Record Details
Field | Value |
---|---|
Title | The relationship of initial weight to growth rate in preweaning pigs |
Names |
Keeler, Joseph Lambert
(creator) England, David C. (advisor) |
Date Issued | 1964-07-07 (iso8601) |
Note | Graduation date: 1965 |
Abstract | Growth data compiled in this study were collected by using pigs farrowed during the fall, 1963 and spring, 1964 farrowing seasons of the Oregon State University swine herd. Thirty-seven trios of light-, medium- and heavy-birth-weight suckling pigs were used to determine the effect of birth weight on subsequent rate of gain under conventional preweaning management conditions. Thirteen pairs of light- and moderate-birth-weight pigs reared from an initial average weight of 8.5 pounds were used to determine the effect of birth weight on rate of gain under a laboratory environment and to compare the relative feed consumption and efficiency of feed utilization under this same environment. For conventionally reared pigs, a significant difference (P < .05) was found between the birth weight groups for the number of days required to grow from 4 to 15 pounds; pigs of heavier birth weights required significantly fewer days. A significant difference (P < .05) was found between birth weight groups for average daily gain from birth to 25 pounds with the pigs of light birth weights gaining more slowly than pigs of heavier birth weights. Highly significant (P < .01) correlation coefficients were found for birth weight with total gain to 56 days and birth weight with the number of days required to grow from 4 to 15 pounds. Birth weight was significantly (P < .05) correlated with average daily gain from birth to 25 pounds. No association (P > .05) was found for birth weight with the number of days required to grow from 10 to 25 pounds or for the number of days required to grow from 4 to 25 pounds, No significant difference (P > .05) was found between birth weight groups for the number of days required to grow from 10 to 25 pounds or from 4 to 25 pounds. The conclusion was drawn that pigs of light birth weight are adversely affected by neonatal environmental conditions in the expression of their ability to grow but become equally as competent as their initially heavier litter mates in this respect during later preweaning life. Under laboratory conditions, no significant differences (P > .05) occurred between pigs of light and moderate birth weights, for rate of gain, total feed consumption or efficiency of feed utilization. From these data it was concluded that: (1) pigs of light birth weight have the innate capacity to grow as rapidly, and with as much efficiency, as pigs of heavier birth weight; (2) the use of a weight constant preweaning test period seems to more accurately indicate actual genotypic differences of pigs than does an age constant test period; (3) when given environmental conditions which adequately provide for their needs, pigs of light birth weight are as economically productive as their littermates which were heavier at birth; and (4) pigs of light birth weight are not genetically inferior and, for this reason, their use in a selection program can increase the number of animals from which selections can be made, with consequent increased opportunity for efficiency of selection. |
Genre | Thesis/Dissertation |
Topic | Swine |
Identifier | http://hdl.handle.net/1957/48593 |