Applied Animal Genetics Working Doc. .docx

**[Applied Animal Genetics]** **Genetics** DNA is the genetic code for living organisms DNA is used to identify animals with a high genetics merit. ---------------- DNA Structure: ---------------- **Genetic Improvement:** Understanding genetics within animals is crucial to comprehend why...

**[Applied Animal Genetics]** **Genetics** DNA is the genetic code for living organisms DNA is used to identify animals with a high genetics merit. ---------------- DNA Structure: ---------------- **Genetic Improvement:** Understanding genetics within animals is crucial to comprehend why certain animals are superior over others. Understanding the genetic makeup of animals allows farmers to improve the genetic merit of their farm and therefore improve the profitability of their farm. **Physical Traits:** Are features that are visible when you look at an animal. E.g. Aberdeen Angus are naturally polled animals that farmers have selected for this physical trait. The gene for the polled condition is dominant over the gene for the presence of horns +-----------------------------------------------------------------------+ | - - - | | | | | | | | - - - - | +-----------------------------------------------------------------------+ **Selective Breeding:** **Line Breeding:** Performance Testing: The evaluation of a bulls performance by comparing its weight gain and feed conversion ratio with other bulls kept under similar feed and housing conditions. The growth rate and feed conversion ratio (FCR) of a bull is tested and compared. +-----------------------------------------------------------------------+ |  | +-----------------------------------------------------------------------+ Progeny Testing: The evaluation of the performance of a bulls offspring compared to other bulls offspring under similar feed and housing conditions. Progeny testing is more reliable than Performance testing. **Genotyping and Genomic Selection:** - - ------------------------  ------------------------ Advantages**:** 1. 2. 3. 4. 5. 6. 7. **Natural Selection:** Otherwise known as 'Survival of the fittest'. Is the process whereby organisms that are better adapted to their environment survive and pass on their adapted traits to their offspring. An animal with a desired trait can be used as a method inbreeding to bring the desired trait into the offspring. Example: High milk yield. In the 1990's The Holstein breed was used in the Irish dairy herd to increase milk yield. This can cause the production of undesirable traits in the offspring. For example while using a Holstein breed to increase milk yield in the Irish herd this concentrated other problems around fertility and lameness in the offspring. A Deleterious gene is one that causes harm or damage. These undesirable recessive genes make the animal less fit for survival. For example the gene in Holsteins is Brachyspina which causes issues with embryonic development. **Agricultural Biotechnology** Cloning produces genetically identical individuals. In horticulture cuttings, grafting and micropropagation all produce genetically identical plants. In 1996 the first animal was cloned from a sheep. Called 'Dolly'. This was done by: 1. 2. 3. Advantages of Cloning: A. Disadvantages: a. b. c. d. **Genetic Modification:** - This means that new genes can be inserted into the genome. Only one method genetic modification approved for livestock. A pharmaceutical drug produced which is used to prevent blood clotting is now produced from goats milk. Atryn is the name of the product. It is inserted into the genome of goats after fertilisation. Advantage: - Disadvantage: -  **Plant Genetic and Breeding - Recap**