برازش برخی از مدل‌های غیر خطی به‌منظور پیش‌بینی کینتیک تخمیر شکمبه‌ای در علوفه‌های مختلف

نوع مقاله : مقاله پژوهشی

نویسندگان

• خلیل زابلی ¹
• سعید مرادی ²

¹ گروه علوم دامی، دانشکده کشاورزی، دانشگاه بوعلی سینا، همدان، ایران.

² گروه علوم دامی، دانشکده کشاورزی، دانشگاه بوعلی سینا، همدان

10.22067/ijasr.2022.70783.1028

چکیده

این آزمایش به­منظور مقایسه دقت برخی از مدل­های غیرخطی در پیش­بینی کینتیک تولید گاز در تعدادی از خوراک­های علوفه­ای انجام شد. ابتدا، آزمون تولید گاز 144 ساعته با استفاده از علوفه­های یونجه (چین اول، چین دوم و چین سوم)، علوفه اسپرس، کاه گندم، کاه جو و سیلاژ ذرت انجام شد. سپس، حجم گاز تولید شده در زمان­های مختلف انکوباسیون با استفاده از مدل­های اکسپونانشیال (EXP)، گومپرتز (GOM)، ریچارد (RCH) و فرانس (FRC) برازش شدند. نکویی برازش مدل­ها با استفاده از آماره­های میانگین مربعات خطا (MSE)، ضریب تعیین (R²)، انحراف مطلق میانگین باقی‌مانده (RMAD) و میانگین درصد خطا (MPE) تعیین شد. از آزمون تست اجرا (run test)، فاکتور صحت (AF)، معیار اطلاعات آکائیک (AIC) و معیار اطلاعات بیزی (BIC) به­منظور بررسی دقت مدل­ها استفاده شد. نتایج نشان داد، پتانسیل تولید گاز (A) پیش­بینی شده توسط مدل FRC (68/104 میلی­لیتر به­ازای 200 میلی­گرم ماده خشک) تفاوت معنی­داری با مدل EXP (18/100 میلی­لیتر به­ازای 200 میلی­گرم ماده خشک) داشت (05/0p<). مدل EXP دارای بیشترین مقدار MSE (11/15) و کمترین مقدار R² (984/0) بود (05/0p<). مقدار RMAD در مدل EXP بیشترین (88/2) و در مدل FRC کمترین (85/0) مقدار بود (05/0P<). مقدار MPE در مدل­های FRC و RCH (به‌ترتیب 32/0 و 48/0) در مقایسه با سایر مدل­ها به عدد صفر نزدیک­تر بود. آزمون تست اجرا در مدل­های EXP و GOM معنی­دار شد (05/0p<) که نشان­دهنده دقت کمتر این مدل­ها بود. به­طور کلی، مدل EXP کینتیک تخمیر شکمبه­ای خوراک­های علوفه­ای را با دقت کمتری پیش­بینی کرد و بیشترین دقت را نیز مدل FRC داشت.

کلیدواژه‌ها

• آزمون تولید گاز
• علوفه
• مدل‌های غیرخطی
• نکویی‌برازش

موضوعات

• نغذیه نشخوارکنندگان

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عنوان مقاله [English]

Fitting of some Nonlinear Models for Predicting Ruminal Fermentation Kinetics in Different Forages

نویسندگان [English]

• Khalil zaboli ¹
• Saeid Moradi ²

¹ Animal Science Department, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran.

² Animal Science Department, Faculty of Agriculture, Bu-Ali Sina University, Hamedan

چکیده [English]

Introduction The in vitro gas production test is used as a laboratory method for studying the ruminal fermentation of feed-stuffs. This method is an ideal technique, because it allows to record gas production at different hours an incubation time. In this technique, the parameters of fermentation kinetic are predicted using nonlinear models. The Exponential Model (EXP) is the easiest nonlinear model which is applied for this regard. However, it has been reported that some nonlinear models predict the parameters of gas production kinetic more accurately than the EXP model. In this study, different forages were used as feed samples and the accuracy of some nonlinear models for predicting the parameters of gas production kinetic has been studied and compared.
Materials and methods For this experiment, alfalfa forage (first, second and third cutting), sainfoin hay, wheat straw, barley straw and corn silage were used as feed samples. Feed samples were analyzed for Dry matter, ash, crude protein, neutral detergent fiber and acid detergent fiber according to standard methods. Rumen fluid was collected from three ruminally fistulated mature Mehraban rams before the morning feeding. Obtained rumen fluids were pooled and strained through four layers of cheesecloth into a pre-warmed (38 to 39 ˚C) insulated flask and immediately transported to the laboratory. In laboratory, ruminal fluid was filtered through four layers of cheese cloth and then mixed continuously with CO₂ and maintained near 39^o C before usage. To evaluate the ruminal fermentation kinetic of feeds, the in vitro gas production test was carried out during 144 h incubation time for 3 run. For this purpose, 200 mg of dried and milled feeds with 30 ml of buffered rumen fluid were poured into glass vials (in 3 replicates). Two glass vials containing 30 ml of buffered rumen fluid without substrate were considered as blanks. After capping (plus tow glass vials as blanks), all glass vials were incubated at 39 ° C. The volume of gas produced was recorded at 2, 4, 6, 8, 10, 12, 16, 20, 24, 36, 48, 72, 96, 120, 144 h after incubation.
The obtained results (volume of gas produced at each incubation time) were fitted to four nonlinear models included the exponential (EXP), Gompertz (GOM), Richard (RCH) and France (FRC) models. The mean square error (MSE), coefficient of determination (R²), residual mean absolute deviation (RMAD) and mean percentage error (MPE) statistics were used as goodness of fit parameters. The run test, accuracy factor (AF), Akaike information criterion (AIC) and Bayesian information criterion (BIC) were used to compare the accuracy of the models for predicting the gas production kinetic.
Results and Discussion The results showed that the asymptotic gas volume (A) predicted by the FRC model (104.68 ml per 200 mg dry matter) was significantly different from the EXP (100.18 ml per 200 mg dry matter) model (p <0.05). But the value of A predicted by the EXP, GOM and RCH models did not show a significantly difference. The rate of gas production (c) predicted by the studied models were significantly different and the lowest value was observed in the FRC model (p<0.05). The highest and lowest values for MSE (15.11) and R² (0.984) were observed in the EXP model, respectively. Which indicated the EXP model goodness of fit was weak compared to the other models. The RMAD statistic in the studied models had significantly difference (p<0.05) and the highest (2.88) and lowest (0.85) values were observed in the EXP and FRC models, respectively. So, the FRC and EXP models had the highest and lowest goodness of fit, respectively. The MPE statistic in the FRC and RCH models were closer to zero (0.32 and 0.48, respectively) compared to the other models (EXP and GOM models), which indicated better goodness of fit in these models. The run test was significant in the EXP and GOM models (p<0.05). So, these models were less accurate for predicting the gas production kinetic. The value of AF, AIC and BIC statistics (2.85, 15.87 and 10.04, respectively) showed that the FRC model had the highest accuracy for predicting the gas production kinetic among the studied models.
Conclusion The results showed that the EXP model had the lowest accuracy for predicting ruminal fermentation kinetic of feeds, among the studied models. However, the FRC model had the highest accuracy.

کلیدواژه‌ها [English]

• Forage
• Gas production test
• Goodness of fit
• Non-linear models

مراجع

1. AOAC. (1995). Official Methods of Analysis, 16^th ed. Association of Official Analytical Chemists, Arlington, VA.

   2. Beuvink, J. M., & Kogut, J. (1993). Modeling gas production kinetics of grass silages incubated with buffered ruminal fluid. Journal of Animal Science, 71(4), 1041-1046. DOI: 10.2527/1993.7141041x
   3. Dhanoa, M. S., Lopez, S., Dijkstra, J., Davies, D. R., Sanderson, R., Williams, A. B., Zileshi, Z., & France, J. (2000). Estimating the extent of degradation of ruminant feeds from a description of their gas production profiles observed in vitro: Comparison of models. British Journal of Nutrition, 83, 131–142. DOI: 10.1017/s0007114500000179
   4. France, J., Dhanoa, M. S., Theodorou, M. K., Lister, M. K., Davies, D. R., & Isac, D. (1993). A model to interpret gas accumulation profiles associated with in vitro degradation of ruminant feeds. Journal of Theoretical Biology, 163, 99–111. DOI:10.1006/jtbi.1993.1109
   5. Huhtanen, P., Seppälä, A., Ahvenjärvi, S., & Rinne, M. (2008). Prediction of in vivo neutral detergent fiber digestibility and digestion rate of potentially digestible neutral detergent fiber: Comparison of models. Journal of Animal Science, 86, 2657–2669. DOI:10.2527/jas.2008-0894
   6. Korkmaz, M., & Uckades, F. (2014). An alternative robust model for in situ degradation studies. Iranian Journal of Applied Animal Science, 4(1), 45-51.
   7. McDonald, P., Edwards, R. A., Greenhalgh, J. F. D., & Morgan, C. A. (1995). Animal nutrition. Longman Scientific and T echnical, New York. USA.
   8. 8. Menke, K. H., & Steingass, H. (1988). Estimation of the energetic feed value obtainedfrom chemical analysis in vitro gas production using rumen fluid. Animal Research and Development, 28, 7-55.
   9. Moradi, S., & Zaboli, Kh. (2018). Prediction of gas production kinetic in tomato pulp using some nonlinear models. Eleventh National Congress on Biosystem, Engineering and Mechanization, university of Bu Ali Sina, Hamadan. Iran (In Persian)
   10. Moradi, S., & Zaboli, Kh. (2018). Prediction of ruminal fermentation kinetics of alfalfa forage using some nonlinear models. Eighth Iranian Animal Science Congress, university of Kurdestan, Sanandaj, Iran (In Persian).
   11. Peripolli, V., Prates, E. R., Barcellos, J. O. J., McManus, C. M., Wilbert, C. A., BracciniNeto, J., Camargo, C. M., & Lopes, R. B. (2014). Models for gas production adjustment in ruminant diets containing crude glycerol. Livestock Research for Rural Development 26 (2), from http://www.lrrd.org/lrrd26/2/peri26028.htm.
   12. Pitt, R. E., Cross, T. L., Pell, A. N., Schofield, P., & Doane, P. H. (1999). Use of in vitro gas production models in ruminal Kinetics. Mathematical Biosciences, 159(2), 145-163. DOI: 10.1016/s0025-5564(99)00020-6
   13. 13. Sahin, M., Uckardes, F., Canbolat, O., Kamalak, A., & Atalay, A. I. (2011). Estimation of partial gas production times of some feedstuffs used in ruminant nutrition. Kafkas Üniversitesi Veteriner Fakültesi Dergisi Journal, 17, 731-734.
   14. SAS, (1999). The SAS system for windows.Release 8.0.1.SAS Institutue Inc, Cary, USA.
   15. Seker, E. (2002). The determination of the energy values of some ruminant feeds by using digestibility trial and gas test. Revue de Medecine Veterinaire, 153(5), 323-328.
   16. Uckardes, F., & Efe, E. (2014). Investigation on the usability of some mathematical models in in vitro gas production techniques. Slovak Journal of Animal Science, 47 (3), 172-179.
   17. Van-Soest, P. J., Robertson, J. B., & Lewis, B. A. (1991). Methods for dietary fiber, neutral detergent fiber and nonstarch polysaccharides in relation to animal nutrition. Journal of Dairy Science, 74, 3583–3597.
   18. Wang, M., Tang, S. X., & Tan, Z. L. (2011). Modeling in vitro gas production kinetics: Derivation of Logistic-Exponential (LE) equations and comparison of models. Animal Feed Science and Technology, 165, 137-150. DOI: https://doi.org/10.1016/j.anifeedsci.2010.09.016
   19. Wang, M., Sun, X. Z., tang, S. X., Tan, Z. L., & Pacheco, (2013). Deriving fractional rate of degradation of logistic-exponential (LE) model to evaluate early in vitro fermentation. Animal, 7(6), 920-929. DOI: https://doi.org/10.1017/S1751731112002443
   20. Zaboli, Kh., Kalvandy, S., & Malecky, M. 2021. The accuracy of some models to estimate the coefficients of gas production test in corn silage. Iranian Journal of Animal Science Research, 12(4), 467-479 (In Persian) DOI:10.22067/ijasr.v12i4.80666
   21. Zaboli, Kh., & Maleki, M. (2016). Prediction of ruminal fermentation kinetic of corn silage using some models by in vitro method. Journal of Ruminant Research, 4(3), 117-134. (In Persian) DOI: 10.22069/ejrr.2017.11674.1475
   22. Zaboli, Kh., & Moradi, S. (2019). Predicting of gas production kinetic in lemon pulp using some nonlinear models. Fifth National Conference on Livestock, Poultry and Aquaculture Management, Shahid Bahonar university, Kerman. Iran (In Persian)
   23. Zaboli, Kh. (2016). Comparison of fitting of some mathematical models to describe the ruminal fermentation kinetics according to gas production technique for alfalfa hay. Animal Production Research, 5(3), 35-47. (In Persian)