Fachbereich Veterinärmedizin



    The effect of feed additives on nutrient digestibility and ileal viscosity in free-range laying hens (2017)

    Iqbal, Z.
    Metzger, F.
    Singh, M.
    Perez-Maldonado, R.
    Ramirez-Cuevas, S.
    Swick, R.
    Zentek, J. (WE 4)
    Ruhnke, I. (WE 4)
    21st European Society of Veterinary and Comparative Nutrition Congress
    Cirencester, UK, 20. – 23.09.2017
    Congress Proceedings 21st European Society of Veterinary and Comparative Nutrition Congress : 20-23 September 2017 Cirencester, UK — European Society of Veterinary and Comparative Nutrition (Hrsg.)
    — S. 84
    URL (Volltext): https://www.researchgate.net/publication/323108719_The_effect_of_feed_additives_on_nutrient_digestibility_and_ileal_viscosity_in_free-range_laying_hens
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    Abstract / Zusammenfassung

    ntroduction: Mortality and morbidity associated with gut impaction resulting from uncontrolled pasture intake can be a major concern to free range egg producers. This impaction restricts the feed passage through the gastrointestinal tract (GIT) leading to reduced feed intake, reduced nutrient supply and eventually death (Ruhnke et al., 2015). The aim of this study was to investigate the benefits of multi-enzymes (xylanases, pentosanases, hemicellulases, betaglucanases) and a combination of benzoic acid and essential oils on nutrient digestibility and viscosity of digesta in free-range laying hens.
    Material and Methods: Three hundred laying hens (Lohmann brown, 16 weeks of age) were fed a typical wheat-soy based diet and allocated to six treatments and five replicates of 10 birds each. Hens were arranged to test the effect of range type {(R1 = no pasture, R2 = pasture: Festuca arundinacea planted 5 months before the trial and grown upto 50 cm.were analysed and values g/kg are CP(186), CF(21.20), Ca (4.63) and P (3.85)} and feed additives (T1 = phytase /xylanase; T2 = phytase/ xylanase/ betaglucanse/ pectinase/ protease; T3 = phytase/ xylanase/ benzoic acid/ essential oils) of short term (6 weeks) and long term (12 weeks) pasture exposure. Hens were adapted to treatments for two weeks before allowing access to the range at 18 weeks of age. After 6 and 12 weeks of treatment, excreta was collected for three consecutive days to determine the alkane content to calculate pasture intake (Mayes et al., 1986). At these times selected hens were euthanised to collect ileum digesta. Proximate analysis was performed to determine the
    nutrient digestibility of crude protein (CP), crude fibre (CF), calcium (Ca) and phosphorus (P). In addition, ileum digesta was used for viscosity measurement. Data was analysed in 2x2x3 (2 time points; 2 range types and 3 feed additives) factorial arrangement using SPSS version 2.2.
    Result and discussion: Hens on R1 (no pasture) had a significantly (p = 0.020; p = 0.050 respectively) higher ileal digestibility of CP (75.3%) and Ca (51.2%) compared to hens on R2 (pasture) 71.3% and 40.1%, respectively. However, hens on R2 had significantly (p = 0.000) higher P digestibility (44.3%), compared to hens on R1 (33.4%). The digestibility values (p = 0.000) of CF in hens on R2 (pasture) were reduced (-32.0%) compared to hens on R1 (no pasture) 16.1%. This reflects the low fermentability of pasture and its accumulation in the GI tract. Multienzyme and organic acid supplementation improved CP (0.013) and P digestibility significantly (p
    = 0.038).In hens fed on T2 and T3; 74.7% digestibility values of CP was measured compared to T1 (70.1%) while P digestibility values in hens fed T2 and T3 were 41.5% & 42.2% respectively compared to hens fed T1 (32.3%). However the digestibility of CF was close to significance (p = 0.062). Hens fed T1 showed -30.8% CF digestibility, while hens fed T2 and T3 accumulated less CF in their ileum (-0.36% and 0.14% respectively). This clearly demonstrates that the use of multienzymes and organic acids resulted in less fibre impaction of the GIT. The duration of treatment had a significant (p = 0.005) effect on the digesta viscosity (3.36 mPa after 6 weeks and 4.29 mPa after 12 weeks of treatment).
    Conclusion: Organic acid and multi-enzyme supplementation in free range layer diets resulted in reduced fibre load in the ileum and subsequently increased the nutrient digestibility.