Current Management Of Tropical Pastures To Feed Lactat1ng Dairy Cattle In Puerto Rico

In order to better understand the role of grazed tropical grass pastures in an intensive Caribbean milk production system, research was initiated in 1996 to study the current grazing management and feeding of lactating dairy cattle in Puerto Rico's dairy industry. Information from the census of 450 dairy farms in Puerto Rico was obtained from official documents. The census data pertained to farm location, pasture acreage, herd size, milk fat test results, and concentrate feed purchases. A representative sample of 100 farms was selected for survey and a subsample of 22 farms chosen for a series of on-farm visits. The survey included pasture management, grazing schedule, and feeding program of the lactating cattle. The series of on-farm visits were used for forage sampling to evaluate the pasture as a feed resource. Forage sampling results indicate that forage nutritive value (14- 24% crude protein and 59-72% in vitro digestibility) was higher than expected and forageon- offer (1.4 - 7.3 Τ DM/ha) could support more intensive utilization of pasture. Of 67 farms responding to the survey, almost all were practicing rotational grazing with hign productivity pasture species - stargrass being dominant on 78% of farms. However, relatively low stocking rates, high levels of concentrates fed (>10 kg/cow) and the island-wide milk butterfat concentration of -3% indicate that farms needing to reduce feed costs could make greater use of their forage resources.