Effects of feeding regimen on semen volume (A), total sperm number (B), and functional sperm number (C) during a 28-wk period. Values were means ± SEM, n = 20–21. The lines represent data from boars on the L (dotted), M (dashed), and H (solid) groups. L, low energy intake; M, medium energy intake; H, high energy intake. The letters (A,B or a,b) show significant differences between any 2 groups, P < 0.01 or P < 0.05. NS represents no significance among treatments (P > 0.05).