Phosphorous is essential for many metabolic functions and the constitution of bones. Poultry have limited ability to use phosphorous from diets, which is mainly excreted and causes environmental concern. For this reason, diets are commonly supplemented with inorganic phosphorus and phytases. It has been suggested that chickens can adapt to an early nutrient restriction by increasing its efficiency of utilization, an adaptation that has been defined as nutritional conditioning. The aim of this study was to investigate a strategy of phosphorous nutritional conditioning by feeding low phosphorous diets during the first week of life as a strategy to improve the efficiency of phosphorous utilization later in life. To test this, 600 male broiler chickens were fed either a standard (control group) or a phosphorous-deficient diet (conditioned group) during the first week of life. Later in life, the effect of conditioning was tested using standard or P-deficient diets during the finishing phase (21-43 d). Conditioning did not affect overall performance, despite finding evidence for reduced relative phosphorous excretion between days 19 to 21, increased duodenal gene expression for the phosphorous transporter SLC34A2 at day 30 (-6% and +17%, respectively), and tendencies for improved phosphorous digestibility (+7%) and tibia mineralization (+6%) at the end of the trial. It is concluded that phosphorous nutritional conditioning early in life can increase subsequent dietary phosphorous utilization and bone mineralization in poultry, although it may not be able to counteract severe phosphorous deficiencies. Further research is required to assess the extent to which phosphorous supplementation in post-conditioning diets may be reduced with this strategy without compromising performance.

Weaning is a decisive event in piglets' life. This study aimed to evaluate whether the inclusion of fish oil, rich in eicosapentaenoic and docosahexaenoic acids (EPA and DHA), in sow and piglet diets, increased the concentration of anti-inflammatory molecules in the blood of weaned piglets and whether the effect was dependent on the pigs being born with either low or a high birth BW (bBW). Thirty-six sows in four consecutive batches were randomly distributed between a control diet with animal fat (15 g/kg in gestation and 30 g/kg in lactation) or a n-3 long-chain fatty acid diet (LCFA; totally or half replacing animal fat by fish oil during gestation and lactation, respectively) from service until weaning (ca. 28 days). At birth, the two lightest (LBW) and the two heaviest (HBW) piglets in each litter were identified and, at weaning, grouped in pens by pairs prioritising their bBW. Pens were further distributed into a control (30 g/kg animal fat) or n-3 LCFA diet (totally replacing animal fat by fish oil) for 28 days. At the end of the trial, blood was collected from piglets in the first batch (n = 48). Serum fatty acids (FAs) were quantified by GC, plasma oxylipins by ultra-HPLC-MS, and plasma immune indicators by ELISA. An interaction between piglet diet and bBW for average daily gain (P = 0.020) and average daily feed intake (P = 0.014) during the whole postweaning indicated that dietary n-3 LCFA-promoted LBW piglets to have a similar growth and intake than HBW piglets reaching 1.5 kg average BW more at the end of the postweaning period than LBW control piglets. Fish oil in piglet diets also increased the concentrations of total n-3 FA, EPA and DHA (all P < 0.001), their resultant oxylipins, particularly their hydroxy derivatives from lipoxygenase enzymatic pathway (all P < 0.001) and tended to increase immunoglobulin M (P = 0.067) in blood. Regarding the bBW category, LBW piglets tend to increase tumour necrosis factor alpha in plasma (P = 0.083) compared to HBW. It is concluded that fish oil in postweaning diets could enhance the daily gain and feed intake of LBW piglets, increasing the concentration of serum n-3 FAs and their derived oxylipins in plasma.

In this study, we focused on the occurrence of respiratory disorders in rabbit farms, as well as several risk factors. We based the assessment on 11 217 visits to 1288 commercial farms in Spain and Portugal from 1996 to 2020. There was a sub-set of 307 visits due to respiratory system issues on 172 farms; the main causes were high prevalence of rhinitis in does and high mortality risk in weaned rabbits. During the 25-yr observational study, we physically examined 29 000 males and 200 000 lactating does to monitor their sanitary status on 894 farms. The mean annual prevalence of clinical rhinitis (CR) and 95% binomial confidence interval (CI) in does was 19.9% (95% CI [19.7-20.1%]). We observed an improvement as prevalence of annual CR fell from 29.6% in 1996 to 15.2% in 2020. The main risk factor for rhinitis was the rabbit line, followed by gender (males become sick more than females) and age of females. The median age of farmed does was 5 parities (minimum to maximum: 1-39). The enabling risk factors were year, season (more often affected in summer) and service timing (lowest prevalence when does were served ≥32 d postpartum). In a sub-set of 208 farms, we determined the prevalence of apparent atrophic rhinitis, which was 0.04% in females and 0.11% in males. Concerning bacteriological studies with 444 samples from 153 farms, Pasteurella multocida and Staphylococcus aureus were the main agents isolated from cases of pneumonia, rhinitis and other issues. We may infer that much work is required to determine in greater detail the factors linked to the farm environment and apply this knowledge in practice.

Although in vitro data with mixed ruminal fluid demonstrated positive effects of posbiotic diet (POS) from lactobacilli on measures of fermentation and microbial profiles, there is a paucity of in vivo data with lactating ruminants. The aim of the study was to evaluate the effects of incorporating POS into diets of lactating goats on energy (E) partitioning, carbon (C) and nitrogen (N) balance, and performance. Ten late-lactation Murciano-Granadina goats were used in a crossover design with 26-d periods. Goats in the control diet (CON) were fed daily at the rate of 1 kg alfalfa hay and 1.5 kg concentrate, and the treatment group (POS) was fed CON with the addition of 3.75 g/d of Probisan Ruminants (PENTABIOL S.L., Navarra, Spain). No differences in DMI were detected. However, ruminal fluid propionate and apparent total tract digestibilities of NDF and ADF were greater (18%, 4.7%, and 5.2%, respectively; P < 0.05) in POS compared with the CON diet. Daily partitioning of E to milk and efficiency of ME intake for milk production greater (11% and 3.0%, respectively; P < 0.05) in POS compared with CON. The nonprotein RQ was greater in POS compared with CON due to greater (P < 0.05) oxidation of carbohydrate (213 vs. 115 kJ/kg of BW0.75 per day) compared with fat (362 vs. 486 kJ/kg of BW0.75 per day). Although no differences were found in C balance, goats in POS had lower (P < 0.05) amounts of C in CH4 (1.1 vs. 1.3 g/kg BW0.75 per day) compared with CON. There were no differences in N intake or N in feces or urine, but N in milk was greater (P < 0.05) in POS compared with the CON diet (0.8 vs. 0.7 g/kg BW0.75 per day). Yield of fat-corrected milk (FCM) (3.20 vs. 2.72 kg/d; P < 0.05) and concentration of true protein (3.4 vs. 3.3 kg/d; P < 0.05) and lactose (4.7 vs. 4.5 kg/d; P < 0.05) were greater in POS compared with CON. These responses were accompanied by lower (P < 0.05) urea (12.3 vs. 16.6 mM/L) and ammonia-N (6.6 vs. 8.8 mg/L) without changes in fat concentration (6.1% vs. 6.0%; P > 0.05) in POS compared with the CON diet. Daily amount of CH4 emission did not differ P > 0.05 between diets. However, when expressed relative to unit of edible product, feeding POS reduced (P < 0.05) the amount of CH4 by 46 g/kg of milk fat, 97 g/kg of milk protein, and 3 g/kg of milk compared with CON. Overall, data indicated that feeding a postbiotic in late-lactation increased energy efficiency for milk production partly by reducing CH4 emission.

Over the last decades, genetic selection has increased sows’ litter size. Consequently, there is a high proportion of piglets born with low weight which are vulnerable. Their viability may potentially be enhanced through early nutrition. The aim of the current study was to evaluate whether including a fish oil rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the diets of the sow and piglets was able to increase concentrations of anti-inflammatory molecules in their blood. Thirty-six sows, in four consecutive batches, were randomly assigned to either a control diet with animal fat (15 g/kg in gestation and 30 g/kg in lactation) or an n-3 long-chain fatty acid (n-3 LCFA) diet from insemination until the end of lactation. From day 11 of lactation, piglets were also offered a diet containing 30 g/kg of animal fat or n-3 LCFA. To prepare the n-3 LCFA diet, 15 g/kg or 30 g/kg of animal fat in the control diet were replaced by an equivalent amount of solid fish oil for sows and piglets, respectively. All the sows were sampled for serum and plasma at day 108 of gestation and at weaning. Additionally, only for the first batch of sows, blood samples were also obtained at weaning from the two lightest (>800 g) and the two heaviest birth weight piglets in each litter. Serum fatty acids (FAs) were quantified by gas chromatography, plasma oxylipins by ultra-HPLC-MS and plasma immunoglobulins (Ig) and cytokines by ELISA. The n-3 LCFA diet increased the concentrations of n-3 FAs in gestating and lactating sows and in piglets (P < 0.001, P < 0.001 and P = 0.011, respectively), particularly EPA (P < 0.001, P < 0.001 and P < 0.001, respectively) and DHA (P < 0.001, P < 0.001 and P < 0.001, respectively), and also their oxygenated derivatives. In addition, fish oil increased plasma IgM in gestating and lactating sows (P = 0.014 and P = 0.008, respectively), interleukin (IL) 6 in sows at weaning (P = 0.012), and IL1β in piglets (P = 0.018). Birth BW of piglets, regardless of diet, slightly influenced some of the n-6-derived oxylipins. In conclusion, fish oil addition in diets increased the blood concentrations of n-3 FAs and their oxygenated derivatives, some of which have anti-inflammatory activity, in gestating and lactating sows and piglets, IgM in gestating and lactating sows, IL6 in lactating sows and IL1β in piglets.

Introduction:Very little is known about the impact of n-3 long-chain fatty acids (n-3 LCFAs) on the microbiota of sows and their piglets. The aim of this study was to evaluate the effect of n-3 LCFA in sow diets on the microbiota composition of sows' feces, colostrum, and milk as well as that of piglets' feces.Methods:Twenty-two sows were randomly assigned to either a control or an n-3 LCFA diet from service to weaning. Sows' and piglets' performance was monitored. The gestating and lactating sows' microbiomes in feces, colostrum, and milk were characterized by 16s ribosomal RNA gene sequencing. The fecal microbiome from the two lowest (>800 g) and the two highest birth weight piglets per litter was also characterized, and the LPS levels in plasma were analyzed at weaning.Results and Discussion:n-3 LCFA increased microbiota alpha diversity in suckling piglets' and gestating sows' feces. However, no effects were observed in colostrum, milk, or lactating sows' feces. Dietary n-3 LCFA modified the microbiota composition of gestating sows' feces, milk, and suckling piglets' feces, without affecting lactating sows' feces or colostrum. In gestating sows' feces and milk, the decrease in genus Succinivibrio and the increase of Proteobacteria phylum, due to the increased genera Brenneria and Escherichia, respectively, stand out. In the feces of suckling piglets, the higher abundance of the beneficial genus Akkermansia and Bacteroides, and different species of Lactobacillus are highlighted. In addition, positive correlations for families and genera were found between lactating sows' feces and milk, milk and suckling piglets' feces, and lactating sows' feces and suckling piglets' feces. To conclude, dietary n-3 LCFA had a positive impact on the microbiome of suckling piglet's feces by increasing microbial diversity and some beneficial bacteria populations, had a few minor modifications on the microbiome of milk and gestating sows' feces and did not change the microbiome in lactating sows' feces or colostrum. Therefore, this study shows the effect of dietary n-3 LCFA on the microbiota of sows, colostrum, milk, and suckling piglets during the lactation period providing crucial information on the microbiota status at the early stages of life, which have an impact on the post-weaning.

Colostrum and milk are the first nutrient sources for newborn piglets. In addition, n-3 fatty acids (FAs) and their oxygenated derivatives (oxylipins) have the capacity to modulate immune components. The aim of the current study was to include a fish oil rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in sow diets to promote an increase of anti-inflammatory molecules in colostrum and milk to benefit piglets. Thirty-six sows were randomly assigned from insemination to the end of lactation to either a control diet with animal fat (15 g/kg in gestation and 30 g/kg in lactation) or an n-3 diet in which animal fat was totally (gestation) or half (lactation) replaced by an equivalent amount of solid fish oil. Performance of sows and piglets was monitored during the study. Colostrum and milk samples were obtained after the birth of the first piglet and at weaning, respectively. From all samples (n = 18 per treatment), FAs were quantified by gas chromatography and immunoglobulins and cytokines by ELISA. Three samples per treatment were randomly selected to analyse oxylipin composition by liquid chromatography-tandem mass spectrometry. In colostrum and in milk, the n-3 FA (P = 0.020 and P < 0.001), particularly EPA (P < 0.001 and P < 0.001) and DHA (P < 0.001 and P < 0.001), and also their oxygenated derivatives were increased in samples from sows fed n-3 diet. Fish oil had no effect on immunoglobulin concentrations, but reduced tumour necrosis factor α (TNFα) (P = 0.011) and a tendency to reduce interleukin 10 (IL10) (P = 0.059) were observed in milk. In conclusion, fish oil in sow diets increased n-3 FA, particularly EPA and DHA, and their oxygenated derivatives in colostrum and milk, reducing TNFα and IL10 in milk.

The study of myxoma virus (MYXV) infections in the European rabbit (Oryctolagus cuniculus) has produced one of the most accepted host-pathogen evolutionary models. To date, myxomatosis has been limited to the European rabbit with sporadic reports in hares. However, reports of widespread mortalities in the Iberian hare (Lepus granatensis) with myxomatosis-like clinical signs indicate a potential species jump has occurred. The presence of MYXV DNA was confirmed by PCR in 244 samples received from regional veterinary services, animal health laboratories, hunters or rangers over a 5-month period. PCR analysis of 4 MYXV positive hare samples revealed a 2.8 kb insertion located within the M009 gene with respect to MYXV. The presence of this insertion was subsequently confirmed in 20 samples from 18 Spanish provinces. Sanger sequencing and subsequent analysis show that the insert contained 4 ORFs which are phylogenetically related to MYXV genes M060, M061, M064 and M065. The complete MYXV genome from hare tissue was sequenced using Ion torrent next-generation technology and a summary of the data presented here. With the exception of the inserted region, the virus genome had no large scale modifications and 110 mutations with respect to the MYXV reference strain Lausanne were observed. The next phase in the evolution of MYXV has taken place as a host species jump from the European rabbit to the Iberian hare an occurrence which could have important effects on this naive population.

During the last years the IRTA-CReSA and ETSIA-Madrid teams, together other European groups, especially from France and Belgium, have demonstrated the role of intestinal microbiota imbalance (specific dysbiosis) in the pathogenesis of Epizootic Rabbit Enteropathy (ERE). Additionally, these teams have hypothesized the role of different bacterial components (Clostridium perfringens, Bacteroides spp., Akkermansia muciniphila...), in combination with the concentration and the type of fiber, and the concentration of protein in the feed on the pathogenesis of ERE. The experimental inoculation of rabbits with specific strains of Clostridium perfringens permitted us the experimental reproduction of ERE symptomatology (caecal impaction) with a mortality rate of 45%. The comparative analysis of the ERE-related and ERE-not-related Clostridium perfringens strains detected some changes in the proteins profile of the bacterial culture supernatant, singularly proteins with molecular mass of 189587 Da and 241521 Da, and the identification of a plasmid with more than 65 kbp. In addition to the aim implicit in the above paragraphs –the experimental reproduction of ERE–, our team has been interested in the development of new ways to control the negative effects of ERE, especially mortality. Inoculating different Bacteroides spp. to naturally ERE infected rabbits we obtained a significant reduction on mortality when compared with non-treated animals. The additional studies conducted with these Bacteroides strains allowed us to infer positive effects on different immunological functions of rabbits. The design of new molecular tools that could help in the diagnostic of ERE, and the development of vaccines and probiotics tools that could help to the prevention of ERE and the reduction of the use of antimicrobials in rabbit farms, are the principal objectives of a new research project funded by INIA and INTERCUN in our country.

A trial was conducted to evaluate the effects of extrusion of different cereals on the performance, nutrient digestion, and VFA concentrations in the cecal digestive contents of weanling pigs. Ninety-six weaned piglets (allocated in 48 pens) were fed 12 different cereal-based diets, consisting of 6 cereals (rice, barley, wheat, corn, oats, and sorghum; 55% inclusion) with or without extrusion processing. Piglets' performance (for 26 d) and nutrient apparent total tract digestibility (ATTD; at d 13) were evaluated. At the end of the trial, the 32 piglets fed the rice and barley diets (with low and high contents of nonstarch polysaccharides, respectively) were slaughtered and samples were obtained to measure apparent digestibility (AD) of nutrients and digesta viscosity in the proximal two-thirds of the small intestine (pSI) and the distal one-third of the small intestine (dSI) and the concentrations of VFA in the cecal contents. Cereal source (CS) or extrusion did not affect piglet performance. Cereal source affected ATTD for all nutrients, whereas extrusion improved ATTD of only GE (86.5 vs. 85.1%) and starch (99.9 vs. 99.8%; P < 0.05). There was a CS x extrusion interaction for ATTD of CP, which was reduced by extrusion but only for rice and oats (84.0 and 84.4 vs. 77.4 and 78.8%, respectively). Extrusion reduced AD of fat in the pSI, whereas a CS x extrusion interaction was observed for AD of starch that was improved by extrusion in barley (88.5 vs. 80.0%) but not rice. Greater AD of DM (72.2 vs. 63.3%) and GE (72.0 vs. 62.7%) in the dSI was observed in rice than in barley, whereas extrusion improved AD of starch (98.6 vs. 96.6%). Interactions (CS x extrusion) were also observed for digesta viscosity in the pSI and dSI (extrusion increased viscosity for barley but not rice). Finally, extrusion reduced (P < 0.05) the concentrations of propionic (20.0 vs. 13.2 mu mol/g) and butyric acids (11.0 vs. 4.4 mu mol/g) in the cecum. It is concluded that both CS and extrusion affect nutrient digestibility but not performance. Cereal source effects are evident over the whole digestive tract, but the effects of extrusion depend on the nature of the cereal and are more evident in the small intestine.

Food animals may serve as a reservoir of bacteria that carry antimicrobial resistance genes that may be transferred to microorganisms found in humans and thereby limit the medical value of antimicrobials. In contrast to Escherichia coli from humans and several other animal species, there is little information on the frequency and mechanisms of antimicrobial resistance of that bacteria isolated from rabbits. The objective of the present study was to determine the antimicrobial resistance profile of 478 E. coli isolates from healthy rabbits. Another objective was to assess the diversity and distribution of the major resistancegenes [ tetA, tetB, tetC , and tetM for doxycycline, bla , bla SHV, and bla for amoxicillin, aac(3)II , aac(3)IV , and ant(2”)I for gentamicin, and qnrA , qnrB , qnrS , aaC(6)Ib , and qepA for enrofloxacin], as well as the mutations in the quinolone resistance-determining region of the gyrA and parC genes, inthese isolates. The percentage of isolates resistant to doxycy CTX-M-9 cline was very high (89.3%). However, relatively few isolates were resistant to amoxicillin (16.1%), gentamicin (2.9%), and enrofloxacin (4.2%). Predominant resistance genes were tetA and tetB in the isolates resistant to doxycycline, and bla in the isolates resistant to amoxicillin. Most E. coli isolates with in termediate resistance to enrofloxacin presented a single mutation in gyrA, while most isolates resistant to it presented double mutations in gyrA and single mutations in parC , or double mutations in both gyrA and parC . The present study provides base line data on frequency and molecular basis of antimicrobial re sistance in E.coli isolates from rabbits. In addition, the results of this study suggest that commensal E. coli isolates from rabbits may be a reservoir of antimicrobial resistance genes.

Avian pathogenic Escherichia coli (APEC) are the major cause of colibacillosis in poultry production. In this study, a total of 22 E. coli isolated from colibacillosis field cases and 10 avian faecal E. coli (AFEC) were analysed. All strains were characterised phenotypically by susceptibility testing and molecular typing methods such as pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). The presence of 29 virulence genes associated to APEC and human extraintestinal pathogenic E. coli (ExPEC) was also evaluated. For cephalosporin resistant isolates, cephalosporin resistance genes, plasmid location and replicon typing was assessed. Avian isolates belonged to 26 O:H serotypes and 24 sequence types. Out of 22 APEC isolates, 91% contained the virulence genes predictors of APEC; iutA, hlyF, iss, iroN and ompT. Of all strains, 34% were considered ExPEC. PFGE analysis demonstrated a high degree of genetic polymorphism. All strains were multi-resistant, including those isolated from healthy animals. Eleven strains were resistant to cephalosporins; six contained bla CTX-M-14, two bla SHV-12, two bla CMY-2 and one bla SHV-2. Two strains harboured qnrA, and two qnrA together with aac(6’)-Ib-cr. Additionally, the emergent clone O25b:H4-B2-ST131 was isolated from a healthy animal which harboured bla CMY-2 and qnrS genes. Cephalosporin resistant genes were mainly associated to the presence of IncK replicons. This study demonstrates a very diverse population of multi-drug resistant E. coli containing a high number of virulent genes. The E. coli population among broilers is a reservoir of resistance and virulence-associated genes that could be transmitted into the community through the food chain. More epidemiological studies are necessary to identify clonal groups and resistance mechanisms with potential relevance to public health.

EFSA Supporting PublicationsVolume 13, Issue 2 1001E External scientific reportOpen Access Preparatory work to support the re-evaluation of technological feed additives (OC/EFSA/FEED/2013/01) N. Tous, N. Tous IRTASearch for more papers by this authorJ. Brufau, J. Brufau IRTASearch for more papers by this authorA. Pérez-Vendrell, A. Pérez-Vendrell IRTASearch for more papers by this authorB. Vilà, B. Vilà IRTASearch for more papers by this authorM. Francesch, M. Francesch IRTASearch for more papers by this authorD. Torrallardona, D. Torrallardona IRTASearch for more papers by this authorM. Castellari, M. Castellari IRTASearch for more papers by this authorJ. Diogene, J. Diogene IRTASearch for more papers by this authorM. Viñas, M. Viñas IRTASearch for more papers by this authorV. Castell, V. Castell ACSASearch for more papers by this authorE. Vicente, E. Vicente ACSASearch for more papers by this authorI. Badiola, I. Badiola ACSASearch for more papers by this authorE. Esteve-Garcia, E. Esteve-Garcia ACSASearch for more papers by this author N. Tous, N. Tous IRTASearch for more papers by this authorJ. Brufau, J. Brufau IRTASearch for more papers by this authorA. Pérez-Vendrell, A. Pérez-Vendrell IRTASearch for more papers by this authorB. Vilà, B. Vilà IRTASearch for more papers by this authorM. Francesch, M. Francesch IRTASearch for more papers by this authorD. Torrallardona, D. Torrallardona IRTASearch for more papers by this authorM. Castellari, M. Castellari IRTASearch for more papers by this authorJ. Diogene, J. Diogene IRTASearch for more papers by this authorM. Viñas, M. Viñas IRTASearch for more papers by this authorV. Castell, V. Castell ACSASearch for more papers by this authorE. Vicente, E. Vicente ACSASearch for more papers by this authorI. Badiola, I. Badiola ACSASearch for more papers by this authorE. Esteve-Garcia, E. Esteve-Garcia ACSASearch for more papers by this author First published: 26 February 2016 https://doi.org/10.2903/sp.efsa.2016.EN-1001 The present document has been produced and adopted by the bodies identified above as authors. This task has been carried out exclusively by the authors in the context of a contract between the European Food Safety Authority and the authors, awarded following a tender procedure. The present document is published complying with the transparency principle to which the Authority is subject. It may not be considered as an output adopted by the Authority. The European Food Safety Authority reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors. Published date: 26 February 2016 Question number: EFSA-Q-2016-00147 AboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL References Commission Regulation (EC) No 429/2008 of 25 April 2008 on detailed rules for the implementation of Regulation (EC) No 1831/2003 of the European Parliament and of the Council as regards the preparation and the presentation of applications and the assessment and the authorisation of feed additives. OJ L 133, 22.5.2008, 1– 65. EFSA (European Food Safety Authority), 2008a. Guidance for the preparation of dossiers for the reevaluation of certain additives already authorised under Directive 70/524/EEC. The EFSA Journal 2008, 779, 1– 9. EFSA (European Food Safety Authority), 2008b. Technical guidance for assessing the safety of feed additives for the environment. The EFSA Journal 2008, 842, 1– 28. EFSA FEEDAP Panel (EFSA Panel on Additives and Products or Substances used in Animal Feed), 2011a. Guidance on the assessment of the additives intended to be used in pets and other non food-producing animals. EFSA Journal 2011; 9(2):2012, 3 pp. doi:10.2903/j.efsa.2011.2012 EFSA FEEDAP Panel (EFSA Panel on Additives and Products or Substances used in Animal Feed), 2011b. Technical Guidance: Tolerance and efficacy studies in target animals. EFSA Journal 2011; 9(5):2175, 15 pp. doi:10.2903/j.efsa.2011.2175 EFSA FEEDAP Panel (EFSA Panel on Additives and Products or Substances used in Animal Feed), 2012a. Guidance for the preparation of dossiers for technological additives. EFSA Journal 2012; 10(1):2528, 23 pp. doi:10.2903/j.efsa.2012.2528 EFSA FEEDAP Panel (EFSA Panel on Additives and Products or Substances used in Animal Feed), 2012b. Guidance for the preparation of dossiers for additives already authorised for use in food. EFSA Journal 2012; 10(1):2538, 4 pp. doi:10.2903/j.efsa.2012.2538 EFSA FEEDAP Panel (EFSA Panel on Additives and Products or Substances used in Animal Feed), 2012c. Guidance on studies concerning the safety of use of the additive for users/workers. EFSA Journal 2012; 10(1):2539, 5 pp. doi:10.2903/j.efsa.2012.2539 Regulation (EC) No 1831/2003 of the European Parliament and of the Council of 22 September 2003 on additives for use in animal nutrition. OJ L268, 18.10.2003, 29– 43. Volume13, Issue2February 20161001E ReferencesRelatedInformation

This study aimed to provide novel insights into the gastrointestinal microbial diversity from different gastrointestinal locations in weaning piglets using PCR-restriction fragment length polymorphism (PCR-RFLP). Additionally, the effect of different feed additives was analyzed. Thirty-two piglets were fed with four different diets: a control group and three enriched diets, with avilamycin, sodium butyrate, and a plant extract mixture. Digesta samples were collected from eight different gastrointestinal segments of each animal and the bacterial population was analysed by a PCR-RFLP technique that uses 16S rDNA gene sequences. Bacterial diversity was assessed by calculating the number of bands and the Shannon-Weaver index. Dendrograms were constructed to estimate the similarity of bacterial populations. A higher bacterial diversity was detected in large intestine compared to small intestine. Among diets, the most relevant microbial diversity differences were found between sodium butyrate and plant extract mixture. Proximal jejunum, ileum, and proximal colon were identified as those segments that could be representative of microbial diversity in pig gut. Results indicate that PCR-RFLP technique allowed detecting modifications on the gastrointestinal microbial ecology in pigs fed with different additives, such as increased biodiversity by sodium butyrate in feed.

La formulacion de un pienso de conejos en crecimiento persigue maximizar los rendimientos productivos (indice de conversion, velocidad de crecimiento y rendimiento a la canal) y limitar la incidencia de trastornos digestivos. Las necesidades de los principales ?principios inmediatos/nutrientes? estan bien establecidas (Tabla 1) para el periodo global de cebo, y permiten optimizar los rendimientos productivos en granjas libres de enteropatia epizootica o que utilicen antibioticos. Sin embargo, la gran incidencia de esta enfermedad durante las dos semanas posteriores al destete ha obligado a profundizar en la fisiologia digestiva de los gazapos durante este periodo para tratar de establecer recomendaciones nutricionales que se ajusten mejor sus necesidades, al igual que sucede con lechones y pollos de primera edad.

In this study we evaluated the effects of high dietary arachidonic acid (ARA) levels on prostaglandin E2 (PGE2) and E3 (PGE3) production and their effect on two morphogenetic processes occurring during metamorphosis: the establishment of the juvenile pigmentation pattern and eye migration and remodeling of cranial bones. In this sense, Senegalese sole larvae were fed from 2 to 50 days post-hatch (dph) with live prey enriched with an experimental emulsion containing high levels of ARA (ARA-H; 10.2 and 7.1% TFA in enriched rotifer and Artemia, respectively) versus a reference commercial enriching product (Algamac 3050®, AGM; 1.0 and 1.4% TFA in enriched rotifer and Artemia, respectively). High dietary ARA levels did not affect larval growth performance at 50 dph, but significantly induced malpigmentation (81.4 ± 7.5%, versus 0.9 ± 0.3% in larvae fed the AGM diet). This malpigmentation was linked to the higher prostaglandin E2 (PGE2) levels observed in pseudo-albino fish as compared to normally pigmented individuals. The PGE2 levels were higher in normally pigmented specimens fed the ARA-H diet than in those fed the AGM diet. The effects of ARA on normally pigmented fish fed the AGM diet and pseudo-albino specimens fed the ARA-H diet were evaluated by means of the density of melanophores and the texture and image segmentation analyses in the dorsal skin of post-metamorphic fish. The skin of pseudo-albino specimens had a more uniform and homogeneous melanophore pattern than normally pigmented fish. Melanophores in pseudo-albino specimens were less abundant and not so aggregated in patches as they were in normally pigmented ones, whereas their shape differed (round vs. dendritic) suggesting their inability to disperse melanin. In addition, fish fed the ARA-H diet presented a higher percentage of cranial deformities (95.1 ± 1.5%) than those fed the control diet (1.9 ± 1.9%) that was significantly and negatively correlated with the incidence of normally-pigmented animals (R2 = − 0.88, P < 0.001). Cranial deformities in pseudo-albino fish were associated with an impaired migration of the eye from the ocular side (the right eye), whereas the left eye migrated from the blind side into the ocular side almost normally. The effects of high dietary ARA levels in the eye migration and cranial bone remodeling processes in post-metamorphic larvae were evaluated by means of the staining of cranial skeletal elements. Pseudo-albino fish showed higher interocular distance and head height than normally pigmented individuals, a different disposition of the eyes with regard to the vertebral column and mouth axes, and a distinct osteological development of some skeletal structures from the neuro- and splanchnocranium, in relation to high dietary ARA contents and high PGE2 production. These results brought new information about possible nutritional forcing factors and physiological mechanisms of pigmentary disorders and impaired eye migration, which are current major bottlenecks in flatfish aquaculture.