Archivos de Zootecnia
versión impresa ISSN 0004-0592
RAMIREZ, M.M. et al. Performance response of grazing lactating dairy cows to chopped fresh maize as supplement. Arch. zootec. [online]. 2011, vol.60, n.231, pp.647-657. ISSN 0004-0592. http://dx.doi.org/10.4321/S0004-05922011000300053.
Twenty four multiparous Holstein dairy cows were rotationally grazed on a mixed alfalfaorchard sward. Three treatments were evaluated: 0, 4, and 8 kg of DM of MFP cow-1 day-1. Each cow received 3.8 kg of concentrate (DM basis). The experimental design was a cross-over (3 treatments, 2 replicates with 4 animals each), with 3 periods lasting 19 days each (10 adaptation plus 9 sampling period). There were no differences on individual milk production nor on milk composition. Herbage dry matter intake decreased (p<0.0001) from 8.4 to 5.2 and 3.1 kg of DM when increasing MFP from 0 to 4 and 8 kg of DM, respectively; while total DM intake increased (p<0.0001) on those cows with the highest level of supplementation, averaging 12.2, 12.9, 14.8 kg of total DM at 0, 4, and 8 kg of DM of FCM, respectively. Substitution rate of pasture for MFP was 0.75 and 0.67 kg of pasture per kg of FCM with 4 and 8 kg of DM of MFP, respective. Consequently, stocking rate (STR) increased (p<0.0001) from 3.8, to 6.2, and 8.8 cows ha-1, with 0, 4, and 8 kg of DM of MFP, respectively; and milk production per hectare increased (p<0.0001) from 39.3 to 64.5 and 95.5 kg of milk with 0, 4, and 8 kg of DM of FCM, respectively. This means that STR increases 0.63 cows ha-1, and 0.75 kg of milk when MFP is increased in one kg of DM. It is suggested that offering MFP as supplement to grazing dairy cows in their final lactation stage had no benefits in individual milk production or milk composition; but on milk production per hectare.
Palabras clave : Dry matter intake; Stocking rate.