Breeding of animals is an important aspect of animal
husbandry. Animal breeding aims at increasing the yield
of animals and improving the desirable qualities of the
produce. For what kind of characters would we breed
animals? Would the selection of characters differ with
the choice of animals?
What do we understand by the term ‘breed’? A group
of animals related by descent and similar in most characters
like general appearance, features, size, configuration, etc.,
are said to belong to a breed. Find out the names of some
common breeds of cattle and poultry in the farms of your
area.
When breeding is between animals of the same breed it
is called inbreeding, while crosses between different breeds
are called outbreeding.
Improved breed of
jersey cattle
Inbreeding :
Inbreeding refers to the mating of more
closely related individuals within the same breed for 4-
6 generations. The breeding strategy is as follows – superior males and
superior females of the same breed are identified and mated in pairs.
The progeny obtained from such matings are evaluated and superior
males and females among them are identified for further mating. A
superior female, in the case of cattle, is the cow or buffalo that produces
more milk per lactation. On the other hand, a superior male is the bull,
which gives rise to superior progeny as compared to those of other
males.
. A similar strategy is used for developing purelines
in cattle as was used in case of peas. Inbreeding increases homozygosity.
Thus inbreeding is necessary if we want to evolve a pureline in any animal.
Inbreeding exposes harmful recessive genes that are eliminated by selection.
It also helps in accumulation of superior genes and elimination of less
desirable genes. Therefore, this approach, where there is selection at each
step, increases the productivity of inbred population. However, continued
inbreeding, especially close inbreeding, usually reduces fertility and even
productivity. This is called inbreeding depression. Whenever this becomes
a problem, selected animals of the breeding population should be matedwith unrelated superior animals of the same breed. This usually helps
restore fertility and yield.
Out-breeding :
Out-breeding is the breeding of the unrelated animals,
which may be between individuals of the same breed but having no
common ancestors for 4-6 generations (out-crossing) or between
different breeds (cross-breeding) or different species (inter-specific
hybridisation).
Out-crossing:
This 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 a mating is known as an
out-cross. It is the best breeding method for animals that are below
average in productivity in milk production, growth rate in beef cattle,
etc. A single outcross often helps to overcome inbreeding depression.
Cross-breeding:
In this method, superior males of one breed are mated
with superior females of another breed. Cross-breeding allows the
desirable qualities of two different breeds to be combined. The progeny
hybrid animals may themselves be used for commercial production.
Alternatively, they may be subjected to some form of inbreeding and
selection to develop new stable breeds that may be superior to the existing
breeds. Many new animal breeds have been developed by this approach.
Hisardale is a new breed of sheep developed in Punjab by crossing
Bikaneri ewes and Marino rams.
Interspecific hybridisation:
In this method, male and female animals
of two different related species are mated. In some cases, the progeny
may combine desirable features of both the parents, and may be of
considerable economic value, e.g., the mule (Figure 9.2). Do you know
what cross leads to the production of the mule? 
Mule
Controlled breeding experiments are carried out using artificial
insemination. The semen is collected from the male that
is chosen as a parent and injected into the reproductive
tract of the selected female by the breeder. The semen
may be used immediately or can be frozen and used at a
later date. It can also be transported in a frozen form to
where the female is housed. In this way desirable matings
are carried. Artificial insemination helps us overcome
several problems of normal matings. Can you discuss
and list some of them?
Often, the success rate of crossing mature male and
female animals is fairly low even though artificial
insemination is carried out. To improve chances of
successful production of hybrids, other means are also used. Multiple
Ovulation Embryo Transfer Technology (MOET) is one such
programme for herd improvement. In this method, a cow is administered
hormones, with FSH-like activity, to induce follicular maturation and super
ovulation – instead of one egg, which they normally yield per cycle, theyproduce 6-8 eggs. The animal is either mated with an elite bull or
artificially inseminated. The fertilised eggs at 8–32 cells stages, are
recovered non-surgically and transferred to surrogate mothers. The genetic
mother is available for another round of super ovulation. This technology
has been demonstrated for cattle, sheep, rabbits, buffaloes, mares, etc.
High milk-yielding breeds of females and high quality (lean meat with
less lipid) meat-yielding bulls have been bred successfully to increase
herd size in a short time.
Bee-keeping
Bee-keeping or apiculture is the maintenance of hives of honeybees for
the production of honey. It has been an age-old cottage industry. Honey
is a food of high nutritive value and also finds use in the indigenous
systems of medicine. Honeybee also produces beeswax, which finds many
uses in industry, such as in the preparation of cosmetics and polishes of
various kinds. The increased demand of honey has led to large-scale beekeeping
practices; it has become an established income generating
industry, whether practiced on a small or on a large scale.
Bee-keeping can be practiced in any area where there are sufficient
bee pastures of some wild shrubs, fruit orchards and cultivated crops.
There are several species of honeybees which can be reared. Of these, the
most common species is Apis indica. Beehives can be kept in one’s
courtyard, on the verandah of the house or even on the roof. Bee-keeping
is not labour-intensive.
Bee-keeping though relatively easy does require some specialised
knowledge and there are several organisations that teach bee-keeping.
The following points are important for successful bee-keeping:
(i) Knowledge of the nature and habits of bees,
(ii) Selection of suitable location for keeping the beehives,
(iii) Catching and hiving of swarms (group of bees),
(iv) Management of beehives during different seasons, and
(v) Handling and collection of honey and of beeswax. Bees are the pollinators
of many of our crop species (see chapter 2) such as sunflower, Brassica,
apple and pear. Keeping beehives in crop fields during flowering period
increases pollination efficiency and improves the yield–beneficial both
from the point of view of crop yield and honey yield.
Fisheries
Fishery is an industry devoted to the catching, processing or selling of fish,
shellfish or other aquatic animals. A large number of our population is
dependent on fish, fish products and other aquatic animals such as prawn,
crab, lobster, edible oyster, etc., for food. Some of the freshwater fishes which
are very common include Catla, Rohu and common carp. Some of the marine
fishes that are eaten include – Hilsa, Sardines, Mackerel and Pomfrets.
Find out what fishes are commonly eaten in your area.Fisheries has an important place in Indian economy. It provides income
and employment to millions of fishermen and farmers, particularly in the
coastal states. For many, it is the only source of their livelihood. In order
to meet the increasing demands on fisheries, different techniques have
been employed to increase production. For example, through aquaculture
and pisciculture we have been able to increase the production of aquatic
plants and animals, both fresh-water and marine. Find out the difference
between pisciculture and aquaculture. This has led to the development
and flourishing of the fishery industry, and it has brought a lot of income
to the farmers in particular and the country in general. We now talk about
‘Blue Revolution’ as being implemented along the same lines as ‘Green
Revolution’.
