Breeding Livestock Adapted to Unfavorable Environments
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FAO LIBRARY AN: 058828 M#71,4,00 BREEDING LIVESTOCK adapted to UFFAVORABLE ENVIEZO MENTS Washington, U.S.A. August 1949 OTHER FAO AGRICULTURAL STUDIES No. 2 Preservation of Grains in Storage: Papers Presented at the International Meet- ing on Infestation of Foodstuffs, London, 5-12 August 1947(February1948) With maps, charts, tables, references and an index, iv + 174 pages. Price $1.50. Available alsoinFrench and Spanish. No. 3 Using Salty Land (February 1948) With tables, charts, and references, iv + 49 pages.Price 50 cents. Out of print.French edition available. No. 4 Soil Conservation: An International Study (March 1948) With a folding map, charts,references,96 halftoneillustrations,viii + 192pages. Price$2.00. Available also in French and Spanish. No. 5 Nutritional Deficiencies in Livestock( May 1948.Reprinted August 1949 )With tables,map,chart,references, 47halftoneillustrations,iv + 102pages. Price $1.00. No. 6 Storing and Drying GraininCanada, in theUnitedStites,inthe United Kingdom (December1948.Reprinted August1949) With tables,references, 9 illustrations, V + 41pages.Price 50 cents.French and Spanish editions in preparation. No. 7 Better Utilizationof Milk (March1949.Reprinted August 1949)With tables and references, 76 pages.Price75cents. French and Spanisheditionsin preparation. No. 8 Ri,nderpest Vaccines, TheirProduction and UseintheField(March1949) With tables, references, 2illustrations,viii-1- 71 pages.Price $1.00.French editioninpreparation. No. 9 Efficient Use of Fertilizers.English edition in press.French and Spanish editions in preparation. 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Photo by Bureau of Land Management, U. S. Department of the Interior. FAO Agricultural Studies No. 1 r).:,,NG LIVES cl pteco ENVIRONM TS An FAO Study Prepared by RALPH W. PHILLIPS Chief, Animal Industry Branch and Deputy Director Agriculture Division Washington, U.S.A. August 1949 FirstprintingJanuary1948 Second printing August 1949 CONTENTS Introduction 1 Conversion Table for Weights and Measures Geographic and Climatic Limitations upon Livestock Production 5 Adaptability of Sheep to Various Environments 15 Stratification of the Sheep Industry in Great Britain 15 Performance of Columbia Sheep in Two Environments 27 Reactions of Various Breeds of Sheep to High Temperatures 35 Observations on Adaptability of Sheep. in China 36 Improving Deccan Sheep by Selection and Grading Up with Merinos 44 Reactions of Southdovvn Sheep to Two Environments . 47 Experience with the Introduction of Sheep in Iceland . 52 Improvement of Navalo Indian Sheep 59 Improvement of Native Sheep in Egypt 64 Adaptability of Cattle to Tropical and Subtropical Climates 67 Adaptability as Measured by Milk Production 81 Adaptability as Measured by Beef Production 84 Observations In Northern Australia 89 Observations in Jamaica and Trinidad 91 Results in Tunisia 98 Development of the Santa Gertrudis Breed in Southern Texas, U.S.A. 99 Work in South Africa 103 Observations on Adaptability of Horses and Swine 107 Adaptability in Horses 107 Adaptability in Swine 114 Use of Less-Known Types of Animals in Livestock Production 133 Water Buffaloes 133 Yaks 138 Reindeer 141 Camels and Dromedaries 145 Llamas and Alpacas 146 Methods of Breeding 153 Selection 154 Inbreeding 163 Crossing 168 Developing New Breeds 171 Reproduction 173 Hybridization 173 Improving the Environment 174 Conclusion 175 Literature Cited 177 vi 1 I RODUCTIO Animals differ widely in their ability to thrive and to perform efficiently under a given set of conditions. Some animals are adapted to cold climates, others to temperate climates, still others are more suited to tropical conditions. Certain types of animals, such as the yak and vicuna, thrive at high altitudes, while others cannot survive satisfactorily there. Animalsvary also in their grazing ability. Some can obtain a satisfactorily living while grazingover extensive range lands, while others require lush pastures and supplementary feeding if they are to perform efficiently. Animals vary also in their adaptability to conditions withina given climatic zone. In the temperate zone, for example, some are able to utilize areas of sparse grazing and are thus able to harvest extensive areas of land that would otherwise be of little use to man. They can thus turn forage into products that are of great importance. Such animals are often limited in their productive capacities when placed under excellent environmental conditions. Theyare able to live and reproduce quite satisfactorily, but they have been 0:-veloped under conditions where natural selection eliminated the weaklings, and where there was relatively little opportunity for expression of, and selection for, superior milk, meat, or fiber production. Thus, under good environmental conditions, itis necessary to select stock that has the inherent capacity to utilize effi- ciently large amounts of good-quality feed, if that feed is to be transformed most effectively into products for human consumption. A few examples will illustrate some of the differences. The Holstein-Friesian breed of cattle was developed in the temperate zone and under conditions of intensive farming. It is well adapted to areas where pastures are good, where itispossible to grow ample supplemental feed, and where there is a market for a sizeable volume of milk. But it is not suited to many areas in the tropics or to areas of scanty feed in the temperate zones. By contrast, the yak is admirably suited to high elevations and extensive grazing condi. tions such as are found on the Tibetan highlands of Central Asia, but it does not produce at a sufficiently high level to use large amounts of good-quality feed efficiently.Still another contrasting type may be found in the water buffalo. This animal is adapted to tropical conditions; andsome breeds, such as the Murrah of India, produce reasonably good quantities of milk while being fed coarse roughage and limited amounts of other feed under tropicalcli- matic conditions that adversely affect Holstein cattle. Neither the yak nor the water buffalo would be suited to areas where intensive dairying is practiced, such as the Netherlands, or Wisconsin and New York states in the United States of America, for they are not adapted 1 to the climatic and other conditions prevailing there, and do not have sufficient inherent milk-producing capacitytoutilizethe available feedefficiently. On the other hand, the Holstein-Friesian, and other highly specialized dairy breeds developed under similar conditions, cannot perform satisfactorily and often are unable to survive under conditions where the yak and the water buffalo can thrive. The variations in adaptability among highly specialized dairy cattle, yaks, and water buffaloes are quite extreme. Similar examples of extreme varia- tions may be found in other classes of livestock. The Rambouillet sheep is able to find a livelihood on the extensive range lands of the western United States of America, and its close relative, the Merino, makes effective use of the extensive grazing areas of Australia, where grazingisalsosparse,a.nd where severe droughts often occur. On the other hand, the Hampshire, Shropshire, and other mutton breeds are better suited to the pastures of the Corn Belt in the United States and to the Dovvn regions of southern England. Still other types, such as the Welsh A/fountain and the Blackfaced Highland, are suited to the rugged environment of the highlands of Wales and Scot- land, where the climate is cold and damp, and where grazing is generally sparse. But there are less apparent variations, even among types and breeds that have been developed under rather similar conditions, thatmay be of considerable importance in determining thesuccess with which anirnals of a given type may be used under a certain set of conditions. It has been demo.n- strated,for example, that Jerseycattle have greater heat tolerance than Holstein-Friesian cattle and are therefore lessaffected by the subtropical conditions that prevail in the Gulf Coast region of the United States during the summer months (Seath and Miller, 1947). Variations in adaptability are important in selecting stock for a given set of conditions. This point has been frequently overlooked in attempts to improve the quality or productivity of stock in a givenarea. This has been particularly truein underdeveloped countries or regions, where rigorous enVironmental conditions prevail, andas a result much time, effort, and money have been expended, often withvery disappointing results. Similar failures have been observed in well-developed countries, in sections where the