Negative effect of phytase superdosing in laying hens
| Autor: | Miloš Skřivan, Michaela Englmaierová, Věra Skřivanová |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: | |
| Zdroj: | Czech Journal of Animal Science, Vol 63, Iss 5, Pp 182-187 (2018) |
| Druh dokumentu: | article |
| ISSN: | 1212-1819 1805-9309 |
| DOI: | 10.17221/113/2017-CJAS |
| Popis: | Hisex hens, aged 24 weeks, were divided into 6 groups. Each group consisted of 4 cages with 10 hens per cage with dimensions and equipment meeting the EU directives. This 2 × 3 factorial experiment included two levels of calcium (Ca; 35 or 42 g/kg) and 3 different additions of 6-phytase OptiPhos® (Ph; 0, 300, and 1500 phytase units (FTU)/kg) to the diet. The content of nonphytate phosphorus (NPP) in all diets was the same (1.8 g/kg). The experiment lasted 12 weeks. A significant interaction of Ph × Ca (P = 0.029) was observed in hen-day egg production. A diet with 35 g/kg Ca and the highest dose of Ph (1500 FTU/kg) resulted in a lower hen-day egg production (84.1%) than did the other treatments (91.5-88.6%). Phytase superdosing negatively influenced egg mass production (P = 0.001) and the feed conversion ratio (P = 0.018). Neither Ph nor Ca influenced eggshell ash content. Both additions of Ph into mixed feed decreased Haugh units (P < 0.001). A higher content of Ca in the diet increased shell thickness (P = 0.024) and shell breaking strength (P = 0.039), while Ph addition increased shell percentage (P = 0.004) and shell breaking strength (P = 0.009). The results of this experiment demonstrate the unsuitability of Ph superdosing in mixed feed for laying hens. |
| Databáze: | Directory of Open Access Journals |
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