Use of an in vitro gas production procedure to evaluate rumen slow-release urea products

Changes in the Solid-, Liquid-, and Epithelium-Associated Bacterial Communities in the Rumen of Hu Lambs in Response to Dietary Urea Supplementation

“…In the present study, the ammonia level in the rumen was increased with urea supplementation ( Table 2), which is consistent with previous results (Spanghero et al, 2018). This result can be attributed to diverse ureolytic bacteria that do not limit the conversion of urea to ammonia (Cook, 1976;Jin et al, 2017), and the increased number of rumen protozoa in the LU treatment in comparison with UC treatment ( Table 6).…”

“…The molar concentrations of butyrate and isovalerate were higher in the HU treatment than in the UC and LU treatments ( Table 2). Similarly, Meng et al (2000) and Spanghero et al (2018) documented that butyrate production increased during in vitro rumen fermentation. Moreover, Jin et al (2018) found that valine, leucine, and isoleucine metabolism were enhanced in the rumen of dairy cattle fed urea.…”

<i>In vitro</i> ammonia release of urea-treated high moisture barley and maize grain

“…Recently, the ammonia release in the rumen from substrates added with very high amounts of urea (around 10%) was indirectly measured by the in vitro gas production (Spanghero et al, 2018), but such procedure must still be verified in cereals with much lower urea additions, such as the samples of present paper. Then, in the experiment 2 a possible effect of the physical form of the grains on the rate of ammonia release was evaluated by a water solubility test.…”

Analysis of NH3-N Slow Release systems for fiber digestibility of low-quality forage: in vitro approach

“…A topic of interest in recent years in ruminant feed has been the search for strategies that can optimize nutrient synchrony between N and carbohydrate compounds in the rumen, and promote better nutrient use and energy efficiency as well as reduce the risk of environmental pollution (Holder et al, 2015;Spanghero et al, 2018;Yan et al, 2018). N retention in the rumen is mainly mediated by the degradation rate of N compounds and carbohydrates, and by the energy available for protein synthesis (Calsamiglia et al, 2010).…”

“…In low-quality forage diets, a source of Non-Protein Nitrogen (or NPN) is needed to improve microbial growth. However, their use is limited because the ruminal degradation rates of fiber (energy) and urea hydrolyses are very different and they can lead to loss of N or even toxicity (Almora et al, 2012;Holder et al, 2013;Spanghero et al, 2018). However, urea is still the most used NPN for this purpose due to its low cost, availability, easy handling and application (Kertz, 2010).…”