doi: 10.2527/jas1958.174909xpmid: N/A
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doi: 10.2527/jas1958.174910xpmid: N/A
Article PDF first page preview Close This content is only available as a PDF.
doi: 10.2527/jas1958.174911xpmid: N/A
Abstract New and younger members of the American Society of Animal Production may not realize that membership in the Society has more than trebled within the past 15 years. Yet the foundations laid in the first 35 years of the Society have been extremely important in shaping the current activities as well as the advances the American Society of Animal Production has encouraged in the realms of research, resident teaching, and extension. It is well for us to review the past as we plan for the future—and the golden anniversary is an appropriate time to view our Society in retrospect. This content is only available as a PDF.
doi: 10.2527/jas1958.174922xpmid: N/A
Summary and Forecast To summarize, the past half century has been an interesting one from the standpoint of beef cattle breeding. Progress has undoubtedly been made by the industry in developing types and kinds of cattle which meet market demands better than was the case many years ago. The evidence is less clear on whether the cattle available are, themselves, inherently more productive than those which were available for use by our grandfathers. Progress in beef cattle breeding research, during this half century and particularly during the past 20 years, has great promise of holding the key to the development of inherently more efficient cattle. It is hoped that definite progress in the industry as a whole can be reported long before this Society celebrates its one hundredth anniversary. This content is only available as a PDF. Author notes 1 The writer is indebted to Keith E. Gregory and C. J. Elam for assembling some of the tabular material and to C. M. Kincaid, J. H. Knox, Leslie E. Johnson, J. L. Lush, Keith E. Gregory, and Willard E. Urban for making helpful suggestions on the manuscript.
doi: 10.2527/jas1958.174944xpmid: N/A
Abstract Sheep breeders of the past 50 years have continued to improve on practices which began possibly 7000 to 8000 years ago (290). In fact the sheep was probably one of the first animals to be domesticated and man has long depended on sheep for clothing and food. Many of the methods of sheep improvement common during the past 50 years, such as selection for improvement of valuable traits and the formation of specialized breeds and types, must have been used before the time of recorded history. Our efforts in the last 50 years have been directed toward adapting these methods and the sheep with which we work to our changing needs. Furthermore, we have gathered and recorded many facts about sheep and animal breeding which have permitted the development of ways of applying these methods more precisely and effectively (278, 302, 313). This content is only available as a PDF. Author notes 1 Sheep, Goat and Fur Animal Research Branch, Animal Husbandry Research Division, Agricultural Research Service, Beltsville, Maryland.
doi: 10.2527/jas1958.174960xpmid: N/A
Summary Breeding practice and experimental trials with swine breeding during the last 50 years, are sketched briefly. Advances in genetics in respect to the topics included in the review are mentioned. Results show that; breed averages differ in important characters; emphasis on meat type hogs has increased; effort is being exerted to improve hogs in economically important traits through selection and breeding practice; variations in most of the important traits are sufficiently heritable to permit additional improvement; inbreeding tends to reduce litter size farrowed and weaned, and growth rate, but inbreeding can be used to hold together a stock containing unusually good genes so that extensive use can be made of such stock; characters affected adversely by inbreeding show heterosis in crosses. Progeny testing of pigs in Denmark and Canada is reviewed. Results indicate that progeny testing can be effective in changing carcass traits, economy of gain and growth rate of pigs. New developments in pig testing, and certifying litters appear to be constructive steps. This content is only available as a PDF.
doi: 10.2527/jas1958.174981xpmid: N/A
Abstract Anyone who has been actively engaged in cattle feeding since the turn of the century is likely to feel that great changes have taken place in the industry in the last 50 years and that these changes have been very rapid since World War II. It is true that significant changes have taken place, but these have come largely under the headings of practical utilization of feeds, management, facilities and transportation rather than in beef cattle nutrition. Anyone who analyzes critically the rations used is bound to be impressed that rations fed today do not differ greatly in content from those used 25 years ago. In the opinion of the writer the major contributions to the field of beef cattle nutrition in the last 50 years have been few. Space does not permit a complete review of the work done in all of these areas. Exhaustive compilations have been made in a number of areas and no attempt will be made to cover those areas in detail. Rather, the reader is referred to published works which already exist. In those areas where the information is scattered, an attempt is made here to summarize. This content is only available as a PDF.
doi: 10.2527/jas1958.1741007xpmid: N/A
Summary Compared to other livestock, only limited research has been done on the nutrition of the horse in the American area over the last 50 years. This has been due not only to the mechanization of armies and farms but also to the high cost and difficulties of running controlled experiments. The research accomplished has done much to define the roughage requirements of the horse. Significant data have been collected on the role of vitamin A and, to a lesser extent, that of a number of B vitamins. Calcium and phosphorus needs have been investigated and the interrelationship of blood levels established. On the whole, most of the nutritional requirements of the horse must still be derived from those determined for other animals. Major problems of the future will be related to the race horse because of the increased use of the animal for this purpose. The nutrient requirements of a horse raced as a 2-year-old may be higher than for a horse used for pleasure riding or the usual farm work. Training and running an immature animal is a stress factor which no doubt needs a special dietary regimen, a problem which may make this a very interesting area for future research. This content is only available as a PDF.
doi: 10.2527/jas1958.1741015xpmid: N/A
Abstract It is most difficult in reviewing the progress that has been made in sheep nutrition to refrain from constantly referring to the progress that has been made in the entire field of animal nutrition. The advances in the nutrition of other species has, in almost every case, contributed to the present knowledge of sheep nutrition. While this review must be limited to work specifically with sheep, acknowledgment is given to the many scientists who have made a contribution to this field although they did not work directly with this animal. It is also important to grant acknowledgment to the vast quantity of research work in Sheep nutrition over the past half a century that cannot be reported herewith for reasons of limitation. Great progress has been made, but only because of the efforts of many scientists throughout the world. This content is only available as a PDF.
doi: 10.2527/jas1958.1741029xpmid: N/A
Abstract About 50 years ago Dawson (1), a Poland China breeder, wrote a book summarizing his “experiences gained during 50 years of breeding and handling hogs”. At that time he wrote to each experiment station in the United States asking for details of the best and most economical rations for hogs of various classifications. Twenty replies were received. For weanling pigs, all respondents stressed the importance of good pasture, alfalfa clover or rape. Several Corn Belt stations replied that good legume pasture, corn and water was the most economical combination. In dairy regions, most of the recommended mixtures were skim milk, corn and shorts. Tankage was suggested as a substitute if milk was unavailable. The Mountain States included barley and Illinois included ground soybeans in the suggested mixtures. Slop feeding was a consistent recommendation. Wood ashes, charcoal and salt were recommended as minerals. One person stressed the importance of not overfeeding, especially with protein and especially when the pig was young. This content is only available as a PDF.
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