What are EPDs and Why Use Them?
By Dr Sara Via
One of the purposes of this set of articles is to illustrate that other major livestock industries utilize EPDs and the principles of statistical genetics in making breeding decisions. They use these methods because it increases their profits. With the exception of an article I wrote about alpaca EPDs (#12), the documents in this folder are collected from websites for the cattle, swine and sheep industries. Some of the articles are brief fact sheets for breeders, others are slightly more technical publications from University Departments of Animal Science.
In cattle, swine and sheep, only part of the industry is involved in producing the genetically improved stock. These are called "pure-bred producers", or "seedstock producers", and they sell improved stock to "commercial producers", who multiply it to produce the animals that are sold for the final product (meat, wool, etc.). Generally, the flow of animals is only one-way, from the pure-bred producers to the commercial herds.
The alpaca industry is very young, and everyone is a "seedstock producer". We are all trying to breed elite animals that will improve the quality of the national herd. Therefore, the genetic principles outlined in these articles apply to nearly all alpaca breeders.
Articles: The following articles are graded according to their complexity.
One star * = simple
Two stars ** = moderate
Three stars *** = technical
Cattle
1- Understanding Expected Progeny Differences, Lesson 3, Lorrie Schott, Extension Educator, American Angus Association. Very good basic introduction to EPDs (don't forget to take the quiz at the end). Includes links to other resources.*
2- Understanding and Using Expected Progeny Differences (EPDs), Dr. Bret Barham, University of Arkansas, Division of Agriculture, Cooperative Extension. A basic introduction to EPD use in cattle.*
3- The Ranchers EPD Guide (www.redangus.com) This publication from a breed organization tells ranchers just why EPDs are so valuable in the cattle industry.*
4- Understanding Expected Progeny Differences (EPDs) Dr. Scott Greiner, Extension Animal Scientist, Virginia Tech. Another good introduction, very oriented toward beef.*
Swine
5- Table of Contents, National Swine Improvement Federation (NSIF) website. NSIF is the group overseeing the use of EPDs in swine breeding. To access the links, you will have to go online (http://www.nsif.com/guidel/guidelines.htm). NSIF has many useful fact sheets that are included in later folders.
6- Fact Sheet on Economic Value of Genetic Improvement, National Swine Improvement Federation.* This article describes how using statistics in breeding increases efficiency and thus increases profit. Tables 3 and 4 illustrate expected profit increases when statistical genetics is used in breeding programs. *
7- Swine Testing and Genetic Evaluation Concepts, AP Schinckel, TS Steward, and DL Lofgren, Department of Animal Sciences, Purdue University and USDA Extension Service. Description of why accurate genetic evaluation is important for the swine industry, and overview of how genetics is used in swine improvement.*-**
Sheep
8- Introduction and Overview of National Sheep Improvement Program (NSIP), Dr. David Notter, Department of Animal Science, Virginia Tech. NSIP is a leader in use of EPDs in livestock improvement, and Dr. Notter provides an overview of how the program functions. There are many fact sheets from NSIP in later folders. Dr. Notter is currently using data collected by the Ideal Alpaca Community to estimate EPDs for alpacas.*
9- NSIP - Frequently Asked Questions. Answers to common questions about how NSIP helps breeders to use statistical genetics in their breeding programs.*
10- Press Release, NSIP. Sheep Producers Use Genetic Tools to Boost Productivity. Article documenting success of NSIP program in producing increased quality and profits for sheep breeders.*
11- EPDs in Marketing. Example of how one sheep breeder uses EPDs as marketing tool on their website.*
Alpacas
12- How EPDs Help You Breed Better Alpacas, Dr. Sara Via, Department of Biology, University of Maryland, and Owner, Meadowlark Farm Alpacas. In this article I describe for members of the Ideal Alpaca Community how EPDs can be used in alpaca breeding.*