Download or read book Effectiveness of Selection for Productive Characteristics in Developing the Montana No I Hogs written by Wesley Charles McEwen and published by . This book was released on 1952 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the most important productive characteristics of hogs is reproductive efficiency. Reproductive efficiency is best measured by litter size at weaning. Litter size at birth and weight of the pigs at birth are among the most important factors affecting litter size at weaning. It has been demonstrated that less than 5 per cent of pigs weighing 1.5 pounds or less at birth survive to be weaned. It was the purpose of this study to determine the selection for litter size and birth weight of the pigs and the effects of this selection on subsequent generations during the development of the Montana No. 1 line of hogs. The data for this study were made available through the agencies cooperating in the development of the Montana No. 1 hogs, the Montana Agricultural Experiment Station and the Bureau of Animal Industry, United States Department of Agriculture. To facilitate comparisons between generations all litters farrowed by sows which were her second or third litter were eliminated from the study. A significant difference between the average birth weight of pigs of gilts whose dams were gilts and the average birth weight of pigs of gilts whose dams were sows was determined by analysis of variance. The pigs farrowed by gilts by sows were heavier. All spring litters farrowed by gilts by gilts were used in the study from farrowing records taken from 1939 to 1949. The selection for litter size, based on the average litter size of the litters from which the individual pigs were selected, was for larger litters. There was an increase in the average litter size of litters farrowed by gilts by gilts. However, environmental influences accentuated the changes in litter size greatly during the period of development studied. The amount of selection, based on the birth weight of the individual pigs selected, weighted for the number of times their genetic influence was weighted on the succeeding generation was not positively associated with the birth weight of their offspring. The selection for birth weight based on the average birth weight of the litter from which individual pigs are selected is the best indication of their inherent ability to utilize available environmental conditions as well as their ability to provide an adequate uterine environment for their offspring. There was selection for pigs from litters with average birth weights below that of average of the population from which they were selected. There was a decrease in the average birth weight of the live pigs farrowed. It has been demonstrated that environmental influences are the major cause of variations in the birth weights of new born pigs within the litter. It is therefore possible that the ability of a sow to farrow pigs of greater uniformity at birth is a heritable characteristic. Using the within litter standard deviation of birth weights of live pigs farrowed for each litter as an index to the uniformity of the birth weights of the litters from which the parents were selected and the uniformity of the birth weights of their litters. It was concluded that the characteristic is heritable. There was selection and progress made in the development of the line toward more uniform litters at birth.

Download or read book The Montana No 1 Hog written by and published by . This book was released on 1957 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Montana No 1 Hog written by Montana Agricultural Experiment Station and published by . This book was released on 1957 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Theses and Dissertations 1943 1959 written by Rodney K. Waldron and published by . This book was released on 1960 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Master s Theses in Science 1952 written by Barton Bledsoe and published by Washington : Biblio Press. This book was released on 1954 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bibliographic Series written by and published by . This book was released on 1960 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bibliographic Series written by Oregon. Library. Forest Research Laboratory and published by . This book was released on 1960 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Review of Agricultural Research written by United States. Congress. House. Committee on Agriculture. Subcommittee on Conservation, Credit, Rural Development, and Research and published by . This book was released on 2005 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Report written by United States. Regional Swine Breeding Laboratory, Ames, Iowa and published by . This book was released on 1966 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Livestock Research of the United States Department of Agriculture and in Cooperation with State Agricultural Experiment Stations written by United States. Department of Agriculture. Livestock Research and Marketing Advisory Committee and published by . This book was released on 1960 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book 1st World Congress on Genetics Applied to Livestock Production Plenary sessions written by and published by . This book was released on 1974 with total page 972 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cumulated Index Medicus written by and published by . This book was released on 1971 with total page 1260 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal of Animal Science written by and published by . This book was released on 1983 with total page 668 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Comparison of Single Trait and Index Selection in Sheep written by John Lax and published by . This book was released on 1975 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Reproductive Efficiency of Swine written by Emmett Jerome Stevermer and published by . This book was released on 1969 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Artificial insemination; Chemotherapeutics; Disease; Environment; Genetics; Nutrition; Physiology.

Download or read book Genetic Resources of Pig Sheep and Goat written by Kalle Maijala and published by Elsevier Science & Technology. This book was released on 1991 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: Evolution and domestication, an introductuio; Civilization and domestication of pigs; Pig breeds of the world: Their distribution and adaptation; Evaluation and utilization of pig breeds; New breed development in pigs; Gene identification in pigs; Breed identification and development in pigs; Conservation of resources in pigs and sheep; Domestication, history and breed evolution in sheep; Classification and distribution of sheep breeds; Breed differences in adaptation of sheep; Breed differences in prolificacy of sheep; Milk breeds of sheep; Breed comparisons for meat production in sheep; Genetic resources for production; Fur breeds of sheep; Breed structure, dynamics, and new breed development in sheep; Milk recording, breeding and selection schemes for milk breeds; Breeding programmes in nordic countries based on filed prodiction recording; State farm breeding in eastern european countries; International exchange of genetic material; Considering the social aspects of sheep breeding programmes; Domestication and history of goats; Classification and distribution of goat breeds; Breed differences in adaptation of goats; Breed differences in production in goats; Evolution of mohair, cashmere and skins; Evaluation and utilization of goat breeds; Gene identification in goats; Breeding programmes and production recording in goats; Maintenance of genetic resources in goats.

Download or read book Bulletin written by University of Alberta and published by . This book was released on 1956 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: