Effect of dietary fish oil and vitamin E on DNA damage in dogs undergoing training

RISSO A; PELLEGRINO FJ; CORRADA Y; NICOLOF N; SEOANE A; RELLING AE

Baltimore, Maryland

Encuentro; American Society of Animal Science (ASAS), Canadian Society of Animal Science (CSAS), Annual Meeting and Trade Show; 2017

ASAS-CSAS

The aim of the present study was to evaluate the effect of dietary supplementation with fish oil (FO) alone or FO and vitamin E (VE) on DNA damage and serum VE concentration in dogs undergoing training. Using a replicate 3 × 3 Latin square design, 6 male dogs (2?6 yr and 21?35 kg) were assigned to 3 groups: 1) a control diet (CG), 2) the same diet supplemented with 54 mg FO/kg BW0.75 (FG), and 3) a similar diet plus FO (54 mg/kg BW0.75) and 400 mg VE (FEG) per day for 60 d. Blood samples were collected on d 0, 30, and 60. Deoxyribonucleic acid damage was measured using a single-cell gel electrophoresis assay in peripheral whole blood leukocytes. Deoxyribonucleic acid damage was classified in 4 classes (I = undamaged, II = minimum damage, III = medium damage, and IV = maximum damage). Furthermore, a DNA damage index (DI) was calculated using the formula DI = [(I) + 2(II) + 3(III) + 4(IV)]/N(0?IV), in which 0?IV represents the nucleoid type and N0?NIV represents the total number of nucleoids scored. Dogs were trained on a treadmill at 8 km/h and a 7.5% slope twice a week for 60 d. Each session lasted 30 min. Data were analyzed using PROC MIXED of SAS (9.4; SAS Inst. Inc., Cary, NC). Treatment, time, and their interaction were considered fixed variables and dog and period were considered random. The SLICE option of SAS was used for mean separation when there was a treatment × time interaction. On d 30, there was a significant increase in DI in FG compared with CG and FEG (P < 0.01). Deoxyribonucleic acid damage index values were 0.002, 0.105, 0.109, 0.053, 0.743, 0.467, 0.175, 0.127, and 0.193, for CG, FG, and FEG on d 0, 30, and 60, respectively. There was a time × treatment interaction for the serum VE concentration (P < 0.01). On d 0 and on d 30, there were no differences in serum VE concentrations of the 3 groups (P > 0.1). However, on d 60, serum VE concentrations were higher in FEG compared with those in CG and FG (6,200 vs. 2,300 vs. 2,000 μg/d, respectively; P < 0.01). In conclusion, FO supplementation produces DNA damage after 30 d but not at 60 d. The supplementation of FO with VE could prevent the damage at 30 d. Supplementation with VE increases serum VE concentration.