An apparatus and method that can allow continuous and precise total collection of urine under normal conditions was developed that could satisfy the urine-sampling requirement of balance studies, metabolic experiments, and hormone trials of cows and heifers. The apparatus is composed of an anterior urethra, a urine cup, and a collection barrel. Total and precise collection of urine can be achieved without leakage, fecal contamination, or urethra infection. The apparatus has few negative effects on the cows and does not influence the cows' normal physiological activities.

In order to develop a new method for determining the phosphorus (P) digestibility in vitro in feedstuffs by dialysis tube, a L 32 (4 9 ) orthogonal experiment with eight factors (4 levels for each factor) and a single factor experiment on the enzymatic reactivity were carried out. The sequence of significance of the eight factors on sample-P dialyzability was as follows: trypsin digestion for 6 h, dialyzing solution at 100 mL, pH of pepsin solution at 2.5, pepsin concentration at 2000 U?mL 21 pepsin digestion for 100 min, at temperature of 35uC, trypsin concentration at 1625 U?mL 21 , and pH of trypsin solution at 6.5, respectively. And in vitro dialyzabilities of P in soybean meal, barley, sorghum, peanut meal, and rapeseed meal were (36.91 ¡ 0.58)%, (27.28 ¡ 0.94)%, (26.95 ¡ 0.58)%, (30.51 ¡ 0.83)%, and (20.82 ¡ 1.09)%, respectively.