Table 2.

Effect of incremental dietary energy density during late gestation and lactation on sow BW and back fat thickness, and sow body condition changes during lactation

Dietary treatment	LL	L	H	HH
MJ DE/kg	13.8	14.5	15.2	15.9	SEM	P-value1
Number of sows	25	25	25	25
BW, kg1
Day 105 of gestation	278.1	277.9	279.5	282.0	7.19	0.84
Farrowing2	239.3	240.6	239.0	243.3	1.44	0.12
Weaning3	256.4	255.0	252.3	261.5	2.70	0.11
Service3	246.5	247.4	243.9	251.4	2.61	0.23
BF, mm
Day 105 of gestation	18.0	18.4	18.0	18.5	0.70	0.91
Day 14 of lactation	15.7	16.0	16.0	16.7	0.41	0.30
Weaning	14.8	14.9	14.8	15.6	0.41	0.40
Service	14.9	15.0	14.4	15.0	0.41	0.63
Sow BW change, kg
Day 105 to weaning4	−19.9	−21.6	−24.1	−18.2	2.61	0.40
Farrowing to weaning4	+17.7	+13.9	+13.7	+18.9	2.92	0.44
Weaning to service5	−10.0	−7.6	−8.5	−10.4	1.56	0.55
Sow BF change, mm
Day 105 to weaning6	−3.1	−3.2	−3.0	−2.7	0.44	0.88
Weaning to service7	+0.1	+0.1	−0.5	−0.7	0.43	0.60

BF, back fat thickness.

¹Treatements with different superscript letters within a row are considered significantly different at P < 0.05 and as tendencies at P > 0.05 but less than P < 0.10. Sow BW and BF at day 105 was used as covariate for the analysis of subsequent sow BW and BF.

²Estimated value: empty farrowing weight = (sow weight at day 105 – (total born × 2.25)). The value of 2.25 kg is an estimate of the increased weight in the gravid uterus and in mammary tissue attributed to each pig in a litter (NRC, 1998).

³Weaning = day 26 ± 0.1 of lactation; service = day 6 ± 0.1 postweaning.

⁴Sow BW change = (sow BW at weaning – sow BW at day 105 of gestation or at farrowing).

⁵Sow BW change = (sow BW at service – sow BW at weaning).

⁶Sow BF change = (sow BF at weaning – sow BF at day 105 of gestation).

⁷Sow BF change = (sow BF at service – sow BF at weaning).