Class 12 Biology

Enhancement in Food Production

Animal Husbandry

The practice of breeding and raising livestock is called animal husbandry. It also includes poultry farming and fisheries.

Dairy Farm Management

Poultry Farm Management

The class of domesticated fowl used for food or for their eggs is called poultry. Poultry includes chicken, duck, and sometimes turkey and geese. Following are the important criteria for poultry farming.

Animal Breeding

Breed

A group of animals related by descent and similar in most characters are said to belong to a breed.

Inbreeding

When breeding is between animals of the same breed, it is called inbreeding. It refers to the mating of more closely related individuals within the same breed for 4 to 6 generations. The breeding strategy for inbreeding is as follows:

Superior males and superior females of the same breed are identified and mated in pairs. The progeny from such mating are evaluated and superior males and females among them are selected for further mating. This helps in developing a pure-line of breed.

Advantages of Inbreeding

It helps in eliminating harmful genes by selection. It also helps in accumulation of superior genes and elimination of less desirable genes.

Disadvantages of Inbreeding

It results in inbreeding depression; which reduces fertility and productivity. In case of problem of inbreeding depression, the population should be mated with unrelated superior animals of the same breed. This helps in restoring fertility and productivity.

Out-breeding

Breeding of unrelated animals is called out-breeding.

Out-crossing: When animals of the same breed (with no common ancestors on either side of their pedigree up to 4-6 generations) are selected for mating, it is called out-crossing. A single outcross often helps to overcome inbreeding depression.

Cross-breeding

When superior males of one breed are mated with superior females of another breed, it is called cross-breeding. This allows to combine desirable traits from two different breeds. The progeny hybrid animals may be used for commercial production. Alternately, they may be subjected to some form of inbreeding and selection to develop new stable breeds. Example: Hisardale is a new breed of sheep, developed in Punjab by crossing Bikaneri ewes and Marino rams.

Inter-specific Hybridization

When cross is done between two different species, it is called inter-specific hybridization. Mule is produced by mating of a male donkey with a female horse.

Artificial Insemination

The semen is collected from the male and injected into the reproductive tract of the selected female. The semen may be used immediately or can be frozen to be used later.

Multiple Ovulation Embryo Transfer Technology (MOET)

The success rate of crossing mature male and female animals is fairly low. To improve the chances of success, other methods are also used. MOET is one such method. In this method, a cow is administered hormones to induce follicular maturation and super ovulation. Super ovulation results in production of 6 to 8 eggs per cycle against the normal production of one egg per cycle. After that, the animal is either mated with an elite bull or is artificially inseminated. Fertilizes eggs at 8- 32 cells stage are recovered non-surgically and transferred to surrogate mothers. This frees the genetic mother for another round of super ovulation. This technology has been successfully used in many animals.

Bee-keeping

Maintenance of hives of honeybees for production of honey is called bee-keeping or apiculture. Following points are important for successful bee-keeping: