NUH OCAK

Prof. NUH OCAK

Department of Animal Science, Faculty of Agriculture, Ondokuz Mayis University, 55139 Samsun, Turkey
orcid

Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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7 June 2021 in Animals
Verified
Journal Article
Open access
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CKcanan kop-bozbay
canan kop-bozbay
AAAhmet Akdağ
Ahmet Akdağ
ABAyfer Bozkurt-Kiraz
Ayfer Bozkurt-Kiraz
Merve GoreMerve Gore
Merve Gore
OKOrhan KURT
Orhan KURT
NUH OCAKNUH OCAK
NUH OCAK
This study investigated the laying performance, egg quality, and egg yolk fatty acids (FAs) and cholesterol content in layer hens housed with free access to chicory- and/or white clover-vegetated areas. During a 16-week study, 400 Lohmann Brown hens (32 weeks old) housed with free outdoor access were allocated randomly into four groups, each with four replicates of 25 hens. Control hens were fed a conventional diet with free access to a soil area (C), whereas other hens were fed on a conventional diet with free access to a chicory (CI)- or white clover (TR)-vegetated area or a CI and TR mixture (MIX)-vegetated area. The C hens consumed more concentrate feed (p = 0.018) than the TR and MIX hens, which had a higher herbage intake than the CI birds (p < 0.001). The C hens produced eggs with a thicker shell than those in the other treatment groups (p = 0.013). Compared with C, the saturated FAs of egg yolk decreased for MIX (p = 0.010). The polyunsaturated FAs were higher in the MIX eggs than in the C and TR eggs (p < 0.001). Although FAs were distributed in all quadrants of the principal component analysis (PCA), three main FA profiles could be identified based on the loadings of natural groupings in the PC2 versus PC1 plot. The present study shows clear evidence for the contribution of herbage to the hen diet without affecting laying performance. In addition, the FA composition of the CI and MIX vegetation contributed to the production of eggs with preferred FA attributes, such as polyunsaturated FAs and a favourable n-6 to n-3 ratio.

1 September 2007 in Clinical Nephrology
Verified
Journal Article
Closed access
MDM. Dirican
M. Dirican
ESEmre Sarandöl
Emre Sarandöl
ZSZ. Serdar
Z. Serdar
NUH OCAKNUH OCAK
NUH OCAK
KDK. Dilek
K. Dilek
Hemodialysis (HD) patients are exposed to oxidative stress which contributes to cardiovascular disease (CVD). The purpose of this study was to investigate the oxidative and antioxidative status in HD patients with (CVD+, n = 38) and without (CVD-, n = 67) prevalent CVD. A total of 105 HD patients and 21 healthy controls were assessed for lipid peroxidation indices (plasma malondialdehyde (MDA)), oxidizability of apolipoprotein B-containing lipoproteins (apo B-deltaMDA) and red blood cells (RBC-MDA) together with various components of the antioxidant system in plasma (paraoxonase/arylesterase activities, total carotenoids, vitamins C and E) and RBC (superoxide dismutase and glutathione peroxidase activities). Plasma MDA and RBC-MDA were significantly higher, vitamin C and total carotenoid levels were significantly lower in both CVD+ and CVD- HD groups than in the control group. Plasma MDA levels were significantly higher and serum paraoxonase activity, uric acid and albumin levels were significantly lower in patients with CVD+ HD patients compared to those of the CVD- patients. This study suggests that the elevated level of plasma MDA and the lower activity of paraoxonase could contribute to the increased incidence of cardiovascular disease in hemodialysis patients.

1 February 2021 in Animal Bioscience
Verified
Journal Article
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CKcanan kop-bozbay
canan kop-bozbay
AAAhmet Akdağ
Ahmet Akdağ
Helin Atan ÇırpıcıHelin Atan Çırpıcı
Helin Atan Çırpıcı
NUH OCAKNUH OCAK
NUH OCAK
Objective: The objectives of this study were to compare the effects of normal and low protein content (PC) of starter diet supplemented or not with blends of branched-chain amino acids (BCAAs) on growth performance of broilers under summer conditions and to investigate whether these effects altered some quality traits and the characteristics of gastrointestinal tract.Methods: A total of 768 mixed-sex broiler chicks (Ross 308, one-d-old) with an average initial body weight (BW) of 47.6±1.03 g were allocated into six treatments with four replications in 2×3 factorial arrangement. Factors were: PC, normal (N, 22% to d 15); and low (L, 20% to d 15); and added BCAA blends, L-leucine, L-isoleucine, and L-valine at zero (0L:0I:0V); 1.0, 0.25, and 0.25 (4L:1I:1V); or 1.0, 0.25, 0.75 (4L:1I:3V) g/kg of diet. Hence, six dietary treatments were named as N0L:0I:0V, N4L:1I:1V, N4L:1I:3V, L0L:0I:0V, L4L:1I:1V, and L4L:1I:3V. Average indoor temperature and humidity were 32.8°C±1.7°C and 61.1%±4.12%, respectively.Results: BW, feed conversion ratio (FCR) and carcass weight were not affected by PC, BCCA and their interaction (p>0.05). The L diets decreased the water holding capacity of the breast (p = 0.002) and thigh (p = 0.050) meats and dressing percentage (p = 0.005) compared to the N diets. The 4L:1I:1V diet decreased breast yield compared to the 0L:0I:0V diets (p = 0.041). The effect of PC on feed intake, mortality and gastrointestinal trait weight were depended on the L:I:V ratios under summer conditions due to interactions between factors (p<0.05). The FI and mortality of L4L:1I:1V broilers were lower than those of N4L:1I:1V birds (p<0.05).Conclusion: It was concluded that the blends of BCAAs used failed to improve performance and to promote breast yields, because diets with normal or with reduced protein supplemented or not with BCAAs up to d 15 produced a similar BW and FCR in broilers raised in hot-climate conditions.


30 September 2008 in Journal of Animal Physiology and Animal Nutrition
Verified
Journal Article
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NUH OCAKNUH OCAK
NUH OCAK
FSF. Sivri
F. Sivri

19 October 2023 in Journal of the Science of Food and Agriculture
Verified
Journal Article
Open access
CKcanan kop-bozbay
canan kop-bozbay
BYBerkan Yılmaz
Berkan Yılmaz
NUH OCAKNUH OCAK
NUH OCAK
BACKGROUND: Dietary l‐leucine or its metabolite 𝛽‐hydroxy‐𝛽‐methylbutyrate (HMB) has a crucial role in the muscle protein metabolism of broilers during the first few‐week growing period. The present study aimed to evaluate the effects of l‐leucine (LLPD) or HMB (HLPD) supplementation in a low‐protein diet (20%, LPD) until 21 days old on performance, carcass weight, muscle yield and meat quality, as well as intestinal morphometry, in broiler chickens.RESULTS: From days 1–42, LPD decreased body weight gain and feed intake (FI) and increased feed conversion ratio compared to a standard protein diet (22%, SPD). The LLPD and HLPD did not affect FI, but the LLPD decreased the body weight gain and increased the feed conversion ratio compared to the SPD. The LPD group had lower body and muscle weights than other groups. Compared to LPD, HLPD increased dressing percentage. The LPD decreased the serum insulin‐like growth factor‐1 content compared to the SPD and LLPD. The duodenal villus height of the LPD and LLPD broilers was smaller than those of the SPD and HLPD birds. The HLPD broilers had lower duodenal villus width than the SPD birds. The duodenal crypt depth and ileal mucosal thickness were higher in the HLPD group than in other groups. The HLPD and LLPD enhanced the ileal villus height compared to the SPD. The LLPD and HLPD treatments did not affect meat quality traits compared to the SPD treatment.CONCLUSION: Dietary HMB could be a conducive approach to reducing dietary protein for broilers until 21 days old. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.