mehrdad nafisi; Mansour Rezaei; sayed abdoullah hosseini; mohamad kazemifard
Volume 21, Issue 1 , April 2019, , Pages 113-125
Abstract
In order to determine effect of various sources of manganese, zinc and copper (Sulfate, foreign and Internal organic) and requirement levels (100, 50% requirement) on performance and immune response of broilers, an expriment was conducted using 480 commercial CAB 500 hybrid broilers in a 2×3 factorial ...
Read More
In order to determine effect of various sources of manganese, zinc and copper (Sulfate, foreign and Internal organic) and requirement levels (100, 50% requirement) on performance and immune response of broilers, an expriment was conducted using 480 commercial CAB 500 hybrid broilers in a 2×3 factorial arrangement with completely randomized design. During the experiment, live body weight (LBW), feed intake (FI) and feed conversion ratio (FCR) were measured. At the end of the experiment, blood sampling was done and total antibody titer against sheep's red blood cell (SRBC), antibody titer against Newcastle Disease virus (ND) and differential count of white blood cells (WBC) were measured. The results showed that mineral sources did not affect the performance of broilers. The sources of minerals had a significant effect on livability percentage (P<0.05) and the highest livability was observed for organic (foreign and local) treatments. Usage of local organic manganese, zinc and copper caused a better response to sheep's red blood cell (SRBC) (P<0.05) relative to foreign form. Moreover, there was significant difference among the treatments in terms of weight (P<0.05), feed conversion (P<0.05) and production index (P<0.05) and treatment with 100% requirement level had maximum impact. The birds fed with 50 % requirement showed a better response to SRBC (P<0.05). According to the results of this experiment, the organic forms of the three manganese, zinc and copper produced in Iran can simultaneously, meet the needs of broilers and can be replaced with inorganic and the foreign sources. In addition, the 100 % requirement level of manganese, zinc and copper, regardless of source, is recommended to achieve the maximum growth performance and 50 % requirement level is recommended for better immune function.
Siamak Mashayekhi; Davoud Hasanloo; Majid Afshar; Mehrdad Nafisi
Volume 18, Issue 2 , June 2016, , Pages 215-223
Abstract
This study carried out for economic investigation on laying hen farms in Tehran province. The data was collected through completion of questionnaire by direct interview from 41 layer farms, which were selected by stratified random sampling method in 2013. Among all types of production functions, the ...
Read More
This study carried out for economic investigation on laying hen farms in Tehran province. The data was collected through completion of questionnaire by direct interview from 41 layer farms, which were selected by stratified random sampling method in 2013. Among all types of production functions, the Cobb-Douglas production function was selected and its coefficients was estimated and average product, marginal product and the ratio of value of marginal product to input prices and inputs’ production elsaticity was estimated. The results showed that more than 87 percent of cost of egg production belongs to the feed and pullet costs. The production elasticity of all studied inputs including feed intake, pullet and labor were positive and less than one, which shows that the producers were utilized these inputs economically. The average production of feed and pullet inputs was 0.49 and 18.5, respectively and on this basis, on an average, 0.49 kilograms eggs were produced for one kilogram of feed and 18.5 kilograms of eggs for one pullet in studied laying hen farms. According to the results, feed intake and pullet were most important effective factors on egg production in Tehran province. Meanwhile, considering the price of purchased inputs and sold egg, producers utilize these inputs economically and efficiently based on the ratio of value of marginal product to input price index.