Date of Award


Degree Name

Master of Science


Animal Science

First Advisor

Apgar, Gary


The objective of this study was to examine the potential effects of supplementing excess crystalline tryptophan (trp) in the lactation diets of sows. Sixty-one sows of varying parity were fed either a control diet (0.26% trp) or a treatment diet with an extra two grams of tryptophan (0.30% trp). Over the 28 day lactation period utilized by the production site, sow and litter performance were recorded. Sow performance was measured by backfat loss, blood urea nitrogen, milk composition, return to estrus, wean to estrus interval, and conception rate. Litter performance was measured as average weaning weight, number weaned, and pre-wean mortality. The control and treatment groups were further subdivided by parity for statistical analysis. Sows of parity one and two were classified as primiparous, while sows of parity three or more were classified as multiparous. There were no significant differences (P≤0.05) between the control and treatment diets even with regards to parity groups. There was one trend (0.05

0.10) in which treatment multiparous sows had higher litter weaning weight (P=0.055) than the control multiparous sows. In summary, these results indicate that increasing the tryptophan level in this lactation diet by two grams did not significantly influence sow or litter performance.




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