Masters Theses

Date of Award


Degree Type


Degree Name

Master of Science


Animal Science

Major Professor

J. P. Hitchcock

Committee Members

J. B. McLaren, Frank B. Masincupp


Two experiments were conducted to evaluate the effect of lysine and form and level of fat on weanling pig performance. In experiment 1, 56 weanling pigs were housed individually and eight pigs were fed each of the seven different diets, a basal and six others containing 1, 2 or 3% added liquid or added dry fat. The pigs were fed twice daily an ad libitum level for two weeks. Pigs fed the dry fat diets had lower average daily gains during the experiment, than did pigs fed liquid fat diets (p < .05). Initial weight affected feed efficiency (p < .05) and feed consumption. Metabolizable energy consumption was not affected by diet (p > .05). Lysine consumption per day was affected by fat source (p < .05). In experiment 2, 54 weanling pigs were housed individually and each pig was fed one of the following diets designed in a 3 X 3 factorial arrangement utilizing 3 levels of lysine (.80, .95 and 1.10) and 3 levels of fat (0, 5% dry or 5% liquid). The pigs were fed their respective diets ad libitum twice daily for three weeks. Pigs fed the control diets had a higher average daily gain (ADG) during the second week (p < .05) than pigs fed either the dry fat or liquid fat diets. Initial weight had an effect on pig gain (p < .05). An increase in lysine level from .80 to .95% in diets with no added fat decreased ADG during the second and third week and overall compared to that of week 1 but increased ADG from .95 to 1.10% (p < .05). For pigs fed the dry fat diets, ADG during week 2,3 and overall increased up to the .95% level of added lysine, and then it decreased (p < .05). Pigs fed the liquid fat diets tended to have (p = .05) a linear decrease in ADG during week 2,3 and overall, as lysine level increased from .80 to .95 to 1.10%. Feed efficiency was improved for pigs fed the control diets compared to pigs fed either of the fat diets during week 2 (p < .05). Animals fed the control diets during the third week consumed less feed (p < .05). There was no diet effect on lysine consumption during week 1, 2 or 3 (p > .05), lysine consumption per kilogram of gain during week 1, metabolizable energy (ME) consumption during week 1, 2 or 3 or ME consumption per gram of gain during all three weeks. Based on these experiments, feeding a level of added fat of 2 or 3%, seems to be the optimum added level to improve performance of weanling pigs. If fat is fed at higher levels than this then the essential amino acids need to be added to the diet in order to compensate for the lack of available nutrients. Key Words: Weanling pigs, Lysine, Metabolizable energy. Fat, Performance.

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