The effect of pregnancy on protein, water and fat deposition in the body of gilts

Abstract

Nineteen mated and 17 unmated Landrace gilts were divided into two feeding groups which were given daily (for 111 days of experiment) 2.5 or 3.5 kg of diet containing 120 g digestible protein (DP) and 12.6 MJ metabolizable energy (ME). On day 112 of experiment the animals were slaughtered and analysed for protein, water and ether extract content in the body. At both feeding levels live weight gain was greater ( P < 0.001) in pregnant than in virgin gilts, while the maternal body gain was greater ( P < 0.05) in pregnant gilts only at the higher feeding level. Pregnant gilts deposited more ( P < 0.01) protein in the whole body than their nonpregnant analogues, but protein deposition in the maternal body was similar in both groups. On the other hand, more ( P < 0.01) water was deposited in the whole and maternal bodies of pregnant versus non-pregnant gilts. No effect of pregnancy, however, was found on the deposition of fat in the body. The energy costs of maintenance and of protein deposition in the body of pregnant gilts were estimated at 444 kJ ME kg −0.75 and 65.4 kJ ME g −1, while in non-pregnant animals the respective values equalled 424 kJ ME kg −0.75 and 104.3 kJ ME g −1.