RBSE Solutions Class 12 Biology Chapter 41 Domestication, Culture & Economic Importance

RBSE Class 12 Biology Chapter 41 Multiple Choice Questions

 

Question 1. Which one of these in indigenous species used for poultry farming?
(a) White Leghorn
(b) Pekin
(c) New Hampshire
(d) Aseel
Answer: (d) Aseel
In simple words: Aseel is an Indian breed of chicken that is commonly used for poultry farming in its native region. These chickens are known for their strength and unique appearance.

🎯 Exam Tip: Remember that "indigenous" refers to species originating from a particular region or country, helping you identify local breeds.

 

Question 3. Poultry farming provides
(a) Eggs and honey
(b) Meat and Lac
(c) Eggs and wax
(d) Meat and eggs
Answer: (d) Meat and eggs
In simple words: Poultry farming mainly gives us both meat and eggs from birds like chickens. These products are important sources of protein for people.

🎯 Exam Tip: Focus on the primary products derived from poultry, which are typically eggs and meat, for a clear answer.

 

Question 4. Which stage of the silkworm, provides silk?
(a) Egg
(b) Caterpillar
(c) Adult
(d) Cocoon
Answer: (d) Cocoon
In simple words: The silk we use is produced during the cocoon stage of the silkworm. The silkworm spins silk threads to make this protective covering.

🎯 Exam Tip: Understand the life cycle of the silkworm and identify the specific stage responsible for silk production.

 

Question 5. The scientific name of Europian honey bee.
(a) Apis welfare
(b) Apis force
(c) Apis Florida
(d) Apis India
Answer: (a) Apis welfare
In simple words: Based on the given choices, "Apis welfare" is the scientific name mentioned for the European honey bee. Scientific names help to uniquely identify each species.

🎯 Exam Tip: Pay close attention to scientific names, as they are specific and must be chosen accurately from the given options.

 

Question 7. Which of the following is not a major carp?
(a) Labeo raita
(b) Catla Catla
(c) Cirrhinus regalia
(d) Chanos Chanos
Answer: (d) Chanos Chanos
In simple words: Chanos Chanos, also known as milkfish, is not considered a major carp species. Major carps are large fish widely farmed for food.

🎯 Exam Tip: Memorize the common and scientific names of major carp species to accurately identify those that do not belong to the group.

 

Question 8. Anthrax disease of cattle is
(a) Viral disease
(b) Helminth disease
(c) Bacterial disease
(d) Protozoan disease
Answer: (c) Bacterial disease
In simple words: Anthrax is a serious disease that affects cattle and is caused by bacteria. The bacteria responsible is called Bacillus anthracis.

🎯 Exam Tip: Distinguish between diseases caused by different types of pathogens like viruses, bacteria, and protozoa.

 

Question 9. Nutritive Plant of Kusumi type lac insect.
(a) Kher
(b) Babool
(c) Shisham
(d) Ber
Answer: (d) Ber
In simple words: The Ber plant is a food source for the Kusumi type lac insect. These insects feed on specific plants to produce natural lac resin.

🎯 Exam Tip: Remember the specific host plants that are important for the cultivation of different types of lac insects.

RBSE Class 12 Biology Chapter 41 Very Short Answer Type Questions

 

Question 1. What is Domestication?
Answer: Domestication is the process where humans raise and breed animals for various purposes. This practice helps animals adapt to living with humans over many generations. It has been essential for human societies, providing food, labor, and companionship.
In simple words: Domestication means raising and breeding animals for human uses and needs.

🎯 Exam Tip: Define key terms clearly and concisely, including the main actions and purpose.

 

Question 2. What you call the hends reared to lay eggs?
Answer: Hens that are raised specifically for laying eggs are called layers. These birds are very important for egg production in poultry farming. Layers are carefully selected and managed to produce as many eggs as possible.
In simple words: Hens raised to lay eggs are known as layers.

🎯 Exam Tip: Use specific terminology where appropriate for biological and agricultural concepts.

 

Question 3. What is the position of India in the world in poultry?
Answer: India holds the sixth position globally in poultry production. This shows its significant role in the world's poultry industry. The poultry sector in India has grown quickly to meet the demand for eggs and meat.
In simple words: India is ranked sixth in the world for producing poultry products.

🎯 Exam Tip: When answering questions about rankings or statistics, state the position or value clearly and accurately.

 

Question 4. What did you call rearing and management of fishes?
Answer: The practice of rearing and managing fish is known as pisciculture. This is a form of aquaculture that focuses on growing fish in controlled environments. It helps ensure a steady supply of fish for food.
In simple words: Rearing and managing fish is called pisciculture.

🎯 Exam Tip: Know the specific terms for different types of animal husbandry and cultivation practices.

 

Question 5. Give the names of two Research centres in India working in pisciculture.
Answer:

• Central Inland Fisheries Research Centre.
• Centre.

Two research centers in India that focus on pisciculture are the Central Inland Fisheries Research Centre and another center referred to as 'Centre'. These institutions conduct studies to improve fish farming methods. Research in pisciculture aims to increase fish production and develop sustainable practices.
In simple words: The Central Inland Fisheries Research Centre and one other 'Centre' work on fish farming research in India.

🎯 Exam Tip: When listing names, ensure they are accurate and complete as per the provided information.

RBSE Class 12 Biology Chapter 41 Short Answer Type Questions

 

Question 1. Describe viral diseases found in hens.
Answer: Hens can suffer from several viral diseases, including Fowlpox, Infectious bronchitis, Lymphoid leukosis, and Ranikhet disease. Among these, Ranikhet disease is very common in fowl, causing symptoms like fever and diarrhea. Vaccination programs are essential to protect poultry from such viral infections and ensure flock health.
In simple words: Hens get viral diseases like Fowlpox and Ranikhet, which often causes fever and diarrhea.

🎯 Exam Tip: When listing diseases, provide specific examples and a brief description of key symptoms if asked to demonstrate comprehensive knowledge.

 

Question 2. Describe the different castes and their roles in a honey bee colony.
Answer: A honey bee colony consists of three main types of individuals or castes: Queen, Drones, and Workers.
1. Queen:

• Each colony has only one adult queen, which is large in size.
• The queen develops from a fertilized egg and is specially fed royal jelly when it is a larva.
• She is the only fertile female in the beehive and has fully developed ovaries.
• Her main role is reproduction; she lays all the eggs for the colony.

2. Drones:

• Drones develop from unfertilized eggs through a process called parthenogenesis.
• Their main function is to mate with the queen to fertilize her eggs.

3. Workers:

• Workers are sterile females that also develop from unfertilized eggs, but without royal jelly feeding.
• Their numbers can range from 3000 to 6000 or more.
• Worker bees have specific roles based on age, including:
• Sanitary bees: These workers clean the hive chambers.
• Nurse bees: These workers take care of the queen and the hive.
• Foster mother (4-6 days old): They feed a mixture of honey and nectar to young bees.
• Nurse workers (7-11 days old): They secrete royal jelly from their maxillary glands.
• Nurse workers (12-15 days old): They secrete wax from wax glands for 4 days, used to repair and build the hive. The wax glands become functional up to the 12th day.
• They also secrete propolis, a gum-like substance.

4. Scout bees:

• These are also known as field or foraging bees.
• They search for new food sources and collect nectar and pollen.
• They collect food 7 to 15 times a day.
• They also gather water for the hive, which needs about 2 liters per day.

Each caste plays a specific role to ensure the survival and functioning of the bee colony.
In simple words: A honey bee colony has a Queen (lays eggs), Drones (male bees that mate with the queen), and Workers (female bees that do all the jobs like cleaning, feeding, making wax, and finding food).

🎯 Exam Tip: When describing castes, clearly outline the main characteristics and primary functions of each type of bee within the colony for a complete answer.

 

Question 3. Give the uses of lac.
Answer: Lac is a versatile natural resin with many uses. It is commonly used in making bangles, polishes, utensils, and toys. Additionally, lac is used in varnishes and for various electrical devices because of its insulating properties. This natural product finds application in both traditional crafts and modern industries.
In simple words: Lac is used for making things like bangles, polish, toys, varnish, and parts for electrical devices.

🎯 Exam Tip: When asked for uses, provide a diverse range of applications to show comprehensive knowledge of the product.

 

Question 4. Give the names of main species of the silkworm and the silk produced by them.
Answer: Different species of silkworms produce various types of silk, often associated with specific host plants.

For example, *Antheraea assamensis* produces Muga silk, often found on the *Machilus bombycina* plant. *Attacus Ricinus* is known for Eri silk, related to *rechinii communis*. Also, *Ethiopia religious* is linked to Dev MUGA silk, which comes from silkworms feeding on *Fucus and machilus*. Each silkworm species and its host plant contribute to the unique quality and characteristics of the silk produced.
In simple words: Different silkworms, like *Antheraea assamensis* and *Attacus Ricinus*, make different kinds of silk, such as Muga silk and Eri silk, often from specific plants.

🎯 Exam Tip: When presenting species and their products, use a table for clarity and ensure accurate association of each silkworm with its silk type.

 

Question 5. Give an account of diseases found in silkworm.
Answer: Silkworms can suffer from several diseases that significantly impact silk production. The main diseases include Pebrine, which occurs in two forms: Virus Pebrine and Protozoan Pebrine.
1. Pebrine:

• 1. Virus Pebrine:
• This type is caused by the *Borrelia bombycis* virus.
• Larvae infected with Virus Pebrine typically start dying 8 to 10 days after infection.
• To prevent its spread, dead larvae should be removed, and all instruments must be cleaned using a 30% solution of trichloroacetic acid for 15 minutes, followed by a water wash.
• 2. Protozoan Pebrine:
• This form is caused by the *Nosema bombycis* protozoa.
• It affects both the larva and the adult silkworms.
• Infected adults show irregular, shrunken bodies, and larvae become smaller.
• Larvae often die before they can form cocoons.
• For protection, it is crucial to use only eggs obtained from healthy worms.

2. Other Viral Diseases:

• Diseases like Fletcher and Brasserie are also caused by viruses that affect silkworms.

Proper hygiene, early detection, and effective management strategies are essential to control these diseases and maintain healthy silkworm rearing.
In simple words: Silkworms can get diseases like Pebrine, which comes from viruses or tiny protozoa, making them sick and sometimes die. Other viruses also cause diseases like Fletcher and Brasserie.

🎯 Exam Tip: Organize your answer by disease type and include causes, key symptoms, and effective prevention methods for a thorough explanation.

RBSE Class 12 Biology Chapter 41 Essay Type Questions

 

Question 1. Write an essay on Pisciculture.
Answer: Pisciculture, or fish farming, is vital in India, as the national demand for fish protein, approximately one crore tonnes annually, far exceeds the current production of about 35 lakh tonnes. This practice offers significant income and employment opportunities, especially for people living in the coastal states of the country.
Various modern techniques are now used to boost fish production to meet this demand. India's inland water bodies cover about 2.34% of the total inland water area, amounting to roughly 75 lakh hectares. Thanks to extensive research conducted at the Central Inland Fisheries Research Institute, fish culture and production have seen a remarkable increase, reaching up to 85000 kg per hectare per year. This marks a revolution in the field of fisheries, which has gained immense importance in encouraging young people to take up small-scale industries as a career.
Pisciculture involves both the production and breeding of various fish species. Fish are an excellent source of protein and also provide essential mineral salts, vitamins (like A and D), and healthy fats. Thus, fish are considered a complete food for humans.
Many fish species are edible and cultured, including freshwater fish like Common carp, Catla, and Rohu, as well as marine fish such as Hilsa, Sardine, and Prophrate. These fish are cultured using scientific techniques due to their high consumption demand. Besides fish, other aquatic animals like prawns, lobsters, and molluscs are also cultivated, a practice known as aquaculture.
Types of Cultivable Fishes:
Cultivable fishes are generally classified into three types:
1. Indigenous or naturally occurring freshwater fishes: These are native species that thrive in freshwater environments. A prime example is Major carps.
2. Some marine fishes which get adapted to freshwater: These are saltwater species that can tolerate and adapt to freshwater conditions, making them suitable for inland farming. Examples include Chanos and Mullets.
3. Exotic fishes: These are fish species introduced from foreign countries into India for cultivation. Examples include Mirror Carp, Chinese carp, Crucian carp, and Common carp.
The advancement of pisciculture is crucial for ensuring food security, improving livelihoods, and promoting sustainable aquatic resource management.
In simple words: Pisciculture is farming fish for food and jobs. India needs more fish, so new ways to grow them are used. Fish give us protein, vitamins, and minerals. Some common fish grown are carp and hilsa. There are three types of fish raised: local freshwater fish, sea fish that can live in fresh water, and foreign fish.

🎯 Exam Tip: For essay questions, provide a comprehensive answer covering its importance, methods, benefits, and types, organized into clear paragraphs for better understanding.

 

Question 2. Give the salient features of lac insect and plant names on which it is cultivated.
Answer: The lac insect exhibits several distinct features. Females live within a resinous sac and are responsible for laying a significant number of eggs, typically 200–500. After about six weeks, the first instar larvae emerge, known as nymphs. These nymphs are active and gather on the small, soft twigs of succulent trees. They secrete lac from their skin glands, which dries upon contact with air to form the resin.
Following 6 to 8 weeks, due to metamorphosis, nymphs develop into approximately 70% wingless females and 30% males with wings. The lac insect typically completes two life cycles each year, occurring around October-November and June-July, usually on nutrient-rich host plants.
Host Plants for Lac Insect:
In India, many plants serve as hosts where lac insects complete their life cycle. These plants provide the necessary nutrition for the insects.

The lac insect feeds by sucking sap from its host plants using its specialized mouthparts. The quality of the lac produced is heavily dependent on the type of plant it feeds on. Kusumic lac, which is highly regarded, is primarily obtained from Ber and Palas plants. Understanding these host plants is crucial for successful lac cultivation.
In simple words: Lac insects live in sticky sacs on trees, lay many eggs, and feed on tree sap to make lac. Their life cycle repeats twice a year. Plants like Fig, Palas, and Shisham are common host plants for lac insects.

🎯 Exam Tip: Describe the insect's lifecycle and habits, and list the host plants clearly, mentioning how they relate to lac quality and cultivation.

 

Question 3. Explain in detail the poultry.
Answer: Poultry farming involves raising birds like chickens, ducks, and turkeys for various purposes, primarily for eggs and meat. It has been practiced by humans for a long time and became a significant cottage industry in the 20th century, meeting the growing demand for nutritious food. Fowl, particularly hens, provide eggs and meat, which are valuable sources of nutrition.
The beneficial aspects of fowl encourage humans to research scientific techniques for their reproduction, hatching, rearing, and maintenance. Successful poultry farming requires knowledge of the fowl's habits, breeds, and reproductive cycles. For populous countries like India, increasing poultry use is essential for a healthy and nutritious food supply.
(1) Birds useful in Poultry: Many species of birds are used in poultry farming.

• White Leghorn, Plymouth Rock, Rhode Island Red, and New Hampshire are examples of breeds considered to be superior varieties for poultry.

2. Ducks:

• Ducks, like *Anas platyrhynchos*, are also sources of eggs and meat. In India, ducks contribute about 6% of the total poultry population, found mostly in southern and eastern states. Indian breeds include Indian Runner, Sylhet Meta, and Nageshwari, while foreign breeds include Muscari, Pekin, Campbell, and Aylesbury.

3. Turkey:

• Turkeys (*Meleagris gallopavo*) have been domesticated more recently. Key breeds include British White, Narfold, Broad Breasted Bronze, and Beltsville Small White.

(2) Selection of fowls for breeding: Careful selection of fowls is crucial for good reproduction.
1. Selection of male fowl for reproduction:

• A rooster's body should be shiny, broad, and strong. Its eyes should be attractive, the beak small and curved, a wide back, thin and elastic skin, and a long tail held upwards.

2. Selection of female fowl for reproduction:

• Hens should have a large and well-shaped body. Good head shape and prominent eyes indicate high quality. Mature hens under one year of age are best for selection.
• A healthy hen that grows fast, matures early, and produces many eggs is ideal. An active bird, ready for defense, will produce healthy chicks.

(3) Systems of Mating of Birds:

• Stud mating: A cock and hen are kept in separate cages, and females are allowed with males for mating as needed.
• Alternating males: Two cocks are used, one for one day and the other for the next, for mating. This method can be challenging for record-keeping.

(4) Systems of Breeding:
1. Inbreeding:

• This involves mating between close relatives (e.g., brother and sister). This method is generally not preferred because it can lead to weaker offspring.

2. Linebreeding:

• Sometimes, one bird is used for breeding repeatedly due to its good quality. In this method, close relatives are typically not crossed.

3. Out Crossing:

• This mating involves birds of the same species but from different strains. For instance, a white leghorn strain that lays many small eggs might be crossed with another strain that produces fewer but larger eggs.

4. Crossing:

• Crossing different bird species results in a hybrid, often showing hybrid vigor (improved qualities).

5. Grading:

• This involves mating a pure male of one species with females of other species. Today's commercial poultry farming mostly rears hybrid species.

(5) Incubation and Hatching:
Eggs develop embryonic membranes but these do not form organs of the embryo.
2. Various stages of embryonic development:

• Before egg-laying: Fertilization occurs.
• Between egg-laying and Incubation: No growth occurs.
• During Incubation (approximately 21 days):
• 16 Hours - First sign of chick embryo appears.
• 20 Hours - Vertebral Column appears.
• 22 Hours - Head formation starts.
• 24 Hours - Eye formation starts.
• 42 Hours - Heartbeat starts.
• 62 Hours - Leg formation initiates.
• 64 Hours - Feathers formation starts.
• 5th Day - Formation of sex organs and sex differentiation begins.
• 6th Day - Beak formation starts.
• 17th Day - Beak turns towards air space.
• 19th Day - Yolk sac enters the coelom.
• 20th Day - Yolk sac completely enters the coelom.
• 21st Day - Hatching of a chick from the egg.

3. Selection of eggs for hatching:

• Eggs must be carefully selected for incubation, as any abnormality can negatively affect hatchability.
• Eggs are chosen based on their shape, color, and shell quality.

4. Artificial Incubation:

• An incubator is used for artificial incubation to ensure eggs hatch within 21 days. Eggs are kept in the incubator for 18 days and then moved to a hatcher for the final 3 days.

(6) Brooding and Rearing:
Brooding refers to the incubation of eggs, while rearing is the care of young chicks after hatching. Rearing can be done in two ways:
1. Natural brooding:

• A hen naturally acts as both brooder and incubator, typically brooding 8-10 eggs at a time by providing body heat.

2. Artificial brooding:

• Eggs are incubated artificially, and chicks are reared without a hen. Advantages include being able to perform it any month of the year and the ability to rear many chicks. Cleanliness and management are easier, and the hen is not needed for brooding.

(7) Brooder House:
1. General:

• Before hatching, a proper brooder house must be prepared. It requires good airflow, temperature control, safety from external factors (animals, storms, cold, heat), and sufficient light. Large brooder houses are partitioned to separate chicks of different ages.

2. Floor brooder:

• Bamboo baskets lined with clay can serve as a good floor brooder for chick development. Wooden, tin, or aluminum brooders are also used.

(8) Poultry Farming using Cage system:
1. General:

• Before cage systems, the deep litter method was common, requiring 3 square feet per hen, demanding large houses. The cage method is more convenient, especially with rising costs of hen houses, as it requires less space per bird.

2. Benefits of Cage system:

• More birds in small space: This system allows rearing up to 2500 birds in the same space that would hold 1000 birds in the deep litter method.
• Protection from diseases: Birds in cages are less likely to infect the entire group, making disease management more effective.
• Less food consumption: Scientists believe hens consume less food in a cage system.
• Easier sorting: Animals can be easily sorted if needed, unlike in the deep litter system.
• Labor saving: Less human labor is required to care for a large number of hens.

3. Management Tips for Cage Layers:

• Fowl manure Management: Fecal matter accumulates in cages, causing odor. Regular cleaning is essential.
• Light Arrangement: Proper and uniform lighting in cages ensures birds ingest food correctly.
• Egg collection: Eggs should be collected at least three times a day.
• Building construction: The height of the building depends on the number of cage tiers. Two-tier cages need a 12-foot high roof, while three-tier cages need 14 feet. A flat roof is ideal. Buildings should be in dry areas to prevent moisture, which can increase insects and hinder manure drying.

(9) Poultry Food:
1. General Poultry food is prepared based on specific objectives for bird health and productivity.
I. Carbohydrate Feeds:

• Carbohydrates make up 70-80% of poultry feed, providing energy, heat, and fat. They are cheaper and widely available.
• Maize: Most used, rich in starch and fat.
• Wheat: Second to maize, with less calcium but more phosphorus, and vitamins B & E. Can be used in various forms.
• Oats: Contains 12% protein, 10.6% fiber, and 4.7% fat; given whole or broken.
• Barley: Also used as feed, similar to oat.
• Sorghum: Resembles maize but lacks vitamin A; beneficial when cheaper than wheat, maize, or oats.
• Rice: Used less often due to higher cost compared to other cereals.
• Molasses: A byproduct of sugar production, used as a 5-10% replacement for cereals.
• Potatoes: Small, inedible potatoes can be boiled and given to hens.

II. Fat Feeds:

• Fat is a primary energy source, comprising up to 2.5% of feed. It improves fowl size, increases hunger, and promotes physical development and egg production. Fats are obtained from:
• Soyabean oil, Ground Nuts oil, Cottonseed oil, Maize oil, Wheat germ oil, Animal fats, Emulsified oils.

III. Protein:

• Proteins are crucial for growth and egg production.
• Milk: An excellent protein source but costly, so not widely used.
• Meat scrap: Provides protein and minerals in chicken food.
• Feather meal: Contains 86-88% protein but lacks essential amino acids; 10-20% can be used.
• Poultry blood meal: Contains 65% protein; used in small amounts.
• Soyabean oil meal: Significant in soybean-producing regions, rich in protein. Groundnut oil cakes are also used in India.

IV. Mineral Meals:

• Minerals are essential for bird health and egg production.
• Calcium: Best source (oyster shells, marble chips, eggshells) for bones and eggshells.
• Phosphorus: Tricalcium phosphate from bone meal provides phosphorus.
• Manganese: Required at 50 parts per million for hatching and bone formation.
• Salt: Essential for taste and digestion (0.5%). Iron and iodine are also added.

(10) Common diseases of Poultry:
Poultry birds are susceptible to various diseases:
1. Viral diseases:

• Main viral diseases include Fowlpox, Infectious bronchitis, Lymphoid leukosis, and Ranikhet disease. Ranikhet is most common, causing fever and diarrhea.

2. Bacterial diseases:

• These include Fowl cholera, Pullorum, Coryza, Mycoplasmosis, and Spirochaetosis.

3. Fungal diseases:

• Aspergillosis is a main fungal disease.

Comprehensive management, including nutrition and disease control, is vital for successful poultry farming.
In simple words: Poultry farming is raising birds like chickens for eggs and meat. This involves choosing good breeds, breeding them properly, and incubating eggs until they hatch. Young chicks are then brooded, either naturally by hens or artificially. Farmers can use cage systems to raise many birds safely. Birds need balanced food with carbohydrates, fats, proteins, and minerals. They can get diseases, so care is important.

🎯 Exam Tip: For a detailed explanation, break the topic into logical sub-sections (breeds, breeding, rearing, feeding, diseases) and provide clear, concise information for each, ensuring all aspects are covered.

 

Question 3. Explain in detail the poultry.
Answer:Poultry farming involves raising various birds like chickens, ducks, and turkeys to produce eggs and meat. This practice has been essential since ancient times and has grown into a significant industry due to the demand for nutritious food. To succeed in poultry farming, it is crucial to understand the birds' habits, breeds, and reproduction cycles. For densely populated countries like India, increasing poultry production helps provide healthy and nourishing food. *This shows how farming practices adapt to meet societal needs efficiently.* Through artificial selection, breeders have developed many species of hens that produce high-quality eggs and meat. For example, some breeds, known as Broilers, are ideal for meat production, while others, called Layers, can produce up to 240 eggs per year, much more than the 60 eggs from normal hens.

(1) Birds useful in Poultry: Many types of birds are utilized in poultry farming. Some key species include:

• White Leghorn
• Plymouth Rock
• Rhode Island Red
• New Hampshire

These breeds are considered superior varieties.

2. Ducks: Ducks, such as Anas platyrhynchos, also provide eggs and meat. In India, ducks contribute about 6% of the total poultry population and are mainly found in the southern and eastern states. Important Indian duck breeds include Indian Runner, Sylhet Meta, and Nageshwari, while popular foreign breeds are Muscovy, Pekin, Campbell, and Aylesbury.

3. Turkey: Turkeys (Meleagris gallopavo) have been domesticated more recently. Key breeds include British White, Narfold, Broad Breasted Bronze, and Beltsville Small White.

(2) Selection of fowls for breeding: When choosing hens for breeding, several factors should be considered to ensure good quality offspring.

1. Selection of male fowl for reproduction: A rooster's body should be shiny, broad, and strong. Its eyes should be attractive, its beak small and curved, its back wide, its skin thin and elastic, and its tail long with an upward position.

2. Selection of female fowl for reproduction: Hens should be large and well-shaped, with a good head shape and prominent eyes. Hens under one year old are best for selection. A healthy, fast-growing hen that matures early and lays many eggs is suitable. An active bird, always ready to defend, indicates it will produce healthy chicks.

(3) Systems of Mating of Birds:

• Stud mating: In this system, roosters and hens are kept in separate cages. Females are only brought to the males for mating when needed.
• Alternating males: Two roosters are used in this mating method. One rooster is used on one day, and the other on the next. Keeping accurate records with this technique can be challenging.

(4) Systems of Breeding:
1. Inbreeding: This involves mating very close relatives of the same species, like brothers and sisters, or fathers and daughters. This method is generally avoided because it can result in weaker offspring.
2. Linebreeding: Sometimes, a single bird with good qualities is used repeatedly for breeding. This is known as line breeding. In this type of breeding, close relatives are not allowed to interbreed.
3. Out Crossing: This is a mating process where birds of the same species but from different genetic strains are bred together. For example, a white leghorn strain that produces many small eggs might be crossed with a strain that produces fewer but larger eggs.
4. Crossing: Breeding different bird species together creates a hybrid, or hybrid vigor. This usually results in offspring that are stronger or healthier.
5. Grading: This involves mating a pure male of one species with females of other species. Modern commercial poultry farming often prefers hybrid species due to their efficiency.

(5) Incubation and Hatching: This process involves keeping eggs warm to allow chicks to develop and hatch.

2. Various stages of embryonic development:

• Before egg-laying: Fertilization takes place.
• Between egg-laying and Incubation: No significant growth occurs.
• During Incubation:
  • 16 Hours - The first signs of a chick embryo appear.
  • 20 Hours - The vertebral column starts to form.
  • 22 Hours - Head formation begins.
  • 24 Hours - Eyes begin to form.
  • 42 Hours - The heartbeat starts.
  • 62 Hours - Leg formation initiates.
  • 64 Hours - Feathers begin to form.
  • 5th Day - Sex organs and sex differentiation start to form.
  • 6th Day - Beak formation starts.
  • 17th Day - The beak turns towards the air space within the egg.
  • 19th Day - The yolk sac begins to enter the coelom (body cavity).
  • 20th Day – The yolk sac fully enters the coelom.
  • 21st Day - The chick hatches from the egg.

3. Selection of eggs for hatching: Eggs chosen for incubation must be selected with care, as any abnormality can negatively affect their hatchability. Eggs are typically selected based on their shape, color, and shell quality.

4. Artificial Incubation: An incubator is used for artificially hatching eggs, which is necessary for eggs to hatch within 21 days. Eggs are usually kept in an incubator for 18 days, then transferred to a hatcher for the remaining 3 days.

(6) Brooding and Rearing: Brooding refers to the incubation of eggs, while rearing is the process of caring for young chicks after they hatch. Rearing can be done in two ways:
1. Natural brooding: In this method, the hen herself acts as the brooder and incubator. A hen can usually brood 8-10 eggs at a time, providing the necessary body heat for incubation.
2. Artificial brooding: This involves incubating eggs artificially and rearing chicks without a hen. It offers several benefits over natural brooding:

• It can be done at any time of the year.
• Many chicks can be reared at once.
• Cleanliness and disease management are easier to control.
• Temperature can be precisely regulated.
• Food is provided to the developing chick according to its needs.
• Hens are not needed for the brooding and rearing of young ones.

(7) Brooder House:
1. General: Before eggs hatch, it is crucial to prepare a suitable brooder house. This house needs good airflow, proper temperature regulation, protection from external factors (like animals), and safety from storms, cold, or heat waves. Large brooder houses should be divided into sections so that chicks of different ages can be kept separately.
2. Floor brooder: Bamboo baskets with clay on both sides are prepared and can be used as an effective brooder floor for the development of chicks. Wooden, tin, or aluminum brooders are also commonly used.

(8) Poultry Farming using Cage system:
1. General: Before the cage system, the dip litter method was common. In that method, many hens could not be reared together as each hen needed three square feet of space, requiring a large house or farm. However, the cage method is now more convenient and widely used because it needs less space, which is beneficial given the increasing cost of hen houses.
2. Benefits of Cage system:

• More birds in small space: This system requires less space compared to the dip litter method. For example, a poultry house that uses the dip litter method for 1000 birds can accommodate up to 2500 birds using the cage system.
• Protection from diseases: Hens are kept in cages, which prevents diseases from spreading to the entire group at once, making this system very effective for disease control.
• Scientists believe that hens consume less food in a cage system.
• In a cage system, individual birds can be easily separated if needed, which is much more difficult in a dip litter system.
• Labor saving: It is believed that the cage system requires less human labor, as one person can manage a large number of hens.

3. Management Tips for Cage Layers:

• Fowl manure Management: Droppings accumulate in cages and can develop a foul odor. Therefore, regular and timely cleaning of cages is essential.
• Light Arrangement: Lighting must be adequate and uniform throughout the cage so that birds can feed properly.
• Egg collection: Eggs should be collected at least three times a day.
• Building construction: The design of a building for a cage system depends on specific needs. The building's height depends on the number of cage tiers. For two-tier cages, the roof should be at least 12 feet high. For three-tier cages, a height of 14 feet is required. A flat roof is generally best. If a hut-style roof is used, the height should be 9-10 feet. The building should be constructed in a dry area to prevent moisture from reaching the droppings, which would attract insects and prevent the droppings from drying.

(9) Poultry Food: Poultry food is formulated with specific nutritional objectives.

I. Carbohydrate Feeds: Carbohydrates make up 70-80% of poultry food. They are used for energy, heat production, and fat storage. They are generally cheaper and readily available. Important sources include:

• Maize: This is used most extensively in poultry feed and is rich in starch and fat.
• Wheat: Second only to maize, it contains less calcium but more phosphorus and vitamins B & E. Wheat can be incorporated into poultry feed in many ways, such as wheat fibers.
• Oats: It contains 12% protein, 10.6% fiber, and 4.7% fat. It can be given either whole or broken into smaller pieces.
• Barley: Can also be used in poultry feed similarly to oats.
• Sorghum: Its shape and structure are similar to maize, but it does not contain vitamin A. It is beneficial primarily when its cost is lower than wheat, maize, or oats.
• Rice: It is also used as a substitute for other cereals but is generally more expensive, so it is used less frequently.
• Molasses: This is a byproduct of sugarcane juice after sugar is extracted. It can be used to replace 5-10% of cereals in the diet.
• Potatoes: Small potatoes, unsuitable for human consumption, can be boiled and given to hens.

II. Fat Feeds: Fat is the primary source of energy and is typically added to feed at up to 2.5%. Fat improves the fowl's size, increases hunger, and promotes better physical development and increased egg production. Fat is obtained from these substances:

• Soyabean oil
• Ground Nuts oil
• Cottonseed oil
• Maize oil
• Wheat germ oil
• Animals fat
• Emulsified oils

IV. Mineral Meals: Minerals are vital components of poultry feed.

• Calcium: Calcium carbonate is the best source, found in oyster shells, marble chips, and eggshells.
• Phosphorus: Tricalcium phosphate is a main substance in bone meal, given to supply phosphorus.
• Manganese: A small amount (50 parts per million) is required, but it is essential for hatching and bone formation.
• Salt: Salt is necessary for taste and digestion (0.5%). Iron and iodine are also added to poultry feed.

(10) Common diseases of Poultry: Poultry birds can suffer from various diseases:
1. Viral diseases: The primary viral diseases in poultry birds are Fowlpox, Infectious bronchitis, Lymphoid leukosis, and Ranikhet disease. Ranikhet is the most common disease in fowls, causing fever and diarrhea.
2. Bacterial diseases: These diseases include Fowl cholera, Pullorum, Coryza, Mycoplasmosis, and Spirochaetosis.
3. Fungal diseases: Aspergillosis is a major fungal disease affecting poultry.
In simple words: Poultry farming is about raising birds like chickens for eggs and meat. It involves careful breeding, housing, feeding, and disease control to ensure healthy birds and good production. Different systems, like cage farming, offer benefits in space and disease prevention. The birds' diet includes carbohydrates for energy, fats for growth, and minerals for health. It's important to manage common diseases like viral, bacterial, and fungal infections to keep the flock healthy.

🎯 Exam Tip: When describing poultry farming, remember to cover the key aspects: breeding, housing systems (natural vs. artificial brooding, cage vs. deep litter), nutrition (carbohydrates, fats, minerals), and common diseases for a comprehensive answer.

 

Rearing of Silkworm

Silkworm rearing is a month-long process that involves several stages, from the egg stage through aestivation, hibernation, incubation, and finally cocoon formation. Grainage technology is important for maintaining a systematic culture of silkworms.

Grainage Management:

A critical stage in sericulture is the production and management of healthy, disease-free eggs, which are vital for the industry's success. The main goals of Grainage Management are to ensure caterpillars are provided with healthy nutrients and to develop disease-free cocoons from them. After the final selection, cocoons are separated by sex using a Naghara instrument, which can cut 10,000 to 15,000 cocoons. Loose cocoons are used for industrial egg production. A mass pebrine detecting machine or a simple microscope is used to check for female adult silkworms and for Sabrin disease-free worms.

Supply of Seed to Rearers and Commercial Rearing:

Following grainage management, the next step is to supply eggs to cultivators. Based on the cultivators' knowledge and experience, there are two types of supply:

• 1. Supply of eggs
• 2. Supply of Instar Caterpillar

Experienced silkworm cultivators generally take eggs directly. However, those without experience typically receive 2nd stage instar caterpillars. The 1st, 2nd, and 3rd stage caterpillars are handled with great care. 4th and 5th stage instar caterpillars are fed nutrients on a nylon net plate. This method helps produce high-quality cocoons. For culturing 1st, 2nd, 3rd, 4th, and 5th instar caterpillars, specific temperatures of 27°C, 27°C, 25°C, 24°C, and 23°C, respectively, must be maintained.

Formation of Cocoon:

During this phase, the caterpillar stops feeding and begins to secrete a sticky substance. The caterpillars are then transferred into spinning trays, which are kept sideways in the sun. After about 3 days, cocoons are formed, marking the final stage of sericulture.

Method of obtaining silk from Cocoons:

• First, cocoons are placed in a hot oven or hot water to destroy the cocoon shells. This process is called Stifling.
• Afterwards, a single cocoon is reeled together to produce a continuous thread. One cocoon can yield between 1000 to 15000 meters of thread. This thread is wound onto a spool (Red silk) and then boiled again in hot water. It is washed with chemical acids to make it clean and shiny. Finally, this process, called spinning, transforms the reeled thread into fiber silk.