Dual-purpose chickens are increasingly used in European organic poultry systems. To test whether lower feed conversion efficiency of dual-purpose chickens could be counterbalanced by less intensive feeds with higher proportions of dietary fibre, a slow-growing conventional broiler genotype (Hubbard JA 757) was compared with a newly developed dual-purpose breed (Coffee & Ouml;TZ), regarding their performance on diets with either low fibre (162 g kg-1 NDF) and high protein (217 g kg-1 CP; diet CON) or high fibre (256 g kg-1 NDF) and low protein (188 g kg-1 CP; diet EXT). In two further treatments, additionally to CON low- or high-quality chopped lucerne hay was offered separately. Forty-eight chicks of each genotype were allocated to the four treatments and fattened over 69 days (conventional broilers) or 77 days (dual-purpose roosters). After slaughter, intestinal organs and digesta were analysed. Voluntary intake of hay amounted to approximately 2% of the total feed eaten. In both genotypes, diet EXT led to higher intake and lower digestibility compared to CON, with less difference in Coffee. Genotype influenced feed intake, growth performance, dressing percentage, and carcass composition, all proving higher efficiency for Hubbard. Feed conversion efficiency was higher in Hubbard. However, in Coffee CP efficiency decreased less and energy efficiency even increased between CON and EXT. Gizzard, small intestine and caeca were larger, and fibre digestibility was higher in Coffee. Short-chain fatty acids in caecum were influenced by genotype. In conclusion, the high-fibre diet appeared suitable to reach appropriate protein and energy efficiency for Coffee roosters.

For reasons of aspired naturalness and cost reduction, vitamin additions should be kept low in organic livestock systems. To define safe lower threshold levels of riboflavin supplementation in organic poultry feeding, 135 hybrid layers were allocated to three dietary treatments supplemented with either 4.5 (R4.5), 3.0 (R3.0) or 1.5 mg (R1.5) GMO-free riboflavin added per kg feed. This resulted in total measured concentration averages of 5.0, 4.5, and 3.1 mg kg(-1) feed for R4.5, R3.0 and R1.5, respectively. For 18 weeks, each treatment was replicated in three groups of 15 hens. Feed consumption, laying performance, egg quality, riboflavin concentration in the yolk, and clinical health scores were assessed. Two hens per group (six per treatment) were slaughtered in weeks 11 and 18, respectively, for measurement of pancreas, spleen, liver and heart weights, and determination of liver riboflavin. No treatment effects on feed consumption, body weight, laying performance, egg weights, eggshell strength and yolk colour or plumage and keel bone integrity were observed. No symptoms of lameness or footpad damage were found. The riboflavin concentration in egg yolks in R1.5 was lower than in other treatments. Liver riboflavin concentration increased between week 11 and 18 in all treatments, but it was also lower in R1.5. Based on these results, the addition of 3 mg riboflavin kg(-1) feed appeared to be sufficient with respect to the health and performance of laying hens. Supplementation with only 1.5 mg kg(-1) resulted in some metabolic signs of deficiency. These results apply only to organic winter diets.

Welche Legehenne eignet sich fur Freilandbetriebe? Welche Anforderungen stellen wir an eine solche Henne? Im EU-Projekt «LowInputBreeds» wird das untersucht und dieser Artikel stellt erste Resultate vor.

Welche Legehenne eignet sich fur Freilandbetriebe? Welche Anforderungen stellen wir an eine solche Henne? Im EU-Projekt «LowInputBreeds» wird das untersucht und dieser Artikel stellt erste Resultate vor.

Gastro-intestinal nematodes (GIN) are the most important problem in small ruminant production with regard to animal welfare and economics. The control of GIN currently relies almost exclusively on the use of synthetic anthelmintics. This is unsatisfactory for organic as well as for conventional small ruminant farmers because of rapid increase of resistant GIN populations and risk of residues in meat and milk. Alternatives to synthetic anthelmintics are therefore needed. This poster presents the main alternative control strategies for GIN. The strategies are divided into measures aimed at freeliving GIN stages (grazing management, biological control) and at stages within the host (genetic resistance, vaccination, anthelmintic plants, feeding strategies).

The aim of our experiments was to investigate the transmission and infectivity of the two main helminth parasites of poultry (Ascaridia galli and Heterakis gallinarum) under different run and litter management regimes. In experiment (a) two stocking rates were simulated in outdoor runs and the effect of a simple management practice (mowing) on helminth transmission was studied during two subsequent flocks. Stocking rate seemed not to change helminth transmission patterns and repeated mowing of runs did not reduce helminth infections. Lower stocking rates led to a substantial improve- ment of the run vegetation. In experiment (b) two litter management regimes (replace or add litter material) were compared to unmanaged litter with regard to parasitological parameters and water content of the litter. The regimes had no significant effect on water content or on parasitological parameters. These results suggest that positive effects of run and litter management regimes on helminth infections of laying hens are often overestimated in practice. Einleitung und Zielsetzung Im ökologischen Landbau werden Legehennen in Systemen mit Einstreu und Grün- auslauf gehalten. Diese Haltungsform ist tierfreundlich, aber Auslauf und Einstreu stellen auch eine bedeutende Infektionsquelle für Parasiten und andere Pathogene dar. Die Rundwürmer Ascaridia galli and Heterakis gallinarum sind in der Hühner- haltung die wichtigsten parasitären Wurmarten. Neben direkten Auswirkungen auf das Tier wird starker Wurmbefall oft auch mit Federpicken in Verbindung gebracht. Da präventive anthelminthische Behandlungen im ökologischen Landbau nicht zulässig sind, ist vorbeugendes Management essentiell. Bei weidenden Wiederkäuern bewirkt eine Senkung des Infektionsdrucks auf der Weide auch eine entsprechende Redukti- on des Wurmbefalls im Tier. Zahlreiche Untersuchungen haben gezeigt, dass tiefere Besatzdichten auf der Weide zu tieferem Trichostrongylidenbefall bei Rindern und Schafen führten. Bei Nicht-Wiederkäuern existieren hingegen nur wenige Studien zu den Übertragungsmustern parasitärer Wurmarten. Besonders beim Geflügel scheint die Reduktion der Besatzdichte als alleinige Massnahme nur einen beschränkten Einfluss auf den Wurmbefall zu haben. Deshalb sollte mit den hier beschriebenen Experimenten (a) der Einfluss von Besatzdichte und Auslaufpflege und (b) der Effekt einfacher Einstreupflegeverfahren auf die Infektiosität und die Qualität des Auslaufs bzw. der Einstreu untersucht werden.