Table 3. Effects of dietary energy and crude protein levels on body weight, backfat thickness, weaning to estrus interval, and daily feed intake of gestating-lactating sows

Energy CP (%) ME 13.40 MJ /kg (%) ME 13.82 MJ/kg (%) SEM p-value
10.5 12 13.5 10.5 12 13.5 ME CP M × C
No. of sows 10 10 10 10 9 10
Body weight (kg)
 Day 35 244.0 239.1 239.7 239.9 239.3 243.0 2.56 0.98 0.91 0.85
 Day 110 259.0 254.0 252.3 252.7 254.0 259.2 2.40 0.96 0.93 0.56
 Change (d 35-110) 15.0 14.9 12.6 12.9 14.7 16.2 1.67 0.97 0.91 0.99
 24 hours. postpartum 239.6 233.4 226.2 230.3 234.4 243.1 2.57 0.57 0.97 0.12
 Day 21 of lactation 238.7 241.2 231.8 230.7 235.0 243.8 2.89 0.93 0.88 0.32
 Changes (d 0-21) 0.9 7.8 5.6 0.4 0.6 0.7 1.36 0.21 0.35 0.42
Backfat thickness (mm)
 Day 35 20.2 20.2 20.2 21.6 21.8 20.2 0.76 0.51 0.90 0.90
 Day 110 20.7 21.4 21.3 23.8 22.8 22.3 0.83 0.30 0.98 0.85
 Gain (d 35-110) 0.5 1.2 1.1 2.2 1.0 2.1 0.71 0.41 0.95 0.75
 24 hours. Postpartum 20.2 18.9 18.7 23.9 22.2 20.4 0.84 0.10 0.47 0.87
 Day 21 of lactation 16.7 18.6 19.6 21.6 21.9 19.1 0.81 0.13 0.84 0.39
 Changes (d 0-21)1) −3.4 −0.3 0.9 −2.3 −0.3 −1.3 0.46 0.73 0.03 0.31
Lactation ADFI (kg/d) 6.58 7.20 6.93 6.49 6.40 6.93 0.139 0.37 0.48 0.48
WEI (d) 4.61 4.61 4.94 4.72 4.93 5.00 0.087 0.37 0.35 0.82
Linear response (p < 0.05) to dietary CP levels when a significant CP effect was detected.
CP, crude protein; ME, metabolizable energy; SEM, Standard error of means; ADFI, average daily feed intake; WEI, weaning to estrus interval.