Table 4.
Urine volume, urination frequency, urine and faecal characteristics and water intake of dairy cows grazing RGWC, PLL and PLH.
| RGWC | PLL | PLH | SEM | p-Value | |
|---|---|---|---|---|---|
| Apparent herbage N intake | 507 | 539 | 560 | 26.8 | 0.392 |
| Urine volume and urination pattern | |||||
| Urine volume (L/cow/day) 1 | 40.8 a | 49.1 ab | 58.9 b | 3.66 | 0.008 |
| Urination (urinations/cow/day) 1 | 13.3 | 14.8 | 17.0 | 1.05 | 0.064 |
| Urination volume (L/urination) 1 | 3.0 | 3.5 | 3.5 | 0.22 | 0.187 |
| Urinary N (g/kg) 2 | 5.5 a | 4.5 b | 3.9 b | 0.23 | <0.001 |
| Urine creatinine (mmol/L) 2 | 2406 | 2140 | 2270 | 106 | 0.199 |
| Urine urea (mmol/L) 2 | 242 a | 197 b | 172 b | 7.0 | <0.001 |
| Urine NH3 (mmol/L) 2 | 2.5 | 2.8 | 2.7 | 0.15 | 0.427 |
| Urine Na (mmol/L) 2 | 88 a | 75 b | 72 b | 3.84 | 0.008 |
| Urine K (mmol/L) 2 | 169 | 176 | 176 | 4.6 | 0.457 |
| Urine Cl (mmol/L) 2 | 121 a | 171 b | 181 b | 6.8 | <0.001 |
| Faecal characteristic | |||||
| Faecal DM content (%) 2 | 11.3 a | 12.6 b | 13.6 c | 0.34 | <0.001 |
| Faecal N (g/kg DM) 2 | 27.7 | 28.1 | 27.4 | 0.38 | 0.485 |
| Water intake | |||||
| Herbage water intake (L/cow/day) 3 | 57 a | 79 b | 86 b | 3.6 | <0.001 |
| Trough water intake (L/cow/day) 3 | 23 a | 16 b | 13 b | 1.5 | <0.001 |
| Total apparent water intake (L/cow/d) 4 | 85 a | 101 b | 105 b | 4.0 | 0.015 |
a,b,c Mean values in the same row with different superscripts differ (p < 0.05). 1 calculated with the data from cows that wore urine sensors (n = 26) with 10 in RGWC, 8 in PLL and 8 in PLH; 2 calculated with the data from all cows (n = 90); 3 calculated with the data from pasture plots (n = 30); 4 assuming cows had similar water from supplements of 5.5 L/cow/day, estimated with the supplement DM% of 45% and the utilisation of 90%.