Strategies for Enhancement in Food Production  Important Questions for CBSE Class 12 Biology Animal Husbandry

1.Animal husbandry is the agricultural practice of breeding and raising livestock. It deals with the care and breeding of livestock like buffaloes, cows, pigs, horses, cattle, sheep, goat, etc. It also includes poultry farming and fisheries. More than 70%*of the world’s livestock population is in India and China. Many new teclsncdogies have also been applied to achieve improvement in quality and productivity.

2. Methods to improve quality and quantity in animal husbandry are:
I. Management of Farms and Farm Animals
(i) Dairy farm management is the management of animals for milk and its products for human consumption.
(a) It deals with processes and systems to improve quality and quantity of milk.
(b) Milk yield depends mainly on the quality of breeds in the farm.
(c) Dairy farm management processes include:
• Selection of good breeds having high yielding potential and resistance to the
diseases.

  • Cattle should be housed-well, should have sufficient water and should be kept in disease-free conditions.
  • They should be fed in a scientific manner, with good quality and quantity of fodder.
  • Stringent cleanliness and hygiene ©f both the cattle and thehandler* are very important, during milking, storage and transport of milk and its products.
  • Regular inspection and keeping proper records of ail the activities of’dairyis also mandatory.
  • Regular visits of a veterinary doctor is necessary.

(ii) Poultry farm management includes the management of poultry which i& the class of domesticated fowl (birds) used for food or for their eggs. It includes chicken, ducks, Turkey and geese.
The poultry farm management includes following processes:

  • Selection of disease-free and suitable poultry breeds.
  • Housing should be proper and safe.
  • Proper food and water should be provided.
  • Health care and hygiene of poultry is mandatory.

II. Bee-keeping or apiculture is the maintenance of hives of honeybees for the large
scale production of honey and beewax. The excessive demand of honey for its nutritive value and bees wax for cosmetics, etc., led to the large scale bee-keeping practices. Bee-keeping can be practiced in any area, where there are sufficient bee pastures of wild shrubs, fruit orchards and cultivated crops. It is not labour-intensive.
There are several species of honeybees, but most common species reared by bee-keepers is Apis indica.
The important points for successful bee-keeping are:

  • Knowledge of the nature and habits of bees.
  • Selection of suitable location for keeping the beehives.
  • Catching and hiving of swarms (group of bees).
  • Management of beehives during different seasons.
  • Handling and collection of honey and beeswax.
  • Keeping beehives in crop fields such as sunflower, Brassica, apple and  pear  during following  period increases pollination efficiency and improves the yield,both crop yield and honey yield.

III. Fishery is an industry, which includes catching, processing or selling of fish, shellfish and other aquatic animals like prawn, crab, lobster, edible oyster, etc…
(i) The common freshwater fishes are catla, rohu and common carp.
(ii) Some of the marine fishes that are eaten include Hilsa, Sardines, Mackerel and
pomfrets.
(iii) Fisheries provides income and employment to millions of fishermen and farmers,
especially in coastal states in Indian economy.
(iv) To meet the increasing demand on fisheries, different techniques like aquaculture and pisciculture are applied.
(v) Blue revolution is the movement launched to increase the production of fish and fish products. It is being implemented in the same lines as green revolution.

IV. Animal breeding is an important part of animal husbandry. It aims to increase the yield of animals and improve the desirable qualities of produce.

  • A breed is a group of animals related by descent and similar in most characters like general appearance, features, size, configuration, etc.
  • Breeding can be divided as given iii the chart below:

important-questions-for-class-12-biology-cbse-animal-husbandry-image 1jpg_Page1
(a) Inbreeding refers to the mating between closely related individuals within the same breed for 4-6 generations.
The strategies for inbreeding are as follow:

  • Identifying superior males and females of the same breed. They are mated in pairs.
  • Evaluation of progeny obtained from the above mating to identify superior males and females among them.
  • A superior female, in case of cattle, is the cow or buffalo that produces more milk per lactation. A superior male is bull, which gives rise to superior progeny as compared to other males.

Effects of inbreeding are:

  • It is used to evolve a pureline (inbreeding increases homozygosity).
  • Harmful recessive genes are exposed by inbreeding, which are then eliminated by the selection.
  • Superior genes can be accumulated by inbreeding, the undesirable genes.
  • Productivity of inbreed population is increased by selection at every step.
  • Continued inbreeding reduces fertility and even productivity. This is called  inbreeding depression.
  • In this case, selected animals of the breeding population are mated with unrelated superior animals of the same breed. This helps to restore fertility and yield.

(b) Outbreeding is the breeding of unrelated animals, either of the same breed but not having common ancestors for 4-6 generations (out-crossing) or of different breeds (cross-breeding) or even different species (interspecific hybridisation).

It can be of the following types:

  • Out-crossing is the practice of mating of animals, within the same breed, but having no common ancestors on either side of their pedigree up to  4-6 generations.

-The offspring of such mating is called an out-cross.

-It is done to increase milk production, growth rate in cattle’s beef, etc.
-A single out cross helps to overcome inbreeding depression

  • Cross-breeding refers to the mating of superior males of one breed with superior females of another breed.

-It helps in accumulate desirable qualities of two breeds into progeny.

-The progeny may be used for commercial production themselves.
-A new sheep breed, Hisardale is developed in Punjab by crossing Bikaneri Ewes and Marino Rams.

  • Interspecific hybridisation refers to crossing between male and female animals of two different related species.

-Progeny may combine desirable features of both the parents.

-Progeny may be of considerable economic value.
-Example of interspecific hybridisation, is a Mule obtained by crossing a male donkey with a female horse.
(c) Artificial insemination is a method of controlled breeding. The semen from selected male parent is injected into the reproductive tract of selective female parent.

  • Its advantages are as follow:

-Helps to overcome problems related to normal mating.

-Semen can be stored and frozen for the later use.

  • The disadvantage is its fairly low success rate

V. Multiple Ovulation Embryo Transfer (MOET) Technology is a programme for herd improvement.

(i) The method includes following steps:

  • A cow is administered with hormones FSH-like activity, to induce follicular maturation and superovulation.
  • The cow produces 6-8 eggs instead of one egg, normally released per cycle.
  • A cow is now mated with an elite bull or artificially inseminated.
  • The fertilised eggs at 8-32 celled stages are recovered non-surgically and transferred to surrogate mothers.
  • The genetic mother can again be used for superovulation.

(ii)This technology is used for cattle, sheep, rabbits, buffaloes, mares, etc.

(iii) High milk-yielding breeds of females and high quality (lean meat with less lipid) meat-yielding bulls have been bred successfully to increase the herd size in a short time.

Previous Years  Examination Questions

1 Mark Questions
1. Write a professional approach at  genetic level that can help the farmer to improve the milk yield of low milk producing cows in his farm.
[Delhi 2013C]
Ans. Out-crossing is the professional approach which will help the farmer to improve milk yield of low milk producing cows.

2. Write the name of the following
(i)The most common species of bees suitable for apiculture.
(ii) An improved breed of chicken.  [All India 2012]
Ans. (i)  Apis indica is the most common species  of bees for apiculture.
(ii) Leghorn is an improved chicken breed.

3. Which one of the following is used  in apiculture Hilsa, Apis indica, Sonalika?                         [Foreign 2009]
Ans. Apis indica.

4.Mention the strategy used to  increase homozygosity in cattle for desired traits.       [All India 2009]
Ans. Inbreeding is the strategy used to increase  homozygosity. It refers to mating of more closely related individuals of the same breed for 4-6 generations.

5. List any two economically important products for human obtained from Apis indica.  [Delhi 2008]
Ans. Honey and beewax are two economically  important products obtained from Apis indica.

2 Marks Questions
6. State the disadvantage of  inbreeding among cattle. How it can be overcome? [Delhi 2014]
Ans. Continued inbreeding among cattles  reduces their fertility as well as productivity, resulting in inbreeding depression.It can be overcome by a single outcross, done by mating of cattle within the same breed, having no common ancestors of their pedigree upto 4-6 generations.

7. Explain the importance of  inbreeding in cattle.                             [2014c]
Ans.  The importance of inbreeding in cattle are:
(i) It increases homozygosity and evolve a pureline.
(ii) Accumulation of superior genes and elimination of less desirable genes by selection.

8. Differentiate between out-crossing  and cross-breeding.  [2014c]
Ans.Differentiate between out-crossing  and cross-breeding.
important-questions-for-class-12-biology-cbse-animal-husbandry-t1-2mq-8jpg_Page1

9. Study the flow chart given below:
important-questions-for-class-12-biology-cbse-animal-husbandry-t1-2mq-9jpg_Page1

  • Identify the events that take place at stages A’and ‘B’,
  • State the importance of the technology explained above.  

 [Foreign 2011]
Ans. (i) (A) The hormone induces follicular  maturation and superovulation, i.e. production of 6-8 eggs per cycle.
(B) Fertilised eggs are recovered and are  transferred to surrogate mother.
(ii) The technology is called MOET that is used to increase the herd size by mating high milk yielding breed of females with high quality meat yielding bulls.

10. How is a pureline in an animal  raised? Explain.  [Delhi 2011c]
Ans.  Pureline in an animal is raised by inbreeding as it increases homozygosity.
(i) Mating of more closely related  individuals within same breed for 4-6 generations is called inbreeding.
(ii) In this process, superior males and superior females of same breed are identified and mated in pairs.
(iii) The progeny obtained from such matings are evaluated and superior males and females among them are identified for further matings.

11. How does inbreeding depression set in? Mention the procedure you would suggest to reverse this.  [All India 2011C]
Ans.Inbreeding depression sets in when there iscontinued and close inbreeding. It reduces fertility and productivity. Whenever, this becomes a problem, selected animals of breeding population should be mated with unrelated superior animals of the same breed. This out cross helps in restoring fertility and yield and overcome inbreeding depression.

12. Honey collection improves, when beehives are kept in crop-fields during flowering season. Explain.  [Delhi 2010]
Ans. During flowering season, the honeybees  visit a number of flowers in search of edible pollen and nectar. Since, they collect nectar from a large number and variety of flowers, honey collection improves both in quality and quantity.

13. MOET programme has helped in  increasing the herd size of the desired variety of cattle. List the steps involved in conducting the programme. [All India 2009]
Ans.Steps involved in MOET programme ere:
(i) A cow is administered hormones with ‘ FSH-like activity to induce follicular maturation and superovulation.
(ii) The cow produces 6-8 eggs instead of one egg produced normally.
(iii) Mating is done either with an elite bull or artificial insemination is carried out.
(iv) When the fertilised eggs attain 8-32 celled stage, they are non-surgically removed and transferred to a surrogate mother.
(v) The genetic mother can be again  superovulated now.

14. List any four important components of poultry farm management.
[Delhi 2009]
Ans.Important components of poultry farm management are:
(i) Selection of disease-free and suitable breeds.
(ii) Proper and safe conditions of farm.
(iii) Proper food (feed) and water should be provided.
(iv) Hygiene and health care of birds is mandatory.

15. Give the scientific name of mostcommon species of honeybee reared in India. Why is it advantageous to keep beehives in crop-fields during flowering periods.  [Delhi 2009c]
Ans.Most common honeybee species reared in India-Apis indica.

During flowering season, the honeybees  visit a number of flowers in search of edible pollen and nectar. Since, they collect nectar from a large number and variety of flowers, honey collection improves both in quality and quantity.

3 Marks Questions
16. Why are beehives kept in a crop  field during flowering period? Name any two crop fields where this is practised.             [Delhi 2014]
Ans.During flowering period, beehives are kept in a crop field so as to increase the efficiency of pollination since, bees are pollinators. It also improves the yield and quality of honey and crops as well as, honeybees visit and collect nectar from a large number and variety of    flowers.
The two Crop-fields, where bee-keeping is  practised are those of Brassica and apple.

17. (i) What is the programme called,  that is involved in improving success rate of production of desired hybrid and herd size of cattle?
(ii) Explain the method used for carrying this programme for cows.
[All India 2012]
or
Describe the technology that has successfully increased the herd size of cattle in a short time to meet the increasing demands of growing human population.           [All India 2011]
Ans.(I) Multiple Ovulation Embryo Transfer (MOET) Technology.
(II)  Steps involved in MOET programme ere:
(i) A cow is administered hormones with ‘ FSH-like activity to induce follicular maturation and superovulation.
(ii) The cow produces 6-8 eggs instead of one egg produced normally.
(iii) Mating is done either with an elite bull or artificial insemination is carried out.
(iv) When the fertilised eggs attain 8-32 celled stage, they are non-surgically removed and transferred to a surrogate mother.
(v) The genetic mother can be again  superovulated now.

18. What is inbreeding depression and how is it caused in organism? Write any two advantages of inbreeding.[Delhi 2011]
Ans.  Inbreeding refers to mating between closely
related individuals within the same breed for p  4-6 generations. It usually results in reductionof fertility and productivity, when continued  for longer time. This is called inbreeding  depression.
Advantages of inbreeding are:
(i) Increases and evolves a pureline.
(ii) Recessive genes are exposed by inbreeding which can then be eliminated by selection.

19. (i) Write the scientific name of most  common species of honey bee reared.
(ii)Mention the kind of areas that are suitable for bee-keeping practices.
(iii) Mention any two uses of beewax.  [Delhi 2011C]
Ans.  (i) Apis indica.
(ii) It can be practiced in any area, where there are sufficient bee pastures of some wild shrubs, fruit, orchards and cultivated crops.
(iii)  Beewax is used in the preparation of cosmetics and polishes of various kinds.

20. What is ‘blue revolution’? Name two  freshwater and two marine edible fishs.                 [All India 2011C]
Ans.‘Blue revolution’ is the movement  launched to increase the production of fish and fish products.
Freshwater fishes are Rohu and catla.
Marine water fishes are Hilsa and Sardines

21. Explain the efforts, which must be  put in, to improve health, hygiene and milk yield of cattle in dairy farm.         [Delhi 2010]
Ans.To improve health, hygiene and milk yield of cattle in dairy farm
(i) They have to be housed well in proper, well-ventilated sheds.
(ii) Cleanliness and hygiene of both the cattle and the handlers are important.
(iii) Regular visit of veterinary doctor is necessary.
(iv) The feeding should be carried out in a scientific manner with special emphasis on quality and quantity of fodder.
(v) Breeding may be necessary for improving the milk yield and to make it disease resistance.

22. List any three outbreeding practices  carried out to breed domestic animals. Explain the importance of each one listed.   [Delhi           2010c]
Ans.Out breeding refers to the crosses between different breeds.
It is of following types:
(i) Out-crossing It is a practice of mating of animals of same breeds, having no common ancestors on either side of their pedigree for 4-6 generations.
A single out cross helps to overcome inbreeding depressions.
(ii) Cross-breeding In this method, superior male of one breed are mated with superior females of another breed.
This helps in combining the desirable qualities of two different breeds into the progeny.
(iii) Interspecific hybridisation In this method, male and female animals of two different related species are mated to combine the desirable features of both the parents into one, e.g. Mule is produced by a cross between male donkey and female horse.

23. (i) Inbreeding is advantageous as  well as disadvantageous. Explain.
(ii)  Differentiate between inbreeding and outbreeding. [Delhi 2010c]
Ans.  Advantages of inbreeding are:
(a) It increases and evolves a pureline.
(b) Recessive genes are exposed by inbreeding, which are then eliminated by selection.
(c) Superior genes can be accumulated by inbreeding and thereby eliminating undesirable genes.
(d) By selection at every step, productivity of inbreed population is increased. Disadvantage of inbreeding is that close inbreeding leads to the reduction of fertility and productivity. This is due to inbreeding depression.
(ii) Difference between inbreeding and outbreeding is:
important-questions-for-class-12-biology-cbse-animal-husbandry-t1-3mq-23jpg_Page124. Explain the advantages of inbreeding in cattle population. What effect does inbreeding depression have on cattle population and how is it overcome?[Foreign 2008]
Ans.  Advantages of inbreeding in cattle population are:
(i) It increases homozygosity, hence evolve a pureline.
(ii) It helps in the accumulation of superior genes and elimination of less desirable genes.
(iii) It exposes harmful recessive genes and their elimination by selection.
Effects of inbreeding depression are:
(i) When continued over a long period of time, it reduces the fertility and over productivity of animals.
(ii) Inbreeding depression can be overcome by out-crossing, i.e. mating of selected animals with unrelated superior animals  of same breed. It helps to restore the  fertility and yield in the cattle.

25. Out-crossing and cross-breeding are two breeding practices in animal husbandry. How are the two practices different from each other and what advantages are they do to the breeders? Explain. [All India 2008C]
Ans.Differentiate between out-crossing  and cross-breeding.
important-questions-for-class-12-biology-cbse-animal-husbandry-t1-2mq-8jpg_Page1Advantages of out-crossing
(i) It is the best method for animals that are below average in productivity in milk production, growth rate, etc. It helps to overcome inbreeding depression.
Advantages of cross-breeding
(i) It allows the desirable qualities of two different breeds to be combined in a single progeny.
(ii) Progeny may be used for commercial production.
(iii) Many new breeds have been developed by this approach, i.e.  Hisardale.

 5 Marks Question
26. (i) State the objective of animal  breeding.
(ii) List the importance and limitations of inbreeding. How can the limitations be overcome?
(iii) Give an example of a new breed each of cattle and poultry.
[All India 2014]
Ans.(i)The main objective of animal breedingis to increase the yield of animals and
improve the desirable and superior  qualities in both the animals and theirproducts.
(ii) Importance of Inbreeding-
Differentiate between out-crossing  and cross-breeding.
important-questions-for-class-12-biology-cbse-animal-husbandry-t1-2mq-8jpg_Page1
Limitations of Inbreeding Thecontinued inbreeding in animals forsubsequent generations reduces theirfertility and productivity, resulting in condition called inbreeding depression.
The inbreeng depression can be  overcome by a single outcross,  i.e. mating between animals of same  breed having no common ancestors up  to 4-6 generations.
(iii) An example of new breed of cattle   is  Hisardale and that of poultry is new  hampshire.

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