Poster Topical Area: Climate/Environment, Health, Agriculture and Improved Nutrition
Poster Board Number: 13
Objective: This experiment was conducted to compare the effect of the supplemental organic chromium (Cr) form on the digestibility and nutrient transporters in laying hens exposed to heat stress (HS).
Methods: Laying hens (n=1800; 16-wk-old; Lohmann LSL-Lite) were kept in cages in temperature-controlled rooms at either 22±2°C for 24 hr/d (thermoneutral, TN) or 34±2°C for 8 hr/d, from 08:00 to 17:00 hr, followed by 22°C for 16 hr (HS) for 12 wks. Hens reared under both environmental conditions were fed 1 of 3 diets: a basal diet and the basal diet supplemented with either 1.600 mg of chromium-picolinate (CrPic, 12.43% Cr) or 0.788 mg of chromium-histidinate (CrHis, 25.22% Cr) per kg of diet, delivering 200 µg elemental Cr per kg diet.
Results: Heat exposure caused decreases in apparent nutrient digestibility (P < 0.001). However, both Cr sources increased apparent digestibility of dry matter (DM), crude protein (CP) and crude fat (CF; P< 0.01). Exposure to HS was accompanied by suppression of the expressions of fatty acid-binding protein1 (FABP1), sodium-glucose transporter 1 (SGLT1), glucose transporter 1 (GLUT1), glucose transporter type 10 (GLUT10), peptide transporters (PepT1 and PePT2) and amino acid transporters (ASCT1, bo,+AT, CAT1, EAAT3, LAT1) in the ileum and amplification of the expression of fatty acid transport protein 1 (FATP1) in the ileum.
Conclusions: Both Cr sources partially alleviated detrimental effects of HS on digestibility and nutrient transporters. The efficacy of Cr as CrHis was more notable than Cr as CrPic, which could be attributed to higher bioavailability.
The study was funded by Small and Medium Business Development and Support Administration of Turkey (KOSGEB) and also in part by Turkish Academy of Sciences (Ankara, Turkey).
Elazig, Elazig, Turkey