Mohaddeseh Esnaashari; Hamed Ahmadi; Farid Shariatmadari; Mostafa Lotfi
Volume 25, Issue 1 , April 2023, , Pages 93-105
Abstract
This study was conducted to investigate the effects of mixer added fat, crude protein and conditioning temperature on the pellet durability index, and electrical energy consumption during feed production using computational modeling tools. A total of 192 broiler feed samples with different levels of ...
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This study was conducted to investigate the effects of mixer added fat, crude protein and conditioning temperature on the pellet durability index, and electrical energy consumption during feed production using computational modeling tools. A total of 192 broiler feed samples with different levels of mixer added fat and crude protein in feed components and different conditioning temperatures to determine the pellet durability index, modified pellet durability index and electrical energy consumption during feed production were used. Multiple linear regression and artificial neural network were used to analyze data. Both models had the ability to predict the value of the pellet durability index, modified pellet durability index and the electrical energy consumption during feed production; but the prediction accuracy of the artificial neural network model was higher than that of the multiple linear regression model for all three outputs. Optimization was done using the artificial neural network model, and in these calculations, in order to achieve the highest possible level of pellet physical quality and the lowest possible level of electrical energy consumption, the crude protein amount was 20-20.5% and the conditioning temperature was predicted to be 85 C. However, the amount of fat was predicted to be 1% for the highest amount of pellet physical quality and 4% for the lowest amount of electrical energy consumption during production. In practical conditions, this model can help in more accurate prediction of electricity consumption and the quality of produced feed in order to achieve the optimal situation in feed production factories.
Ali Nazari; Hamed Ahmadi; Farid Shariatmadari
Volume 24, Issue 1 , April 2022, , Pages 59-65
Abstract
This study was performed to investigate the relationship between apparent digestibility of magnesium (Mg) with body weight, feed intake and phytase enzyme with 120 individual B-line Arian male broilers. Birds were assigned two standard diets and a diet supplemented with one gram of phytase (FTU / 500 ...
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This study was performed to investigate the relationship between apparent digestibility of magnesium (Mg) with body weight, feed intake and phytase enzyme with 120 individual B-line Arian male broilers. Birds were assigned two standard diets and a diet supplemented with one gram of phytase (FTU / 500 kg). Daily feed intake, weekly weight gain, feed conversion ratio during rearing and Mg digestibility were measured at 28 to 30 days. Using Gompertz model, growth rate (c), initial weight (b) and maximum growth potential (m) were analyzed. Growth rate and maximum growth potential were higher in the group consuming phytase enzyme (P <0.05). Weight gain and feed conversion ratio improved under the effect of phytase supplemented diets (P <0.05). Magnesium digestibility was higher in phytase enzyme diets than standard basal diets (P <0.05). The results showed that the modeled growth rate affected the Mg digestibility so that birds with higher growth rate (faster growth potential) had more potential for Mg digestion (P <0.05). The relationship between Mg digestibility and body weight gain was positive and the higher the Mg digestibility, the greater the weight gain (P <0.05). Birds with higher growth potential have the ability to digest more of the mineral Mg, and this digestibility is increased by the use of the phytase enzyme. Therefore, in the breeding programs of Arian chickens, more attention can be paid to the relationship between the use of magnesium and the growth rate parameter.
ali nazari; hamed ahmadi; farid shariatmadari
Volume 24, Issue 1 , April 2022, , Pages 59-65
Abstract
This study was performed to investigate the relationship between apparent digestibility of magnesium (Mg) with body weight, feed intake and phytase enzyme with 120 individual B-line Arian male broilers. Birds were assigned two standard diets and a diet supplemented with one gram of phytase (FTU / 500 ...
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This study was performed to investigate the relationship between apparent digestibility of magnesium (Mg) with body weight, feed intake and phytase enzyme with 120 individual B-line Arian male broilers. Birds were assigned two standard diets and a diet supplemented with one gram of phytase (FTU / 500 kg). Daily feed intake, weekly weight gain, feed conversion ratio during rearing and Mg digestibility were measured at 28 to 30 days. Using Gompertz model, growth rate (c), initial weight (b) and maximum growth potential (m) were analyzed. Growth rate and maximum growth potential were higher in the group fed phytase enzyme (P <0.05). Weight gain and feed conversion ratio improved under the effect of phytase supplemented diets (P <0.05). Magnesium digestibility was higher in phytase enzyme diets than standard basal diets (P <0.05). The results showed that the modeled growth rate affected the Mg digestibility, so that birds with higher growth rate (faster growth potential) had more potential for Mg digestion (P<0.05). The relationship between Mg digestibility and body weight gain was positive and with increasing Mg digestion, weight gain improved (P<0.05). Birds with higher growth potential have the ability to digest more Mg, and this digestibility is increased by the use of the phytase enzyme. Therefore, in the breeding programs of Arian chickens, more attention can be paid to the relationship between the use of Mg and the growth rate parameter.
Hamed Ahmadi; Vahid Rasoli Marivani; Yousef Mohammadi
Volume 22, Issue 2 , June 2020, , Pages 281-288
Abstract
The goal of this study was to determine regression equations to predict metabolizable energy of wheat samples given their chemical compositions using meta-analytical approach. A database compromising chemical compositions and apparent metabolizable energy corrected for the nitrogen (AMEn) ...
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The goal of this study was to determine regression equations to predict metabolizable energy of wheat samples given their chemical compositions using meta-analytical approach. A database compromising chemical compositions and apparent metabolizable energy corrected for the nitrogen (AMEn) of 111 published sources of wheat strains was used. Sample information contains crude protein (CP), ether extract (EE), crude fiber (CF), ash and AMEn. Average values for AMEn was calculated as 2917.46 (kcal/kg), while for the CP, EE, CF, ash was calculated as 12.53, 2.12, 1.61and 1.56 (% dry matter), respectively. Meta-regression equations for predicting AMEn wheat based on chemical composition were developed and evaluated by means of provided database. Best equation obtained as: AMEn (kcal/kg)=1648+45.8 %CP+175.8 %EE+ 185.4 %CF. This equation can be used for predicting energy of wheat variates in feed-factories and poultry farms.
Alireza Shahtalab; Hamed Ahmadi; farid shariatmadari
Volume 21, Issue 4 , January 2020, , Pages 441-450
Abstract
The objective of this research was to compare the growth patterns of commercial broiler chickens, native chickens and domestic pigeon raised in Iran. The growth curves and their parameters were estimated by the Richards function. Body weight data of mixed-sex of commercial broiler chickens ...
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The objective of this research was to compare the growth patterns of commercial broiler chickens, native chickens and domestic pigeon raised in Iran. The growth curves and their parameters were estimated by the Richards function. Body weight data of mixed-sex of commercial broiler chickens (n=326000), native chickens (n=244000) and pigeon (n=4000) were used. Birds were fed ad libitum and weighed in alternating periods on their life. The accuracy of the curve fit was high in all species (R2 = 0.996 to 0.970). The y+/A ratios (weight at the inflection point over mature weight), which determine the shape of the growth curve, were 0.358, 0.379 and 0.352 in chickens, native birds and pigeons, respectively. The age at the inflection point confirmed the high early growth of pigeons (t+ = 10.2 d) and chickens(t+ = 36.6 d). The phenotypic correlations between the inflection parameters t+ and y+ were higher in commercial broiler chicken than native and pigeon. The inflection parameter t+ and y+ were positively associated with the maturing index k in all birds, in this way, the evolutionary aspects are discussed. In practical view, these results could be used to develop the production strategies for native chicken breed and domestic pigeon to positively affect the growth parameters, efficiency as well as conservation of local genetic resources.
Motalleb Ebrahimi; Hamed Ahmadi; farid shariatmadari
Volume 21, Issue 3 , September 2019, , Pages 339-348
Abstract
The goal of the present study was to determine the true metabolizable energy corrected for nitrogen (TMEn) content, chemical compositions of the poultry by – product meal (PBPM), the relationship between their chemical compounds and TMEn in adult roosters. To examine the nutritional values of ...
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The goal of the present study was to determine the true metabolizable energy corrected for nitrogen (TMEn) content, chemical compositions of the poultry by – product meal (PBPM), the relationship between their chemical compounds and TMEn in adult roosters. To examine the nutritional values of PBPM, a total of 30 fresh samples were collected from different slaughterhouses in the country. For TMEn estimation, each sample (25 g) was used to force feed to the 4 birds raised in individual metabolic cages. Dry matter (DM), gross energy (GE), crude fat (EE), crude protein (CP), ash and total volatile nitrogen (TVN) were measured according to standard methods. Average values for DM, EE, ash, CP, TVN and TMEn were obtained as 90.05%, 22.10%, 7.50%, 60.30%, 220 mgN/100g, and 3907 kcal/kg, respectively. There was a positive correlation between TMEn and EE, while the correlation between ash and TMEn was negative. Compared with EE and ash, the CP was less correlated (P<0.05) with TMEn, while the TVN had no significant effect. The determined values of chemical composition and TMEn were used in fitting the simple regression equations, which can be in practice used to predict energy contents of PBPM samples in factory and production farms.
Hamid Reza Khajavi; Mohammad Amir Torshizi; Hamed Ahmadi
Volume 16, Issue 2 , October 2015, , Pages 113-122
Abstract
In order to evaluate the effect of feeding different levels of vermi-humus supplement (as a source of humic acid) on the performance of broiler chickens an experiment was conducted using 240 broiler chickens (Ross 308) in a completely randomized design by four treatments (vermi-humus levels of 0, 0.5, ...
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In order to evaluate the effect of feeding different levels of vermi-humus supplement (as a source of humic acid) on the performance of broiler chickens an experiment was conducted using 240 broiler chickens (Ross 308) in a completely randomized design by four treatments (vermi-humus levels of 0, 0.5, 1 and 1.5 percent) and five replicates of 12 chickens per each for 42 day. The experimental treatments had no significant effect on the growth performance, carcass percentage, internal organs weights, serum concentrations of calcium and phosphorus and tibia bone ash. Increasing the levels of vermi-humus up to one percent of diet resulted in linear decline in pH of breast meat (P<0.05), although the level of 1.5 percent increased the pH value. The thigh meat pH increased at 1 and 1.5 percent levels of vermi-humus supplementation in diet compared to control and 0.5 percent groups. The concentration of malon dialdehyde of fresh and preserved thigh meat decreased linearly with increasing the levels of vermi-humus supplementation in diet, while the malon dialdehyde of breast meat changed in quadratic manner (P<0.01). Water holding capacity of meat increased linearly with enhancement of level of vermi-humus supplement in the diet (P<0.01). Addition of vermi-humus at the level of one percent in diet leads to improvements in the color, smell, juiciness and overall acceptance of breast meat compared to the control (P<0.05), but these parameters had not affected in thigh meat. The results showed that feeding vermi-humus up to one percent of diet could improve the breast meat quality, taste and flavor without adverse effect on performance.