|Wang, Y - UNIV NEBRASKA, LINCOLN|
|Hanford, Kathryn - UNIV NEBRASKA, LINCOLN|
|Van Vleck, Lloyd|
Submitted to: American Society of Animal Science Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: March 3, 2006
Publication Date: July 1, 2006
Citation: Wang, Y., Wise, T.H., Rohrer, G.A., Hanford, K.J., Van Vleck, L.D. 2006. Effects of physiological traits on weaning-to-estrous interval in first-litter gilts [abstract]. Journal of Animal Science. 84 (Supplement 1):269. (Abstract #328) Technical Abstract: Delayed return to estrus after weaning is a significant problem for swine producers. We investigated relationships among weaning-to-estrous interval (WEI) and body weight (BW), backfat (BF), plasma leptin (L), choline (C), glucose (G), albumin (A) and litter traits to identify physiological traits associated with WEI. Data were from sows in 2002 and 2003 prior to farrowing (f, 110 d gestation), at weaning (w) and at first estrus (e) after weaning. In 2001, Yorkshire-Landrace sows were crossed with Duroc or Belgium/German Landrace boars to establish two lines. Sows from these two crosses farrowed in 2002 (n=247). The cross of the two crosses farrowed in 2003 (n=228). Separate analyses by year showed that WEI was positively associated with L_e or with L_e_-L_w, and was negatively associated with A_e (p<0.05). At f, w and e, BF was positively associated with L and A (p<0.05). Correlations were positive between changes in BW and L between f, w and e (p<0.05). With WEI classified as early/normal (1-10 d, EI), late (11-20 d, LI), very late (>20 d, VI) and no estrus (NI), stepwise logistic regression was used to generate models with reduced sets of traits to discriminate between pairs of populations: EI vs. LI+VI+NI (M1), EI+LI vs. VI+NI (M2), EI+LI+VI vs. NI (M3), EI vs. LI+VI (M4), EI +LI vs. VI (M5). M1, 2, 3 included traits through weaning, M4, 5 included all traits. For 2002 farrowing gilts, number of pigs weaned in litter (NWL), L_w had significant effects with M1. With M2, effects of A_w, NWL were significant. With M3, L_w, NWL and number of pigs born (NB) had greatest effects. With M4, A_e, NWL had significant effects. With M5, A_e had greatest effect. For 2003 farrowing gilts, BW_e-BW_w, number of pigs alive at birth (NAB), C_w and A_w had significant effects with M1. With M2 and M3, BW, A_w were significant, respectively. With M4, BW_e-BW_w, NAB and A_e had significant effects. With M5, L_e, BW_e-BW_w, BF_w, A_w-A_f had greatest effects. These results suggest there are metabolic components associated with normal and late return to estrus that may have genetic basis.