Milk Fatty Acid Composition Analysis

There were no significant differences between results from recordings or analyses from samples obtained on lactation d 10 and d 17, except for piglet performance. The mean of values observed for d 10 and d 17 were therefore used in the statistical analysis. All data were analyzed using the PROC MIXED procedure of SAS (version 9.4, SAS Institute Inc). For gene expression data, the delta Ct values (ΔCt = Ct of the target gene – mean Ct of the reference genes) of genes were used for statistical analysis. All the data were analyzed in 2 ways: as orthogonal contrasts between low-fat and the four high-fat diets, and by multiple comparisons between the four high-fat diets. Treatment differences between groups were determined using the PDIFF option, and the results were expressed as least-squares means with pooled-standard error, except for the genes relative abundance, which were reported as a mean ± 95% confidence limits. The CORR procedure of SAS was used to analyze the correlations of digestible FA intake and milk FA output, and the amounts of de novo synthesized fat using the two prediction methods. For the statistical evaluation, P ≤ 0.05 was declared as a significant response, while P ≤ 0.10 was declared as a tendency.