Summary and Implications
The effect of feeding different lysine and metabolizable energy (ME) levels to 1221 crossbred Large White × Landrace developing gilts housed in groups from 100 d of age until slaughter (approximately 260 d of age) on age at puberty and reproductive tract measurements were evaluated. Gilts were randomly allotted to six corn-soybean diets formulated to provide two standardized ileal digestible lysine levels [100% (high, HL) and 85% (low, LL)] and threemetabolizable energy levels [ME, 90% (low, LME), 100% (medium, MME), 110% (high, HME). Average age at puberty was 193 d of age. There were no effects of the dietary treatments on age at puberty or any of the reproductive tract measurements. Despite significant differences in the lysine:energy ratio in the diets, the expected differences in reproductive traits were not observed. Other factors such as body weight (BW) and days of estrous cycle had a greater effect on the traits recorded than feed provided.
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.
Calderón Díaz, Julia A.; Vallet, Jeffrey L.; Lents, Clay; Nonneman, Danny; Miles, Jeremy; Wright, Elaine; Rempel, Lea; Cushman, Robert; Freking, Bradley; Rohrer, Gary; Phillips, Christina; DeDecker, Ashley; Foxcroft, George; and Stalder, Kenneth J.
"Optimal Dietary Energy and Protein for Gilt Development: Age at Puberty, Ovulation Rate, and Reproductive Tract Traits,"
Animal Industry Report:
AS 661, ASL R3022.
Available at: https://lib.dr.iastate.edu/ans_air/vol661/iss1/85