Browsing by Author "Ozdemir, T."

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Determination of the Ideal Growth Curve of Angora X Coloured Mohair Goat Cross and Coloured Mohair Goat Kids
(2009) Kucuk, M.; Eyduran, E.; Bolacali, M.; Ozdemir, T.
The aim of this study was to determine the best growth model explaining growth of body weights of Angora goat x coloured Mohair goat cross-breed F 1 and coloured Mohair goat kids using Gompertz, 3 parameter Logistic, Richards and 4 parameter Logistic growth models. Kids were divided into four groups, Angora goat x coloured Mohair goat cross-breed F1 male (genotype Im) and female (genotype If) kids, and oloured Mohair goat kids male (genotype llm) and female (genotype IIf) kids. In order to determine the best growth model, coefficient of determination (R2), Root of Mean Square Error (RMSE), and asymptotic correlations among growth parameters were used. Contrary to other growth models, absolute asymptotic correlation coefficients among parameters of Gompertz growth model for all groups were found higher than 0.95. As a result, it was concluded that Gompertz growth model was the best model for growth at early phase of four groups of goats studied.
New Approaches To Determination of the Best Nonlinear Function Describing Growth at Early Phases of Kivircik and Morkaraman Breeds
(Medwell online, 2008) Eyduran, E.; Kuecuek, M.; Karakus, K.; Ozdemir, T.
The present study was to determine the most suitable nonlinear growth model explaining growth at early stage of lambs of Morkaraman and Kivircik breeds from birth to 180th days of age. For this aim, Monomolecular, Gompertz, Logistic with 3 parameter, Richards, logistic with 4 parameter growth models were used for explaining the body weight-time relationship on 4 breed-sex groups; namely, Morkaraman-Male, Morkaraman-Female, Kivircik-Male and Kivircik-Female. These growth models were fitted to weight-age data on basis of averages of all groups at each period. Body weights of these lambs were recorded fortnightly from birth to 180th days of age. Criteria such as R(2) and Root Mean Square Error (RMSE) and Asymptotic Correlation Coefficients (ACC) between growth parameters in all models were used to determine the best growth model explaining growth at early stage of weight-age of these lambs, Apart from these criteria, we developed two new approaches derived from Asymptotic Correlation Coefficients (ACC), namely, Absolute Reduction Ratio (%) (ARR) and Absolute Reduction Ratio for Cut-off value (%) (ARRC). It was concluded that the most appropriate growth model explaining body weight-time relationship at early phase of four groups was found to be Gompertz growth model and new approaches gave more effective results about testing effectiveness of growth models.
Some Factors Influencing the Birth Weights of Norduz Kids
(Scientific Issues Natl Centre Agrarian Sciences, 2010) Karakus, K.; Aygun, T.; Budag, C.; Eyduran, E.; Ozdemir, T.
The present paper was conducted to determine the effects of some environmental factors on Norduz kids raised at Research and Application Farm of Agricultural Faculty, Yuzuncu Yil University, Van, Turkey. For this aim, birth type (single and twin), gender (male and female), dam age at lambing (1, 2, 3, 4, 5, and 6), and birth year (2005, 2006, and 2007), and birth weights (kg) of 155 Norduz kids were recorded. According to results of the present paper, effect of gender factor on birth weight of kids was found to be non-significant, the influences of dam age (P<0.05), birth type (P<0.05), and birth year (P<0.001) on it were found significant. As a result, the birth weight trait provides useful information for early selection criteria in breeding program. Determination and adjustment of the effects of environmental factors influencing it are very important for achieving more accurate genetic parameters and effective application of breeding and selection methods on the trait.