1Instituto de Investigación de Zonas Desérticas, Universidad Autónoma de San Luis Potosí, S.L.P. México.
2Ganadería, Colegio de Postgraduados, Montecillo, México.
For correspondence: Altair 200. Fracc. del Llano, San Luis Potosí, S.L.P. 78377, México, Tel: +52 444 8422359; E-mail: jpinos@uaslp.mx.
The aims of this study were to determine: 1) nitrogen (N) release of a polymer-coated urea (PCU), 2) effects of PCU on the in vitro dry matter degradation (IVDMD) of a diet for lactating cows and 3) effects of addition of PCU (1%) to the diet on milk production of dairy cows. The N release of urea, PCU and soybean meal (SBM) were evaluated under in vitro conditions for 12 h. N release of PCU was lower than urea, but higher as compared to SBM. IVDMD of the diet with or without PCU was similar. The PCU increased the in vitro ammonia N and volatile fatty acids concentration. Milk yield, fat-corrected milk and components were not affected by PCU. Thus PCU did not affect production and quality of milk in dairy cows.
Polymer-coated urea, in vitro degradation, dairy cows
