Tropical Grasslands (2001) Volume 35, 110
Leucaena for weaned cattle in south Florida
R.S. KALMBACHER1, A.C. HAMMOND2, F.G. MARTIN3, F.M. PATE1 and M.J. ALLISON4
1University of Florida, Range Cattle Research and Education Centre, Ona
Two experiments using newly weaned heifers or steers compared leucaena (Leucaena leucocephala) (0.4 ha) + bahiagrass (Paspalum notatum) (0.4 ha) vs bahiagrass (0.8 ha) (3 replicates). In Experiment I, 18 heifers were inoculated with dihydroxypyridine-degrading (DHP) bacteria and placed on treatments from June 1994–January 1995. Presentation yields of leucaena leaf in June were 1800 kg/ha with 30% crude protein, and 62% IVOMD. Liveweight gains (LWG) for 1994 were greater for heifers grazing leucaena + bahiagrass (34 kg/hd) vs bahiagrass alone (12 kg/hd) even though heifers ate little leucaena until September. Experiment I continued with the same group of heifers grazing the same treatments from April–December 1995. Leucaena leaf was 1200 kg/ha in April and virtually nil by June. LWGs were similar for both groups. In Experiment II, two different groups of 18 steers each grazed from July–November 1996 and 1997. Initial presentation yields of leucaena leaf in July 1996 and 1997 averaged 2200 kg/ha and declined to 400 kg/ha in November each year. Mean LWG over 112 days in 1996 and 1997 was 53 kg/hd for steers grazing bahiagrass + leucaena and 8 kg/hd for steers grazing bahiagrass alone. Passive transfer of DHP-degrading bacteria was demonstrated. Leucaena is a dependable legume and can provide a high level of nutrition for weaned cattle in Florida providing its use is deferred until late summer when bahiagrass nutritive value is low. Weaned cattle not accustomed to leucaena may require adaptation by grazing with cattle used to grazing leucaena in order to hasten acceptance and permit transfer of rumen bacteria with DHP-degrading ability.