Untersuchungen zur Wirkung von Phosphorsäurephenylesterdiamid als Inhibitor der Pansenurease bei der Milchkuh

Abstract

Two lactating cows with duodenal re-entrance cannulae were fed with rations containing 180g urea (A) resp. urea modified with the urase inhibitor phosphoric phenyl ester diamide (PPD, 1 g PPD/100 g N). The cows, accustomed to urea, were not adapted to PPD (B) resp. had been adapted to PPD for 30 days (C). From A to C the digestibility of the organic matter in the stomachs amounted to 52, 47 and 52% and in the total tract to 78, 77 and 79%; the digestibility of crude cellulose amounted to 64, 50 and 62% resp. 69, 64 and 68% and that of starch to 91, 87 and 95% resp. 100% in each case. 71, 66 and 70% of the N were digested. The passage rate of N in the duodenum was 90, 102 and 106% of the N-intake. In the intestines 61, 68 and 76% of the N-intake were absorbed. The passage of bacteria-N in the duodenum was 67, 92 and 71% of the N-intake, that of the sum of NH3- and urea-N 6,8 and 8%. The conclusion is that, with unchanged digestibility of darbydrates, the N-supply of cows should be improved by the modification of urea with PPD after the adaptation of the cows. Cellulose fermentation is inhibited at the beginning of the adaptation to PPD.

Ureases in the gastrointestinal tracts of ruminant and monogastric animals and their implication in urea-N/ammonia metabolism: A review

“…A decreased fiber fermentation at the beginning of urease inhibitor supplementation was also observed for PPD by Voigt et al [108] together with a longer lasting increase in the acetate:propionate ratio [109] . The activity of urease, the hydrolysis rate of urea and the ammonia concentration in the rumen were lower than control after 0.5–2 h of feeding.…”

“… Increased urinary nitrogen excretion and decreased nitrogen retention linearly Ludden et al [105] N (n-butyl) thiophosphoric triamide (0.25 and 4 g/day) Sheep fed 1.1 and 2% urea Decreased ruminal urease activity and ammonia linearly and increased ruminal urea linearly Inhibitor activity reduced with day No effect on dry matter, fiber and nitrogen digestibility Increased urinary nitrogen excretion quadratically and decreased nitrogen retention linearly Ludden et al [105] Acetohydroxamic acid (90, 180 and 360 or 375 mg/kg body weight) Sheep Rumen ammonia peaks were decreased at 360 mg/kg No effect on total or individual rumen short chain fatty acid concentration, digestibility and counts of bacteria and protozoa Nitrogen retention increased at 375 mg/kg Streeter et al [106] Acetohydroxamic acid at 5 and 10 mM In vitro Decreased the growth in the following way: Fibrobacter ( Bacteroides ) succinogenes S85 ≫ Prevotella ( Bacteroides ) ruminicola 23 > Butyrivibrio fibrisolvens D1 ≥ Butyrivibrio sp. C 3 > Megasphaera ( Peptostreptococcus ) elsdenii B159 > Selenomonas ruminantium GA192 Changed the volatile fatty acid production pattern Chan and Jones [56] Hydroquinone at 0.01, 0.1, 1 and 10 mg/L In vitro sheep rumen fluid Reduced urease activity by 25–63% Increased cellulase activity Zhang et al [107] Phosphoric phenyl ester diamide (1 g/100 g N) Dairy cows Digestibility of carbohydrates, Improved N-supply Cellulose fermentation inhibited at the beginning of the adaptation to the compound Voigt et al [108] Phosphoric phenyl ester diamide at 0.1, 0.5 and 1.0% of N Cows The activity of urease, the hydrolysis rate of urea and the ammonia-concentration in the rumen reduced 0.5–2 h after feeding The effects decreased...…”