Effects of Energy Restriction during Gilt Development on Milk Nutrient Profile and Progeny Biomarkers

Research at the University of Nebraska investigating the effects of energy restriction on gilt development (including 14 batches with data collected over 4 parities per batch) has lead to the observation that this approach increases sow longevity but may also provide beneficial effects to first parity progeny with respect to health and growth. Specifically, parity 1 progeny may have increased weaning weight compared to progeny derived from gilts fed an ad libitum control diet. Thus, our objective was to evaluate the effects of energy restriction during gilt development on milk nutrient profile and post-natal progeny biomarkers. During the development period, gilts (n = 128, 8 gilts/pen) were fed three dietary treatments including: 1) Control diet formulated to NRC (2012) specifications (CTL); 2) Restricted (20% energy restriction via addition of 40% soy hulls; RES); and 3) Control diet plus addition of crystalline amino acids equivalent to the SID Lys:Met of the RES diet (CTL+). All diets were fed ad libitum and applied in a 3 phase feeding regimen during gilt development (d 120 to 240). Average daily feed intake was used to estimate daily ME intake (Mcal/d) during each phase (Phase 1: 10.13, 6.97, 9.95; Phase 2: 11.25, 8.05, 10.94; and Phase 3: 9.47, 7.95,11.07) for CTL, RES, and CTL+, respectively. At 240 d of age gilts were bred and fed a common diet. For this preliminary analysis, milk samples were collected from batch 14 gilts (n = 7/treatment) on d 0 and 14 post-farrowing for analysis of N, CP, DM, GE and milk insulin, and piglet blood samples (n= 6 piglets/sow) were obtained on d 1 and 15 for quantification of glucagon-like peptide-2 (GLP-2) and insulin. No effects of diet were observed for milk N, CP, or insulin; however, N, CP, and insulin were increased (P < 0.05) on d 1 compared to d 14. When evaluating DM and GE, no diet or time effects were observed. For piglet GLP-2, a treatment by time interaction was observed (P < 0.009); specifically, GLP concentrations were greater (P < 0.001) in CTL+ compared to RES (6.73 vs 1.21 ng/mL). For serum insulin, a treatment by time interaction was observed (P < 0.01); specifically, insulin in RES was greater (P < 0.03) than CTL on d 1. In conclusion, nutritional management of the developing gilt may impact piglet serum biomarkers during lactation.