The Effect Of Urease Inhibitors On Nitrogen Metabolism And Rate Of Nutrient Digestion In Goat Rumen

Four 20kg six-month old goats with permanent remen cannula were used to study the effect of three kinds of urease inhibitors acetohydroxamic acid (AHA), hydroquinone (HQ), yucca extract (YU) on nitrogen metabolism, nutrient degradability in rumen and nutrient digestibility. The goats were feed one of four diets with 1% Urea that contained basic diet, AHA 25mg/kg ,YU 120mg/kg ,HQ 40mg/kg. The experiment design was a 4+4 Latin Square. Trial 1 pH value. Ammonia concentration and Urea-N concentration of ruminal fluid were sampled at 0, 2, 4, 6 and 8 h after feeding. The result showed that pH values were decreased after feeding and begin to get back after feeding 6h. HQ decrease Ammonia concentration 15.24%(p<0.05) before feeding,decrease 14.32% after feeding 2h (p<0.05). AHA, YU, HQ each decrease 33.12%, 24.15%, 31.69% of Ammonia concentration after postfeeding 2h on the higher dose. Add urease inhibitors in dietary can control the Ammonia concentration of ruminal fluid fluctuation violently. There are no significantly difference on the Urea-N concentration.The AHA.YU and HQ can increased the concentration of WA at 2h pastfeeding (p<<0.05).The propionic acid concentrations of ruminal fluid is significantly increase in HQ diet than control treatment. The acetic acid to propionic acid did not change greatly (p>0.05).Trial 2 The experiment dietary, the experiment animals and The experiment design were the same as the Trial 1. The effect of the AHA, YU and HQ on the degradability of DM,CP, NDF and ADF in the rumen were evaluated. The result showed that the AHA and HQ increase the degradability of DM 13.87% and 16.85%, AHA increased the degradability of CP was 6.89%(p<0.05). AHA and HQ increase the degradability of NDF 9.39% and 13.44% compared with control treatment (P<0.05).Compared with control treatment HQ increase the degradability of ADF was 13.67%(P<0.05).Trial 3 The experiment dietary. The experiment animals and The experiment design were the same as the Trial 1. In this experiment the effect of AHA, YU,HQ on the nutrient apparent digestibility of DM, CP, NDF and ADF were studied.The result showed that the HQ can increase the digestibility of DM 12.31%(p<0.05). The AHA and HQ compared with control treatment increase the digestibility of CP 6.27% and 4.46%(P<0.05). AHA and HQincrease the apparent digestibility of NDF 6.58% and 5.93%(P<0.05).Trial 4 The experiment dietary, The experiment animals were the same as the Trial 1. The design was comparison. This experiment was designed to determine the effect of AHA.YUand HQ on total counts of rumen microorganism in goat rumen. The result showed that the urease inhibitors did not changed the populations of bacteria (p>0.05). Yucca extract can decrease the population of protozoa significantly(P<0.05).Master candidate: Li DagangSupervisor: Prof. Li JieMajor: Animal nutrition and feed science...