Animal feed resources information system

Rego et al., 2006. Rev. Bras. Zootec., 35 (3): 691-698

Document reference 
Rego, F. C. de A. ; Damasceno, J. C. ; Martins, E. N. ; Cortes, C. ; Fukumoto, N. M. ; Roeshi, L. ; Santos, G. T. dos, 2006. Influence of structural characteristics and chemical composition of tropical grasses on the instantaneous forage intake rate. Rev. Bras. Zootec., 35 (3): 691-698

Steer forage intake rate (IR) was evaluated in pastures of Brachiaria brizantha, Panicum maximum cv. Tanzania, Arachis pintoi and mixture of Brachiaria brizantha with Arachis pintoi. The objectives were to define sward structural characteristics and chemical composition of each pasture most determinant of forage intake rate by grazing steers. The steers grazed in pairs, passing through all grass species maintained at different sward heights in successive days. After 3 h of fasting, the animals were allowed to graze each experimental area for 60 min and had their grazing time and bite numbers were registered. Forage intake was estimated by the double sampling technique. Sward structural characteristics used in the model for estimation of IR were: average sward height, morphological component proportion (%), morphological component mass (tonne DM/ha) and density of morphological components (kg DM/ha/cm). The chemical composition was expressed as crude protein (CP) and neutral detergent fibre (NDF). Sward variables were selected using the stepwise statistical procedure. The IR equations defined from the studied characteristics were: Marandu grass: IR=59.8980+0.7299 GL+3.5777 DMA-1.2459 NDFL+0.2882 SH (GL - proportion of green leaves, FM - forage mass, NDFL - NDF of leaves, SH - average sward height); Tanzania grass: IR=111.762-4.1532 CPL+0.3469 GL-0.5207 NDFL (CP of leaves, GL - proportion of green leaves, NDFL - NDF of leaves); groundnut forage: IR=-196.589+12.1978 CPS+8.3406 DMA+1.1060 GS+17.3669 GLA (CPS - stem CP, DMA - dry matter availability, GLA - green leaves availability); and mixed pasture: IR=-7.25+1.15HA-0.22HI+18.49AA-9.88GLA+0.49HM+1.00CPL (HA - groundnut forage height, HI - weed species height, AA - Arachis availability, GLA - green leaf availability of Marandu grass, HB - Marandu grass sward height, CPL - CP of leaves of Marandu grass).

Citation key 
Rego et al., 2006