نوع مقاله : مقاله پژوهشی
نویسندگان
گروه علوم دامی، دانشکده کشاورزی دانشگاه تهران. کرج ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
This experiment was conducted to determine the prediction equations of standardized ileal digestible amino acids) SID (contents of poultry by-products meal (PBM) based on its chemical compositions. A total of 270 one-day-old Ross 308 male broiler chicks in nine dietary treatments (five replicates/six birds) were used. The treatments were included eight semi-purified diets containing each of PBM as the only source of dietary protein and one nitrogen free diet in order to determine SID amino acids. On day 28, the birds were euthanized to collecting ileal digesta for further analyses of acid insoluble ash and amino acids. The SID contents of Met and Lys was varied from 0.52 to 0.89% and 1.88 to 2.46%, respectively (P< 0.05). Finally, according to adjusted coefficient of determination and standard error of prediction the best prediction equations were selected to predict 10 SID amino acids of PBM. For example, the prediction equations of Lys, Met, Met + Cys and Thr was recommended as:
dLys = 0.937 + 0.022 × CP - 0.057 × Ash (SEP 0.033; Adjusted R2 0.966)
dMet = 0.0550 + 0.009 × CP (SEP 0.550; Adjusted R2 0.806)
dMet + dCys = 0.250 × CP (SEP 0.114; Adjusted R2 0.994)
dThr = 0.023 × CP + 0/015 × EE (SEP 0.085; Adjusted R2 0.997)
کلیدواژهها [English]
Extended Abstract
Introduction and Objective
The costs and provision of protein sources are significantly challenging for animal production and feed industries. Previous research has focused on developing animal feed sources such as fish poultry by-product meal (PBM) to replace conventional feed ingredients. PBM quality is more variable due to the higher inclusion of low-quality by-products such as feathers, heads, and feet. The cost of these animal protein sources depends on the world supply and demand for the product. It is necessary to evaluate the nutrients and energy utilization of those ingredients. There are many options to determine amino acids values of PBM for diet formulation, such as in vivo experiments or biological methods, international tables, near-infrared reflectance spectroscopy (NIR) device, and prediction equations in the articles. These alternatives, including biological methods and NIR devices, entail significant expenses due to the requirement for various items such as cages, birds, time, and expertise. A rapid way to determine the SID amino acids value can be established through prediction equations developed based on the chemical composition of feedstuffs, which is easy and quick to obtain in most cases. Therefore, defining an appropriate prediction regression equation for SID amino acids of conventional PBM with modern broiler strains is necessary. Due to the importance of SID amino acids in poultry nutrition and the effectiveness of prediction equations to determine the SID amino acids value of rations accurately, the objectives of this study were to evaluate the chemical composition of different origins of PBM to determine their SID amino acids prediction regression equations based on the chemical composition.
Material and Methods
Chemical composition of eight different origins samples of PBM were obtained from different producer in Iran. These origins were: Urom chakavak, Urom ghohardaneh, Peygir, Behparvar, Nickpeykar, Varamine, Ghoghnos, and Sepid makian. Each PBM sample with 3 replicates were analyzed. AOAC International (2000) analytical methods (930.15, 920.39, 990.03, 978.10 and 942.05 respectively) was used to analyze dry matter (DM), ash, crude protein (CP), crude fiber (CF), and ether extract (EE) of all PBM samples neutral detergent fiber (NDF) and acid detergent fiber (ADF) were analyzed. The gross energy (GE) of samples was measured by an adiabatic calorimetric bomb (Ika- Calorimeter; C400 adiabatisch, Germany). The general linear model procedure and least-squares means method were used to compare means of chemical compositions, SID amino acids. To predict each of individual SID amino acids content of PBM samples, the Simple and multiple linear regression were used by SPSS software version 19. A total of 270 one-day-old Ross 308 male broiler chicks in nine dietary treatments (five replicates/six birds) were used. The treatments were included eight semi-purified diets containing each of PBM as the only source of dietary protein and one nitrogen free diet in order to determine SID amino acids. Birds were allowed ad libitum access to a corn- soybean meal starter diet until 10 days, a grower diet from 11 to 23 days, and then experimental diets from 24 to 28 days of age. On day 28, the birds were euthanized to collecting ileal digesta for further analyses of acid insoluble ash and amino acids.
Results
The SID contents of Met and Lys was varied from 0.52 to 0.89% and 1.88 to 2.46%, respectively (P< 0.05). Finally, according to adjusted coefficient of determination and standard error of prediction the best prediction equations were selected to predict 10 SID amino acids of PBM. For example, the prediction equations of Lys, Met, Met + Cys and Thr was recommended:
dLys = 0.937 + 0.022 × CP - 0.057 × Ash (SEP 0.033; Adjusted R2 0.966)
dMet = 0.0550 + 0.009 × CP (SEP 0.550; Adjusted R2 0.806)
dMet + dCys = 0.250 × CP (SEP 0.114; Adjusted R2 0.994)
dThr = 0.023 × CP + 0/015 × EE (SEP 0.085; Adjusted R2 0.997)
Conclusion
According to the results of this study, it is concluded that the SID amino acids content of PBM were variable. Therefore, it is not feasible to consider a fix value for amino acids content in diet formulation. On the other hand, it is difficult for poultry nutritionists to measure the SID amino acid contents of different PBM. It seems that the prediction equations obtained from this study can be used for poultry nutritionists to predict the SID amino acid contents of PBM easily and fast with high accuracy.
All authors contributed equally to the conceptualization of the article and writing of the original and subsequent drafts.
Data available on request from the authors.
The authors would like to thank all participants of the present study.
The study was approved by the Ethics Committee of the University of Tehran (Ethical code: IR.UT.RES.2024.500). The authors avoided data fabrication, falsification, plagiarism, and misconduct.
The author declares no conflict of interest.
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