Investigating the amount of bacterial contamination of unhatched eggs in a hatchery in Mahabad city

Dissertation:

To receive the degree of professional doctor of veterinary medicine (D.V.M)

Title: Investigating the amount of bacterial contamination of unhatched eggs in hatcheries in Mahabad city

Incubation is an important part of the poultry industry and in compliance with health principles It is possible to prevent the spread of bacterial diseases. In this research, samples were taken from 200 unhatched egg samples under sterile conditions in four seasons of the year, and in 26% Escherichia coli, 19% Staphylococcus epidermis and 16% Proteus were isolated, and in the remaining 39% no causative species was isolated. It should be noted that in isolated cases, only Escherichia coli can be the causative agent, and cases such as yolk sac infection, panophthalmitis, colibacillosis, etc. to create According to the results obtained, the percentage of contamination with E.coli in autumn and winter is much higher than in spring and summer, which is due to two reasons: contamination in the farm or hatchery, which is a small percentage according to the number of our samples. It seems that the contamination of E.coli in fertilized eggs in the farm in cold seasons is due to unfavorable ventilation and the increase in the number of bacteria in the environment, considering that the number of staph was also isolated in the cultured samples, but The observed staph is not among the main pathogenic staph in poultry and probably cannot be involved in the pathogenesis and process of hatching eggs. It is suggested that disinfection and smoking of eggs be done in different stages with more control and precision, and periodic sampling should be carried out according to a written program for the prevention and control of pathogen agents. style="direction: rtl;"> Kashi is like a main chain link in poultry farming. As we know, a good breeding happens when the hygiene is at its highest from the first stage of chicken production. No matter how well a poultry farm has performed in terms of hygiene and rehabilitation, when the chicken produced in the hatchery is infected, it will both transfer the contamination to the poultry farm and also cause many problems for the poultry farmer from the breeding point of view. Lack of proper disinfection and non-observance of hygiene principles can cause irreparable damage to the poultry farmer. Therefore, it is necessary that every day and every time after the chickens leave the hatchery and when the eggs enter the grading part of the hatchery, the basic principles of hygiene are observed and all the parts are washed with suitable disinfectants, including fumigation and washing; be disinfected to prevent the spread of microbial and fungal pathogens such as E.coli; Mycoplasmas, Salmonella and Aspergillus, which cause the most damage to the poultry industry and are among the pathogenic agents, should be prevented. winter; In the summer and spring of 1991 and 1992, he went to the hatchery of Mahabad Agriculture and Sanat Company, and each time 50 unhatched eggs were sampled in sterile conditions, and after conducting the relevant tests, E. coli was found in 52 cases; 32 cases of Proteus; 38 cases of Staphylococcus epidermidis were isolated and 78 samples were free of bacterial contamination, which can only be caused by E. coli and diseases such as yolk sac infection; cause bacillosis and umbilical cord infection.

According to the issues mentioned about the management and health of the hatchery and hatchable eggs, this research has been carried out in the hatchery of Mahabad Agriculture Company, it is hoped that it can take an effective step in preventing bacterial contamination in hatchable eggs and transferring it to production chickens.

Morning Covenant

Summer 1392

Chapter One

Overview

1-1 research objectives

Investigation of bacterial pathogens in the hatchery of Mahabad Agriculture Company in different seasons of the year and mother flocks of different ages

Identifying bacterial pathogens and providing suggestions to minimize the amount of contamination caused by them.

Introduction:

In recent years, many changes have been made in hatcheries, including the computerization of machine control and also the automation of many daily hatchery activities, in addition, the awareness of the role of hatcheries in disease control has increased. .

1-2 Egg structure:

The complete egg has the following parts:

1. Germinal disc or vegetative plate. 2. Yolk. 3. White.

4. Shell membranes.

5. shell.

The embryonic body is placed on top of the yolk attached to the yolk membrane. When the egg is broken in a glass container, the embryonic body can be seen as a transparent spot with the naked eye. As mentioned before, the embryonic body in the fertilized egg grows and develops after formation and becomes the plastoderm or blastoderm embryonic plate. When the egg is placed in the hatching machine, the embryo is formed from the growth of the blastoderm.

The yolk is located in the center of the egg and is about 30% of the total weight of the egg and 35 The percentage of the usable part of the egg is the specific weight of the yolk is about 1.0293, because half of the yolk is made of fat, so its specific weight is low and lighter than the white. For this reason, it tends to climb to the upper part of the egg.

There is a membrane in the two yolks, which is called the yolk membrane, around the yolk and also in the middle of it there is a whiter substance, which is called the bright yolk, which extends to the part of the embryo that is outside the yolk and is placed in the shape of a bottle.

Egg white makes up 65% of the egg's weight and is made up of protein and its specific gravity is 1.04028. The white consists of 4 layers or parts, which are:

1. The thick white inner layer that covers the two yolks and keeps it fixed in the middle of the egg. Chalaza is formed from this part and goes to the two ends of the egg from the side of the membrane and tilin, and its task is to keep the egg yolk in the central position. Shalaja prevents the yolk from rising upwards.

2. The inner layer is thin white.

3. Thick white outer layer.

4. The outer layer of thin egg white.

The egg white is surrounded by two membranes called shell membranes, one of which is internal and the other external. At the wide end of the egg, these two membranes move away from each other and form a space called the air sac. In fresh eggs, the air chamber is very small and unnoticeable, but in old eggs, due to evaporation and gas production, the size of the air chamber is increased, therefore measuring the air chamber is a good guide to determine whether the egg is fresh or old.