Degree Type


Date of Award


Degree Name

Doctor of Philosophy


Animal Science


Twenty-five crossbred gilts were used in an experiment to determine the valine requirement for reproduction. L-valine was added to a fortified corn-gelatin diet to attain valine levels of intake of 3.27, 5.54, 7.81, 10.08, and 12.35g per day. All diets were fed at the rate of 1.82 kg daily before mating, during three pregnancies and during the weaning-conception intervals. During each three week lactation all sows were fed the same 12.6% crude protein corn-soybean meal-gelatin diet. Litter size and feed intake were standardized during both lactations;Five day nitrogen balance trials were initiated on day 45 and 90 of both pregnancies and on day 15 of both lactations. There were no differences among treatments for retained nitrogen. A linear (P < .01) and quadratic (P < .05) effect was observed for plasma urea nitrogen and for plasma valine concentration. The retained nitrogen reached a maximum at 5.5g of valine intake per day. No effect of valine level was observed for retained nitrogen during lactation, but the sows fed 5.5g of valine per day had the maximum retention;No significant differences among treatments were observed for litter size, average pig birth weight or average pig weight gain. A quadratic effect (P < .05) was observed for the number of services that there were no differences among treatments for days to estrus, total embryos, live embryos or in the number of corpora lutea;Sow gestation weight gain increased linearly (P < .01) with increasing levels of valine intake. All sows were slaughtered at 24.8 (+OR-) 2.9 days. No significant differences were observed for any of the carcass measurements attributable to level of valine intake. Considering all the parameters, a level of 5.5g of valine per day (.32% at 1.82 kg per day), will meet the requirement for pregnant swine.



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Copyright Owner

Alberto Robles-Cabrera



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86 pages