TERMINOLOGY

  • Animal breeding: Branch of animal science that addresses the evaluation (using best linear unbiased prediction and other methods) of the genetic value (estimated breeding value, EBV) of domestic livestock.
  • Backcross: Backcross is the mating of a two–breed animal back to one of the two parental breeds
  • Crossbreeding: Mating of different breeds to produce multi-breed offspring.
  • Dominance: A dominant gene affects the appearance of the phenotype.
  • Estimated Breeding Value (EBV): An estimate of an animal’s genetic merit for a particular trait based on the individual’s performance and the performance of relatives.
  • Expected Progeny Difference (EPD): The expected difference between the progeny performance of a breed average animal and the performance of an individual’s progeny for any given trait(s). An animal’s EPD is ½ of its EBV and is equal to ½ (Sire EPD + Dam EPD).
  • F1: Progeny resulting from the mating of a purebred ram and a purebred ewe of different breeds.
  • Gnotype: The actual genetic make-up of an individual as determined by its genes.
  • Half-sibs: Individuals who have the same sire or dam (i.e. half brothers and half sisters).
  • Heredity: The transmission of characteristics from parents to their offspring through genes.
  • Heritability: Is the proportion of a measured or observed trait that is transmitted to the offspring by genes.
  • Heterosis (Hybrid Vigour): The increase in performance observed for a specific crossbred above the average performance of the parental lines.
  • Heterozygous: Each gene of a specific gene pair is different in an individual (i.e. Aa).
  • Homozygous: Each gene of a specific gene pair is the same in an individual (i.e. AA).
  • Inbreeding: Production of progeny from closely related parents.
  • Linebreeding: A form of inbreeding which increases the average relationship of the individuals in a flock to an outstanding ancestor or line of ancestors.
  • Linecross: Progeny produced by crossing two or more inbred lines.
  • Multiple Trait Selection: Selection for more than one trait at the same time.
  • Mutation: A rare change in the DNA. Extent to which mutations influence the inheritance of farm livestock is not known precisely.
  • Outcrossing: Mating of individuals within a breed that are not closely related.
  • Persistency: The degree to which milk yield is maintained from month to month by the cow during her lactation.
  • Pnetrance: The ability of a gene or group of genes to cause their characteristic to develop under the conditions of a particular environment.
  • Pure breeding: Also straight breeding. The mating of purebreds of the same breed
  • Random Mating: A mating system where all ewes have the same chance of being mated to any ram used.
  • Rotational Crossbreeding: Systematic crossing of two or more breeds in which the crossbred ewes are mated to rams of the breed contributing the least genes to that ewe’s phenotype.
  • Sibs (Full Sibs): Brothers and sisters from the same sire and dam.
  • Super-ovulation: The administration of a hormone causing a female to develop and release more eggs than normal

THE CELL AND CELL DIVISION

Cell

  • DNA molecule: 4 bases + a peptone sugar + A phosphate group
  • Lysosomes (animal only) - production of intracellular digestive enzyme
  • Mitochondria (rice shape)- Energy production (Kreb’s cycle), also called power house of cell which provide the 90% of the energy requirements
  • Ribosome-Site of protein synthesis
  • Plasma membrane- permeable membrane
  • The smallest body cells are found in blood stream, while, and largest are nerve cells.
  • Cell is the individual unit of living structure
  • Robert Hooke of England applied the term “cell”
  • Bases: Purines
  • Adinine
  • Guanine
  • Pyrimidines
  • Cytosine
  • Thymine

@ In RNA Uracil is replaced by Thymine of DNA and pentose ribose is replaced by deoxyribose

@ RNA:

  • m-RNA: Carry coded information from DNA to ribosomes
  • r-RNA: Part of ribosome
  • t-RNA: or soluble RNA (s-RNA) recognize specific amino acids in the cytoplasm

@ There is at least one specific S-RNA for each amino acid.

Cell division

1.      Mitosis: Division of somatic cells when 2 daughter nuclei are formed with same chromosome as parent cell

Stages:

  • Interphase: Chromosomes are visible, centrosome divides into 2 parts of centrioles
  • Prometaphase: Spidle mechanisms are formed
  • Metaphase: Each chromosome 2 chromatids with single centromere
  • Anaphase: 2 sister chromatids are converted to independent chrosomomes
  • Telophase: Spindle disappear

Karyokinesis: Nuclear division

Cytokinesis: Cytoplasmic division

2.      Meiosis: Division I: Prophase I:

  • Leptonema: Bead like structure
  • Zygonema: Synapsis, Zipper like
  • Pachynema: Crossing over
  • Diplonema: Chiasmata
  • Diakinesis: Termination completed

Metaphase I, Anaphase I, Telophase I

Division II: Equational like mitosis cell division

SEGREGATION AND RECOMBINATION OF GENE

  • Zygote:  Fertilized egg before first cleavage
  • Synapsis: Pairing of homologous chromosomes during prophase of meiosis I
  • Sex limited traits: Traits controlled by gene located on the X-chromosome
  • Sex limited gene expression: Heritable traits determined by only one sex (Beard in man)
  • Sex influenced dominance: Dominance in one sex and recessive to other (Baldness in man)
  • Pleiotropy: Where a single gene produced 2 or more phenotypic effects
  • Multiple allele: 3 or more possible alleles (ABO blood group in humans)
  • Autosomes: The chromosomes present in the same number in both sexes of any species
  • Gregor Johann Mendel is called “father of Genetics”
  • Law of segregation: Tall × Dwarf In mono hybrid cross: 3:1 (F1) and 1:2:1 (F2) ratio

CHROMOSOME NUMBER (2N) 

  • Cattle: 60,   Horse: 64,   Waterbuffalo: 50, Donkey(Ass): 62, 
  • Swamp buffalo: 48, Mule: 63, Goat: 60, Dog: 78, Sheep: 54, 
  • Cat: 38,  Pig: 38, Foul: 78, Yak: 60, Elephant: 56 .
 

INDIGENEOUS BREEDS OF LIVESTOCK & POULTRY

CATTLE

  1. Siri (Local hilly cow):
  • Black and white in colour
  • Famous draft breed of esteem hills of Nepal (Ilam District)
  • Fairly good milkers (360kg/lactation @1.5kg milk/day)
  • Av. Body wt. 315kg, age of 1st calving 63 months, C.I-12-20 months
  1. Achami:
  • World smallest breed of cow found in Nepal only
  • They are less than 1 meter in height at withers
  • Suitable in hill condition and low input system (Achham, Doti, Bajura)
  • Body colour is varies from black and white.
  • Maximum body wt. is 150 kg
  • Av. Milk yield is 1.5 kg/day
  1. Khaila:
  • Found in Himalayn region of Nepal particularly in Mustang, Humla & Mugu districts (suitable for mid-hills)
  • Good draught type animal located in far-western region of Nepal
  • Larger indigenous breed in the country and difficult to handle
  • Bulls and cows  are breed with Naks and Yaks
  • Av. Milk yield is 2.5 kg/day
  1. Terai:
  • They are light coloured animal mostly white and suitable for terai region (hot climate)
  • They are low milk yielder (2.1 kg/day)  and good draught breed
  • Use terai cattle for genetic improvement to the 62.5% of exotic breed & 37.5% to 50% terai cattle
  1. Lulu:
  • Small size Bos taurus cattle found in high mountains of Nepal (suitable for cool & dry place and good for low input system)
  • This is the only breed of cattle in the country that is humpless.
  • They are located in the Mustang and some parts of Manang & Dolpa
  • Av. Milk yield is 1.6 kg/day
  1. Phadi:
  • They are mostly black in colour
  • Located across the hills conditions and good draught breed
  • Av. Milk yield is 1.1 kg/day
  1. Yak and Nak:
  • They are the mountains (14,000-20,000 ft) cattle and localized in the northern belt of the country
  • Body colour is varies from black and white.
  • Chauries are good milk yielders and Jhopkyos are sterile & good for transportation as pack animals
  • Wool production of Yak and Nak is 1.2 & 0.7 kg respectively
  • Maximum body wt. is 355 (Yak) and 325 (Nak) kg
  • Av. Milk yield is 0.6 kg/day with fat 6.6%

Mating of Yak (male) × hill cattle (female)

  • Urang Chauri (female, fertile)
  • Urang Jhopkyos (male, sterile)

Mating of Nak (female) × hill cattle (male)

  • Dimgo Chauri (female, fertile)
  • Dimgo Jhopkyos (male, sterile)

Mating of Yak (male) × Dimgo Chauri (female)

  • Tolmu Chauri (female, fertile)
  • Tolmu Jhopkyos (male, sterile)

BUFFALO

  1. Lime:
  • This buffalo is grey in colour with white hair colour around the jaw and brisket region
  • Body medium sized with sickle shaped horns cuverd toward the back
  • Can withstand under low pasture condition and resistant to disease
  • Live wt. 250-400 kg, MY-255ltr/lactation, @2.1 ltr/Day, Fat 7.5%, CI-80wks, Calving period- Swrawa- Aswin, age of 1st calving- 4 years
  1. Parkote:
  • This buffalo is mainly black in colour with long face, black muzzle and flat head white hair colour around the jaw and brisket region
  • Body medium sized with sword shaped horns directed toward the back
  • Suitable for hills, high milk yielders, adaptable to brash environment
  • MY-2.0-2.5 kg/day
  1. Gaddi:
  • They are located in the far western region in Nepal
  • This buffalo is mainly black in colour with white round patches on the forehead.
  • Long face, flat face and horns are long half curved
  • Suitable for hills, high milk yielders, adaptable to brash environment
  • MY-4.6 kg/day

GOAT

  1. Khari:
  • They are located in the Mahabharata, mid hills region of Nepal & represent 56% of the total goat population of the country
  • They are prolific and good for meat purpose of 30 kg body wt and 3.5% fat in milk
  • They are hardy and well adopted in local environment
  • Body color varied from white (Seti) to black (Kali)
  1. Terai:
  • They are light coloured (mostly white) breed located in the Terai region
  • Good meat types of breeds of 30 kg body wt.
  • From conservation point of view they are at risk as it is difficult to find as a pure form
  1. Sinhal:
  • Found in south hill mountains (1500-3000 m) of Nepal as pack animals
  • They are heaviest native breed of goat and represent 16% of the total goat population of the country
  • They are good meat and draught types of breeds of 35 kg body wt.
  1. Chyangra:
  • Found in hill hills of Nepal as pack animals along with Bhyanglung type of sheep
  • They represent 1% of the total goat population of the country
  • They are used for meat and Mohair or Pashmina (cashmere=500-740gm) production
  • Body color varied from pure white to pure black of 25-40 kg body wt.

SHEEP

  1. Kage:
  • Suitable for lower hills, hardy, short tailed breed, course wool type & suitable for making radi/pakhi (Blankets)
  • They represent 21% of the total sheep population of the country
  • They are mainly used for wool and smallest among the indigenous breed with better prolificacy (18% twining)
  • It is the purest Neplease breed of sheep
  • Male are sickle shaped horns and female are polled.
  • The coat colour is white except in the head region (brown)
  • Av. Wt. is 16-24 kg, 3 lambing/2years, 700gm.year
  1. Lampuchhre:
  • They extremely heat tolerance and suitable for terai region, hardy, long tailed (0.5-0.6m) breed, good fighting quality, meat type
  • They represent 12% of the total sheep population of the country
  • The body colour is mostly white
  • Av. Wt. is 25-30 kg
  1. Baruwal:
  • Suitable for hills, hardy, good grazing instinct, wool suitable for making radi/pakhi
  • They represent 63% of the total sheep population of the country and concentrate in mountains (41%) & hills (22%)
  • They are also used as pack animals
  • Av. Wt. is 40kg (male) & 30kg (female) kg, Wool production 1.65kg (male) &  1.2kg (female)
  1. Bhyanglung: (Tibetan Sheep)
  • Suitable for high hills (2500 -4000 m), hardy, carpet wool type
  • They represent 4% of the total sheep population of the country
  • Av. Wt. is 60-90 kg, Wool production 1.0kg/2shearing
  1. Bhote:
  • Found in the Northern part of Nepal

PIG

  1. Hurrah:
  • They are the largest sized pig amongst indigenous breeds
  • Suitable for terai, hardy, suitable for backyard rearing
  • They are mainly used for meat
  • They represent 23% of the total pig population of terai
  • They are rust brown in colour, well suited for scavenging conditions
  • Body wt. is 40-55 kg, produce 7 piglets in a litter with Av. Wt. of 0.8 kg
  1. Chwanche:
  • Suitable for hills, hardy, suitable for backyard rearing
  • They represent 58% of the total pig population of the country
  • They are black in colour, hardy and well suited for local environment
  • Body wt. is 25-40 kg, produce 5 piglets in a litter with Av. Wt. of 0.6 kg
  1. Bampudke (Sano bandel):
  •  They are the smallest hog breed in the world
  • They are found in both wild and domestic form and are very hard animal, meat quality
  • Found in Chitwan, Nawalparasi
  • Body wt. is 18-25 kg

Poultry: Sakini, Pwankhulte, Ghantikhuile