01946naa a2200253 a 450000100080000000500110000800800410001902200140006002400550007410000220012924501320015126000090028352011470029265300250143965300190146465300220148370000190150570000160152470000250154070000200156570000260158570000230161177300580163421185592023-03-13       2020    bl uuuu     u00u1 u    #d  a1678-992X7 ahttp://dx.doi.org/10.1590/1678-992x-2018-03832DOI1 aCRUZ, C. C. T. da  aAnalysis of NH3-N slow release systems for fiber digestibility of low-quality foragebin vitro approach.h[electronic resource]  c2020  aUrea is a common non-protein supplement used in ruminant feed; however, excessive consumption may lead to poisoning by NH3. Although the slow release of urea into the rumen has shown to be an essential aspect for ruminant feed, to date only a few studies have addressed this matter. In this study we examined the influence of five different NH3-N slow release systems based on clay-urea nanocomposites on the fiber digestibility of low-quality forage (sugarcane straw) in vitro. Physical properties of nanocomposites were evaluated and their effects on digestibility were tested in vitro using pristine urea as a positive control (level of 1 % of DM of sugarcane straw sample) and sugarcane (with no additives) as a negative control. Ammonia release and digestibility were evaluated at 12, 24, 36, 48, 72 and 96-h. Generally, all nanocomposites increased (p &lt 0.05) digestibility of fiber over control under all the conditions stipulated, but the samples with hydrogel content were more expressive. We concluded that an ideal release rate and optimum environment for microbial synthesis are necessary to maximize the digestion of sugarcane.  aNon protein nitrogen  aRuminants feed  aSlow release urea1 aPEREIRA, E. I.1 aSATO, P. S.1 aGUIMARÃES, G. G. F.1 aSOUZA, G. B. de1 aBERNARDI, A. C. de C.1 aOLIVEIRA, C. R. de  tScientia Agricolagv. 77, n. 5, e20180005, dec. 2020.