C. Breeding

Question 1

are mating animals used to produce a purebred or a crossbreed, which is important in pig improvement to increase production. the traits of the animal could be developed or combined by practicing different breeding systems.

Answer 1

Breeding systems

Question 2

. Breeding of closely related animals.
This is done to purity the blood line of the animals since the similarity of the animals within the group is increased. Strong & weak points of the animal will be exposed under this system.

Answer 2

INBREEDING

Question 3

is not recommendable due to its negative effect on the production performance of the animal. It usually decreases vigor because it brings together the recessive genes with undesirable effects in the resulting crossbreed.

Answer 3

Continuous inbreeding

Question 4

Effects of inbreeding, if not properly done:

Answer 4

Reduction in the strength & vigor of piglets

Decrease in the number of pigs born & weaned

Decrease in the weight of piglets at birth & weaning

Sterility & abortions

Retardation of physiologic maturity
Occurrence of abnormalities (hernia, cryptorchidism)

Question 5

. A system of breeding wherein animals of the same breed are mated to each other.

Answer 5

PUREBREEDING

Question 6

. Breeding of 2 animals from different breeds.
This is practiced to combine traits of different breeds.

Answer 6

CROSSBREEDING

Question 7

Crossbreeding
This is the system recommendation for the production of market hogs for 2 important reasons;

Answer 7

To obtain hybrid vigor or heterosis (the superiority exhibit by the crossbreed individuals over the average of the parental breeds);
To bring together the desirable characteristics of the parental breeds

Question 8

Advantages of crossbreed over purebred animals;

Answer 8

Superior in terms of litter & weight at birth & at weaning
Sows are better mothers
Fast growing

Question 9

Advantages of crossbreeding:

Answer 9

1.Increased vigor & growth rate of litters
2.Large litters
Increased production efficiency to about 5 – 10%
4.Increased disease resistance

Question 10

Crossbreeding can be differentiated as follows:

Answer 10

Two-way cross mating with the use of 2 different breeds

Example: LARGE WHITE x LANDRACE or PIETRAIN x DUROC

Three-way cross mating with the use of three breeds

Example: LARGE WHITE x LANDRACE (1st cross)
DUROX x LARGE WHITE/LANDRACE (2nd cross)
DUROX/LARGE WHITE/LANDRACE (progeny)

Four-way cross-mating with the use of four different breeds

Example: PIETRAIN x DUROC LARGE WHITE x LANDRCE
PIETRAIN x DUROC x LARGE WHITE x LANDRCE
PIETRAIN/DUROC/LARGE WHITE/LANDRACE

Question 11

. A system of breeding wherein an inferior breed is improved by continued crossing.

Answer 11

UPGRADING

Question 12

Commonly used among native breeds crossed with exotic breeds of swine to improve the common stock.

In this procedure, selected female pigs are bred to purebred boars of any preferred breed. The female progenies are bred to boars of the same breed. The procedure is repeated until the resulting offspring’s approach the characteristics of the purebred.

	      Example: (female local breed)			(male purebred)
				A			X		B
				AB			X		B
				ABB			X		B
						        ABBB

Answer 12

Upgrading

Question 13

Judging of pigs can be seen as a way to ___________ can be seen on the external parts of the pig.

Answer 13

recognize and evaluate economic features which

Question 14

The removal of unwanted pigs.

It is the opposite of selection and as culling is intensified, the faster the improvement of the herd.

Answer 14

Culling

Question 15

This is done to maintain the production supply of the breed & to acquire the best available genetic material at reasonable prices.

Answer 15

Purebreeding

Question 16

. Some gilts and sows do not come into heat despite proper feeding and management. Others do not conceive after two or more mating with proven boars or boars without sex desires or cannot impregnate even a proven sow
Example: SOWS/GILTS

Answer 16

Reproductive failures

Question 17

– oviduct distened with fluid

Answer 17

Hydrosalpinx

Question 18

– oviduct distened with pus-like materials

Answer 18

Pyosalpinx

Question 19

– blind uterine body, infantilism; cystic ovaries

Answer 19

Unilateral blind uterine horn

Question 20

. Some sows have cannibalistic tendency during and after farrowing especially the first-farrowed sow

Answer 20

Poor maternal instincts

Question 21

. A sow should be able to produce milk for her litter of 8 for at least 3-4 weeks after farrowing.

Answer 21

Poor-milkers

Question 22

. Strong legs and feet are desirable to avoid breeding difficulties.

Answer 22

Feet and leg problem

Question 23

. A sow should be culled on a litter to litter performance basis. First litter performance often is not a good indication of what the next litter would be like. First farrowed gilts should be given chance. Normally, the breeding efficiency of sow starts to decline after the 6th or 7th litter.

Answer 23

Poor litter size

Question 24

. A sow is must profitable if she produces more than 2 litters a year or else she is considered as “profit eater”.

Answer 24

Long dry period

Question 25

is a vital source of nourishment for the piglets. It is highly susceptible to infection especially during lactation because of the presence of milk which is a very good medium for multiplication of infectious microorganism. Injured sections become inflamed and gangrenous and are difficult to treat.

Answer 25

Damaged udder section. The udder section

Question 26

are few of the diseases commonly associated with abortion and usually transmitted by an infected boar.

Answer 26

Diseases. Leptospirosis and Brucellosis

Question 27

. It can lower the quality of the whole herd. The most common are hernias, atresia ani and cryptorchidism.

Answer 27

Abnormalities