Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 6, 2003
Publication Date: April 10, 2003
Citation: Williams, M.J., Chase, C.C., Hammond, A.C. 2003. Performance of cows and their calves creep grazing rhizoma perennial peanut. Agronomy Journal. Vol.96, pp. 671-676. Interpretive Summary: Rhizoma perennial peanut (RRP) is a tropical forage legume with nutritive value similar to alfalfa. Adapted throughout much of the Gulf Coast region of the US, it is now estimated that about 15,000 acres has been planted with most of this occurring in Florida and Georgia. Because it is expensive to establish, most of this material is used for commercial hay production with little used for pasture even though studies have consistently shown between 1.5 to 2.0 lb/day gain for various classes of cattle grazing RPP. Creep grazing, utilization of a high quality forage species that only the calves have access to during the preweaning stage, may be one method for cow-calf producers to efficiently utilizing limited acreage of RPP. In a three year study looking at RPP creep, calf performance was variable in part due to yearly variation in utilization. Improvements in calf gains of 0.3 lb due to creep grazing RPP were similar to what had been previously reported for RPP in a one year study, but no affect on cow parameters was noted. For the calves, the benefits due to creep grazing were greater later in the grazing season as quality of the bahiagrass base pasture and cow milk production declined.
Technical Abstract: Where tropical grasses make up the base forage, creep grazing legumes, such as rhizoma perennial peanut (RRP), Arachis glabrata, should be beneficial. The objective of this three year study was to determine the effect of breed (Angus vs. Romosinuano) and creep grazing of RPP on the performance of cows and calves grazing bahiagrass, Paspalum notatum, in a subtropical environment. Treatments of creep and no creep were set stocked (n=24, 20, and 32 cow/calf pairs per treatment replicate combination in 1997, 1998, and 1999, respectively) on either of four treatment/ replicate combinations for an 84-d grazing period (June - September). Forage DM availability on the base pastures was similar for all three years (avg. 2.81, 2.63 and 3.13 Mg/ha for 1997, 1998, and 1999, respectively) and for both treatments (2.84 and 2.87 Mg ha-1 for creep and no creep, respectively). Forage DM availability in the creep areas averaged approximately 3.0 Mg/ha and was composed of about 60% grass and 30% RPP. Nutritive value of RPP was usually 60 mg kg-1 higher for CP and 200 mg/kg higher for IVOMD compared with the associated grass (97.7 mg/kg CP and 415.8 mg/kg IVOMD). Utilization of creep area varied with year and breed of calf (Angus <10% vs. Romosinuano >50%). As a consequence, performance of Angus calves was not affected by creep grazing, but full season average daily gain (ADG) for Romosinuano calves with access to creep area was higher (+0.14 kg/d) than calves with no creep. There was also a treatment X date interaction for body condition score (BCS) which was higher in August and September for creeped Romosinuano calves. Creep grazing the calves had no effect on cow performance (weight, ADG, BCS, or PUN).