Degree Type


Date of Award


Degree Name

Master of Science


Animal Science

First Advisor

Mark S. Honeyman


The objective of this study was to investigate an alternative feedstuff, Iowa-grown field peas, for finishing pigs. Field peas (winter, spring, and summer types) grown in southeast Iowa during 2005 and 2006 were sampled and analyzed for nutrient content. Overall, the peas averaged 86% DM, 2.8% ether extract, 5.7% crude fiber, 3% ash, 19.3% CP, 1.54% lysine, 0.20% methionine, 0.18% tryptophan, and 0.74% threonine. Finishing pigs, barrows (n = 64), were randomly assigned to 16 pens with four pigs each.

There were four replications per treatment group. Each pen was assigned one of the four diets. The four diets were: 1) winter pea 30% of the total diet (by weight), 2) summer pea 30%, 3) spring pea 30%, and 4) corn-soybean meal as the control. The three pea diets contained corn but no soybean meal. Each of the four diets had 0.64% lysine based on calculated analysis. Crystalline amino acids (lysine, tryptophan and threonine) were added to the pea diets. The pigs started the experiment at 80 y 2.5 kg live weight and were fed the experimental diets for 39 d. Pigs were weighed individually at the start, at 14-d intervals, and at the end of the experiment.

At final weighing, backfat and loin muscle area was ultrasonically evaluated on each pig. There was no difference in final pig weight (123 y 3 kg) for the four treatment groups (P > 0.10). There were no treatment effects on average daily gain (ADG) (P = 0.22) across dietary treatments. Average daily feed intake (ADFI) was influenced by dietary treatments (P < 0.10). Pigs tended to consume less corn-soybean meal and spring pea diets than the winter and summer pea diets, with ADFI of 4.0, 3.8, 3.5, and 3.4 kg/d for winter, summer, spring, and the control diets, respectively (P < 0.10). Feed:Gain (F:G) was not different among the treatment groups (P > 0.10). Pigs fed winter peas had greater backfat (BF) than pigs fed spring peas or the control diet (P < 0.10). Pigs fed summer peas were intermediate in BF and did not differ from the other treatments (P > 0.10). There were no differences between dietary treatments for loin muscle area (LMA), although the pigs fed spring peas had numerically smaller loin muscle areas (P > 0.10). There were no differences in the overall fat-free lean values (P > 0.10). In this study, the results showed no decrease in performance of finishing pigs at the inclusion rate of 30% field peas in a corn-based diet. The 30% field pea inclusion rate was enough to replace all of the soybean meal and reduce the amount of corn in the diet.


Copyright Owner

Josephat Gichobi Njoka



Date Available


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64 pages