LIVESTOCK PRODUCTION III (SELECTION AND BREEDING)

This topic entails:

• Reproduction and reproductive systems
• Cattle
• Poultry
• Selection in cattle ,sheep ,goats ,pigs and camels
• Meaning
• Factors to consider in selecting a breeding stock
• Methods of selection
• Mass selection
• Contemporary comparison
• Progeny testing
• Breeding and breeding systems
• Identification of livestock on heat/signs of heat
• Description of methods used in serving livestock.
• Signs of parturition in cattle ,pigs and rabbits

1. What does the term ‘epistasis’ mean in livestock improvement?

• The combination of genes which individually could have been undesirable or inferior. In this way the effect of some recessive genes are masked such that they cannot be expressed.

 

2. What is upgrading as used in livestock production?

• A type  of mating  where  the female of  low grade  is  mated  to a pure  bred sire of  superior  quality

 

3. Differentiate between crutching and ringing in livestock management

• Crutching is the cutting of wool around the vulva of sheep while ringing is the trimming of wool around the penis sheaths of rams.

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4. State the gestation period of the following farm animals
5.  a) Pigs

• 112 – 117 days/3months 3weeks 3days

 

1. b) Rabbits

• 28 – 32 days

 

1. c) Cow

• 270 – 285 days

 

5. What is selection in live stock production

• It is the process of allowing certain animals to be the parents of the future generations while culling others

 

6. State three methods used in selection of livestock

• Mass selection
• Progeny testing
• Contemporary comparison

 

7. Outline two characteristics of livestock that are used in mass selection

• Age of the animal
• Size/weight of an animal
• Physiological condition of an animal
• Production level of the animal

 

8. Give four advantages of contemporary comparison as a method of selection in livestock breeding.

• Possible to compare animals of different age groups since heifer locations are used.
• It eliminates differences brought about by the environment since average performance of the herd is used
• It is possible to make direct comparison of bulls at different A.I centres since environmental differences are removed.
• It is accurate.

9. Give four signs of heat observed on female rabbit

• Frequent urination.
• Swollen vulva.
• The doe throws itself on its side.
• She (doe) rubs herself against the wall or any other solid object.
• The doe tries to contact other rabbits in the next hutch by peeping through the cage walls.

 

10. State four reasons for culling a breeding boar

• Boar is infertile/lacks libido
• Loss of sight, limb, cannot mate
• Old age
• Poor health/Perpetual sickness
• Reproductive diseases
• Boar is too fat and lazy
• Develops bad temperament/Aggressiveness/wildness
• Avoid inbreeding

 

11. Describe five factors to consider when selecting a breeding boar

• High libido
• Fertile
• Free from hereditary defects
• High feed conversion ratio
• Fast growing rate
• Good body conformation
• Free from physical defects
• Suit environment conditions
• Should be mature
• Should be healthy

 

12. Describe the factors a farmer would consider when selecting a young female pig (gilt) for breeding.

• Good body conformation of the gilt.
• Lack of physical defects
• Have 12-14 teats
• Prolificacy of gilt from records of the parent /ancestors
• Healthy, without history of many diseases
• Fast growth rate/fast maturing
• Ability to withstand stresses
• Good mothering ability from record of parents
• Age
• Temperament of behaviour
• Adaptability

 

13. Define the following terms as used in livestock breeding
14. Heterosis

• Increased vigour/ performance resulting from mating two superior unrelated Breeds

1. Epistasis

• The combination of genes which individually could have been undesirable or inferior. In this way the effect of some recessive genes are masked such that they cannot be expressed.

 

14. State two advantages of natural mating

• Accurate hence high conception rates.
• Less laborious
• Useful in silent heat

                                                                                                        

15. State three disadvantages of natural methods of mating in cattle breeding

• A lot of semen is wasted
• High chances of inbreeding
• Large males can injure small females
• Expensive to transport bull over long distance
• May need extra pasture, extra cost/Keeping males increase costs of production
• Encourages transmission of breeding diseases
• Few cows can be mated by one bull
• Keeping breeding records is difficult
• Spread of external parasites
• Risky to keep aggressive bulls

 

16. a) What is out crossing?

• Mating unrelated animals within the same breed.

 

1. b) Give four disadvantages of outcrossing

• Harmful characteristics can be spread quickly by one bull to the offspring the bull sires.
• It requires skilled labour
• Low chances of conception because semen can die due to problems in storage and transportation/by wrong timing in respect to heat periods.
• It requires more labour than natural service i.e. taking the cow to insemination centre and checking for heat signs.

 

17. Distinguish between inbreeding and out crossing in livestock production

• In breeding is mating closely related animals whereas out crossing is mating animals within the same breed.

 

18. Differentiate between out crossing and cross- breeding

• Out crossing – Mating of distantly related animals of the same breed.
• Cross- breeding – Mating of animals of different breeds.                              

 

19. How does crossbreeding improve livestock production

• By concentrating genes from the parents to the offspring’s

 

20. State three advantages of cross-breeding in livestock production.

• Improves quality of offspring due to heterozygosity
• Introduces new genes into the herd
• Offsprings perform better than parents
• Offsprings combine traits from parents leading to high performance
• A quick method of producing the required animal
• Offsprings can adapt well to different environments.

 

21. Outline ten factors considered when selecting dairy cattle for breeding

• age-young animals have  longer  productive live and are more productive and economical to keep than old animals
• level of performance-animals  with highest production level  be kept
• health-consider animals which are less susceptive to  disease
• body confirmation  go  for ones well people dairy characteristics
• temperature/behaviour select only decline animals which are easy to  handle mothering ability
• adaptable under suitability to  the environment
• prolificacy- ability to give  birth to  many  off springs at a time
• physical defects
• quality of products

 

 

22. Describe the factors to consider when selecting a breeding stock.

• Adaptability of breed to climate or area/ local ecological conditions
• Production level – use the production level record of the parents and other contemporaries.
• Physical fitness – select animals without any defects like extra teats for dairy animals.
• Health – select disease free animals because their health determines their fertility, longevity and fecundity.
• Body conformation to type of livestock. For example, for dairy cows, select those with wedge shaped body, well sprung ribs, well set hind quarters and large udder.
• Temperament – the selected animals should be docile.
• Quality of products-select animals with good quality product
• Mothering ability incase of females – select animals with good instinct of taking care of their young ones up to weaning.
• Prolifically – is used to denote whether many or few off springs result from a given mating or from a certain individual female during its lifetime.
• Breeding efficiency – measures the reproducing ability of an adult animal. The breeding efficiency depends on the number of services per conception, the percentage of non-returns, length of the calving interval and pregnancy period
• Fertility – should be fertile
• Offspring performance should be good
• Age of animal – young not given birth more than 3 times
• Disease resistance

 

23. Name the type of breeding system represented below
    • Ayrshire sire x Boran Dam          F₁ heifer x Hereford

• Upgrading/ grading up

                                                           

24. State two reasons for breeding livestock.

• Introduces new genes hence increasing productivity
• For economic reasons; livestock with high growth rates mature faster thus cheap to produce.
• Expands inherited potential of the animal.
• Satisfy consumers’ taste
• Overcome production problems caused by environment such as diseases, pests and adverse climatic conditions

 

25. State two signs of farrowing in pigs.

• Enlargement of vulva
• Loss of appetite
• Restlessness
• Slackening of muscles on each side of the tail
• Udder and teats become enlarged
• Presence of milk in teats
• Sow collects litter at one corner to build a nest.

 

26. Describe the procedure of embryo transplant using non-surgical method

• Remove embryo by flooding the uterus with a liquid media
• Massage the uterus to dislodge the embryo the uterine lumen to flow out with the solution
• Withdraw solution containing the uterus using a tube to a syringe
• Syringe taken to the lab where the fertilized ova are selected and separated under high powered microscope
• Recipient cow is then restrained anaesthetized and shaved on the area of operation
• Incision made in the left flank to allow horn of uterus to be pulled out
• Fertilized ovum inserted into the uterus using a pipette or syringe, through the tiny hole in the uterine wall
• Pipette checked under microscope to ensure that the transplant is complete
• Uterine horn retracted to its position

 

27. The diagram below illustrates the reproductive system of a farm animal. Study it and answer the questions that follow
28. Name the parts labeled A, B, C and D

• A- Oviduct B-Ovary
• C- Uterus D- Vagina

 

1. State the functions of the parts labeled A and B

• A-Passage of ova / female sex cells

                  -Site of fertilization

• B-Production of ova

                 -Production of female sex hormones

 

1. c) Give four signs of Oestrus in cows

• Restlessness
• Frequent mooing /bellowing
• Frequent urination
• Jelly-like mucus discharge from vulva
• Mounting other animals
• Stands still when mounted
• Loss of appetite
• Drop in milk production

 

28. Give two signs that would show that a doe is just about to give birth.

• Plucking off fur to line up the nest
• Making nest

 

29. Give the breeding system involved in each of the following cases

(a) Friesian sire mated with Ayrshire dam.

• Cross breeding

 

(b) Friesian sire (father) mated with Friesian dam (daughter)

• Inbreeding

                                                                          

30. a) What is hybrid vigour?

• Improved performance resulting from mating two unrelated superior breeds

 

(b) Give three ways in which an animal will express hybrid vigour

• Increase in growth rate
• Increase in production
• Increased fertility
• Improved body conformation

                                                           

31. Study the diagram of an oviduct of a hen and answer questions that follow:

 

 

1. Name the parts marked A, B, C, and E.

A- Ovary

B- Infundibulum/oviduct/fallopian tube

C- Magnum

E- Shell gland/uterus

 

1. b) Describe two changes that occur on the yolk from part B to E.

B-(Infundibulum)

• Fertilization occurs here
• Addition of Chalaza

C-(Magnum)

• Addition of albumen
• Addition of water and salts

D-(Isthmus)

• Addition of Albumen
• Addition of water minerals and vitamins
• Formation of shell membranes

E-(Shell gland/ uterus)

• Addition of water and salts
• Shell pigments are added
• Formation of egg shell

 

1. c) Give two functions of isthmus in female bird

• Shell membranes formed/ determines shape of egg
• Water mineral salts and vitamins added

 

32. State four disadvantages of inbreeding

• Leads to decline in fertility of animals
• Leads to high rate of prenatal mortality/Increase embryonic mortality/abortion
• Reduces disease resistance ability
• Increase in embryo mortality / abortion
• Reduce vigour / becomes weak/ heterosis
• Reduce yield / performance

 

33. Differentiate between artificial insemination and embryo transplant

• I is the introduction of semen into the female reproductive tract by hand using syringes or tubes while Embryo transplant is where ova (eggs) are harvested from a female animal (donor) fertilized in test tubes and then embryo’s that develop are transplanted into foster mothers(recipient)

34. a) Define Raddling in sheep management

• Is the practice of fitting the rams with breeding chutes on the underside which are painted with colours during breeding

 

1. b) State two reasons for raddling.

• Used to identify rams which have mated.
• Helps to identify ewes that have been mated.
• Helps to identify fertile rams.

 

35. The diagram below shows reproductive system of a hen. Study it and answer the Questions that follow.
36. a) State one component added to the egg during formation at regions A and B.

• A-Chalazae are added
• B-shell is added round the egg.

 

1. b) What happened if blood spot drops at the part labelled A.

• The blood spot will be added to the egg contents during egg formation.

 

36. Give two advantage of embryo transplant in livestock breeding

• Improves performance / production
• Stimulates milk production in a female that was not ready to produce milk.
• Easier to transplant embryos in test tube than the whole animal
• Embryo can be stored for a long time awaiting a recipient female
• Highly productive female animal can be spread over a large area to benefit many farmers
• It is possible to implant embryo from a high quality female to less valuable female and hence improve the performance of the offspring
• Calf produced gains passive immunity to local diseases from mother.

 

37. List three disadvantages of embryo transplant.

• Expensive
• Requires highly skilled labour
• Require special equipment for fertilization & storage
• If the uterus of the animals to receive the embryo is not ready implantation will not occur

 

38. A cow gives birth to two offsprings in a period of three years. One offspring is a male named Chemosi and another, female named Lelkina.  Two years later Chemosi is mated to Lelkina and another offspring, called Daisy is given birth to.
39. i) Identify the specific system of breeding between Chemosi and Lelkina.

• Inbreeding

 

(ii) Give four disadvantages of such a system of breeding)

• Leads to loss of hybrid vigour
• May lead to decline in fertility leading to species extinction
• Reduce disease resistance.
• Bring reduction in performance.
• Leads to high rate of pre-natal mortality/High embryonic mortality.

 

39. Differentiate between the terms tupping and crutching as used in sheep management

• a)Tupping
• Removal of wool around the anus, vulva and udder in preparation for  lambing

 

• b) Crutching
• Removal of dung massed wool around the anus and vulva in preparation for mating.

 

40. State four signs of infertility in a dairy cow

• No heat signs
• The cow has irregular heat period
• The cow has prolonged heat signs
• It produces abnormal discharges from the reproductive organs
• The cow does not conceive after several services.

 

41. Give four causes of infertility in cattle

• Damaged uterus due to abortion, injury, infection.
• Infections by venereal diseases e.g. virginities, brucellosis
• Retained placenta after birth causing infections
• Blocked fallopian tubes due to infections.
• Lack of essential nutrients/elements e.g. Vitamin E, manganese, selenium
• Freemartin, a heifer born twin with a bull is 90% infertile.
• Hormonal failure/imbalance.                                                              

 

42. Give two reasons why teaser rams are introduced to a flock of ewes some weeks before tupping

• To induce heat /synchronize ovulation in ewes
• To accelerate ovulation

 

43. Suggest two factors that can lead to conception failure after the females have been served.

• Poor nutrition (flushing)
• Poor timing of service
• Infertility of either bull or the female

44. Give four disadvantages of using artificial insemination (A.I) in serving a cow

• Collecting / storing and administering semen is labour intensive and time consuming.
• Require skill / trained personnel
• Not feasible in areas not easily accessible by A.I offices.
• Poor detection of heat / oestrus period may lead to failure in administering A.I
• Harmful traits/diseases can spread fast.
• Low chances of conception due to poor timing/death of sperms.

 

45. Give two reasons why artificial insemination is not popularly used as a mating system in pigs

• Difficult to note heat signs
• It requires long time for maximum fertilization of eggs
• Difficult to preserve the semen while viable for long

 

46. Describe five advantages of artificial insemination in livestock breeding.

• Semen of one bull can serve many cows
• Controls the transmission of breeding diseases
• Eliminates fighting and injury during mating
• Eliminates the expenses of keeping a bull as regards feed drugs
• Semen can be stored for long period of time.
• controls unwanted breeding on the farm eg inbreeding
• enables correct keeping of breeding records on the farm
• An effective research tool on the farm.
• Small scale farmers who cannot afford superior bulls get their cows served at low costs.
• Eliminates problems of bull specializing in one cow only .
• Timely breeding.

47. State four desirable characteristics to be considered when selecting heifer for milk production

• Docile/mild temperament
• High milk production records from ancestors
• Free from physical deformities
• Good health
• Good size/weight for the breed.

 

48. State two reasons for culling breeding sows.

• old age
• low fertility/production
• difficulty in furrowing
• Less milk/Agalactic
• When offspring shows bad traits e.g. umbilical hernia, atrophic rhinitis.
• Poor health/ chronic diseases/ serious injuries.
• Poor mothering ability e.g. lying on young ones, refusing to suckle the young one(s)

 

49. Give four methods that can be used to improve local breeds of livestock.

• Cross breeding
• Back crossing
• Grading up/ up grading
• Control of parasites and diseases
• Proper feeding of animals
• Proper housing

 

50. State four signs of heat in pigs(sow)

• Restlessness
• Frequent urination
• Swelling and reddening of vulva
• Clear or slimy mucus discharge from vulva
• Responds positively to riding test.
• Frequent mounting others.
• Sow mounts other pigs and allows others to amount it
• Loss of appetite
• Produces grunting noise
• Sow tries to reach out to other pigs in adjacent pens.

 

51. Explain the meaning of the following terms.
52. Epistasis-The combination of genes which individually could have been undesirable or inferior. In this way the effect of some recessive genes are masked such that they cannot be expressed.

(b) Hybrid vigour –is the increased ability and performance of the offspring above the average of the two unrelated parents or one of the parents.

 

52. State three signs of parturition in cows.

• Restlessness/ Cow lies down frequently
• Loss of appetite
• Enlargement of udder
• Enlargement of vulva/ Swollen vulva
• Cow isolates herself from the rest of the herd.
• Pelvic muscles relax.
• Mucous discharge from the vulva
• Presence of thick milk if teats are squeezed/pressed/ Presence of Colostrum in teats
• Relaxation of pelvic muscles/Slackening of pelvic muscles or relaxing of hip muscles
• Full and distended udder
• Water bag appears which may burst.

 

53. Outline four objectives of livestock breeders

• Increase resistance to diseases
• Increase tolerance to pests
• Adapt animal to local environment.
• Increase productivity
• Increase prolificacy
• Enhance good mothering ability
• Maintain uniformity in colour.

 

54. State two factors considered during tupping

• Size of sire and dam.
• Health of males and females
• Ratio of sire to dam/females to males

 

55. The diagram below shows a reproductive system of a bull. Study it and answer the questions that follow.
56. a) Identify the parts labeled M, N, O and P

M – Scrotum

N – Testes

O-Urethra

P – Seminal vesicles                       

 

1. b) State the function of the part labeled L

• Carries the sperm to the urethra.

 

56. If a dairy cow is noticed to be showing first signs of heat at 6.00am, what time should it be inseminated?

• From 12.00 to midnight (any time between 12.00 and midnight.)

 

57. List six causes of sterility in dairy cows.

• Freemartinism
• Nutrient deficiency
• Damaged uterus
• Retained placenta
• Blocked fallopian tubes
• Diseases of reproductive organs.

 

58. Outline two reasons for adopting proper breeding programmes by farmers.

• To prevent transfer of diseases
• For high quality offsprings and/ or products

 

59. What is the duration of oestrus cycle in a cow?

• 18- 22 days

 

60. Study the diagrammatic representation of breeding programme below occurring in two stages;

 

 

 

 

 

 

 

 

 

1. a) Identify the specific breeding system at stages I and II.

• Stage   1- upgrading
• Stage – Inbreeding

 

1. b) State two disadvantages of the breeding system represented by stage II

• Bad traits may be expressed/ lowering production or vigour
• High rate of pre -natal mortality
• Reduction in performance
• Decline in fertility / species extinction

 

61. What term is used to refer to the condition during calving in which the hind legs come out first?

• Breech/rear presentation/malpresentation.

 

62. Study the illustrations of parturition F and G below and answer the questions that follow

 

(a) Which of the foetus is in the correct position of parturition?

• G

 

(b) Name the type of parturition given to foetus F and G above.

• F= Breech / Rear presentation
• G= Normal presentation

 

(c) What name is given to the type of parturition when the foetus is born dead?

• Still birth

 

63. List two abnormalities which may arise during egg formation

• Lack of shell
• Soft shelled eggs
• Double yoked eggs
• Tiny eggs

 

64. Give two function of testis in the reproductive system of male cattle.

• Produce the spermatozoa
• Produce male sex hormones

 

65. What is the function of chalazae in a formed poultry egg?

• Chalaza holds the egg yolk in position

 

66. State two methods of service in livestock

• Natural mating
• Artificial Insemination.

67. Distinguish between Caponization and embryo transplant as used in livestock breeding

• Caponization: It is the act of making male birds loses their male characteristics. While Embryo transplant: ova are harvested from high quality animals, fertilized in test tubes and then embryos that develop are implanted into foster mother.

 

68. The illustration below shows a livestock equipment. Study it and answer the questions that follow

 

 

 

 

 

 

 

 

 

 

 

 

1. a) Identify the equipment

• Artificial vagina

 

1. b) Identify parts labelled L and K

• L – warm water
• K- Collected semen

 

69. Diagram below illustrate livestock production tool

(a) What is the suitable name of the livestock production tool above?

• Elastrator and rubber ring

 

• (b) State one function of the above tool
• Castration
• Docking
• Dehorning

 

70. Differentiate between dominant gene and a recessive gene

• Dominant gene is a breeding characteristic/trait while recessive gene is the trait suppressed by another characteristics/traits

 

71. State four management practices that should be carried out during the mating season in sheep

• Crutching of ewes
• Ringing the rams
• Raddling of rams
• Flushing i.e. giving nutritious food during mating.

 

72. The illustration below show different livestock families Use it to answer the questions that follow

	Zebu Family                                                   Hereford Family

 

 

 

1. a) Identify the breeding system between

(i) C and A

• Close breeding

 

(ii) D and T

• (ii) Cross breeding

 

(b) State two advantage of the breeding system identified in a (ii) above

• Offsprings exhibit hybrid vigour
• Introduces new genes in the herd
• Decline infertility
• High rate of offspring mortality

 

(c) Why is the breeding system identified in a(i) not recommended in dairy cattle

• Leads to loss of vigour

 

73. Explain three methods of collecting bull’s semen.

• Use of artificial vagina
• Use of breeders bag
• Recovery of semen from the female vagina soon after natural mating
• Electrical stimulation of the bull to ejaculate
• By the massage method of the bull to ejaculate

 

74. Describe ten methods of pregnancy diagnosis in cattle

• Absence of heat periods
• Decline in milk output in lactating cows
• Vaginal temperature raising slightly
• Feel method, application of pressure on the right flank of the foetus.
• Thick milk secretion in teats
• Change in density of cervical mucus drastically.
• Change in cervical pH drastically
• Rectal palpation to feel minute movements of the foetus.
• Blood analysis for the presence of pregnancy hormones.

 

75. Name three systems of breeding used to improve livestock.

• Upgrading
• Inbreeding
• Out crossing
• Cross breeding

 

76. Explain the following terms as used in livestock production
77. Embryo transfer

• Method of breeding  which involve  removal of ova  from a  superior animal, fertilize externally   in a test tube  then transfer to a foster mother which carry pregnancy to term

1. Artificial insemination

• Introduction of semen in to the females reproductive system by  use of a tube

1. Line breeding

• Is mating of distantly related animals but  within the same breed

1. Cross breeding

• Mating of animals  belonging  to  different breeds e.g. Friesian bull and  jersey cow

1. Up-grading

• Is the  mating  of high grade  bull/sire  to a low  grade cow/dam