Performance Traits

Overzicht

Two bulls at a Kano market look almost identical: same frame, same coat, same asking price. Only one of them, it turns out, sires daughters that give twice the milk. No amount of staring at the bulls would have told a buyer that. What separates a genuinely superior breeding animal from an ordinary-looking one is not visible at a glance, it has to be measured, and the measurement is called a performance trait.

In this lesson you will learn what a performance trait is and why it, not appearance, drives good breeding decisions. You will learn the sharp line between qualitative traits, which sort an animal into one of a few either/or categories, and quantitative traits, which vary smoothly across a whole range and are shaped by many genes acting together with feeding and management. You will meet the performance traits that actually decide which poultry, cattle and pigs get kept for breeding on a Nigerian farm, and see why recording them, patiently and repeatedly, is what turns guesswork into genetic improvement.

Doelstellingen

  1. Define performance traits
  2. Give examples of performance traits used in animal selection
  3. Distinguish between qualitative and quantitative traits
  4. Explain the importance of performance traits in animal improvement
  5. Explain how performance traits are recorded and used

Lesnotitie

A trader in Kano is choosing between two young bulls to keep for breeding, same age, same White Fulani type, same price. He cannot tell, just by looking, which one will sire calves that grow faster or whose daughters will give more milk. Body shape and coat pattern are visible in a moment; growth rate and milk yield are not, they only show up in records kept over weeks and seasons. A breeder who buys on looks alone is choosing blind.

Lesevaluatie

Gefeliciteerd met het voltooien van de les op Performance Traits. Nu je de sleutelconcepten en ideeën, het is tijd om uw kennis op de proef te stellen. Deze sectie biedt een verscheidenheid aan oefeningen vragen die bedoeld zijn om uw begrip te vergroten en u te helpen uw begrip van de stof te peilen.

Je zult een mix van vraagtypen tegenkomen, waaronder meerkeuzevragen, korte antwoordvragen en essayvragen. Elke vraag is zorgvuldig samengesteld om verschillende aspecten van je kennis en kritisch denkvermogen te beoordelen.

Gebruik dit evaluatiegedeelte als een kans om je begrip van het onderwerp te versterken en om gebieden te identificeren waar je mogelijk extra studie nodig hebt. Laat je niet ontmoedigen door eventuele uitdagingen die je tegenkomt; beschouw ze in plaats daarvan als kansen voor groei en verbetering.

  1. A performance trait is best described as one that is: A. Visible at a glance B. Measured and used to judge breeding merit C. Present in every breed D. Fixed at birth and never recorded Answer: B
  2. Which of the following is a qualitative trait in poultry? A. Egg number B. Body weight C. Comb type D. Feed conversion ratio Answer: C
  3. Quantitative traits are controlled by: A. A single dominant gene only B. Many genes together with the environment C. Chance alone D. The breed name of the animal Answer: B
  4. Which performance trait is most directly used to select breeding sows in pig production? A. Coat colour B. Litter size C. Ear shape D. Snout length Answer: B
  5. A broiler eats 4.0 kilograms of feed and gains 2.0 kilograms of weight. Its feed conversion ratio is: A. 0.5 B. 1.0 C. 2.0 D. 4.0 Answer: C

Aanbevolen Boeken

Introduction to Animal Science: Global, Biological, Social and Industry Perspectives
Introduction to Animal Science: Global, Biological, Social and Industry Perspectives
Ondertitel: Sixth edition
Uitgever: Pearson
Jaar: 2017
ISBN: 978-0-13-443605-0
Beschrijving: A comprehensive introduction to animal science covering anatomy and physiology, nutrition, genetics, reproduction, animal health and the major farm animal species and their production systems.
Small-scale Poultry Production: Technical Guide
Small-scale Poultry Production: Technical Guide
Uitgever: Food and Agriculture Organization of the United Nations
Jaar: 2004
ISBN: 978-92-5-105082-8
Beschrijving: An FAO Animal Production and Health Paper written by a Nigerian animal scientist, covering breeds, housing, feeding, incubation, disease control and marketing for small-scale poultry keepers in developing countries.
Tropical Animal Feeding: A Manual for Research Workers
Tropical Animal Feeding: A Manual for Research Workers
Uitgever: Food and Agriculture Organization of the United Nations
Jaar: 1995
ISBN: 978-92-5-103758-4
Beschrijving: An FAO Animal Production and Health Paper on the principles of ruminant and non-ruminant nutrition and the practical use of tropical feed resources, including crop residues and by-products, in sustainable livestock systems.