Effect of prepubertal feeding regimen on reproductive development of gilts

The effect of prepubertal feed level on growth and reproductive development of gilts was investigated. At 13 wk of age, white crossbred gilts were pen ned individually and assigned to the following treatments: Ad lib, ad libit um intake from 13 to 25 wk of age (n = 64); Control, ad libitum intake from 13 wk of age until 100 kg BW and then 90% of ad libitum intake until 25 wk of age (n = 65); and Restricted, 74% of dd libitum intake from 13 wk to 25 wk of age (n = 64). Feed was formulated to primarily restrict energy intak e. The study was replicated in two seasons. At 25 wk of age, gilts were mov ed to group pens, approximately 16 gilts/pen, allowed ad libitum access to feed, and estrus detection was initiated. Gilts were mated at first estrus and those recycling were remated. After mating, gilts were moved to gestati on stalls and fed 1.5x maintenance. At 30 d of gestation, reproductive trac ts were harvested, and numbers of corpora lutea (CL) and live embryos were recorded. From 13 to 25 wk of age, feed consumption was 258 for Ad lib, 251 for Control, and 189 kg/gilt for Restricted, and, from 13 wk of age until 30 d of gestation, total feed consumption was 367 for Ad lib, 356 for Contr ol, and 299 kg/gilt for Restricted gilts. Age at puberty (196 d) and pregna ncy (200 d) was not affected (P > .18) by treatment. However, the rate at w hich gilts attained puberty (e.g., percentage pubertal at 28 d) was greates t in Ad lib (75) and least in Control (61) gilts. Number of CL and live emb ryos at 30 d of gestation/gilt assigned to the study was unaffected (P > .2 1) by treatment. Quantity of feed consumed from 13 wk of age to 30 d of ges tation per live embryo in gilts assigned to the study was 40.0 for Ad lib, 39.8 for Control, and 30.6 kg/gilt for Restricted gilts. These results indi cate that moderate feed restriction of gilts during prepubertal development may increase efficiency of swine production without negative impact on rep roductive performance through 30 d of gestation.