| Summary: | 碩士 === 國立屏東科技大學 === 熱帶農業暨國際合作系所 === 99 === The objective of this research study was to investigate the effects of contaminated corn, DDGS, semen pH, and backfat on boar semen quality and sexual behavior. Two sets of experiments were conducted for the project. For both sets of experiments, 8 hybrid boars (Landrace × Yorkshire × Duroc), aged about 10 months were used. The first phase of experiment 1 involved training of the boars for successful semen collection while the second phase involved feeding of DDGS and control diets; thereby test for their semen quality and sexual behavior performances. The contamination levels of mycotoxin in the DDGS diet were 50-120 ppm Aflatoxin, 222 ppm Vomitoxin, and 10-200 ppm Fumonisin. The treatment and design structures used in experiment 1 were one-way classification and Completely Randomized method respectively. The boars were randomly assigned to the control and DDGS treatments. Each boar was considered a replicate, and there were four replications per treatment. Period length was 10 weeks. Experiment II was a continuation of experiment 1 but contaminated corn (CC) was used as a treatment diet for a period of 6 weeks. The mycotoxin concentrations in the contaminated corn were 1.7 ppm Aflatoxin, 1,550 ppm Vomitoxin, 800 ppm Fumonisin, and 1.6 ppm Ochratoxin. The same eight boars were used, but with three (3) treatment groups: control, 25%, and 50%
CC - one factor with 3 levels. The eight boars were randomly assigned to the three sets of treatments: 2 boars on the control, 3 on the 25%, and 3 on the 50% CC respectively. Semen collections and assessments, behavior observations, weighing, and back fat thickness measurements were carried out on weekly basis for both experiments one and two. All data from the two experiments were gathered and statistically analyzed. The effect of treatments, semen pH, and back fat thickness were evaluated by either T-test or analysis of variance. The differences among the means of the semen quality and sexual behavior variables were compared using the Duncan’s Multiple Range Test. Results in experiment one for “treatment” showed significant differences in mean values for gross motility, survival rate, and the individual motility of sperms (<0.05, <0.01, <0.05 respectively) but were in favor of the DDGS treatment group. Other semen quality and sexual behavior characteristics were not significantly affected (>0.05). The results in experiment II for “treatment” showed that gross motility, survival rate, and individual motility were significantly affected by the treatments (<0.001, <0.01, and <0.001 respectively) but only the group that was fed the 25% CC was most affected. False mounting was significantly affected (<0.05), and boars fed the 50% CC were most affected in false mounting behavior than those fed the 25% CC and the control diets. Generally, the treatments for both experiments one and two showed no major influence on the semen quality and sexual behavior of the boars. However, interestingly the semen pH and backfat thickness had greater influence over the semen quality and sexual behavior characteristics of the boars. Boars that had the semen pH ranging from 6 to 7.4 obtained better results in relation to semen quality and sexual behavior performances. Backfat (P2) thickness also tended to influence the boar semen quality and sexual behavior performances. Boars that had backfat thickness of >11 mm score significant results for semen quality and sexual behavior performances.
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