Grazing patterns, diet quality, and performance of cow-calf pairs using continuous or rotational grazing in the Texas panhandle USA

Abstract

This study 1) measured diet quality and performance of cow-calf pairs; and 2) compared defoliation patterns and changes in standing crop of functional groups relative to the proximity of water over a grazing season under continuous (CG) or rotational (HSD) grazing at the same stocking rate and stocking intensity. Eighty lactating cow-calf pairs were weighed and assigned among shortgrass-dominated rangeland pastures (three replicates per treatment). Standing crop by species was measured at study initiation and completion. Frequency of grazed plants was measured along 0.39km point transects radiating from water troughs. Cow and calf weights and average daily gains were compared between treatments. Mean dietary CP was higher for CG cattle. Forage quality for major species (blue grama and gummy lovegrass) did not differ between treatments. Y-intercepts of regression lines predicting probability of defoliation differed between treatments following the 1st, 6th, and 7th 16-day intervals of the 112-day grazing study. Final standing biomass of gummy lovegrass was lower in HSD. Final cool-season annual grass biomass was lower in CG. HSD grazing can regulate the frequency and timing of defoliation, thereby changing relative proportions of plant species, inter-species competition and animal performance over time.