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Öğe A Bayesian approach for describing the growth of Chukar partridges(EUGEN ULMER GMBH CO, 2019) Iqbal, F.; Eyduran, E.; Mikail, N.; Sariyel, V.; Huma, Z. E.; Aygun, A.; Keskin, I.In this article, a Bayesian approach was employed for estimating the body growth of Chukar partridge (Alectoris chukar). Nonlinear growth models commonly used to estimate the growth curve of birds were fitted to weight-age data and estimates of model parameters and their credible intervals were obtained via a formal Bayesian framework. More specifically, the Gompertz, Brody, Logistic and von Bertalanffy growth models were fitted to weekly body weight data of 108 female and 72 male partridge chicks from hatch to 20 weeks of age. Deviance Information Criteria (DIC) and the coefficient of determination (R-2) were employed as the goodness of fit for comparing the fitted models. The DIC and R-2 values of the models ranged from 172.9 to 204.2 and 0.9765 to 0.9913, respectively. The von Bertalanffy model was found to provide the best fit in terms of lower DIC and higher R-2 values, followed by the Gompertz model for both male and female partridge data. The Bayesian approach was found to be adequate for fitting complex nonlinear functions to weight-age data of Chukar partridges.Öğe Comparison of growth curve models in partridge(OXFORD UNIV PRESS, 2017) Sariyel, V.; Aygun, A.; Keskin, I.This study was conducted in order to determine the goodness of fit of Brody, Gompertz, Logistic, and von Bertalanffy growth curve models in partridge (Alectoris chukar). The growth curve parameters A (upper asymptote or mature weight parameter), B (scale parameter related to initial weight), and K (instantaneous growth rate parameter) were determined as 623.4, 1.05, and 0.075 for females and 723.8, 1.06, and 0.073 for males in the Brody model, respectively, 472.9, 3.47, and 0.207 for females and 565.3, 3.59, and 0.192 for males in the Gompertz model, respectively, 440.2, 12.89, and 0.332 for females and 517.0, 14.13, and 0.319 for males in the Logistic model, respectively, and 498.9, 0.77, and 0.164 for females and 608.8, 0.79, and 0.150 for males in the von Bertalanffy model, respec-tively. While determining which growth curve model presented the better fit, the coefficient of determination (R-2), adjusted the coefficient of determination (adj. R-2), mean square predicted error (MSPE), Durbin-Watson value, correlation between estimated live weight and residual values (RESC), Akaike's information criteria (AIC), and Bayesian information criterion (BIC) were used. As a consequence of the study, it was determined that the Gompertz model yields a better fit to the data for the partridge, as its coefficient of determination and adjusted coefficient of determination are high, its values of MSPE, RESC, AIC, BIC are low and there is not an autocorrelation between the residual values. As a result, the Gompertz model presented a better fit with the partridge data.Öğe Comparison of Six Different Mathematical Models to the Lactation Curve of Simmental Cows Reared in Kazova State Farm(MEDWELL ONLINE, 2008) Cilek, S.; Keskin, I.The aim of this study was to investigate the fitness of Incomplete Gamma (WD), Quadratic (Q), Cubic (C), Exponential (WIL), Mixed Log (ML) and Polynomial Regression (AS) models to the lactation curve of Simmental Cows. Data were collected from 752 Simmental cows raised on the Kazova state farm in Turkey. Milk yield was recorded monthly. Total milk yields estimated by the 6 models were very close to real total milk yield. The 6 models were found to be adequate for estimation of milk yield. ML model underestimated the peak yield significantly. The differences between peak yields of the models and real peak yield were statistically insignificant (p > 0.05) and they were ranged from 13.19-18.591. Cubic models forecasted peak time earlier than real peak time. The differences between the persistency values of the 6 models were insignificant (p > 0.05). The 6 model's persistency value was nearly equal to real persistency value. W values of the 6 models changed from 92.69-95.14%. The highest value of R(2) was found in AS model. Furtermore, least value of MSPE was found in AS model. Consequently, the entire model's showed the best fit to the lactation data of Simmental cows and allowed a suitable definition of the lactation curve.Öğe Effect of Silybum marianum on acute hepatic damage caused by carbon tetrachloride in rats(SCIENTIFIC PUBLISHERS INDIA, 2012) Öztürk, Mustafa; Akdoğan, Mehmet; Keskin, I.; Kişioğlu, Ahmet Nesimi; Öztaş, S.; Yıldız, K.The study was designed to test the efficiency of of Silybum marianum in different doses to treat carbon tetrachloride (CCl4) induced liver damage. Thirty-five Wistar albino rats were divided randomly into five groups as follows: Control Group: 4 ml saline; CCl4 Group: 4 ml saline plus 2 ml/kg CCl4; 2.5% Infusion Group: 2 ml/kg CCl4 plus 2.5% infusion of Silybum marianum; 5% Infusion Group: 2 ml/kg CCl4 plus 5% infusion of Silybum marianum; 10% Infusion Group: 2 ml/kg CCl4 plus 10% infusion of Silybum marianum. Infusions were given once a day for 5 consequtive days. CCl4 was administered intraperitoneally (2 ml/kg) on days 2 and 3. At the end of the 5th day, animals sacrificed and their bloods were drawn for biochemical tests and liver samples were taken for histopathologic investigation. CCl4 caused to incease in glucose and to decrease in albumin, total cholesterol and trigliceride levels. Silybum Marianum treatment improved these changes. All liver function tests were elevated by of CCl4 administration and than reduced, by Silybum Marianum treatment. CCl4 caused to hepatocyte degeneration, central ven dilatation, congestion, and to increase in the number of Kuppfer cells and histopathological injury scores. Treatment with Silybum marianum infusion showed slightly preventive effect on CCl4 induced liver damage by biochemically and histologically.Öğe Estimation of growth curve parameters in Konya Merino sheep(SOUTH AFRICAN JOURNAL OF ANIMAL SCIENCES, 2009) Keskin, I.; Dag, B.; Sariyel, V.; Gokmen, M.The objective of this study was to determine the fitness Of Quadratic, Cubic, Gompertz and Logistic functions to the growth curves of Konya Merino lambs obtained by using monthly records of live weight from birth to 480 days of age. The models were evaluated according to determination coefficient (R-2), mean square prediction errors (MSPE) and Durbin Watson (DW) statistics. The R-2 values of the models ranged from 0.96 to 0.99 for females and from 0.96 to 0.99 for males. The Cubic model gave the best R value oF 0.99 in females, while the Logistic model gave the lowest R-2 value of 0.96 in females. The results indicated that the Quadratic and Gompertz models showed the best fit to growth of Konya Merino ewe lambs by having higher R-2 values, lower MSPE and non autocorrelation. By using these models live weights at later ages could be predicted from early partial live weight data. Further studies should be carried Out on growth curve characteristics at later ages including adult age.Öğe Identification of genetic variation in the major histocompatibility complex gene region in Turkish sheep breeds(SOUTH AFRICAN JOURNAL OF ANIMAL SCIENCES, 2016) Ilhan, F.; Keskin, I.; Tozluca, A.The major histocompatibility complex (MHC) in sheep, Ovar-Mhc, remains poorly characterized relative to other domestic animals. However, its basic structure is similar to that of other mammals, comprising class I, II and III regions. In this study, the Ovine MHC class II DRB1 and DRB3 genes were amplified by polymerase chain reaction in eight sheep breeds reared in Turkey. Informative restriction fragment length polymorphisms (RFLPs) were obtained with five restriction enzymes for DRB1 and with two restriction enzymes for DRB3. The digestion of DRB1 exon 2 with NciI, SacI, SacII, Hin1I each produced three genotypes and two alleles (viz., a and b) with frequencies of 0.69 and 0.31; 0.65 and 0.35; 0.91 and 0.09; 0.57 and 0.43, respectively. The digestion of DRB1 exon 2 with DdeI produced four genotypes and three alleles (viz., a, b and c) with frequencies of 0.62, 0.28 and 0.10, respectively. On the other hand, the digestion of DRB3 exon 2 with NdeII and BsaI each produced three genotypes and two alleles (viz., a and b) with frequencies of 0.72 and 0.28; 0.96 and 0.04, respectively. This study presents the genetic profiles of the exon 2 region of the MHC DRB1 and DRB3 genes in native Turkish sheep breeds.
