An Alternative Robust Model for in situ Degradation Studies “Korkmaz-Uckardes”
محورهای موضوعی : Camel
ام. کرکمز
1
(
Department of Mathematics, Ordu University, Ordu, 52200, Turkey
)
اف. یوکاردس
2
(
Department of Biostatistics, Adıyaman University, Adıyaman, 02040, Turkey
)
کلید واژه: mathematical model, in Situ degradation, Korkmaz-Uckardes model,
چکیده مقاله :
The first purpose of this study is to present an alternative robust model in order to describe ruminal degradation kinetics of forages and to minimize the fitting problems.For this purpose, the Korkmaz-Uckardes (KU) model, which has a logarithmic structure, was developed. The second purpose of this study is to estimate, by using the Korkmaz-Uckardes (KU)model, the parameters tp (the time to produce p% of partial dry matter disappearance in rumen) and Rtp (the rate of the partial dry matter disappearance in rumen at the time tp). These parameters will provide more useful data to compare feedstuffs in in situ degradation studies. The third purpose is to evaluate the performance of the Korkmaz-Uckardes (KU)model. Statistical criteria used to evaluate the performance of a model were analysis of residuals (Runs and Durbin Watson test) and goodness-of-fit test (residual mean square, coefficient of determination and accuracy factor). The analysis of residuals of the Korkmaz-Uckardes (KU)model was found to be non significant (P>0.05). The residuals are normally distributed. According to the goodness-of-fit test, the Korkmaz-Uckardes (KU) model applied to all data showed a very good fit (residual mean square (RMS)=15.854, R2=0.9853 and accuracy factor (AF)=1.0387). According to the Pearson's correlation analysis, a significant relationship (r2=0.969) was found between observed and predicted values (P<0.001). The results indicate that the Korkmaz-Uckardes (KU) model can be used as an alternative model for describing and interpreting in situ dry matter degradation from natural feedstuffs.
هدف اول این مطالعه ارائه یک مدل قوی جایگزین به منظور توصیف کینیتیک تجزیه شکمبه‌ای علوفه و همچنین حداقل نمودن مشکلات برازش بود. برای این منظور مدل (KU) Korkmaz-Uckardes که یک ساختار لگاریتمی دارد توسعه داده شد. هدف دوم این مطالعه تخمین پارامترهای tp (زمان برای تولید p درصد از ناپدید شدن جزئی ماده خشک در شکمبه) و Rtp(نرخ ناپدید شدن جزئی ماده خشک در زمان t) با استفاده از مدل KU بود. این فراسنجه‌ها داده‌های مفیدتری را برای مقایسه خوراک‌ها در مطالعات تجزیه‌ای در شرایط آزمایشگاهی فراهم خواهند نمود. هدف سوم، ارزیابی عملکرد مدل بود. معیارهای آماری استفاده شده برای ارزیابی عملکرد مدل عبارت از آنالیز باقیمانده‌ها (تعداد اجرا و آزمون دوربین-واتسون) و آزمون شایستگی برازش‌ها (مربعات میانگین باقیمانده‌ها، ضریب تعیین و فاکتور صحت) بودند. آنالیز باقیمانده‌های مدل KU معنی‌دار نبود (05/0P<) باقیمانده‌ها نرمال توزیع داشتند. مطابق با شایستگی برازش‌ها، مدل KU برای تمامی داده‌ها برازش خیلی خوب نشان داد. مطابق با آنالیز همبستگی پیرسون یک همبستگی معنی‌دار (989/0r2=) بین مقادیر مشاهده شده و پیش‌بینی شده بود (01/0P<). نتایج مشخص نمود که مدل KU می‌تواند به عنوان یک مدل جایگزین برای توصیف و تفسیر تجزیه ماده خشک در شرایط آزمایشگاهی برای خوراک‌های طبیعی استفاده شود.
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