A Study on production, reproduction performance and egg quality in Marandi chickens

The existence of geographical diversity in Iran has been caused a significant racial diversity in the domestic livestock and poultry of the country. The number of racial groups of indigenous chickens is not exactly known, but some researchers have been reported up to 35 racial groups. Natural selection during successive generations in environmental conditions has been caused the adaptation these breeds and the evolution of many unique and valuable talents in them. Raring native chickens in order to provide animal protein is widespread in the country's villages and it is valuable from economic point of view. On the other hand, native breeds are considered as important genetic reserves and are considered as national genetic capitals. Studying and researches is necessary in order to preserve these genetic resources. To carry out this research, fertilized eggs were collected from different regions, especially East Azarbaijan province, and placed in the incubator machine separately and chicks were produced in industrial incubation conditions for 21 days. Raring of chickes until maturity and egg production stage took place in Saeed Abad educational campus of East Azerbaijan Agriculture and Natural Resources Research and Education Center. Chicks produced at different ages were weighed and their production and reproduction traits were measured after maturity. This bird is currently spread in various region of East Azarbaijan Province (especially Marand, Tabriz, Sufian, Khosrowshahr, etc.) and also some provinces like Gilan, Alborz, Isfahan, West Azarbaijan, Ardabil, Zanjan, etc . The whole body of the black Marandi chicken is covered with black feathers, which cover the feathers in a uniform black color. The black feathers of this bird reflect a pale green color when the sun shines. The cover of black feathers of this bird extends to the legs, which are thinner and more beautiful than the feathers of the body.
The results showed that the live body weight of birth in female chicks is 31.28±3.33 gr and in male 33.12±4.00 gr. But in general, the birth weight of male chickens for the whole population was 31.90±3.66 gr, which obtained from eggs with an average weight of 47.32±7.10 gr. At the age of week 4, male chickens of Marandi breed were about 26% heavier than females and reached an average of 196.36±73.76 gr, but the weight of females was 155.58±64.94 gr. At the end of week 8 of age, male Marandi chicks reached an average of 504.31±115.91 gr and female chickens reach 377.45±124.78 gr, the weight difference of the two sexes reached about 127 gr. Male chicks were 33.6% heavier than females. The weight of female chicks at the end of 12 weeks was about 675.33±151.07 gr and the weight of male at this age was measured on average at 929.97±119.65 gr, the difference between the two sexes reached 254.64 gr and male chickens were about 37.7% heavier than female chickens. Marandi chickens at the end of 16 weeks have a weight equal to 849.77±183.31 gr in females and 1152.64±161.88 gr in male, which are almost 302 gr heavier than females and have a 35.6% increase in weight. At the age of 20 weeks, Marandi female chickens weighed 1040.35±219.64 gr and its male weighed about 1406.15±220.81 gr. The difference in the weight of the two sexes at this age reaches about 366 gr. At the end of 24, 28 and 32 weeks, females reach the weight of 1186.97±175.40 gr, 1409.54±165.67 gr and 1426.97±179.04 gr respectively, while the weight of males at these week is 1609.47±227.63 gr, 1800.05±164.38 gr and 1812.41±239.54 gr respectively. The trend of weight gain up to 12 weeks is incremental, which means that the slope of weight gain is higher in the second 4 weeks compared to the first 4 weeks, and this situation is repeated in the third 4 weeks compared to the second 4 weeks. But after the end of the 12th week until the end of the 28th week, the trend of weight gain has been almost constant, that can be seen is the insignificant and negligible difference in the weight in the 32nd week compared to the 28th week. Which means that until the age of 28 weeks, Marani chickens have spent their weight gain period and after that, growth should not be expected.
The breeding results showed that the start of egg production in the Marandi breed is at the end of 5 months (150 days) and at this age they gradually start to lay eggs. At the end of three weeks from the start of laying eggs, egg production reaches its peak, which is about 44% and lays eggs with almost the same percentage until the end of the production period. Marandi chickens produced more than 160 eggs during the one-year laying period after starting to lay eggs. The average weight of Marandi eggs is 47.32±7.10 gr and its average specific weight is 1.075±0.006 gr/cm3. The results of the study showed that the average strength of eggs is 2.64±0.31 kg/cm2. The weight of the egg shell is 4.42±0.73 gr, and its thickness is 0.27±0.03 mm. Haugh unit, albumin height, albumin weight and yolk weight were estimated as 86.03±9.40 %, 6.92±1.53 mm, 29.36±5.99 gr and 14.10±1.74 gr in Marandi breed egg, respectively. Approximately, 10% of the egg weight is the shell, 30% is the yolk, and 60% is the albumin. Fertility rate of Marandi breed eggs in the conditions of natural insemination and using one male for every 10 chickens is 82.38±11.09 % and the hatchability is 76.85±12.33 %. Marandi chicken has good potentials for supplying some part of the food protein source.