New Panicum Maximum Cultivars for Intensive Milk Production.

Most of the Brazilian intensive grazing systems are based on species of Panicum maximum grasses. In this context, Embrapa has recently launched two cultivars with a greater production potential and other favorable characteristics. This study was carried out to evaluate milk production of cows in pastures of two Panicum maximum cultivars (BRS Zuri and BRS Quênia) managed under rotational stocking during the rainy season. The experimental design was in randomized blocks with three replicates of the area. Each paddock had 830 m². The rest period corresponded to the light interception of 95% by the canopy. The grazing period was three days with four Holstein x Zebu cows per paddock seeking a canopy height retraction of 40-50%. Extra (non-lactating) cows were available to ensure the required canopy retraction. To evaluate milk production, each cow was considered an experimental unit. Data were analyzed as repeated measures (four grazing cycles) using the Mixed Procedure of SAS®. Means were estimated using the "LSMEANS" command and comparisons made with Student t-test with 10% significance level. The pre-grazing forage mass did not differ between cultivars with an average value of 6,098 kg dry matter/ha. The average rest period was 15 and 16.5 days for BRS Zuri and BRS Quênia, respectively. However, for BRS Quênia one extra cow was used to achieve the required canopy retraction. Consequently, the stocking rate were 10 and 10.4 cow/ha for BRS Zuri and BRS Quênia, respectively. The average milk production per cow did not differ between cultivars (13.9 and 13.2 L/day for BRS Zuri and BRS Quênia, respectively; P>0.10). As a result, the estimated milk production per hectare was 138 L/ha/day. In conclusion, no difference was observed between the two cultivars and both demonstrated a high forage mass production and potential for intensive pasture-based milk production systems. (Support: FAPEMIG/CNPq)