Harald Hetland

Effect of access to wood shavings and processed paper in the litter bath of modified cages on performance, gizzard activity, plumage condition, and peck damages was studied for layers fed a wheat-based diet. Egg production was similar for all treatments, but birds with access to paper showed higher feed consumption than the control birds and birds with access to wood shavings. This resulted in a corresponding difference (P < 0.05) in feed utilization. A significantly higher AME_n was observed for birds with access to wood shavings than in the control. Consumption of wood shavings and paper from the litter bath was 4 and 11 g/hen per day, respectively. Weights of empty gizzard and gizzard contents were considerably higher for birds with access to wood shavings. The median particle size in the duodenum decreased with access to wood shavings. In contrast, birds with access to paper showed a higher mean particle size in the duodenum.

1. Three experiments were performed to study the effect of Hagberg falling number in wheat on performance, nutrient digestibility and AME_N in broilers. In two experiments, one hard and one soft wheat variety were used to study the interaction between falling number and hardness of wheat with regard to nutritional value. In these experiments, wheat batches with high falling number when harvested under dry conditions were used in broiler diets. 2. Wheat with reduced falling numbers (high, medium and low) was obtained by controlled germination. In the third experiment, wheat with reduced falling numbers were obtained by delayed harvesting times. 3. In each experiment, a total of 4 cereal batches with different falling numbers from each wheat variety were used to produce corresponding experimental diets with wheat as the major ingredient. Each diet was fed to broiler chickens ad libitum from d 1 to d 17 of age. 4. There was no consistent effect of falling number on performance. Low falling number did not improve feed utilisation or AME _N compared to the original wheat, despite a higher AME _N associated with higher starch digestibility. This phenomenon was not observed after reduction of falling number by delayed harvesting. Apparently, natural reduction of falling number resulted in enhanced degradation of arabinoxylans compared to controlled germination.

Human health may be improved if dietary intakes of selenium and omega-3 fatty acids are increased. Consumption of broiler meat is increasing, and the meat content of selenium and omega-3 fatty acids are affected by the composition of broiler feed. A two-way analyses of variance was used to study the effect of feed containing omega-3 rich plant oils and selenium enriched yeast on broiler meat composition, antioxidation- and sensory parameters. Four different wheat-based dietary treatments supplemented with 5% rapeseed oil or 4% rapeseed oil plus 1% linseed oil, and either 0.50 mg selenium or 0.84 mg selenium (organic form) per kg diet was fed to newly hatched broilers for 22 days. The different dietary treatments gave distinct different concentrations of selenium and fatty acids in thigh muscle; one percent linseed oil in the diet increased the concentration of the omega-3 fatty acids 18:3, 20:5 and 22:5, and 0.84 mg selenium per kg diet gave muscle selenium concentration at the same level as is in fish muscle (0.39 mg/kg muscle). The high selenium intake also resulted in increased concentration of the long-chain omega-3 fatty acids EPA (20:5), DPA (22:5) and DHA (22:6), thus it may be speculated if high dietary selenium might have a role in increasing the concentration of EPA, DPA and DHA in tissues after intake of plant oils contning omega-3 fatty acids. Moderate modifications of broiler feed may give a healthier broiler meat, having increased content of selenium and omega-3 fatty acids. High intakes of selenium (organic form) may increase the concentration of very long-chain omega-3 fatty acids in muscle.