| Hand-clipped, hand-plucked, and rumen-fistula sampling methods have long been used to evaluate the nutritive value of grazing cattle diets. The objective of this study was to compare these techniques to determine the best method for south Texas ranchers to use in developing a low-cost supplementation programs. Ruminally-cannulated steers continuously grazing two pastures for 24 months were sampled monthly, along with monthly hand collected samples. Pasture A was comprised of Old World Bluestem (OWB) and Buffelgrass, whereas pasture B was comprised of Coastal bermudagrass and OWB. Hand-clipped samples were used to estimate standing crop and forage utilization rates on each pasture. Hand-clipped and hand-plucked forage samples were compared to rumen-fistula samples in estimating CP, NDF, and ADF. Standing crop and forage utilization changed over time and varied between pastures. The hand-plucked method was lower (P = 0.03) than the fistula method in estimating CP for pasture A; however, no difference (P > 0.05) was found between methods in estimating CP for pasture B. No difference (P > 0.05) was found between methods in estimating fistula NDF or ADF for either pasture. Both hand-sampling methods are viable techniques for estimating the nutritive value of grazing cattle diets on monoculture and mixed pastures in south Texas. |
