Highly viscous barley plus Avizyme 1210 gives good broiler performance
The aim of the present study was to investigate further the effect of using a commercial enzyme preparation Avizyme 1210 containing xylanase and beta-glucanase on the performance and feed utilization of broilers fed diets based on wheat and high viscosity barley.
Four diet combinations were randomly assigned to the pens within each block. The dietary treatments were four inclusion levels of barley (0, 150, 300 and 450g/kg). Avizyme 1210 in liquid form was administered via the feed, post pelleting (65oC), following thorough mixing of the appropriate quantities.
The diets were presented to the trial birds in a crumbled form for starter birds (1-21 days) and as pellets in the grower/finisher stage (22-42 days). Diet and water were supplied ad libitum.
Bird liveweights were measured at 1, 21 and 42 days of age and bird feed intake was measured at 21 and 42 days of age. At 21 days of age three birds from each pen were euthanased by cervical dislocation and the contents of the lower half of the ileum was collected.
At eleven days of age, some birds on the highest barley inclusion level (450g/kg) were observed to have rotated legs, curling of the toes, inability to walk, diarrhoea and appeared stunted. After veterinarian inspection, the diagnosis was nutrient mal-absorption and thus the treatment was withdrawn from the experiment.
Viscosity of barley could not be determined as it was too viscous and a supernatant was unable to be obtained. Viscosity of wheat was 10.65 cPs. No significant differences in digesta viscosity (2.745 - 2.970 cPs) were detected between the three treatments despite the extremely high viscosity of the barley grain used. This suggests that the enzyme was effective in reducing gut viscosity to normal levels.
Feed intake in the first 21 days increased significantly (p<0.05) when birds were offered barley when compared to the control diet particularly at the 300g/kg barley inclusion level. Feed intake during the period of 21 to 42 days of age and the overall intake from 0 to 42 days did not differ significantly, however the overall trend was for higher intake with increasing levels of barley in the diet.
Both bird live- weight and live-weight gain were significantly higher at 21 days of age with the inclusion of barley in the diet.
Live-weight gain from 21 to 42 days did not differ significantly although there was a trend towards higher values with increasing level of dietary barley. At 42 days of age, the highest level of barley inclusion (300g/kg) produced significantly higher bird live-weight and live-weight gain than other treatments. This suggests that the nutrient modifications made to barley may have underestimated the actual enzyme effects.
Feed conversion ratio did not differ significantly throughout the trial period, although the trend was for improvement in FCR as the level of barley increased.
The inclusion of 0.5 kg/t of Avizyme 1210 to up to 300g/kg of extremely high viscous barley in a wheat/soy bean meal based broiler diet had a significant positive effect on growth rate and feed intake during both the starter and grower phases. Feed conversion efficiency tended to improve as the level of barley increased in the diet.
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Article made possible through the contribution of the Australian Poultry Science Symposium (APSS) 2006.