283 Ordered logistic regression analyze the effect of elements in serum and seminal plasma on abnormal sperm rate in boars
Abstract Poor sperm morphology decrease sow litter size and the economic profitability of breeding herds. Our previous results revealed elements in serum and seminal plasma, such as copper, iron, and lead affects abnormal sperm rate (ABR) in boars. In this study, sperm morphology and elements in serum and seminal plasma of 385 boars were analyzed using CASA and ICP-MS, respectively from June to August in 2016. Multivariate ordered logistic regression model, which includes variables of boar breed, age, serum and seminal plasma elements was used to identify the influence degree of elements on ABR. The degree of ABR was classified grade 0: < 10%, grade 1: 10–20%, and grade 2: > 20%. Results showed ABR was influenced by boar breed, serum Cu and Fe, and seminal Pb contents (P < 0.0001). Yorkshire boars (OR: 0.321; CI: 0.187 to 0.551) and Landrace boars (OR: 0.224; CI: 0.135 to 0.371) had lower ABR than Duroc boars. Boars with serum Cu ≤2.0 mg/L had lower ABR than those with serum Cu ≥2.5 mg/L (OR: 0.483; CI: 0.281 to 0.830). ABR of boars with serum Fe ≤ 1.0mg/L was greater than that of boars with serum Fe 1.5 mg/L (OR: 2.213; CI: 1.188 to 4.120). In addition, boars with seminal plasma Pb 0 μg/L had lower ABR than those with seminal Pb ≥ 10 μg/L (OR: 0.362; CI: 0.174 to 0.757). In conclusion, Duroc boars had more risk of ABR compared with Yorkshire and Landrace boars. The decrease of seminal plasma Pb and serum Cu, and increased of serum Fe content can decrease ABR in boars.