Furthermore, bones (tibiotarsus, os femoris) were collected from 32 birds per treatment, chosen at random, for chemical analysis (ash, P, Ca), bone area and density (computer tomography) and occurrence and scoring of the degree of dyschondroplasia. It can be concluded that Econase Wheat Plus at BXU kg -1 has no detrimental effects on performance, mortality rate or carcass characteristics of the chickens (Table 3). The previous SCAN opinion (2003) identified many leg disorders. In the present experiment, leg disorders were very low (1 bird per treatment) during the whole experiment. The incidence of dyschondroplasia-like aberrations (20-25 % of all investigated bones) were not different from those on the control diet. Measure of the in-feed enzyme activity suggests that the studies were done at about 6.5 times 7.5 times the highest recommended dose of xylanase and glucanase respectively. However, FEEDAP Panel believes that this difference with the added enzyme is due to analytical problems

5 Opinion on Econase Wheat Plus for chickens for fattening 5/6 Table 3. Effect of feeding Econase Wheat Plus on performance, carcass traits and some bone parameters of chickens for fattening, fed a wheat-based diet during 35 days Control Econase Wheat Plus BXU kg -1 Econase Wheat Plus BXU kg -1 Average feed consumption (g bird -1 ) Starter b 474 ab 486 a Grower/finisher Total Average daily gain (g day -1 ) Starter 26.4 c 28.8 b 30.2 a Grower/finisher Total 49.8 b 50.8 ab 52.0 a Feed /Gain ratio Starter a a b Grower/finisher Total a b b Mortality (%) Starter Grower/finisher Total Live weight at day 35 (g) 1733 c 1769 bc 1808 ab Carcass yield (%) 63.2 b 64.5 a 65.1 a Abdominal fat (%) 0.76 a 0.87 a 0.99 b Total bone area (mm 2 ) Total bone density (mg cm -3 ) Corticalis strength index Tibia weight (g) 13.9 b 15.9 ab 16.8 a Tibia ash (% DM) 37.6 a 35.8 b 36.2 b Tibia Ca (% DM) 12.6 a 11.5 b 11.6 b Tibia P (% DM) 6.4 a 5.9 b 6.2 ab Tibial dyschondroplasia (n) 6/30 7/26 7/27 a,b,c: means in a row with different superscripts are significantly different (P 0.05) 1 Analysed values for xylanase and β-glucanase (starter, grower, finisher) 42900, 50300, BXU kg -1 and 7800, 6100, 4900 BU kg -1 2 Analysed values for xylanase and β-glucanase (starter, grower, finisher) , , BXU kg -1 and 62800, 62500, BU kg -1 3 Starter feed: days 0-14; grower feed: days 15-30; finisher feed: days CONCLUSIONS The tolerance test demonstrated no detrimental effects on performance, mortality rate, carcass characteristics of the chickens for fattening and tibial discondroplasia was not affected. Consequently, the FEEDAP Panel is of the opinion that the safety of Econase Wheat Plus for chickens for fattening has been demonstrated.

6 Opinion on Econase Wheat Plus for chickens for fattening 6/6 DOCUMENTATION PROVIDED TO EFSA 1. Supplementary dossier. Econase Wheat Plus. New tolerance data on broilers and answers to the questions of Austria, France, Germany, The Netherlands and The United Kingdom. February Submitted by AB Enzymes Oy, Finland. 2. Dossier on Econase Wheat Plus as an additive in feedingstuffs for chickens and turkeys for fattening. Supplement 3. Answers to the questions of the United Kingdom and France; final reports of new efficacy studies on chickens and turkeys for fattening. February Submitted by AB Enzymes Oy, Finland. PANEL MEMBERS Arturo Anadón, Margarita Arboix Arzo, Georges Bories, Paul Brantom, Joaquim Brufau de Barberà, Andrew Chesson, Pier Sandro Cocconcelli, Joop de Knecht, Noël Dierick, Gerhard Flachowsky, Anders Franklin, Jürgen Gropp, Ingrid Halle, Anne-Katrine Lundebye Haldorsen, Alberto Mantovani, Kimmo Peltonen, Guido Rychen, Pascal Sanders, Amadeu Soares, Pieter Wester and Wilhelm Windisch