UPSC Mains Answer PYQ 2023: Animal Husbandry Paper 1 (Section- A) | Animal Husbandry & Veterinary Science Optional for UPSC PDF Download

Section - A

Q1: Answer the following questions in about 15U words each :  (10x5=50)
(a) Justify why more than one digestibility trial needs to be conducted during indirect method of digestibility determination of feed.      (10 Marks)
Ans: 
Introduction: 
Digestibility trials are crucial in determining the nutritional value of feed for animals. Indirect methods, like the use of markers, are employed to estimate digestibility. Conducting multiple trials is essential for reliable results.
1. Variability in Feed Composition:

• Different batches of feed can have variations in nutrient composition due to factors like soil type, climate, and agricultural practices.
• Example: Two batches of alfalfa hay may have different fiber contents affecting digestibility.

2. Animal Variability:

• Animals have individual variations in their digestive physiology, metabolism, and gut microbial populations.
• Example: Two goats of the same breed and age may metabolize feed differently.

3. Environmental Factors:

• Environmental conditions can influence digestion. Temperature, humidity, and stress levels can affect microbial activity.
• Example: Higher temperatures might reduce microbial activity in the rumen, impacting digestibility.

4. Adaptation Period:

• Animals need time to acclimate to a new diet. One trial may not capture the full extent of digestibility.
• Example: Goats may take a few days to adjust to a diet rich in legumes.

5. Excretion of Markers:

• Markers used in indirect methods (e.g., acid-insoluble ash) may not be excreted consistently over a short period.
• Example: If a marker is excreted rapidly, it may not accurately reflect nutrient absorption.

Conclusion: 
Conducting multiple digestibility trials is imperative in ensuring accurate and reliable results. This practice helps account for variability in feed composition, animal physiology, environmental conditions, adaptation periods, and marker excretion. Such comprehensive data is essential for formulating balanced and effective animal diets.

(b) Describe the physiological adjustments of goats during hot weather.        (10 Marks)
Ans: 
Introduction: 
Goats, like many animals, undergo physiological changes to cope with high temperatures. These adaptations help them maintain normal bodily functions in hot conditions.
1. Increased Water Intake:

• Goats increase their water consumption to counteract dehydration due to sweating and increased respiration.
• Example: A dairy goat may double its water intake during a heatwave.

2. Reduced Feed Intake:

• High temperatures reduce appetite. Goats may eat less to decrease the heat produced during digestion.
• Example: A goat that normally consumes 2 kg of feed might only eat 1 kg during hot weather.

3. Panting and Sweating:

• Goats pant to release excess heat through evaporation. They also sweat, primarily from their footpads, to cool down.
• Example: A goat with an elevated body temperature will pant rapidly.

4. Seeking Shade and Rest:

• Goats naturally seek shade during hot periods to avoid direct sun exposure.
• Example: A goat will rest under a tree or in a sheltered area during the hottest part of the day.

5. Altered Grazing Patterns:

• Goats may adjust their grazing habits, foraging during the early morning or late evening when temperatures are lower.
• Example: A herd of goats may be observed grazing in the early morning hours.

Conclusion: 
Goats employ a range of physiological adaptations to cope with hot weather. These include increased water intake, reduced feed consumption, panting, sweating, seeking shade, and adjusting grazing behavior. Understanding these adjustments is crucial for effective management of goats in regions prone to high temperatures.

(c) Write in brief about the stages of spermatogenesis in bulls.        (10 Marks)
Ans: 
Introduction: 
Spermatogenesis is the process by which spermatozoa, or sperm cells, are produced in the testes of male animals. In bulls, this process involves several distinct stages.
1. Proliferation Phase:

• Occurs in the basal compartment of the seminiferous tubules.
• Spermatogonia, the undifferentiated germ cells, undergo mitotic divisions to increase their numbers.
• Example: A single spermatogonium divides to produce two identical daughter cells.

2. Meiotic Phase:

• Spermatocytes, derived from spermatogonia, undergo meiosis, a specialized form of cell division.
• Primary spermatocytes undergo two successive divisions, resulting in the formation of haploid secondary spermatocytes.
• Example: A primary spermatocyte with 46 chromosomes divides to form two secondary spermatocytes with 23 chromosomes each.

3. Differentiation Phase:

• Secondary spermatocytes mature into spermatids.
• The process involves a series of morphological changes, including the formation of the acrosome and the flagellum.
• Example: A round spermatid undergoes complex structural alterations to become a mature spermatozoon.

4. Spermiogenesis:

• The final phase of spermatogenesis.
• Spermatids transform into fully mature, motile spermatozoa through a series of structural and biochemical modifications.
• Example: The Golgi apparatus in the spermatid transforms into the acrosomal cap of the mature sperm.

5. Spermiation:

• Mature spermatozoa are released from the seminiferous epithelium into the lumen of the tubules.
• They are then transported to the epididymis for further maturation and storage.
• Example: Spermatozoa are expelled from the testicular tissue into the tubule's lumen.

Conclusion: 
Spermatogenesis in bulls is a complex, multistage process involving the proliferation, meiotic division, differentiation, and maturation of germ cells. Understanding these stages is crucial for comprehending the reproductive physiology of bulls and for effectively managing their breeding programs.

(d) Explain the importance of goat rearing in the upliftment of socio-economic status of farmers.        (10 Marks)
Ans: 
Introduction: 
Goat rearing plays a pivotal role in the socio-economic development of farmers, especially in rural areas. It offers a range of benefits that positively impact the livelihoods and economic status of farming communities.
1. Income Diversification:

• Goat farming provides an additional source of income, reducing dependence on a single agricultural activity.
• Example: A farmer supplementing crop-based income with revenue from goat sales.

2. Low Initial Investment:

• Compared to larger livestock, goats require relatively low initial capital and infrastructure, making it accessible to smallholder farmers.
• Example: A farmer can start a goat enterprise with a modest investment in fencing and shelter.

3. Quick Turnover and High Reproductive Rate:

• Goats have a shorter gestation period and reach maturity earlier than many other livestock species, leading to faster breeding cycles and increased herd size.
• Example: A doe can give birth to 2-3 kids every 8-9 months.

4. Nutrient-Rich Products:

• Goats provide valuable products like milk, meat, and fiber, which are essential for household consumption and can be sold for additional income.
• Example: Goat milk is rich in protein, vitamins, and minerals, contributing to improved nutrition.

5. Climate Resilience:

• Goats are hardy animals that can thrive in diverse environments, including regions with limited resources and harsh climates.
• Example: In arid areas, where other livestock may struggle, goats can graze on marginal lands.

Conclusion: 
Goat rearing serves as a catalyst for socio-economic upliftment by offering income diversification, requiring low initial investment, ensuring quick turnover, providing nutrient-rich products, and exhibiting climate resilience. It empowers farmers, particularly in rural communities, by enhancing their economic stability and overall well-being. This makes it a valuable component of sustainable agricultural practices.

(e) Describe the different covariance components for resemblance between animal relatives.        (10 Marks)
Ans: 
Introduction:
 Covariance components are crucial in quantitative genetics for understanding the genetic and environmental contributions to traits within a population. They quantify the variance attributable to different sources, such as additive genetic effects, common environment effects, and individual-specific environment effects.
1. Additive Genetic Variance (VA):

• Represents the genetic variation passed from parents to offspring. It is the variance attributable to the sum of all additive genetic effects.
• Example: In a population of dairy cows, VA would account for the variation in milk yield due to the additive genetic influence from both parents.

2. Dominance Genetic Variance (VD):

• Reflects the variation due to interactions between alleles at the same locus. This component captures the effects of dominant genes.
• Example: In a population of chickens, VD would account for the variation in comb size due to the interactions between alleles at the comb gene locus.

3. Maternal Genetic Variance (VM):

• Represents the genetic influence from the mother, particularly for traits influenced by maternal care or provisioning.
• Example: In a population of sheep, VM would contribute to the variation in lamb birth weight due to genetic effects passed down through the ewe.

4. Common Environmental Variance (VC):

• Accounts for the shared environmental influences among individuals in a common environment, like siblings raised together.
• Example: In a litter of puppies, VC would contribute to the variation in weight due to factors like shared maternal care and nutrition.

5. Permanent Environmental Variance (VP):

• Represents the individual-specific environmental effects that persist over time but are not shared with relatives.
• Example: In a herd of dairy cattle, VP would account for the variation in milk yield due to factors like individual differences in feeding management.

Conclusion: 
Understanding covariance components is essential for accurate breeding value estimation and genetic improvement programs in livestock. By dissecting the sources of variation, breeders can make informed decisions to enhance desirable traits and selectively breed for improved performance in animal populations. This knowledge is instrumental in achieving genetic progress and advancing the productivity and quality of livestock.

Q2:
(a) Describe the methods for evaluation of protein quality in ruminant animals.        (20 Marks) 
Ans: 
Introduction:
Evaluating protein quality in ruminant diets is crucial to ensure optimal animal growth, reproduction, and production. Various methods are employed to assess protein quality.
1. Biological Value (BV):

• BV measures the proportion of absorbed protein that is retained and utilized for growth and maintenance.
• Example: A feed with a high BV ensures efficient protein utilization, promoting better animal performance.

2. Protein Efficiency Ratio (PER):

• PER evaluates the ability of a protein source to support growth in a specific species, considering both the quality and quantity of protein.
• Example: Fish meal has a high PER due to its balanced amino acid profile, making it a valuable protein source.

3. Net Protein Utilization (NPU):

• NPU assesses the proportion of ingested protein that is retained and utilized for physiological functions.
• Example: Soybean meal has a high NPU, indicating its suitability as a protein source in ruminant diets.

4. Protein Digestibility-Corrected Amino Acid Score (PDCAAS):

• PDCAAS considers both protein digestibility and amino acid profile, providing a comprehensive evaluation of protein quality.
• Example: Milk protein has a high PDCAAS due to its excellent digestibility and balanced amino acid composition.

5. Rumen Degradability:

• This method assesses how quickly a protein source is degraded in the rumen, impacting nutrient availability for microbial fermentation.
• Example: Soluble proteins are rapidly degraded, while insoluble proteins have slower degradation rates.

Conclusion: 
Evaluating protein quality in ruminant diets is crucial for formulating balanced and efficient nutrition plans. Utilizing methods like BV, PER, NPU, PDCAAS, and rumen degradability allows for informed decision-making in selecting appropriate protein sources to meet the nutritional needs of ruminant animals.

(b) Enlist the hormones secreted from anterior pituitary gland and describe the physiological role of these hormones.        (15 Marks) 
Ans:
Introduction: The anterior pituitary gland, also known as the adenohypophysis, plays a vital role in regulating various physiological processes in animals through the secretion of specific hormones.

1. Growth Hormone (GH):

• Role: Stimulates growth and cell division in various tissues, including muscles and bones.
• Example: GH promotes muscle development in young animals, influencing overall body size.

2. Prolactin (PRL):

• Role: Initiates and maintains lactation in mammals, promoting milk production in mammary glands.
• Example: PRL levels surge in lactating cows, ensuring a continuous milk supply for their calves.

3. Thyroid-Stimulating Hormone (TSH):

• Role: Stimulates the thyroid gland to produce and release thyroid hormones (T3 and T4), regulating metabolism.
• Example: TSH ensures optimal thyroid function, influencing energy metabolism in animals.

4. Adrenocorticotropic Hormone (ACTH):

• Role: Stimulates the adrenal glands to produce and release cortisol, a stress hormone that helps the body respond to challenges.
• Example: ACTH levels rise in response to stressors, aiding in the body's adaptation to stressful situations.

5. Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH):

• Role: Regulate reproductive processes, including follicle development, ovulation, and hormone production in the gonads.
• Example: FSH and LH work together in the estrous cycle of female animals, influencing ovulation and hormone secretion.

Conclusion: 
The hormones secreted by the anterior pituitary gland play pivotal roles in regulating growth, lactation, metabolism, stress responses, and reproduction in animals. Understanding these hormonal interactions is crucial for effective management and reproduction programs in livestock. 

(c) Describe the nutritional factors affecting the composition of milk in dairy cows.        (15 Marks) 
Ans: 
Introduction: 
Milk composition is influenced by various nutritional factors, which in turn, impact the quality and yield of dairy products. Understanding these factors is essential for optimizing dairy cow nutrition.

1. Dietary Energy and Protein Levels:

• Higher energy and protein diets lead to increased milk yield and improved milk protein content.
• Example: Feeding a balanced diet with adequate energy and protein promotes optimal milk production.

2. Fiber Content and Digestibility:

• High-quality forages with good fiber digestibility enhance milk fat content and overall milk yield.
• Example: Including alfalfa hay in the diet provides a rich source of digestible fiber for dairy cows.

3. Mineral and Vitamin Supplementation:

• Proper mineral and vitamin supplementation ensures the cow's metabolic functions are supported, influencing milk composition.
• Example: Supplementing with calcium and phosphorus maintains proper milk mineral content.

4. Fat Content of the Diet:

• Including fats or oilseeds in the diet can increase milk fat content, which is important for butterfat production.
• Example: Feeding soybean meal, a source of oil, can positively influence milk fat content.

5. Water Intake:

• Adequate water intake is crucial for milk production. Water deficiency can lead to reduced milk yield and altered composition.
• Example: Providing access to clean, fresh water at all times ensures proper hydration for dairy cows.

Conclusion: 
Nutritional factors play a significant role in determining milk composition in dairy cows. Balancing the diet to meet energy, protein, fiber, mineral, and vitamin requirements is essential for optimizing milk quality and quantity, ultimately impacting the profitability and sustainability of dairy operations.

Q3:
(a) Mention the general functions of minerals in animals. Justify the importance of Vitamin D in optimum calcium and phosphorus nutrition in animals.        (20 Marks) 
Ans: 
Introduction: 
Minerals are essential nutrients required by animals for various physiological functions. Among these, Vitamin D plays a critical role in ensuring proper calcium and phosphorus metabolism.

Functions of Minerals in Animals:
1. Structural Component:

• Minerals like calcium and phosphorus are vital for the formation and maintenance of bones and teeth.
• Example: Calcium forms the structural framework of bones, providing strength and support.

2. Nerve Function:

• Minerals like sodium, potassium, and calcium are involved in nerve impulse transmission, ensuring proper nerve function.
• Example: Sodium ions play a crucial role in generating action potentials in nerve cells.

3. Muscle Contraction:

• Minerals such as calcium, potassium, and magnesium are essential for muscle contraction and relaxation.
• Example: Calcium ions bind to proteins in muscle fibers, initiating the contraction process.

4. Enzyme Activation:

• Minerals like zinc, copper, and selenium serve as cofactors for various enzymes, facilitating metabolic reactions.
• Example: Zinc is a cofactor for enzymes involved in DNA replication and protein synthesis.

5. Osmotic Balance:

• Minerals help maintain the osmotic pressure of body fluids, ensuring proper cell hydration and function.
• Example: Sodium and potassium ions play a crucial role in regulating cell volume and fluid balance.

Importance of Vitamin D in Calcium and Phosphorus Nutrition:
1. Calcium Absorption and Utilization:

• Vitamin D enhances the absorption of dietary calcium in the intestines, ensuring it is available for bone formation and other physiological processes.
• Example: In the absence of adequate Vitamin D, even with sufficient dietary calcium, animals may experience calcium deficiency.

2. Regulation of Blood Calcium Levels:

• Vitamin D helps regulate blood calcium levels by promoting calcium absorption from the gut and reducing calcium loss in urine.
• Example: In dairy cows, Vitamin D deficiency can lead to milk fever, a condition characterized by low blood calcium levels.

3. Phosphorus Metabolism:

• Vitamin D is essential for proper phosphorus absorption and utilization in the body, working in conjunction with calcium for bone health.
• Example: In poultry, Vitamin D deficiency can lead to poor bone development and reduced eggshell quality.

Conclusion: 
Minerals serve various crucial functions in animal physiology, including structural support, nerve function, muscle contraction, enzyme activation, and osmotic balance. Vitamin D plays a pivotal role in ensuring optimal calcium and phosphorus nutrition, highlighting its significance in maintaining overall animal health and productivity.

(b) Discuss the physiological functions of plasma proteins in animals.        (15 Marks) 
Ans:
Introduction: 
Plasma proteins play diverse roles in the physiology of animals, contributing to various biochemical and physiological processes within the circulatory system.
1. Osmotic Regulation:

• Albumin, the most abundant plasma protein, helps maintain colloidal osmotic pressure, preventing excessive fluid loss from blood vessels.
• Example: In cases of liver disease, reduced albumin production can lead to edema due to decreased osmotic pressure.

2. Transport of Substances:

• Plasma proteins act as carriers for various substances, including hormones, lipids, and minerals, ensuring their distribution to target tissues.
• Example: Globulins transport antibodies, aiding in the immune response.

3. Blood Clotting:

• Fibrinogen is a plasma protein essential for blood clot formation, preventing excessive bleeding in case of injury.
• Example: During a wound healing process, fibrinogen is converted to fibrin, forming a stable blood clot.

4. Immune Response:

• Immunoglobulins (antibodies) are plasma proteins that play a crucial role in the body's defense against pathogens, enhancing the immune response.
• Example: When exposed to a specific pathogen, the immune system produces antibodies that bind to and neutralize the invader.

5. Buffering Capacity:

• Plasma proteins, particularly albumin, act as buffers, helping maintain the pH of blood within a narrow range.
• Example: In cases of metabolic acidosis, increased levels of plasma proteins assist in stabilizing blood pH.

Conclusion:
Plasma proteins contribute significantly to the maintenance of homeostasis and proper physiological functioning in animals. Their roles in osmotic regulation, substance transport, blood clotting, immune response, and pH buffering are essential for overall health and survival. Understanding the functions of plasma proteins is crucial for diagnosing and treating various diseases and disorders in animals.

(c) Suggest the feeding and management of animals under flood-affected conditions.        (15 Marks) 
Ans: 
Introduction: 
Flood-affected conditions pose significant challenges for animal husbandry. Proper feeding and management strategies are crucial to ensure the welfare and survival of livestock during such events.

Feeding Strategies:
1. Provide Access to High Ground:

• Move animals to elevated areas to prevent them from being trapped in floodwaters, ensuring their safety.
• Example: Transporting livestock to higher ground or constructing temporary platforms for them.

2. Emergency Rations:

• Supply easily digestible and nutrient-dense feeds, such as concentrates and high-quality forages, to maintain animal nutrition.
• Example: Offering supplemental feed like alfalfa pellets or grain mixes to compensate for reduced grazing opportunities.

3. Water Quality Assurance:

• Ensure a clean and safe water source, as floodwaters may be contaminated. Provide access to uncontaminated water to prevent dehydration.
• Example: Using portable water tanks or providing treated water from alternative sources.

4. Monitor Body Condition:

• Regularly assess the body condition of animals to identify and address malnutrition or weight loss promptly.
• Example: Conducting visual assessments and palpating key areas, such as the ribs and backbone.

Management Strategies:
1. Health and Welfare Checks:

• Conduct frequent health checks to identify and treat injuries, illnesses, or signs of stress in animals.
• Example: Observing for lameness, respiratory distress, or other signs of discomfort.

2. Minimize Stress and Confinement:

• Avoid overcrowding and provide sufficient space for movement to reduce stress levels among animals.
• Example: Creating temporary holding areas with enough space for animals to move freely.

3. Record Keeping:

• Maintain accurate records of animal numbers, health status, and treatments administered for documentation and future management decisions.
• Example: Using digital or paper-based record-keeping systems to track important information.

Conclusion: 
Effective feeding and management strategies are crucial in mitigating the impact of flood-affected conditions on livestock. Providing access to safe food and water, monitoring animal health, and minimizing stress levels are key components of ensuring the welfare and survival of animals during such challenging circumstances. Implementing these strategies in a timely and organized manner is essential for the long-term recovery and well-being of the affected livestock population.

Q4:
(a) Describe nutritional characteristics of feed ingredients which are generally incorporated in formulation of poultry feed.         (20 Marks) 
Ans: 
Introduction: 
Poultry feed formulation involves selecting and combining various feed ingredients to meet the nutritional requirements of birds at different stages of growth and production. Here are the key nutritional characteristics of commonly used feed ingredients in poultry diets:
1. Protein Content:

• Essential for growth, feathering, egg production, and overall muscle development.
• Example: Soybean meal is a high-quality protein source commonly used in poultry feeds.

2. Amino Acid Profile:

• Essential amino acids like lysine, methionine, and tryptophan should be present in adequate amounts to support optimal growth and production.
• Example: Corn, although lower in protein, is a valuable energy source with balanced amino acids when combined with protein-rich ingredients.

3. Energy Content:

• Provides the calories needed for metabolic processes, growth, and production.
• Example: Corn and sorghum are important sources of energy in poultry diets due to their high carbohydrate content.

4. Fat Content:

• Important for energy, as well as for the absorption of fat-soluble vitamins (A, D, E, and K).
• Example: Soybean oil is commonly used to increase the energy density of poultry feeds.

5. Fiber Content:

• Helps maintain gut health, aids in digestion, and regulates feed passage rate.
• Example: Wheat bran is a common source of dietary fiber in poultry feeds.

6. Calcium and Phosphorus Levels:

• Essential for bone development, eggshell formation, and metabolic functions.
• Example: Limestone is a primary source of calcium in poultry diets.

7. Vitamin Content:

• Essential for various metabolic processes, growth, and overall health.
• Example: Fish meal is rich in vitamins like B12 and riboflavin, making it a valuable ingredient in poultry feeds.

8. Mineral Content:

• Important for skeletal development, enzyme function, and other physiological processes.
• Example: Dicalcium phosphate is a common source of supplemental phosphorus in poultry feeds.

Conclusion: 
Balancing these nutritional characteristics is crucial in formulating poultry feeds that meet the specific requirements of different poultry species and production stages. The selection and combination of these feed ingredients are tailored to achieve optimal growth, production, and overall health of poultry.

(b) Enlist hemorrhagic disorders in animals and describe congenital thrombocytopenia in dogs.        (15 Marks) 
Ans: 
Introduction: 
Hemorrhagic disorders in animals are characterized by abnormal bleeding due to defects in the blood-clotting process. One such condition, congenital thrombocytopenia, is a rare inherited disorder affecting platelet production.

Hemorrhagic Disorders in Animals:
1. Hemophilia:

• An inherited disorder characterized by a deficiency of specific clotting factors, leading to prolonged bleeding.
• Example: Hemophilia A in dogs is caused by a deficiency of factor VIII.

2. Von Willebrand Disease:

• A genetic disorder resulting in a deficiency or dysfunction of von Willebrand factor, a protein critical for platelet adhesion.
• Example: Scottish Terriers are predisposed to a type of von Willebrand Disease.

3. Thrombocytopenia:

• A condition characterized by a low platelet count, which can lead to bleeding disorders.
• Example: Immune-mediated thrombocytopenia (ITP) is an acquired form, while congenital thrombocytopenia is inherited.

Congenital Thrombocytopenia in Dogs:
1. Definition:

• Congenital thrombocytopenia is a hereditary disorder characterized by a reduced number of platelets in the blood.

2. Cause:

• It is typically caused by a genetic mutation affecting platelet production or survival.
• Example: Gray Collies are known to inherit a form of congenital thrombocytopenia.

3. Clinical Signs:

• Animals with congenital thrombocytopenia may exhibit excessive bleeding from minor injuries, prolonged bleeding after surgery, or spontaneous bleeding.

4. Diagnosis:

• Diagnosis involves a complete blood count (CBC) to assess platelet counts and evaluate other blood components.

5. Treatment:

• Management may include supportive care, blood transfusions, and in severe cases, treatment with platelet-stimulating medications.

Conclusion: 
Hemorrhagic disorders, including congenital thrombocytopenia, can significantly impact an animal's health and quality of life. Early diagnosis and appropriate management are essential in providing affected animals with the best possible care and minimizing the risk of bleeding episodes.

(c) What is idealized animal population ? Describe the chromosomal theory o f sex determination in animals.        (15 Marks) 
Ans: 
Introduction: 
An idealized animal population is a theoretical concept used in population genetics to represent a population that adheres to certain genetic assumptions. The chromosomal theory of sex determination explains how sex is determined in many animals based on genetic factors.

Idealized Animal Population:
1. Assumptions:

• Random mating: Individuals mate randomly within the population.
• Large population size: Ensures that genetic drift has minimal effect on allele frequencies.
• No migration: The population is isolated, preventing gene flow from other populations.
• No mutation: Genetic variation only arises from recombination and segregation.

2. Hardy-Weinberg Equilibrium:

• The idealized population adheres to the Hardy-Weinberg equilibrium, which describes the relationship between allele frequencies and genotype frequencies.

Chromosomal Theory of Sex Determination:
1. XX-XY System:

• In this system, females have two similar sex chromosomes (XX), while males have one X and one Y chromosome (XY).
• Example: Humans, mammals, some insects.

2. ZZ-ZW System:

• Females have two different sex chromosomes (ZW), while males have two similar sex chromosomes (ZZ).
• Example: Birds, some reptiles, and butterflies.

3. XX-XO System:

• Females have two similar sex chromosomes (XX), while males have only one X chromosome (XO).
• Example: Grasshoppers and some insects.

4. Haplodiploidy System:

• In this system, females develop from fertilized eggs (diploid), while males develop from unfertilized eggs (haploid).
• Example: Hymenoptera insects like bees, wasps, and ants.

Conclusion:
The idealized animal population concept is crucial in understanding population genetics, while the chromosomal theory of sex determination explains the genetic basis for sex determination in various animal species. Both concepts are fundamental in the study of genetics and play a significant role in animal breeding and conservation efforts.