A protocol to induce lactation was applied to non-pregnant gilts. In Experiment I, five gilts with oestrus synchronized through oral supplementation of 20 mg altrenogest for 18 days received: 10 mg oestradiol cypionate (EC) on the last day of oestrous expression (D0); 10 mg EC and 300 mg long-acting progesterone (P4) on D26; and two 0.53 mg doses of a prostaglandin F2α analogue (PGF) 12 h apart on D36. Blood was collected on D12, D19, D26 and D33. Milk secretion started in all gilts 24 h after PGF administration and lasted at least 8 days. Milk samples were collected from D37 to D45. The serum P4 concentration was lower on D12 than subsequently (p < .05), but the oestradiol concentration was unaltered (p > .05). The milk produced during the induced lactation was generally richer in protein and poorer in fat compared to the milk from the lactation of a reference sow. In Experiment II, the same protocol induced lactation in two gilts, which nursed fostered piglets for 22 days. Thus, lactation was induced in all treated gilts and the milk produced was capable to nurture fostered piglets.

The increase in litter resulted in increased demand for milk in farrowing rooms to improve piglet survival. This study tested a protocol for induction of artificial lactation (AL) in non-pregnant gilts as a mean to supply milk to newborn piglets. In Experiment I, five gilts received 10 mg estradiol cypionate (EC) on the last day of estrus expression (D0), 10 mg EC and 300 mg long-acting progesterone (P4) on D26, and two doses of a prostaglandin F2α analogue (PGF) I.M. on D36 (0.53 mg each, 12 h apart). Blood was collected on D12, D19, D26 and D33. Milk secretion occurred in all treated gilts 24 h after the PGF administration, lasting at least 8 d. Milk samples were collected from D37 to D45. The circulatory P4 concentration was lower on D12 than subsequently (P < 0.05), but the estradiol concentration did not differ (P > 0.05). The milk produced during the AL was generally richer in protein and poorer in fat than the milk produced during the lactation of a control sow, but both concentrations were only altered near to the 3rd d of the AL. In Experiment II, the same protocol for induction of AL was administered to two gilts. After milk secretion started, each gilt received four 5-d old piglets fostered from other litters. The piglets were nursed for 22 d and weaned weighing approximately 5 kg. Considering both experiments, AL was induced in all treated gilts and the milk produced was capable to nurture fostered piglets.