Chickens have a sign of early plumage e. The most common diseases of chickens: symptoms and methods of treatment

Where A And With– number of recombinants of each type,
n– total number of offspring,
x– distance between genes in morganids.

Problem 6-18

In chickens, the early plumage trait (E) dominates the late plumage trait (e), and the pockmarked plumage (B) dominates the black plumage (b). Genes B and E are linked and show 20% crossing over. A homozygous early-fledged black hen is crossed with a heterozygous rooster. What kind of offspring will be produced by crossing?

Problem 6-19

If we assume that genes A and B are linked and the crossover between them is 20%, then what gametes and in what quantitative ratio will the diheterozygote produce?

Problem 6-20

The distance between genes C and D is 4.6 morganids. Determine the percentage of gametes of each type: CD, cd, Cd and cD produced by the diheterozygous organism.

Problem 6-21

In corn, smooth seeds (S) dominate over wrinkled ones (s), and colored ones (C) dominate over colorless ones (c). The S and C genes are located on the same autosome at a distance of 3.6 morganids. Establish what types of gametes and in what ratio will be formed in plants that are diheterozygous for these traits.

Problem 6-22

If we assume that genes A and B are linked and the distance between them is 8 morganids, and gene C is in another linkage group, then what kind of gametes and in what quantity will the triheterozygote and .

Chromosome mapping

To compile chromosome maps calculate the mutual distance between individual pairs of genes and then determine the location of these genes relative to each other.

So, for example, if three genes are arranged in the following order: A B C, then the distance between genes A and C (percentage of recombinations) will be equal to the sum of the distances (percentage of recombinations) between pairs of genes AB and BC.

If the genes are arranged in order: A C B, then the distance between genes A and C will be equal to the difference in distances between pairs of genes AB and CB.

Problem 6-23

Genes A, B and C are in the same linkage group. Between genes A and B, crossing over occurs with a frequency of 7.4%, and between genes B and C - with a frequency of 2.9%. Determine the relative position of genes A, B and C if the distance between genes A and C is equal to 10.3% of crossing over units. How will the relative position of these genes change if the frequency of crossing over between genes A and C is 4.5%?

1. According to the conditions of the problem, the distance from gene A to gene C (10.3 M) is equal to the sum of the distances between genes A and B (2.9 M) and genes B and C (7.4 M), therefore, gene B is located between genes A and C and the location of the genes is as follows: A B C.
2. If the distance from gene A to gene C was equal to the difference in distances between pairs of genes AB and BC (4.5 = 7.4 - 2.9), then the genes would be located in the following sequence: A C B. And in this case, the distance between extreme genes would be equal to the sum of the distances between intermediate ones: AB = AC + CB.

Problem 6-24

When analyzing the crossing of the triheterozygote AaBbCc, organisms corresponding to the following types of gametes were obtained:

1. A test cross segregation close to 1:1 indicates that all three pairs of genes are on the same chromosome.
2. The distance between genes A and B is: 1.7 + 1.7 = 3.4 M.
3. The distance between genes B and C is: 0.8 + 0.8 = 1.6 M.
4. Gene B is located between genes A and C. The distance between genes A and C is: 1.7 + 1.7 + 0.8 + 0.8 = 5.0 M.
5. Map of a chromosome region:

Answers and solutions to problems in Chapter VI

6-1. a) AB CD EF, ab cd ef, AB cd ef, ab CD EF, ab CD ef, AB cd EF, AB CD ef, ab cd EF;
b) ABC D EF, abc D ef, ABC D ef, abc D EF;
c) ABCDEF and abcdef.

6-2. a) Gametes AB and ab will be formed;

b) gametes Ab and aB will be formed.

6-3. Since genes can be located on chromosomes in a cis or trans position, this problem has 4 solution options, in each of which 4 types of gametes are formed.

6-4. 50% of children will be multifingered, 50% will inherit cataracts.

6-5. The genotype of a man can be or, so the problem has two solutions. In the first case, 50% of children will have both anomalies, 50% will be healthy. In the second, half of the children will suffer from elliptocytosis, half from cataracts.

6-6. 25% of children will have cataracts, elliptocytosis and polydactylism, 25% will be healthy, 25% each will have cataracts and elliptocytosis or polydactylosis.

6-7. All F 1 hybrids will have lobed eyes and a short body. The following phenotypes will be observed in the F 2 offspring: lobed eyes, short body; lobed eyes, normal body; round eyes, normal body in a ratio of 1:2:1.

6-8. Explanation in the text.

6-9. Explanation in the text.

6-10. Along with the gametes AB and ab, which will be the majority, a certain number of gametes will be produced
Ab and aB.

6-11. This organism will produce gametes:

(not crossover)

At all times, keeping and breeding chickens has been a very popular activity. This is how it is now.

Like all living beings, these birds are susceptible to various diseases, which is one of the main problems of chicken farming. Ideally, it is better to prevent a disease than to treat it, and for this purpose preventive measures should be taken. But sometimes even they are not effective. Therefore, to successfully combat chicken diseases, both experienced and novice farmers must have a sufficient understanding of them.

This material covers most common diseases that can affect chicken stock: clinical picture, modern diagnostic and treatment methods, as well as effective preventive measures.

How to recognize that a chicken is sick?

In order to recognize the disease in time, you should regularly inspect the chicken population and constantly monitor them.

Inspecting the bird you need to pay attention to:

If you do find pets that can be assumed to have some kind of disease - isolate them from others and keep watching. Ideally, you should take the animal to a veterinarian.

The main groups of diseases to which domestic chickens are susceptible

Diseases that affect chickens are divided into two large groups: contagious (transmitted from bird to bird) and non-contagious (not transmitted).

Pullorosis or typhus- a disease transmitted by airborne droplets. Affects birds of all age groups. The gastrointestinal tract suffers: the animal has a lack of appetite and constant thirst. The bird is apathetic and lethargic. The ridge sags and turns pale, and tachypnea (rapid breathing) is observed.

The main condition for the treatment of this pathology is a quick diagnosis. Sick chickens are given antibiotics of the aminoglycoside group (neomycin, biomycin) or penicillins (ampicillin) with water. Intramuscular administration of these drugs is possible.

For preventative purposes, hygiene should be maintained in the chicken coop. If an outbreak of pullorosis occurs, sick birds should be isolated and the chicken coop should be disinfected.

Pseudoplague (Newcastle disease)- a viral infection transmitted by airborne droplets. Sources of infection are sick animals, their food and water. The disease affects the nervous and respiratory systems, and the gastrointestinal tract. The bird has poor coordination of movements (shaky gait, constantly falls on its stomach), mucus accumulates in the mouth. The chicken is forced to breathe with its beak open, and distant wheezing is heard when breathing. No appetite, profuse diarrhea.

This disease cannot be cured. Chickens with such symptoms should be immediately isolated, killed and burned.

If this is not done, then you can lose your entire chicken population. To prevent pseudoplague, it is necessary to timely disinfect the chicken coop and vaccinate the birds.

A viral pathology that often affects domestic chickens. Its main symptom is the presence of ulcers on the skin (pockmarks). Infection occurs through contact. The source may be:

• a sick laying hen or other pet,
• feed,
• water.

The target of the virus is the cornea and internal organs. The main condition is to start treatment at the initial stage of the disease. External lesions are treated with antiseptics: boric acid solution or furatsilin. Tetracycline is added to food for 7-10 days. If the disease could not be recognized at the initial stage, then all infected birds must be disposed of.

Salmonellosis- the causative agents of this infection are pathogenic strains of Salmonella. Progressing rapidly, the disease affects all chicken organs. Laying hens become infected through feed and water. The main symptom of this disease is profuse, loose and foamy stools. Sick animals are lethargic, there is no appetite, but there is thirst. The joints of the limbs are swollen.

If domestic chickens suffer from salmonellosis, eating raw eggs is strictly prohibited, since they are the main source of human infection with salmonellosis. These bacteria die only after prolonged heat treatment.

Treatment of this infectious pathology is carried out within 21 days. At this time, furazolidone is added to the chickens' drink. Streptomycin can be given with food. To prevent the spread of infection, sick individuals must be isolated. It is necessary to treat the chicken coop with disinfectants. To avoid salmonellosis, birds must be vaccinated.

Tuberculosis- a bacterial infection transmitted by airborne droplets. Caused by human and avian strains of Mycobacteria. The disease occurs when birds are kept in unsanitary conditions. A sick laying hen is lethargic, drowsy, with a pale comb. An important sign is the absence of eggs. Animals are actively losing weight.

It is not possible to cure this infection, so sick animals must be disposed of. For preventive purposes, it is necessary to constantly maintain cleanliness in the chicken coop.

Ornithosis (psittacosis)- a particularly dangerous disease that affects the nervous, respiratory and digestive systems of chickens. Poultry become infected through airborne droplets or the fecal-oral route. They lose their appetite and become emaciated, defecating liquid droppings. The main symptom is heavy, hoarse breathing and feathers sticking together. Also, the following sign may indicate ornithosis: mucus is released from the bird’s nose.

Treatment consists of watering the birds with water containing potassium permanganate and antibiotic therapy with tetracycline or fluoroquinolone drugs. Contact but apparently healthy chickens should also be given antibiotics for two days as a preventive measure. The chicken coop and all equipment must be disinfected.

Colinfection (colisepticemia) - a disease caused by Escherichia coli bacteria. The disease occurs due to non-compliance with the sanitary and hygienic regime in the place where chickens are kept. A laying hen can also become infected through feed of questionable quality. An alarming symptom is lethargy and loss of appetite against the background of increasing thirst. Breathing is hoarse and heavy. A characteristic sign of co-infection is a significant increase in body temperature.

Treatment consists of timely diagnosis and immediate antibiotic therapy. For these purposes, furazolidone and ampicillin are used.

Chicken flu- a viral disease that affects the respiratory and digestive systems. The disease is transmitted by airborne droplets. The main symptom is difficult to identify. A sick laying hen becomes lethargic, loses her appetite, and her earrings and comb turn blue. Along with this, difficult noisy breathing and significant loosening of the stool are observed. There is no cure for this infection! Sick birds are destroyed.

Coccidiosis- a disease caused by protozoan coccidia, which does not spare either adults or young individuals. Chickens can not only get sick, but also be asymptomatic carriers of the infection. The disease affects the gastrointestinal tract and its main symptom is loose, bloody stools. In addition, loss of appetite and general asthenia of animals are observed. Birds become infected through poor-quality food. When the first symptoms appear, the disease spreads like lightning. If measures are not taken, the entire livestock may die. Therefore, animals with manifestations of coccidiosis should be isolated as quickly as possible.

To prevent coccidiosis in the chicken coop, it is necessary to maintain a sanitary and hygienic regime and avoid dampness. Pet food must meet the required quality standards.

Helminthiasis

A group of diseases that are caused by helminths (worms). They are classified as contagious diseases.

At an early stage, the disease responds well to treatment with phenothiazine. In advanced stages, treatment does not make sense.

Cestodosis- a disease caused by a tapeworm. Its symptoms include seizures and weight loss. Infection occurs through low-quality food. The drug Filixan is used for treatment.

They are considered contagious, but pose less danger than infectious ones. Their treatment almost always ends in recovery, but if they are ignored, the sick animal may die. Infection occurs through contact of chickens with sick brothers.

Ringworm- affects the feather cover and skin of birds. Pale yellow lesions appear on the comb and catkins. Later, feathers begin to fall off and stool upset occurs, then body weight rapidly drops. Unfortunately, there is no point in treating this disease. A preventive measure is to keep the bird house clean.

Aspergillosis- a disease caused by mold and affecting the respiratory tract.

• Chickens cough and sneeze and their breathing is noisy.
• Nasal discharge and bloody excrement appear.

This pathology can be cured with the help of copper sulfate, which must be added to the water and food of birds for several days.

Effective and quite old is method of treating chickens' homes with dust. But this is a dubious method, because due to its toxicity, dust can cause the death of animals.

You can get a more clear and complete picture of chicken diseases, their prevention and treatment by watching this video.

1. Name the genotypes of the parents
2. Name the genotypes of the parents if the splitting is 3:1
3. Phenotypes of parents if the offspring are the same.

A rooster without a comb was crossed with a black hen with a comb. Half of the offspring have a crest, half with black plumage, half with red. Determine the genotypes of parents and chicks, was there any crossing over?
WITH DECISION!!!

crossing a homozygous white ball pumpkin with a homozygous yellow disc pumpkin.
2. In mice, long ears are inherited as a dominant trait, and short ears are inherited as a recessive trait. A male with long ears was crossed with a female with short ears. In F1, all the offspring turned out to have long ears. Determine the genotype of the male
3. In humans, the polydactyly allele (6 fingers) dominates over the normal five-fingered hand. In a family where one parent has a six-fingered hand and the other has a normal hand structure, a child was born with a normal hand. Determine the probability of having a second child without an anomaly. Please really need to decide

can be obtained from crossing a heterozygous black bull with a solid head color with a red, white-headed cow if the latter is heterozygous for white-headedness. The genes for both traits are located on different chromosomes.

2) the oat resistance gene to smut dominates over the gene for susceptibility to this disease. what offspring will be obtained from crossing homozygous immune individuals with plants affected by smut.

3) the gene for giant oat growth is recessive; the gene for normal growth is dominant. what plants need to be crossed to obtain offspring of uniform growth.

4) in dogs, the gene for black coat color is dominant over the gene for brown coat color. the black female was bred several times with the brown male. In total, 15 black and 13 brown puppies were received. determine the genotypes of parents and offspring.

5) in wheat, the dwarfism gene dominates over the normal growth gene. what are the genotypes of the original forms if 3/4 of the plants in the offspring turned out to be dwarf.

Please help me decide.