THE YAK
SECOND EDITION
 
RAP Publication 2003/06
 
Table of Contents
   

REVISED AND ENLARGED by
GERALD WIENER
HAN JIANLIN
LONG RUIJUN

Published by the Regional Office for Asia and the Pacific
Food and Agriculture Organization of the United Nations, Bangkok, Thailand

Food and Agriculture Organization of the United Nations
Regional Office for Asia and the Pacific
Bangkok, Thailand

This publication is produced by

FAO Regional Office for Asia and the Pacific

Research funded by
FAO Regional Project
"Conservation and Use of Animal Genetic Resources in Asia and the Pacific"
(GCP/RAS/144/JPN)
The Government of Japan

Jacket design and illustration and frontispiece by John Frisby, RIAS

© FAO 2003

RAP Publication 2003/06

ISBN 92-5-104965-3

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FIRST EDITION

CAI LI
B.Sc.
Professor of Animal Science and vice-chairperson of the Academic Committee,
Southwest Nationalities College and deputy director of the Animal Science and
Veterinary Medicine Institute (SWNC), Chengdu, Sichuan, China

GERALD WIENER
B.Sc., Ph.D., D.Sc., F.R.S.E., C.Biol. F.I.Biol.
Honorary Professor, Gansu Agricultural University, China; Centre for Tropical
Veterinary Medicine, University of Edinburgh and Roslin Institute, Edinburgh, UK.
Lately deputy director of former AFRC Animal Breeding Research Organization, UK

SECOND EDITION
REVISED AND ENLARGED by

GERALD WIENER
B.Sc., Ph.D., D.Sc., F.R.S.E., C.Biol. F.I.Biol.
Honorary Professor, Gansu Agricultural University, China; Centre for Tropical
Veterinary Medicine, University of Edinburgh and Roslin Institute, Edinburgh, UK.
Lately deputy director of former AFRC Animal Breeding Research Organization, UK

HAN JIANLIN
B.Sc., Ph.D.
Molecular Geneticist, International Livestock Research Institute, Kenya; Professor of Animal Genetics
and Breeding, Gansu Agricultural University, China; Executive Secretary of the International Yak
Information Center and China Yak Breed Association, Lanzhou, China

LONG RUIJUN
B.Sc., M.Sc., Ph.D.
Professor of Pastoral Science and Dean of Faculty of Grassland Science, Gansu Agricultural University,
China; Senior Scientist, Northwest Plateau Institute of Biology, the Chinese Academy Science, China;
vice-chairperson of Chinese Grassland Society, China

Table of Contents

PREFACE TO THE SECOND EDITION

ACKNOWLEDGEMENTS (second and first editions)

FOREWORD TO THE FIRST EDITION

PREFACE TO THE FIRST EDITION

1 ORIGINS, DOMESTICATION AND DISTRIBUTION OF YAK

Overview
Introduction
Origins
Domestication and historical distribution
Present distribution

In Asia and traditional territories
Distribution outside Asia in modern times

The name of the yak - a historical note
Some observations on the wild yak
Feral yak
Yak in the culture of the people
The spread of knowledge of the yak outside its "native" area

2 YAK BREEDS

Overview
Introduction
Breeds in China
Postscript on breeds in China
Breeds in countries apart from China

3 BREEDING, CROSSBREEDING AND HYBRIDIZING OF YAK

Overview
Pure-breeding
Selection objectives for the chief yak breeds in China

A "traditional" selection procedure used by herdsmen in the Jiulong area of Sichuan
More recent provincial schemes: the example of the Tianzhu White
Other schemes

Consideration of inbreeding in yak
Crossbreeding within the yak species
Size of pure wild yak
Crossbreeding of wild yak with domestic yak
Breed conservation
Hybridization of yak with cattle of other species

Local names for hybrids
Distribution of hybrids
Hybridization policy
The use of "improved" breeds.
Limits to hybridization

4 THE YAK IN RELATION TO ITS ENVIRONMENT

Overview
Introduction
Distribution in relation to environmental factors

The effect of air temperature
The effect of altitude
The effect of precipitation and relative humidity
The effect of sunshine

Adaptive characteristics

Resistance to cold
Adaptation to low atmospheric oxygen and high solar radiation
Adaptive characteristics related to grazing conditions
Adaptation of reproduction
General behaviour in relation to adaptation

5 REPRODUCTION IN THE YAK

Overview
Introduction
Reproduction in the female

Female organs
Oestrous of the female yak
A general comment on reproduction in yak
Gestation and parturition
Calving season
Calf survival - prenatal and postnatal
Other factors influencing reproductive efficiency and calf survival
Length of reproductive life

Reproduction in the male

Male organs
Puberty and mating

Artificial insemination
Relations with other cattle species

6 PRODUCTION CHARACTERISTICS OF YAK

Overview
Introduction
Growth

Body weight
Other effects on birth weight and growth
Linear body dimensions

Milk production

General considerations
Factors influencing milk yield
Milk production in a second year without calving again
Factors influencing milk composition
The yak udder

Meat production

Meat quantity
Composition of meat

Fibre production and hides

Fibre
Hides

Draught performance
Opportunities for improving the production

7 PERFORMANCE OF HYBRIDS OF YAK WITH BOS TAURUS AND BOS INDICUS CATTLE

Overview
Introduction
Interpreting the results of hybridization (the question of heterosis from yak-cattle hybrids)
Reproduction and fertility

Female
Male

Production characteristics

Body size
Meat production
Milk production
Concluding comment on milk yield
Draught

8 MANAGEMENT OF YAK

Overview
Introduction
Herdsmen's activities according to seasonal cycle
Yak pastures and grazing habits

Herd ownership in relation to management

Yak herd management

Utilization of grazing
Problems of overgrazing
Adjustment of herd structure
Supplementary feeding

Equipment and penning
Management of yak herds on the range

Controlling the herd
Daily schedules

Management of the individual animal

Calf rearing
Milking
Mating of female yak
Pregnancy detection
Calving
Training of bulls for semen collection
Castration of males
Harvesting fibre

Management of yak in agricultural areas

9 DISEASE IN THE YAK (Chapter revisions by Tashi Dorji in collaboration with Walter Roder and by Yu Sijiu)

Overview
Introduction
Bacterial diseases
Viral diseases
Parasitic diseases

Ectoparasites
Endoparasites

Miscellaneous conditions
Traditional veterinary practices

10 PRODUCTS FROM YAK AND THEIR UTILIZATION

Overview
Introduction
Milk and milk products
Meat and meat products
Viscera and offal
Bone
Hair and down fibre
Hide and pelt
Head and tail
Faeces
Bezoar

11 YAK IN DIFFERENT AREAS AND COUNTRIES OF THE WORLD

Overview
Part 1 Yak production in six provinces (regions) in China by Han Jianlin

Tibetan Autonomous Region
Qinghai province
Sichuan province
Gansu province
Xinjiang Uigur Autonomous Region
Yunnan province

Part 2 Yak in other countries with a long tradition of yak keeping

Bhutan by Tashi Dorji, Walter Roder and Lham Tshering

Importance of yak at the national and regional level
Genetic and physical characterization of yak populations
Hybridization
Production parameters
Production systems
Yak health
Grassland resources and their management
Future of yak

Countries of the Commonwealth of Independent States (including the Russian Federation and a special contribution on Buryatia)

Section 1 - CIS countires in general by Gerald Wiener
Section 2 - Buryatia - with some notes on Yakutia account based on information from E.V. Katzina

Buryatia
Yakutia

Yak husbandry in India by R.N. Pal

Yak types
Breeding and hybridization
Management and nutrition
Yak diseases
Reproduction and production
Yak in the cultural and religious life of the highland peoples
Yak in the Indian development plans

Yak in Mongolia by A. Magash

Yak keeping
Yak population
Mongolian yak
Reproduction
Size and meat production
Milk production
Other uses of the yak in Mongolia
Hybridization

Yak in Nepal based on information supplied by D.D. Joshi
Yak keeping in Western High Asia: Tajikistan, Afghanistan, Southern Xinjiang Pakistan, by Hermann Kreutzmann

Tajikistan
Afghanistan
Southern Xinjiang
Pakistan

Part 3 Yak in nontraditional environments by Gerald Wiener

Overview
North America

A historical note on the introduction of yak to Canada and Alaska
Characteristics and performance
Feeding and management
Discussion

Europe
New Zealand
Yak in zoos and wild animal parks

Whipsnade Wild Animal Park

12 SOCIAL, CULTURAL AND ECONOMIC CONTEXT OF YAK PRODUCTION by Wu Ning

Overview
Cultural role of yak in Tibetan tradition
Socio-economic significance of yak keeping

From subsistence to marketing purpose
From mobile to sedentary system
From common to private ownership
From traditional to modern practices

13 ALPINE RANGELAND ECOSYSTEMS AND THEIR MANAGEMENT IN THE QINGHAI-TIBETAN PLATEAU by Long Ruijun

Overview
Background and present status
Climate
Effect of climate on alpine rangeland formation and evolution
Vegetation characterization
Nutritive value of alpine vegetation

Chemical composition profile
Intake, acceptability and dry matter digestibility
Phenolics-related compounds

Types of alpine rangeland

Alpine meadow
Alpine steppe
Alpine desert
Alpine soil type and its characterization

Utilization and management of alpine rangelands

Grazing utilization systems
Management of the seasonal pastures
Critical grazing periods

The potential for improvement of the alpine rangeland

Irrigation
Fertilizing
Control of toxic plants and rodents
Use of forage crops and sown-grass swards

Postscript

14 YAK NUTRITION - A SCIENTIFIC BASIS by Long Ruijun

Overview
Introduction
Feed Intake

Feed types
Feeding conditions
Climate
Age, size and sex of yak

Feed digestion and metabolism in the rumen

Rumen volume
Outflow rate of rumen fluid and digesta
Volatile fatty acid production
NH3-N concentration
Dry matter and protein degradability

Energy nutrition

Dietary energy digestion and metabolism
Fasting heat production
Metabolizable energy for maintenance
Energy requirements for standing and walking
Energy requirements for growth
Energy requirements for lactation

Protein nutrition

Dietary protein digestion and metabolism
Non-protein nitrogen metabolism
Purine and creatinine metabolism
Protein requirements for maintenance
Protein requirements for growth
Protein requirements for lactation

Mineral nutrition

Mineral and trace element deficiency

Feeding

Forage availability to grazing yak
Seasonality of forage nutrients
Relation between the nutrient supply of forages and physiological states of grazing animals
Supplementation feeding

15 MOLECULAR AND CYTOGENETICS IN YAK - A SCIENTIFIC BASIS FOR BREEDING AND EVIDENCE FOR PHYLOGENY by Han Jianlin

Overview
Introduction
Chromosomal work - cytogenetics
Biochemical markers in blood and milk of yak
Molecular genetics

A general background
Molecular genetic markers

Quantitative variations

The genetic basis of quantitative traits is complex
Quantitative trait loci - a way forward?

Systematics and phylogeny of the yak

Morphological array
Molecular evidence

16 CONCLUDING THOUGHTS - A PERSPECTIVE FROM A DISTANCE by Gerald Wiener

Background and problems
The present position
Research and gaps in knowledge
Prospects

APPENDIX - Map of Qinghai-Tibetan Plateau