Impact of diet deprivation and subsequent overallowance during gestation on lactation performance of primiparous sows1

Abstract The impact of diet deprivation followed by overallowance during gestation on metabolic status of pregnant gilts and their lactation performance was determined. Gilts were fed a standard diet until day 27 of gestation and were subsequently reared under a control (CTL; n = 28) or an experimental (treatment, TRT; n = 26) dietary regimen. The experimental regimen provided 70% (restriction diet, RES) and 115% (overallowance diet, OVER) of the protein and NE contents provided by the CTL diet. The RES diet was given from days 28 to 74 of gestation followed by the OVER diet from day 75 until farrowing. Blood samples were obtained from all gilts on days 28, 75, and 110 of gestation, and on days 3 and 20 of lactation to measure concentrations of IGF-1, urea, FFA, and glucose. Milk samples were collected from 12 sows per treatment on day 19 of lactation and sow feed intake was recorded daily throughout lactation. Piglets were weighed at 24 h (after standardization of litter size), and on days 7, 14, and 21 (weaning). The TRT gilts gained less BW than CTL gilts (17.3 vs. 31.7 kg; P < 0.01) from days 28 to 75 of gestation and more BW (29.5 vs. 21.9 kg; P < 0.01) from days 75 to 110, but their overall gain from mating to day 110 was lower (61.4 vs. 67.2 kg; P < 0.05). Metabolic status during gestation was affected, with TRT gilts having less IGF-1 and urea, and more FFA than CTL gilts on day 75 (P < 0.01), and more urea on day 110 (P < 0.01). Growth rate of suckling piglets, sow lactation feed intake, and standard milk composition in late lactation (DM, fat, protein, lactose) were not affected by treatment (P > 0.10). In conclusion, diet deprivation of gilts as of day 28 of gestation followed by overfeeding from day 75 of gestation until farrowing did not improve lactation performance. It is likely that the compensatory growth that took place in late gestation was not adequate to illicit beneficial effects.