Effects on puberty attainment in gilts of continuous or limited exposure to boars

Abstract

To identify alternative practical procedures for stimulating early puberty in gilts, 64 crossbred gilts were allotted to 1 of 4 treatments as follows: (1) 5-min daily boar exposure, (2) 15-min daily introduction to an area adjacent to 5 boars in their pens, (3) continuously housed with a mature vasectomised boar, or (4) control, no boar exposure. Experimental treatments commenced when the gilts averaged 176 days of age, and continued until oestrus was detected or the gilts reached an average age of 212 days. All treatment groups were significantly different from the control group for the following parameters; the percentage of giltsdetectedin oestrus (93.3, 68.8, 81.3 and 31.3%, respectively), the estimated age at puberty or first ovulation (189.0, 194.9, 188.0 and 203.4 days, respectively), and the percentage of gilts estimated to have attained puberty (100, 81.3, 100 and 43.8%, respectively). We conclude that daily introduction to a corridor adjacent to mature boars and continuous housing with a mature vasectomised boar are as effective in stimulating early puberty in gilts as is daily introduction to a mature boar, and may be more practical in several commercial situations.