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. 2019 May 15;97(7):3016–3026. doi: 10.1093/jas/skz169

Table 4.

Nitrogen retention variables and the threonine (Thr) efficiency in gestating gilts fed Thr limiting diets at early (day 48 to 52), mid- (day 75 to 79), and late (day 103 to 107) gestation

P-value
Variables Thr-1
60%		 Thr-2
70%		 Thr-3
80%		 Thr-4
90%		 SEM Linear Quadratic
Day 48 to 52
 No. of gilts 10 11 11 12
 Initial BW, kg 167.48 165.54 166.08 164.83 2.07
 Final BW, kg 173.31 171.10 170.82 170.50 2.05
 Nitrogen intake1, g/d 36.44 36.20 36.15 36.38 0.05 0.439
 SID Thr intake1, g/d 5.28 5.86 6.45 7.04 – <0.001
 Nitrogen digestibility, % 85.78 84.89 83.87 84.95 0.27 0.113 0.048
 Urine nitrogen, g/d 24.03 23.22 23.02 24.33 0.37 0.807 0.127
 Nitrogen retention, g/d 7.23 7.51 7.31 6.58 0.38 0.480 0.468
 Whole-body Thr retention, g/d 1.69 1.76 1.71 1.54 0.09 0.492 0.463
 Thr efficiency, % 31.89 29.93 26.56 21.90 1.38 0.005 0.596
Day 75 to 79
 No. of gilts 10 11 11 11
 Initial BW, kg 185.50 181.07 177.98 182.16 2.09
 Final BW, kg 188.60 185.28 183.10 186.46 2.02
 Nitrogen intake1, g/d 35.86 35.71 37.12 35.75 0.08 0.167
 SID Thr intake1, g/d 5.08 5.67 6.26 6.65 – <0.001
 Nitrogen digestibility, % 85.19 84.88 84.22 85.30 0.23 0.901 0.157
 Urine nitrogen, g/d 19.02 18.78 18.67 18.78 0.37 0.797 0.811
 Nitrogen retention, g/d 11.53 11.54 12.62 11.74 0.38 0.628 0.558
 Whole-body Thr retention, g/d 2.62 2.64 2.90 2.69 0.09 0.555 0.538
 Thr Efficiency, % 51.67 46.54 46.29 40.50 1.46 0.013 0.918
Day 103 to 107
 No. of gilts 10 10 11 12
 Initial BW, kg 197.50 195.50 192.03 194.17 2.22
 Final BW, kg 209.20 205.70 204.25 205.92 2.11
 Nitrogen intake1, g/d 43.78 43.11 43.43 43.98 0.08 0.159
 SID Thr intake1, g/d 7.43 8.37 9.30 10.23 – <0.001
 Nitrogen digestibility, % 85.63 84.47 85.42 84.74 0.23 0.298 0.524
 Urine nitrogen, g/d 17.82 17.18 14.44 13.74 0.28 <0.001 0.948
 Nitrogen retention, g/d 19.68 19.24 22.65 23.53 0.25 <0.001 0.210
 Whole-body Thr retention, g/d 4.36 4.27 5.10 5.31 0.05 <0.001 0.192
 Thr efficiency, % 58.59 51.02 54.81 51.90 0.63 0.009 0.087

1Daily feed allocation was set at 2.13 kg/d in early and mid-gestation and 2.53 kg/d in late gestation.