AbstractHaemorrhagic bowel syndrome (HBS) is one of the most common causes of death in fattening pigs worldwide. The objective of this descriptive study was to systematically assess predictors or causal components for the appearance of HBS using case farms (mortality rate caused by HBS ≥ 1.5%) in comparison with control farms (mortality rate caused by HBS ≤ 0.25%), focusing on feed ingredients, feed quality and size, and gastrointestinal pathogens. The inclusion of sugar beet as a feed component in liquid feeding systems was found to be associated (p = 0.03) with farms identified as HBS cases. Another predictive or causal factor found for liquid feeding systems, but only for those using meal, was particle size. A higher percentage of small particles (< 2 mm) in the meal was associated with a higher risk of being an HBS case farm (p = 0.02), while no relevant association was detected for the use of pellets. Sugar beet in the diet was also associated with the incidence of HBS.The microbial quality of the feed in dry feeding systems, specifically the number of total aerobes at the first and last outlet tubes, was associated with a higher incidence of HBS (p = 0.03). Faecal sample analysis showed a difference (p < 0.05) in the prevalence of B. pilosicoli in the herd category (case vs. control herd). In this descriptive study, five predictive or causal factors were identified for an HBS farm with a mortality rate due to HBS ≥ 1.5%. These included the number of aerobes in dry matter samples from the first and last feeders, the particle diameter of the meal used in liquid feeding systems and sugar beet as a component of liquid feeding rations, and the presence of B. pilosicoli as an infectious agent at animal level. Relevant associations reinforce the findings of the previously published Swiss study that HBS is a multifactorial syndrome involving different aspects of pig production and cannot be attributed to a single cause. Further studies are needed to develop evidenced based causal models for HBS in swine.

Dans les regions a densite animale elevee, le bilan import/export est utilise pour depister l�emploi de fourrages appauvris en phosphore et azote de chaque exploitation et relever les rejets de fertilisants differents de la valeur standard. Le travail presente ici analyse les bilans import/export de 1665 exploitations porcines du canton de Lucerne pour l�annee 2008; ils ont ete enregistres dans une banque de donnees Access creee specialement. Les 899 exploitations d�engraissement ont ete soumises a une analyse detaillee. L�efficacite moyenne de l�azote (export/import N) de ces exploitations s�eleve a 32 % pour une teneur moyenne en matiere azotee de 159 g par kg de ration totale (13,74 MJ EDP). Les resultats revelent une influence importante et fondamentale de l�exploitation sur l�efficacite et les rejets d�azote, meme a affourragement similaire. Il existe manifestement un potentiel d�optimisation considerable du cote des techniques de production, de la sante et de la gestion. L�efficacite de l�azote dans les exploitations d�engraissement pourrait servir d�indicateur pour quantifier les effets des mesures de bonnes pratiques agricoles. Malheureusement, il semble difficile, dans des exploitations mixtes elevage/engraissement, d�estimer cet indice pour l�engraissement uniquement.

N-Efficacy in fattening pigs In regions with high density of animal production, Import/Export-balances (IMPEX) are used to monitor the use of diets with reduced P- and N- concentrations. Based on the IMPEX data, the farms can claim a reduction in waste nutrients. The aim of the presentment study was to analyze 1165 IMPEX-balances from pig farms in the state of Lucerne (Switzerland). All data were from 2008. The data from 899 grower/finisher farms were analyzed in more detail and N-efficiencies (N-Export/N-import) estimated. The average N-efficiency for grower/finisher farms was 32% with an average dietary crude protein (CP) concentration of 159 g/kg (13,74 MJ DE). The between farm comparison showed a large farm effect on both, N-efficiency and N-output as manure. Only a minor portion of this variation could be explained by feeding strategy. The data suggest that a large optimization potential for N-efficiency exists with respect to production technique, animal health and overall farm management. The N-efficiency in grower/finisher farm is a good indicator for the evaluation of good farm practices. However, in farrow-to finish operations, it is very difficult to evaluate the N-efficiency for different production phases.

In Switzerland, surgical castration of piglets without anaesthesia has been banned since January 1, 2010 due to welfare concerns. Castration has been practised in pig meat production as it guards against ‘boar taint’ – whereby an off odour is released when heating fat or meat from some entire male pigs. The main compounds involved in boar taint are androstenone, skatole and indole. As a vaccine against boar taint is now available, and field experience shows that its use is practical and effective, this may provide an acceptable solution. However, such practice must be acceptable to consumers regarding welfare and safety concerns. In addition, the procedure must guarantee good meat quality. The aim of the present study was to evaluate the acceptance of meat produced with or without vaccination against boar taint (immunocastration) via sensory evaluation of the meat and personal views regarding the use of such a procedure by consumers, who had been informed on the subject. It comprised a sensory evaluation comparing meat from immunocastrated and conventionally produced pigs (surgically castrated male pigs) as well as a survey to examine the attitude to different methods of boar taint control among consumers. Meat derived from immunocastrated pigs and castrates did not show any differences with respect to the sensory grading of appearance, tenderness, taste and juiciness (P>0.05). Twenty-two percent of the interviewees indicated no prior knowledge of the problem of boar taint. Sixty-eight percent agreed on immunocastration being an acceptable alternative whilst 15% rejected this method. Respondents who judged immunocastration as comprehensible (they were of the opinion that they understood the procedure and the basics behind it) were more favourable of it compared to interviewees who considered it as sophisticated and unclear. The results of the survey showed that immunocastration can reach good acceptance among consumers within this region, and acceptance of this

Protein content in compound feed for pigs: survey of 2008As most European countries, Switzerland has signed the Gothenburg Protocol to abate acidification, eutrophication and ground-level ozone. The protocol puts pressure on Swiss livestock producers to implement measures to reduce their ammonia emissions. Dietary modifications (optimization of crude protein concentration) will affect, as a begin-of-pipe measure, all emission stages from barn to field. The aim of the present study was to gain an overview of the current pig-feeding practices in Switzerland. A survey was conducted based on data from manufactures, comprising 70-80% of the Swiss pig-feed market. The declared crude protein values comply with analyzed values. The survey showed that, depending on the feed category, 70-75% of the feed is sold with reduced nitrogen (crude protein) and phosphorus concentrations (NPr feed). Based on an energy concentration of 13,5 MJ DE, the average CP concentrations for fattening pigs are 172,3 g CP/kg for standard and 155,5 g CP/kg for NPr diets. Finisher diets only have a marginal CP reduction compared to fattening diets. The difference in CP concentrations between standard and NPr feed is much smaller for piglet and sow diets compared to fattening diets. 25-30% of pig feed is not sold as NPr diets. In addition, part of the diets for finishing pigs and gestating sows are overformulated regarding CP. Adaptations in these areas offer potential for reducing ammonia emissions.

SUMMARY In Switzerland, surgical castration of piglets without anaesthesia has been banned since January 1, 2010 due to welfare concerns. Castration has been practised in pig meat production as it guards against ‘boar taint’ – whereby an off odour is released when heating fat or meat from some entire male pigs. The main compounds involved in boar taint are androstenone, skatole and indole. As a vaccine against boar taint is now available, and field experience shows that its use is practical and effective, this may provide an acceptable solution. However, such practice must be acceptable to consumers regarding welfare and safety concerns. In addition, the procedure must guarantee good meat quality. The aim of the present study was to evaluate the acceptance of meat produced with or without vaccination against boar taint (immunocastration) via sensory evaluation of the meat and personal views regarding the use of such a procedure by consumers, who had been informed on the subject. It comprised a sensory evaluation comparing meat from immunocastrated and conventionally produced pigs (surgically castrated male pigs) as well as a survey to examine the attitude to different methods of boar taint control among consumers. Meat derived from immunocastrated pigs and castrates did not show any differences with respect to the sensory grading of appearance, tenderness, taste and juiciness (P>0.05). Twenty-two percent of the interviewees indicated no prior knowledge of the problem of boar taint. Sixty-eight percent agreed on immunocastration being an acceptable alternative whilst 15% rejected this method. Respondents who judged immunocastration as comprehensible (they were of the opinion that they understood the procedure and the basics behind it) were more favourable of it compared to interviewees who considered it as sophisticated and unclear. The results of the survey showed that immunocastration can reach good acceptance among consumers within this region, and acceptance of this

Piglet nutrition with valine supplementation The goals of these trials were to investigate the effects of different dietary amino acid concentrations and valine:lysine ratios on piglet performance and health. Two 4-week trials with 90 weaned piglets (3 treatments and 6 replicates) each were conducted. All diets contained 14 MJ DE: Trial 1: (i) 180 g CP, 12,5 g lysine, 8,6 g valine; (ii) 165 g CP, 11,5 g lysine, 7,99 valine; (iii) 165 g CP, 11,5 g lysine, 8,59 valine. Trial 2: (i) 180 CP, 12,4 g lysine, 8,6 g valine; (ii) 165 g CP, 12,4 g lysine, 7,9 g valine; (iii) 165 g CP, 12,4 g lysine, 8,6 g valine. In trial 1, the higher crude protein and amino acid concentrations led to a significant improvement in FCR (1,43(a) vs 1,53(b) and 1,51(b) kg/kg; P<0.05). Increasing the amino acid concentrations in the treatment with reduced CP concentration allowed performance to be maintained at the level of the standard diet in trial 2. The supplementation of the essential amino acid valine did not affect animal performance.

The objective of the present trial was the determination of growth performance, carcass quality and boar taint of entire male pigs fattened on a Swiss commercial farm. From 2005 to 2007, 1094 entire males were fattened on the Juchhof with a liquid, ad libitum feeding system (15,5 MJ DE/kg DM). From the first to the second experimental year, the average age at slaughter (165 to 180 days) and the carcass weight (72 - 82 kg) increased. The average daily weight gain was 727 g/d (2(nd) year). The mean lean meat percentage of the carcass was 57,2 %. The majority of the carcasses reached the optimal classification group. According to HPLC analyses, 5,5 % of the tested adipose tissue samples surpassed the sensory acceptable threshold value for androstenone and/or skatole in fat. The data show that it is possible to efficiently control skatole concentration through adapted nutrition and good hygiene. However, androstenone is more difficult to control. In order to limit the risk of boar taint, animals should be slaughtered at 100 - 105 kg live weight. Not surpassing this slaughter weight is particularly important in early spring, when the risk of boar taint was elevated. In conclusion, producing entire males at commercial scale is feasible in Switzerland. However, as long as no objective boar taint detection systems are available at the slaughter line, it is likely that fattening entire male pigs will just be practiced in niche markets.

To prevent the occurrence of meat with boar taint, which is not accepted by the consumer, male piglets are surgically castrated without anaesthesia. As this method of castration will be banned in Switzerland by 1st January 2010, the project ProSchwein investigated different alternatives.A device for inhalation anaesthesia (anaesthetic gas: isoflurane) showed a good anaesthesia for more than 90 % of the castrated animals under field conditions. The studies on rearing entire male pigs revealed a good feed conversion ratio and a high lean meat percentage. The portion of carcasses with boar taint was 5.5 % or higher. Through dietary addition of raw potato starch it was possible to reduce the content of skatole but not the concentration of androstenone. The electronic nose developed by ALP Posieux is capable to detect between 95 and 100 % of the samples exhibiting boar taint according to the classical HPLC method at a laboratory scale. The application of the electronic nose in practice requires technical adaptations to allowing operation under conditions of a slaughter house. The vaccination against boar taint prevented boar taint effectively. The vaccine has been registered in Switzerland. Vaccinated animals exhibited similar growth performance and a better feed conversion ratio and a higher carcass quality compared to castrates. Acceptance for the vaccination among consumers is achievable but requires a considerable effort in communication. From ail economic point view anesthesia and the vaccination against boar taint can be recommended for larger farms. For smaller farms the investment for the device for inhalation anesthesia is high.

A common problem in rabbits is the occurrence of digestive disorders just after weaning. This problem is associated with instability of the cecal microflora and characterized by diarrhea, loss of appetite and increased mortality. In the current study the effects of mannan oligosaccharide (MOS, Bio-Mos (R), Alltech Inc., USA), a natural growth promoter, were compared to a commonly used antibiotic growth promoter (AGP, Zn-Bacitracin).The five experimental treatments were as follow: Control (no additives); MOS 1 (Bio-Mos (R), 1 g kg(-1)); MOS 1.5 (Bio-Moso, 1.5 g kg(-1)); MOS 2 (Bio-Moso, 2 g kg(-1)) and AGP (Zn-Bacitracin; 0.1 g kg(-1)). Experimental diets were based on alfalfa, sunflower meal, wheat and beet pulp and were offered ad libitum through out the experiment. Trial I used 400 weaned mixed-sex rabbits divided into the five treatments with 10 replicates and 8 rabbits/replicate. Rabbits were weighed at weaning (day 32) and at the end of the experiment (day 67). Weight gain, feed intake, feed conversion ratio (FCR) and mortality were evaluated using a commercial grow-out facility. Trial 2 used 220 weaned rabbits divided into the same five experimental treatment groups and housed in groups of 4 in 11flat deck cages located in an experimental rabbit house. In trial 2 performance, intestinal morphology and cecal fermentation were determined.In both trials, rabbit daily weight gain and feed intake were not affected by treatments. However, in trial 1 MOS rabbits had better (P < 0.05) FCR than control rabbits and similar to AGP rabbits. Also in this trial, the mortality with MOS and AGP treatments tended to be lower (P=0.052) than with control diet.Results in trial 2 showed longer villi (P < 0.05) in rabbits fed MOS or AGP compared to the control group, this resulted in increased absorption surface. Cecal volatile fatty acid (VFA) concentration differed (P < 0.05) between treatments. Rabbits fed MOS at 1 g kg(-1) had higher total VIA concentration compared to the Control as well as the AGP treatment. Furthermore, cecal pH was significantly lower in rabbits fed MOS at 1 and 2 g kg(-1) compared to the control. A reduction on total bacterial count in ileum contents (P < 0.05) and Coliforms and Enterococci in cecal contents with MOS supplementation of diet was observed. (c) 2005 Elsevier B.V. All rights reserved.

A common problem in rabbits is the occurrence of digestive disorders just after weaning. This problem is usually associated with instability of the cecal microflora and characterized by diarrhea, loss of appetite and increased mortality. In the current study the effects of a mannan oligosaccharide (MOS, Bio-MOS ® , Alltech Inc. USA) was compared to a commonly used antibiotic (AGP, Zn-Bacitracin). The current study investigated the effects of MOS and AGP on intestinal morphometry and cecal VFA production. A total of 220 weaned mixed-sex rabbits (32d) were divided into 5 experimental treatments and housed in groups of 4 in 55 flat deck cages located in an experimental rabbit house. The 5 experimental treatments were as follow: Control (no additives);MOS 1 (1 kg MOS/t); MOS 1.5 (1.5 kg MOS/t); MOS 2 (2 kg MOS/t) and AGP (0.1 kg/t). Experimental diets were based on alfalfa, sunflower meal and wheat and beet pulp and were offered ad libitum through out the experiment. Intestinal morphology and cecal fermentation was determined in 8 rabbits per treatment slaughtered at day 46. Histologic examination showed significantly longer villi (P<0.05) in rabbits fed MOS (503.1, 518.6 and 508.8 for MOS 1, MOS 1.5 and MOS 2, respectively) or AGP (502.5) compared to the control group (403.0). This was also translated into a numerically increased absorption surface. Cecal volatile fatty acid (VFA) concentration differed significantly (P<0.05) between treatments. Rabbits fed MOS at 1 kg/t had the highest total VFA concentration (98.02 vs. 51.57 in MOS 1 and Control) and higher butyric acid (14.09 vs. 4.59 in MOS 1 and Control). Furthermore cecal pH was significantly lower in rabbits fed MOS at 1 kg/t and 2 kg/t (5.79 and 5.92) compared to the control (6.33). Results for this study suggest that MOS has a stimulating effect on villi development and production of cecal VFA and reduce cecal pH, which could improve the health status of growing rabbits.

Feed grains available in Britain contain low concentrations of natural selenium. As the grains in most cases do not cover the requirements of the animals, selenium supplementation of diets is a standard practice in feed manufacturing. Selenium supply to the breeder hens impacts the selenium content of the egg, the developing embryo and therefore the antioxidant status of the chick at hatch (Surai, 2000). The aim of this study was to determine the effect of selenium from Sel-Plex® (Alltech Inc.) on the transfer of selenium into the egg of broiler breeder hens under commercial conditions.

The ability of different enteric pathogens and coliforms to trigger agglutination of a yeast cell wall preparation (MOS), a yeast culture (Saccharomyces cerevisiae, NYCC 1026) and haemagglutination was studied. Three strains which agglutinated MOS (Salmonella typhimurium 29E, Salmonella dublin and Escherichia coli 15R) and one non-agglutinating strain (S. typhimurium 27A) were then selected as challenge organisms. The effects of dietary MOS on cecal concentrations of these challenge organisms and on activities and concentrations of the cecal microflora were evaluated in chicks under controlled conditions. Furthermore, the effects of MOS on ileal morphology were investigated. Five of seven strains of E. coli and seven of ten strains of S. typhimurium and Salmonella enteritidis agglutinated MOS and S. cerevisiae NYCC 1026. Strains of Salmonella choleraesuis, Salmonella pullorum and Campylobacter did not lead to agglutination. Agglutination of both yeast products could be inhibited by 25 mM of mannose. All strains that agglutinated the yeast products also triggered haemagglutination. However, haemagglutination of E. coli K99 could not be inhibited by mannose. Mannose sensitive agglutination of the yeast products and mannose resistant haemagglutination by £ coli K99 suggest that these strains express both a mannose sensitive (type-1) and a mannose resistant (K 99) type of fimbriae. In a series of three trials in which 3 d old chicks were orally challenged with 104 CFU of S. typhimurium 29E, birds receiving 4000 ppm of dietary MOS had reduced cecal S. typhimurium 29E concentrations (5.40 vs. 4.01 log CFU/g; P < 0.05) at d 10. In a second series of three trials with S. dublin as challenge organism the number of birds that tested salmonella positive in the ceca at d 10 was lower when MOS was part of the diet (90 % vs. 56 %; P < 0.05). Mannanoligosaccharide also reduced the number of birds from which the challenge organism £ coli 15R could be recovered (75 % vs. 15 %). In order to test the effect of MOS on concentrations of bacteria that do no express type-1 fimbriae, a challenge trial was conducted with S. typhimurium 27A. However, strain 27A did not colonize the birds sufficiently to evaluate if MOS affected its