Location: Reproduction ResearchTitle: Effect of feeding three lysine to energy diets on growth, body composition and age at puberty in replacement gilts Author
|Calderon-diaz, Julia - Iowa State University|
|Vallet, Jeffrey - Jeff|
|Boyd, R - Hanor Family Of Companies|
|Prince, Terry - Prince Nutrition Service Llc|
|Dedecker, Ashley - Murphy Brown Llc|
|Phillips, Christina - Murphy Brown Llc|
|Foxcroft, George - University Of Alberta|
|Stalder, Kenneth - Iowa State University|
Submitted to: Animal Reproduction Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/20/2017
Publication Date: 9/1/2017
Publication URL: https://handle.nal.usda.gov/10113/5706980
Citation: Calderon-Diaz, J.A., Vallet, J.L., Boyd, R.D., Lents, C.A., Prince, T.J., DeDecker, A.E., Phillips, C.E., Foxcroft, G., Stalder, K.J. 2017. Effect of feeding three lysine to energy diets on growth, body composition and age at puberty in replacement gilts. Animal Reproduction Science. 184:1-10. https://doi.org/10.1016/j.anireprosci.2017.06.007.
Interpretive Summary: There is interest among swine producers in developing gilts at a reduced growth rate because previous results suggest that this might be advantageous for later retention in the breeding herd. However, most gilts are fed ad libitum during their development, and ad libitum-fed diets that successfully reduce growth rate are needed. In this experiment, dietary metabolizable energy was held constant and digestible lysine was progressively reduced to determine the effects of lysine reduction on growth rate and age at puberty. Reducing the digestible lysine in the diet progressively reduced growth rates in ad libitum-fed gilts without affecting age at puberty. However, only about a third of the gilts achieved puberty in this experiment, likely due to the effect of a porcine epidemic diarrhea virus outbreak that occurred during the trial. Nevertheless, diets were successfully developed that reduced growth rate in ad libitum-fed gilts, and the effects of these diets will be tested in a future trial to determine their influence on sow retention in the breeding herd up to third parity.
Technical Abstract: This study evaluated the effect of diets differing in standard ileal digestible (SID) lysine on lysine intake, growth rate, body composition and age at puberty on maternal line gilts. Crossbred Large White×Landrace gilts (n =641) were fed corn-soybean diets differing in SID lysine concentration (%, g SID lysine:Mcal ME); diets were not isocaloric. Gilts received three grower, finisher diet combinations: low (0.68% lysine grower, 0.52% lysine finisher), medium (0.79% lysine grower, 0.60% lysine finisher) or high (0.90% lysine grower, 0.68% lysine finisher). Grower diets were fed from 100 until 142 days of age, and finisher diets were fed until they reached 220 days of age. Body weight (BW), backfat thickness (BF), and loin depth (LD) were recorded every 28 days. From 160–220 days of age, gilts were exposed daily to vasectomized boars and observed for behavioral estrus. Gilts fed the low lysine diet had lower average daily gain and BW (P < 0.05), but not fat depth:LD ratio. The percentage of gilts that displayed natural estrus by 220 days of age was low but not different among dietary treatments (low 27.7%, medium 31.0% and high 37.7%, respectively; P=0.1201). Gilts fed the high and medium diets reached puberty 10 and 6 days earlier, however, than gilts fed the low lysine diet (P < 0.05). The rate of puberty attainment may have been less because all gilts contracted porcine epidemic diarrhea (PEDv) just as boar exposure was to begin for the first group of gilts. Results from the present study indicate that growth rate and age at puberty can be altered by ad libitum fed diets that differ in SID lysine concentration.