UPSC Mains Answer PYQ 2024: Animal Husbandry Paper 1 (Section- B) | Animal Husbandry & Veterinary Science Optional for UPSC PDF Download

Section B

Q5: Answer the following questions in about 150 words each: (10 × 5 = 50 Marks)

(a) Mention the steps involved in cryopreservation of bull semen. (10 Marks)
Ans: Cryopreservation is the process of preserving cells or whole tissues by cooling them to sub-zero temperatures. In animal reproduction, it is extensively used to store bull semen for artificial insemination (AI) programs, improving genetic dissemination and fertility management.
Steps Involved

1. Semen Collection

   • Collected using an artificial vagina (AV) or electro-ejaculation.

   • Ensures minimal contamination and optimal sperm viability.

2. Initial Evaluation

   • Gross examination: Volume, color, and consistency.

   • Microscopic evaluation: Motility, concentration, morphology.

3. Dilution with Extender

   • Semen is diluted with a protective extender containing cryoprotectants (e.g., egg yolk-citrate, Tris-citric acid with glycerol).

   • Glycerol acts as a cryoprotectant by preventing ice crystal formation.

4. Cooling

   • Gradual cooling from body temperature (37°C) to 4–5°C over 2–3 hours.

   • Maintains sperm membrane integrity.

5. Equilibration

   • Semen is kept at 4°C for 4-6 hours to allow glycerol penetration and stabilization.

6. Packaging

   • Filled into 0.25 mL or 0.5 mL straws, sealed with polyvinyl alcohol powder or heat-sealing.

7. Freezing

   • Controlled freezing in liquid nitrogen vapors (-120°C) before plunging into liquid nitrogen (-196°C).

   • Specialized programmable bio-freezers are often used.

8. Storage

   • Stored indefinitely in liquid nitrogen tanks at -196°C.

9. Post-Thaw Evaluation (Optional)

   • To assess sperm viability, motility, and membrane integrity after thawing.

Example: Successful AI programs in India, such as those led by NDDB (National Dairy Development Board), rely heavily on cryopreserved semen of superior bulls.

Cryopreservation ensures long-term conservation of valuable genetic material, significantly improving cattle breeding programs, enhancing productivity, and maintaining biodiversity.

(b) Discuss the points to be considered during care and management of neonatal calf. (10 Marks)
Ans: Neonatal calf care is crucial for survival, health, and future productivity. Mortality in calves is mainly due to poor management immediately after birth. Effective neonatal care minimizes mortality rates and promotes rapid growth.
Important Points

1. Immediate Post-birth Care

   • Clear nostrils and mouth to ensure breathing.

   • Rub the calf vigorously with a clean towel to stimulate circulation.

2. Colostrum Feeding

   • First feeding within 1–2 hours of birth; critical for passive immunity.

   • Feed at least 10% of body weight within the first 24 hours.

3. Naval Cord Care

   • Dip the umbilical cord in 7% tincture of iodine to prevent infections like naval ill.

4. Thermal Regulation

   • Protect from hypothermia, especially in colder climates.

   • Use calf jackets, heaters, or dry bedding.

5. Housing

   • Clean, dry, and well-ventilated area to reduce risk of pneumonia and diarrhea.

   • Individual calf pens or hutches preferred.

6. Health Monitoring

   • Observe daily for signs of diarrhea, dehydration, or respiratory issues.

   • Regular temperature checking and vaccination schedules.

7. Nutrition Beyond Colostrum

   • Introduce milk replacers or calf starters after the first few days.

   • Gradual weaning to solid feed by 6–8 weeks.

8. Dehorning and Identification

   • Perform disbudding within 2-3 weeks if necessary.

   • Ear-tagging for proper record-keeping.

Example: High-quality calf management practices have been instrumental in raising elite breeding stock at institutions like NDRI (National Dairy Research Institute), Karnal.

Systematic neonatal care ensures a strong foundation for the calf’s future growth, enhances herd profitability, and ensures a steady supply of healthy, productive animals.

(c) Write the characteristics of Gir and Sahiwal cattle. (10 Marks)
Ans: Gir and Sahiwal are among India's best-known indigenous cattle breeds, famed for their milk production, disease resistance, and adaptability to tropical climates. Understanding their characteristics aids in effective breeding and conservation efforts.
Characteristics of Gir Cattle

1. Origin

   • Native to Gujarat, especially the Gir forest region.

2. Physical Appearance

   • Distinctive convex forehead ("bulging dome"), long ears, and horns that curve backward.

   • Coat color varies: red with white spots, black, or pure white.

3. Milk Production

   • Average milk yield: 1200–1800 kg per lactation.

   • High butterfat content (~4.5%).

4. Temperament

   • Docile, gentle, and easy to handle.

5. Adaptability

   • Highly heat-tolerant and disease-resistant.

   • Suitable for harsh, drought-prone areas.

Characteristics of Sahiwal Cattle

1. Origin

   • Native to Punjab region, especially the Montgomery district (now in Pakistan).

2. Physical Appearance

   • Color: reddish dun, sometimes light brown.

   • Short horns, broad forehead, and drooping ears.

3. Milk Production

   • High milk yield: 2000–3000 kg per lactation.

   • Good butterfat percentage (~4-5%).

4. Temperament

   • Extremely docile and easily manageable.

5. Adaptability

   • High resistance to tropical diseases and heat stress.

   • Performs well even under poor feeding conditions.

Example: Crossbreeding programs with Gir and Sahiwal have significantly improved milk production in tropical and sub-tropical countries like Brazil and Kenya.

Gir and Sahiwal cattle represent the genetic treasure of India's dairy sector, offering sustainable productivity, environmental resilience, and disease resistance, making them invaluable assets in livestock improvement programs.

(d) Discuss the feeding strategies of goat for chevon production. (10 Marks)
Ans: Goat farming is an important sector for meat (chevon) production in India. Proper feeding strategies are crucial for achieving optimal growth, reproductive performance, and health in goats, ensuring higher meat yield and quality.
Feeding Strategies for Chevon Production

1. Nutritional Requirements

   • Energy: Goats require a balanced intake of carbohydrates and fats to meet their energy demands, essential for growth and meat production.

   • Proteins: Protein is critical for muscle development. It should constitute 12-18% of the total diet for young goats.

   • Minerals and Vitamins: Calcium and phosphorus are important for bone development. Vitamin A and E are essential for immunity and overall health.

2. Forage-Based Feeding

   • Natural Grazing: Goats are browsers, preferring shrubs, leaves, and bushes. Grazing on quality pasture helps in meeting roughage requirements.

   • Fodder Crops: Cultivating leguminous fodder like lucerne, berseem, or subabul improves protein intake and enhances weight gain.

   • Silage and Hay: When pasture availability is limited, preserving green fodder in the form of silage or hay ensures a steady feed supply.

3. Concentrates and Supplementation

   • Concentrates: The addition of grains like maize, wheat, and barley helps in meeting the energy requirements. A grain-to-forage ratio of 30:70 is ideal for fattening goats.

   • Protein Supplements: Feed protein supplements such as soybean meal, groundnut cake, and cottonseed cake to improve growth rates.

4. Ad Libitum Feeding

   • Goats should be provided with adequate amounts of feed without restriction to encourage consistent weight gain.

   • Water Availability: Always ensure that goats have access to clean drinking water to prevent dehydration and support digestion.

5. Feeding Strategy for Different Growth Stages

   • Kids: Feed colostrum for the first 24 hours. Start feeding them with a high-quality milk replacer, and gradually introduce solid feeds.

   • Growing Goats (Weaning to Market Age): Provide high-protein and energy-dense feeds to enhance growth rates. A balanced mix of forage and concentrates supports muscle development.

   • Mature Goats: Maintain a low to moderate feed intake to prevent excessive fat deposition. Focus on high-fiber, low-energy diets.

Example: In regions like Rajasthan and Gujarat, traditional grazing systems combined with supplemental feeding have been highly effective in improving chevon production in local goats.

Effective feeding strategies are key to optimizing goat growth and health for meat production. Balanced nutrition, proper supplementation, and age-specific diets ensure the sustainable production of high-quality chevon.

(e) Explain the breeding system used for pig production in India. (10 Marks)
Ans: Pig production is an integral part of livestock farming in India, particularly in North-Eastern states. Understanding the breeding systems is vital to improving productivity, growth rates, and meat quality in pigs.
Breeding Systems for Pig Production in India

1. Natural Mating (Traditional Breeding System)

   • Description: In this system, the boar is allowed to mate naturally with sows. It is widely used in small-scale and traditional farming systems.

   • Advantages:

     • Simple and cost-effective.

     • No need for special infrastructure.

   • Disadvantages:

     • Limited genetic improvement.

     • Higher risk of disease transmission.

2. Artificial Insemination (AI)

   • Description: The collection of semen from a selected boar and its artificial introduction into the sow’s reproductive tract.

   • Advantages:

     • Improves genetic potential by using semen from superior boars.

     • Reduces the risk of disease transmission and enhances the reproductive success.

   • Disadvantages:

     • Requires skilled technicians and proper facilities.

     • Higher initial costs for equipment and semen.

3. Crossbreeding System

   • Description: Crossbreeding between indigenous breeds and exotic pigs (e.g., Large White, Landrace) to combine desirable traits like growth rate, reproductive efficiency, and disease resistance.

   • Common Crosses:

     • Indigenous x Exotic Cross: For improved productivity and adaptability.

     • Exotic x Exotic Cross: To enhance growth and meat quality.

   • Advantages:

     • Increased growth rate and meat production.

     • Improved disease resistance.

   • Disadvantages:

     • Loss of indigenous breed characteristics.

     • Need for management of genetic compatibility.

4. Systematic Selection

   • Description: Selection based on performance traits such as growth rate, feed efficiency, and reproductive performance.

   • Advantages:

     • Focused on improving specific traits.

     • Long-term genetic improvement.

   • Disadvantages:

     • Requires record-keeping and a systematic breeding program.

5. Herd Replacement System

   • Description: Boars and sows are replaced periodically to ensure better genetic traits.

   • Advantages:

     • Helps maintain a healthy gene pool.

     • Avoids inbreeding.

   • Disadvantages:

     • Continuous monitoring and selective breeding needed.

Example: In India, the introduction of AI and crossbreeding programs, especially with breeds like Large White and Landrace, has significantly increased pig production in states like Nagaland and Mizoram.

The breeding systems used in India, including natural mating, artificial insemination, and crossbreeding, play a crucial role in enhancing pig productivity. Adoption of modern systems can contribute significantly to the growth of the pig farming industry in India.

Q6: (a) Justify the statement that "Maintenance of sires in good condition is essentially required for the success of breeding programmes". Discuss the important points for the management of breeding males in good condition. (10 + 10 = 20 Marks)
Ans: The success of any breeding program relies not just on the quality of the breeding females, but also the health, fertility, and management of the breeding males (sires). A well-maintained sire ensures high fertility rates, genetic diversity, and overall success in achieving the breeding objectives.
Justification of the Statement

1. Fertility and Reproductive Performance

   • Sires in good condition are more likely to have high libido, optimal sperm quality, and motility, leading to better fertility rates in females.

   • Poor health or malnutrition can lead to low sperm count, poor semen quality, and reduced reproductive performance.

2. Genetic Potential and Quality

   • Healthy sires pass on superior genetic traits like growth rate, disease resistance, and productivity. A poorly maintained sire might not express these traits fully, thus impacting the genetic quality of offspring.

3. Reduced Risk of Diseases

   • Healthy sires are less prone to diseases like infectious reproductive disorders (e.g., brucellosis, tuberculosis), ensuring better health of the offspring and preventing the spread of diseases in the herd.

4. Economic Impact

   • A fertile, healthy sire can serve multiple females and produce a larger number of offspring, maximizing returns on investment.

   • Poor management or failure to maintain sires in good condition can lead to longer periods of non-productivity and financial losses.

Important Points for the Management of Breeding Males in Good Condition

1. Nutrition Management

   • Provide a balanced diet that includes adequate protein, energy, vitamins, and minerals to support the sire’s reproductive health and overall condition.

   • Supplement with trace minerals such as zinc, selenium, and vitamins A, D, and E to promote fertility.

2. Exercise and Physical Condition

   • Regular exercise ensures that the sire remains physically fit and maintains good body condition. However, excessive exercise or overuse should be avoided to prevent fatigue.

   • Adequate space for movement and access to clean, dry bedding helps prevent injuries.

3. Health Management

   • Regular health check-ups and vaccinations to prevent reproductive diseases and general illnesses.

   • Deworming and parasite control are critical for maintaining good condition.

4. Monitoring and Evaluation

   • Regular semen evaluation to check for motility, morphology, and concentration. Sires that exhibit poor semen quality should be replaced or given rest.

   • A proper breeding schedule, with breaks between mating seasons, ensures the sire remains in optimal condition.

5. Breeding and Rest

   • Avoid overuse of sires by limiting the number of females mated during a breeding season.

   • Allow adequate rest periods to help maintain the sire’s fertility.

Maintaining sires in good condition is crucial to achieving success in breeding programs. Proper nutrition, health care, and management practices lead to better reproductive outcomes, ensuring healthy and high-quality offspring.

(b) Describe the methods of oestrus detection in sheep. (10 Marks)
Ans: Accurate detection of oestrus (heat) in sheep is essential for efficient breeding programs. Timely mating during the oestrus period improves conception rates and productivity.
Methods of Oestrus Detection in Sheep

1. Visual Observation

   • Behavioral Changes: During oestrus, ewes exhibit restlessness, frequent bleating, and increased interaction with other animals, especially rams.

   • Standing Heat: The ewe may stand still and allow mounting, which is a clear indication of oestrus.

2. Ram Effect

   • Introducing a ram to a group of ewes can induce oestrus due to pheromonal signals emitted by the ram. This is used as a technique to synchronize estrus cycles in ewes.

3. Vaginal Discharge

   • Ewes in heat show a clear, slightly viscous discharge from the vagina. This can be noticed on their hindquarters or the bedding.

4. Changes in Genitalia

   • The vulva of the ewe becomes slightly swollen and red during oestrus, signaling that she is in heat. A veterinarian can examine this for accurate detection.

5. Use of Heat Detection Aids

   • Bristle Marking Harness: A ram fitted with a bristle-marking harness will leave a mark on the ewe when mating, which helps identify those in heat.

   • Raddle Marking: Similar to the bristle-marking harness, but using a colored paste applied to the ram’s chest, which leaves a mark on the ewe’s back.

6. Hormonal Methods (Progestogens and GnRH)

   • Hormonal treatments such as progestogens can be used to synchronize estrus in ewes. A veterinarian might administer hormones to control and detect oestrus.

Example: In commercial sheep farming, such as in Australia and New Zealand, the ram effect and use of marking harnesses are commonly used to improve the accuracy and efficiency of oestrus detection.

Efficient oestrus detection in sheep allows for timely mating and improved reproductive success. Visual observation, the ram effect, and the use of hormonal aids are key methods employed by farmers and breeders to enhance productivity.

(c) Enumerate different types of natural calamities which may be encountered by the livestock rearer. Draw strategies for feeding and management of livestock during natural calamities to minimize the production losses. (5 + 15 = 20 Marks)
Ans: Natural calamities, such as floods, droughts, and storms, pose significant challenges to livestock rearers. These events can lead to direct losses (death, injury) and indirect impacts (feed shortages, diseases). Proper management strategies can mitigate these losses.
Types of Natural Calamities Encountered by Livestock Rearers

1. Floods

   • Resulting in loss of grazing land, contamination of water sources, and the spread of diseases like leptospirosis and anthrax.

2. Droughts

   • Reduced availability of water and fodder leads to poor nutrition and dehydration, affecting livestock growth and reproduction.

3. Storms and Cyclones

   • Damaging infrastructure (sheds, fences), loss of grazing areas, and increased risk of injury or death to livestock.

4. Heatwaves

   • Elevated temperatures cause heat stress, leading to reduced feed intake, lower milk yield, and infertility in livestock.

5. Snowstorms and Extreme Cold

   • Frostbite, hypothermia, and reduced pasture growth can threaten the health of livestock in colder climates.

Strategies for Feeding and Management During Natural Calamities

1. During Floods

   • Relocation: Move livestock to higher ground and provide temporary shelters.

   • Feed Supply: Use stored fodder and ensure a continuous supply of clean drinking water.

   • Health Management: Monitor for waterborne diseases and vaccinate against common infectious diseases.

2. During Droughts

   • Fodder Management: Use silage, hay, and concentrates to supplement forage. Consider crop residue or forage cultivation.

   • Water Conservation: Implement rainwater harvesting and provide artificial watering points.

   • Nutritional Supplementation: Offer mineral supplements to meet nutritional deficiencies.

3. During Storms/Cyclones

   • Protection: Secure shelters and enclosures for livestock to avoid injuries.

   • Stockpile Feed: Store adequate feed supplies well in advance to prevent shortages.

4. During Heatwaves

   • Shade and Cooling: Provide shade and cool areas for livestock. Use fans or sprinklers in commercial setups.

   • Hydration: Ensure constant access to fresh water and encourage frequent drinking.

5. During Cold Weather

   • Shelter: Provide adequate housing with insulation or bedding to protect from cold.

   • Feeding: Increase the nutritional value of the diet to generate body heat. Use grains and energy-dense feeds.

Example: In areas prone to drought, such as Rajasthan, farmers employ rainwater harvesting and conserve fodder during good seasons to ensure livestock survival during dry spells.

Livestock rearers must be prepared for natural calamities by developing proactive management and feeding strategies. Timely preparation and efficient response can reduce the impact of these events and minimize production losses.

Q7: 
(a) Suggest the strategies which should be implemented by the dairy farmers to ensure round the year supply of green fodder. (15 Marks)
Ans: Green fodder is essential for the proper nutrition and health of dairy cattle, contributing to their milk production, reproduction, and overall well-being. Ensuring a continuous supply of green fodder throughout the year is a challenge for dairy farmers, especially during off-seasons like summer and winter. Proper strategies can help maintain this supply.

Strategies for Ensuring Year-Round Supply of Green Fodder

1. Fodder Diversification

   • Grow a variety of fodder crops such as lucerne, berseem, maize, sorghum, napier grass, and fodder trees (e.g., Subabul, Leucaena) to ensure a consistent supply.

   • Different crops have varying growth seasons, allowing for staggered harvesting throughout the year.

2. Use of Hydroponics

   • Grow hydroponic fodder (e.g., barley, wheat, oats) in controlled environments. This method is especially useful during dry seasons, as it can be grown indoors with minimal water usage and space.

3. Fodder Preservation Techniques

   • Silage Making: Preserve excess fodder during the peak growing seasons (monsoon) through silage making. Silage is a fermented feed that can be stored for months and used during lean seasons.

   • Hay Production: Dry green fodder during the rainy season to create hay, which can be stored and fed during dry months when fresh fodder is scarce.

4. Crop Rotation and Intercropping

   • Practice crop rotation and intercropping to enhance soil fertility and maintain a steady supply of fodder crops throughout the year. For example, planting leguminous crops (e.g., groundnut, soybean) with grasses helps fix nitrogen in the soil, enhancing fodder quality.

5. Utilization of Marginal and Waste Lands

   • Grow fodder crops on marginal or waste lands (e.g., saline, waterlogged) where traditional crops might not grow well, thus optimizing land use for fodder production.

6. Water Management

   • Implement efficient irrigation systems such as drip irrigation or sprinkler systems to ensure consistent water supply for fodder crops, especially in areas prone to water scarcity.

7. Fodder Storage Facilities

   • Build proper storage (e.g., silos, haylofts) to store silage, hay, and other preserved fodders, protecting them from spoilage and pests.

8. Agroforestry and Fodder Trees

   • Integrate fodder trees (e.g., Gliricidia, Leucaena) into the farm’s ecosystem. These trees provide continuous fodder and improve soil fertility.

Example: In areas like Punjab, dairy farmers combine green fodder crops like berseem and lucerne with preserved fodder like silage to ensure a continuous supply of green feed for their cattle, even during winter.

Through diversification, preservation techniques, and efficient management practices, dairy farmers can ensure a consistent and sustainable supply of green fodder, improving the health and productivity of dairy cattle year-round.

(b) Differentiate between the following: (5 × 4 = 20 Marks)
(i) Quantitative and qualitative traits
Ans: 

1. Quantitative Traits

   • These traits are controlled by multiple genes and are influenced by environmental factors. They exhibit a continuous variation and can be measured in numerical terms (e.g., milk yield, body weight, growth rate).

   • Example: Milk production in cows is a quantitative trait.

2. Qualitative Traits

   • These traits are usually controlled by a single gene and exhibit discrete categories. They do not show continuous variation and are not affected by environmental factors (e.g., coat color, horn presence).

   • Example: Coat color in cattle (black, brown, white) is a qualitative trait.

(ii) Sex limited and sex influenced characters
Ans: 

1. Sex Limited Characters

   • These traits are expressed in only one sex, despite being inherited by both males and females. The expression of these traits is limited to one sex due to hormonal differences (e.g., milk production in cows, egg-laying in hens).

   • Example: Milk production is a sex-limited trait, present in females but not males.

2. Sex Influenced Characters

   • These traits are influenced by the sex of the individual but are expressed in both males and females. The trait expression varies between sexes due to hormonal influence (e.g., beard growth in males, baldness in males).

   • Example: Baldness in humans, more prominent in males than females, is a sex-influenced trait.

(iii) Production and reproductive traits
Ans: 

1. Production Traits

   • These traits are related to the output or yield of a farm animal, such as milk production, wool yield, meat quality, and growth rate.

   • Example: Milk yield in dairy cows is a production trait.

2. Reproductive Traits

   • These traits are related to the ability of an animal to reproduce, including fertility, conception rate, gestation length, and calving interval.

   • Example: Conception rate in cows is a reproductive trait.

(iv) Anoestrus and repeat breeding
Ans: 

1. Anoestrus

   • Anoestrus is the condition when a female animal does not exhibit estrus (heat) for a prolonged period, often due to hormonal imbalance, stress, or poor nutrition.

   • Example: A cow not showing estrus for several months due to poor nutrition is in anoestrus.

2. Repeat Breeding

   • Repeat breeding refers to the failure of a female to conceive after repeated inseminations, despite showing regular estrus cycles.

   • Example: A cow that shows heat but fails to conceive after multiple inseminations due to infections or other issues is suffering from repeat breeding.

(c) Describe in detail the advantages and disadvantages of artificial insemination in animals. (15 Marks)
Ans: Artificial Insemination (AI) is a widely used reproductive technology in animal husbandry. It involves the collection of semen from a male and its artificial introduction into the reproductive tract of a female. AI has revolutionized breeding practices by improving genetic potential, disease control, and reproductive efficiency.
Advantages of Artificial Insemination

1. Improved Genetics

   • AI allows the use of superior genetics from high-quality bulls, thus improving the herd's overall genetic potential for traits like milk yield, growth rate, and disease resistance.

   • Example: AI with semen from high-yielding bulls can significantly improve milk production in dairy herds.

2. Disease Control

   • AI reduces the risk of disease transmission (e.g., brucellosis, tuberculosis) that can occur through natural mating, ensuring the health of the herd.

   • Example: AI eliminates the risk of venereal diseases that could spread during natural mating.

3. Increased Reproductive Efficiency

   • AI allows the use of a single bull to service multiple females, thus increasing the reproductive efficiency and ensuring timely conception.

   • Example: One bull can serve hundreds of cows through AI, improving herd management and productivity.

4. Cost-Effectiveness

   • Reduces the need for maintaining a large number of bulls on the farm, saving on feed, care, and infrastructure costs.

   • Example: Smallholder farmers can access the genetics of high-quality bulls without the cost of maintaining them.

5. Use of Frozen Semen

   • Semen can be frozen and stored for long periods, ensuring the availability of genetic material from superior animals for future use.

   • Example: Semen from top-performing bulls can be stored and used years later to improve offspring quality.

Disadvantages of Artificial Insemination

1. Technical Expertise Required

   • AI requires skilled technicians for semen collection, handling, and insemination, making it less accessible in areas lacking training and resources.

   • Example: In rural areas, farmers may struggle with the technical knowledge required for AI, leading to poor success rates.

2. Costs of Equipment and Semen

   • Initial setup costs for AI equipment (e.g., insemination tools, semen storage tanks) and purchasing high-quality semen can be high.

   • Example: For small farmers, the cost of AI services and semen from superior bulls may be prohibitive.

3. Failure Rates

   • AI does not guarantee conception. Fertility can be affected by factors like improper handling of semen, incorrect insemination timing, and female reproductive issues.

   • Example: Poor timing of insemination can result in failed pregnancies, reducing the efficiency of AI.

4. Limited Access to Quality Semen

   • In some regions, access to quality semen from genetically superior bulls may be limited, reducing the overall benefit of AI.

   • Example: Remote areas may not have access to semen from elite bulls, hindering genetic improvement.

Artificial Insemination has significantly improved livestock breeding by enhancing genetic quality and reproductive efficiency. However, the challenges related to technical expertise, costs, and failure rates must be addressed for optimal results. When managed properly, AI offers substantial benefits to the livestock sector.

Q8: 
(a) Define gene frequency. Describe the method of estimation of gene frequency from genotypic frequency with the help of a suitable example. (20 Marks)
Ans: Gene frequency, also known as allele frequency, refers to the proportion of a specific allele among all allele copies in a population. It is a fundamental concept in population genetics and plays a critical role in the evolution of species, genetic diversity, and selection practices in animal breeding.
Definition of Gene Frequency
Gene frequency is the proportion of a particular allele at a locus in a population. It can be calculated for dominant, recessive, and heterozygous alleles. Understanding gene frequency allows breeders to predict the inheritance patterns of traits in subsequent generations and helps in improving desirable traits through selective breeding.
Method of Estimation of Gene Frequency from Genotypic Frequency

1. Understanding Genotypic Frequency
   Genotypic frequency refers to the proportion of different genotypes (homozygous dominant, heterozygous, and homozygous recessive) in a population. The genotypic frequency can be used to estimate the gene (allele) frequencies in the population.

2. Steps for Estimating Gene Frequency
   Suppose we are studying a gene with two alleles, A (dominant) and a (recessive), and the frequencies of the genotypes in the population are as follows:

   • Homozygous dominant (AA): 0.36

   • Heterozygous (Aa): 0.48

   • Homozygous recessive (aa): 0.16

   • a. Calculating the Allele Frequency of A (p):

   • The allele frequency of A is calculated by taking into account both the homozygous dominant (AA) and the heterozygous (Aa) genotypes. The formula is:
     Substituting the given genotypic frequencies:
     So, the allele frequency of A is 0.60.
     b. Calculating the Allele Frequency of a (q):

   • The allele frequency of a can be calculated similarly:Substituting the given genotypic frequencies:
     So, the allele frequency of a is 0.40.

3. Hardy-Weinberg Equilibrium
   The Hardy-Weinberg equilibrium principle states that the allele frequencies in a population remain constant from generation to generation unless acted upon by evolutionary forces (e.g., natural selection, mutation, migration). For a gene with two alleles, the genotype frequencies can be predicted using the formula:
   p² + 2pq + q² = 1az
   Where:

• p² is the frequency of homozygous dominant (AA),
• 2pq is the frequency of heterozygous (Aa),
• q² is the frequency of homozygous recessive (aa).

Example: In a population of cattle, if the frequencies of genotypes AA, Aa, and aa are 0.36, 0.48, and 0.16 respectively, we calculated that the gene frequencies for A and a are 0.60 and 0.40, respectively.

Gene frequency provides valuable insights into the genetic composition of a population. Estimating gene frequency from genotypic frequency is a straightforward process that can be used to predict the genetic structure of populations and guide selective breeding programs in animal husbandry.

(b) Write the role of NDDB in rural development. (10 Marks)
Ans: The National Dairy Development Board (NDDB) is a government body in India that plays a crucial role in promoting dairy farming and rural development. NDDB has contributed significantly to improving the economic status of rural farmers by focusing on enhancing the dairy industry, increasing milk production, and improving rural livelihoods.
Role of NDDB in Rural Development

1. Promotion of Dairy Cooperatives

   • NDDB promotes the formation of dairy cooperatives, which help small and marginal farmers access better prices for their milk and other dairy products.

   • Example: The success of Amul, a cooperative formed with NDDB’s support, has significantly improved the livelihoods of millions of dairy farmers in Gujarat and other parts of India.

2. Improvement of Dairy Farming Practices

   • NDDB provides training, technical assistance, and guidance on improving dairy farming practices, including better breeding, feeding, and management practices. This helps farmers increase milk yield and improve herd health.

   • Example: NDDB has supported artificial insemination programs, improving the genetic quality of livestock and increasing milk production.

3. Rural Employment Generation

   • By promoting dairy farming and processing, NDDB helps create jobs in rural areas, not just in dairy farming but also in milk processing, marketing, and transportation.

   • Example: The establishment of dairy processing plants and milk collection centers has generated employment for thousands of rural people.

4. Rural Infrastructure Development

   • NDDB aids in the development of rural infrastructure, such as cold storage, transportation, and milk processing facilities, which are essential for efficient dairy production and distribution.

   • Example: NDDB’s support to Operation Flood led to the establishment of rural milk collection systems, reducing post-harvest losses and improving milk distribution networks.

5. Income Enhancement for Farmers

   • NDDB’s initiatives, such as the promotion of dairy farming and the establishment of cooperative societies, help increase farmers' income by providing them with better market access and fair prices for their produce.

   • Example: The White Revolution initiated by NDDB has helped millions of dairy farmers increase their income through enhanced milk production and fair pricing.

NDDB plays a pivotal role in rural development by promoting dairy cooperatives, improving farming practices, creating rural employment, and enhancing farmers’ incomes. Its efforts have led to significant improvements in the rural economy, especially in dairy farming, benefiting millions of farmers across India.

(c) Write short notes on the following: (5 × 4 = 20 Marks)
(i) Methane inhibitors
Ans:

• Definition: Methane inhibitors are substances that reduce methane production in the rumen of livestock, particularly in ruminants like cattle, sheep, and goats.
• Purpose: These inhibitors are used to reduce the environmental impact of livestock farming by decreasing methane emissions, which are potent greenhouse gases.
• Example:3-NOP (3-nitrooxypropanol) is a commonly used methane inhibitor that has been shown to significantly reduce methane emissions in dairy cattle.
• Advantages: Reduces greenhouse gas emissions, improves feed conversion efficiency, and enhances animal productivity.

(ii) Role of rumen in feed fermentation
Ans: 

• The rumen is the first compartment of the ruminant stomach where feed fermentation occurs.

• It contains a diverse microbiota (bacteria, protozoa, fungi) that breaks down complex carbohydrates like cellulose into volatile fatty acids, which are used as energy by the animal.

• The rumen also plays a role in protein metabolism, producing essential amino acids and vitamins.

• Example: In cows, the fermentation process in the rumen helps digest fibrous plant materials like grass, which cannot be directly digested by monogastric animals.

(iii) Chemical regulation of respiration
Ans: 

• The chemical regulation of respiration involves the control of breathing rate and depth based on the levels of gases like oxygen (O₂), carbon dioxide (CO₂), and hydrogen ions (H+).
• Chemoreceptors in the carotid and aortic bodies monitor these gases. A rise in CO₂ or a drop in O₂ stimulates the chemoreceptors, triggering an increase in respiration rate.
• Example: In livestock, during physical exertion, increased CO₂ levels stimulate faster breathing to expel the excess CO₂.

(iv) Blood-brain barrier
Ans: 

• The blood-brain barrier (BBB) is a selective permeability barrier that prevents certain substances in the bloodstream from entering the brain, protecting it from toxins and pathogens.
• It is formed by tightly packed endothelial cells of capillaries in the brain, with specific transport mechanisms for nutrients like glucose and amino acids.
• Example: The blood-brain barrier prevents harmful substances such as bacteria and large molecules from entering the brain, but it can also limit the effectiveness of certain drugs in treating brain conditions.