Genetics - Biology Notes PDF

**Genetics** - science that deals with the study of heredity and variations **Animal Breeding** - Application of principles of genetics to select the best animals based on human needs **Gregor Mendel** - He postulated that traits are carried by genetic material, which now known as **"gene"*...

**Genetics** - science that deals with the study of heredity and variations **Animal Breeding** - Application of principles of genetics to select the best animals based on human needs **Gregor Mendel** - He postulated that traits are carried by genetic material, which now known as **"gene"** - He discovered that genes exist in 2 different form, **"allele"** - Alleles of different genes are inherited 3 differently **James Watson and Francis** Crick - Discovered that DNA exist as double helix, In 1953. **Gene** - A gene is the basic physical and functional unit of heredity. Made up of DNA **(Deoxyribonucleic acid)** **DNA** - is the hereditary material in almost all other living organisms **Structural Gene** - responsible for the synthesis of certain biochemical products (hormones & enzymes) during cell metabolism **Regulatory Gene** - control and regulate the functions of other genes (on/off) **Nucleotides --** DNA code of gene - A -- Adenine - T -- Thymine - G -- Guanine - C -- Cytosine **Ribonucleic acid (RNA)** - functional molecules that translate DNA code **Protein** - Provide body's main building materials - Form cell architecture and structural components - Limitation: multiplication **Replication --** DNA multiplication **DNA Polymerase** - reads new template DNA strand and stitches together the complementary new strand **Mutation** - Occasional deletion or duplications during replication - Others are caused by the environment: sunlight and chemicals - error in gene sequence - Incorrect protein - No protein - Not all are harmful (ex. Brown eyes) **Chromosomes** **Homologous -** chromosome pairs that are similar in length, gene position, and centromere location. **Heterologous** - chromosomes are the chromosomes that differ in type, function, or size **Locus** / **Loci**-- location of a gene in a chromosome **Gene in a loci** **Homozygous gene -** gene correspond to each other **Heterozygous gene** -- gene contrast in response **Allele** - those genes that occupy corresponding loci in homologous chromosomes but that affect the same characteristics in a different way - Alternative versions of the same gene pair - **Dominant Allele --** Gene that overpower/dominates the expression of the other (Capital) - **Recessive Allele --** Allele whose expression is suppressed - **Phenotype** - Characteristics that can be perceived by the naked eye - **Genotype** -- Actual genetic make-up **Cell Division** **Autosome --** body cells - Diploid - Di (2) - Ploid (sets of chromosome) - Cell Division : mitosis **Sex cells --** gametes: egg and sperm cell - Haploid - Cell division : mitosis and meiosis **Gene Interactions** **Linear Interaction -** gene interaction on the same chromosome **Allelic Interaction -** gene interacts with the corresponding gene in a homologous chromosome **Epistatic Interaction -** gene in heterologous chromosome **Internal Interaction --** Interaction with hormone **External Interaction --** Interaction with external environment **Allelic Interaction** ⮚ Dominance interaction ⮚ Lack of Dominance ⮚LL -- long ears, ll -- short ears Ll- earless ⮚Overdominance ✔Heterosis -- implies that heterozygotes possess greater vigor or are more desirable in other ways ✔Hybrid vigor -- higher productivity **Epistatic Interaction -** A gene or a pair of gene in one pair of chromosomes may alter or mask the expressions of gene in other chromosome **Types of Crosses** 1. Monohybrid cross 2. Dihybrid cross 3. Backcross 4. Test cross **Breeding** - application of animal genetic principles to improve animal performance; ❑ quantity ❑ efficiency of production ❑ quality of animals / products **TANDEM**- genetic progress is aimed over a group of 2 or 3 traits one at a time **SELECTION INDEX** -- most applicable when selecting for more than 1 quantitative trait simultaneously with their corresponding importance or weights **CROSSBREEDING -** Mating of 2 or more unrelated different breeds **Animal Health -** physical and physiological well-being of an animal **Disease --** deviation from normal health with marked physiological, anatomical or chemical changes in the animal body - **Infectious --** caused by living organisms, can be transmitted by direct or indirect - **Contagious --** transmitted (direct or indirect) - **Non-infectious --** caused by factors other than living organisms, mechanical or lesions **Bacteria -** small, single-celled plant cocci, (round or oval), bacilli (rod-shaped) or spirilla (long twisted) **Virus -** very small, can be seen in electron microscope, live on entirely parasitic existence invading cells of other organisms **Protozoa -** single-celled animals, larger than bacteria, can be seen under ordinary microscope **Parasites -** live in or on other organisms or animals referred to as hosts (ectoparasites: ticks, mites, fleas, lice) (endoparasites: flukes, flatworms, roundworms **Fungi -** microscopic plants (example, ringworm) **Viral Diseases (SWINE)** **Hog cholera or Swine fever --** Pestivirus **Transmissible gastro-enteritis --** Coronavirus **Pseudorabies --** Herpesvirus **Nutritional Diseases** **Rickets -** disease of the skeletal system of young animals (deficiency in vitamin D, Ca) **Osteomalacia -** deficient bone calcification in mature animals (vit. D, Ca) **Anemia -** Iron (Fe) deficiency, ↓number of RBC or hemoglobin in the bloodstream **Xeropthalmia -** form of conjunctivitis; dry, lusterless eyes - deficiency of vitamin A **SLAUGHTERING AND MEAT PROCESSING** **Slaughtering And Meat Fabrication** a. **Age of the animal** Recommended age of livestock for slaughter: **Swine --** 6 to 12 months **Cattle and Carabao** -- 3 years and younger **Goats** -- 1 year b. **Sex of the animals** c. **Size** d. **Degree of fatness** e. **Health of the animals** **Management of Animals Prior to Slaughter** a. **Fastings** It is the withdrawal of solid feed and only water is provided ad libitum. Hogs are fasted for 12 to 24 hours and ruminants for 24 to 48 hours **Advantages of fasting** **--**Savings of feed --Ease of cleaning entrails --Ease of cleaning and eviscerating carcass --Thoroughly-bled and brightly colored carcass --Long shelf-life --Low shrinkage b. **Relaxing the animal** c. **Handling the animals gently** d. **Clean animals** **Slaughtering Procedure (SWINE)** - **Stunning** (unconscious) - **Sticking** (bleeding) - **Scalding and scraping** - **Removal of the head** - **Evisceration** (removal of visceral organs) - **Splitting** - **Chilling** **Slaughtering Procedure (cattle and carabao)** - **Stunning** - **Sticking** - **Flaying/Skinning** (removal of the hide) - **Removal of the shank and head** - **Evisceration** - **Splitting/Quartering** - **Shrouding** (Wrapping carcass with a cheesecloth) - **Chilling** **Dressing Percentage** Hog -- 70% Sheep and goat -- 50% --------------- ----------------------- Duck -- 71% Turkey -- 80% Cattle -- 60% Chicken -- 66% to 76% Goose -- 69% **\ ** **Wholesale Cuts Of Beef And Carabeef Carcass** **Front Quarter** Ribs Brisket Plate or short plate ------- ----------- ---------------------- Chuck Foreshank **Hindquarter** ------------- ------ ------- Flank/navel Loin Round ------------- ------ ------- **Wholesale cuts of pork carcass** Shoulder Loin ---------- --------------- Ham Belly or side **Meat -** defined as those animal tissues, which are suitable for use as food 1. **Beef** -- from cattle over a year of age 2. **Veal** -- from calves 3 months of age or younger 3. **Pork** -- from swine 4. **Mutton** -- from mature sheep 5. **Chevon** -- from goat 6. **Poultry meat** -- comes from flesh of domestic birds 7. **Sea foods** -- flesh of aquatic organism (ex. Fish) 8. **Game meat** -- flesh from non-domesticated animals **Types of Processed Meat** **Cured meat-** ham, bacon, tocino, tapa are classic example **Sausages**- ground, salted and seasoned, stuffed in casing/formed in molds, Classified as "ground and emulsion type products" **Restructured meat products**- made from flaked, ground or sectioned beef or pork shaped into roast, steaks or loaves **Composition of animal products** **Eggs** - Composition:Shell and shell membrane (11%) surrounds the egg, - Albumen ( 58%) surrounds the yolk - Yolk (31%)-- yellowish colored Mineral content of shell is approximately 94% calcium carbonate - Nutrient Content: - Albumen -- high in protein ; - Yolk -- fat and cholesterol, vit. A,D,E,K, folic acid,B2,B12,pantothenic acid,minerals: Fe,P,S,Cu,K,Na, Mg,Ca Cl and Mn **Milk** - "Nearly perfect food" - Colostrum -- first milk produce by mammals Nutrient content: - Protein: casein and whey protein - Fat: milk fat - Carbohydrates: lactose - Minerals: Ca, P, Zn - Fat soluble vitamins: A,D, E, - Water soluble vitamins: B6, B12, thiamine and panthothenic acid **Milk Processing** **Heat Treatment** Pasteurization: LTLT -63 C for 30 min HTST -- 72 C for 15 sec UHT -- 142 to 145 C for 2-3 secs **Cooling --** 10 C immediately after milking stops dev. Of microorganisms **Traditional use of salt or sugar** **Filtering-** way to remove impurities **Standardization-** required to meet market standard (if butterfat is high, portion of cream is removed) **Cream separation-**fat globules sp. gravity= 0.63, skim milk= 1.035 **Homogenization-**breaking up of the fat globules (diameter about= 1-18 microns) to prevent fat from rising during storage forming a cream layer **Reconstitution-** dissolving milk powder in water (lower quality due to low solubility of milk powder) **Recombination-**standardizing reconstituted skim milk with butter oil **Toning-** blending fresh milk with high fat with water and skim milk powder **Marketing of Live Animals and Its Products** 1. **Livestock market** animals for sale brought to concentration yard (Auction market) Transaction could be: - Traders to traders - Farmer to trader - Trader to farmer 2. **Barrio agents** buying of from backyard farms and sell to viajeros or they act as viajeros and sell directly to retailers 3. **Wholesaler or viajeros** buy in wholesale quantity, resell to other wholesaler and retailers 4. **City Dealers** intermediators between the provincial viajeros and wholesalers in the city 5. **Retailers** Buy animals and sell to consumers 6. **Contract growing scheme** a mother company takes the animals produced and takes care of the processing before final sale to consumers