Goat weight gains, forage selectivity and forage quality dynamics in three cultivated warm season pastures in north-central Texas

Abstract

Cultivated warm-season pastures are needed to compliment range-based goat production in south central USA. Boer×Spanish does averaging 25 kg were evaluated to determine average daily gain (ADG) and selectivity for six legumes, redroot pigweed, and crabgrass grown in full-sun grass-only, full-sun mixed, and pecan grove shaded mixed paddocks during two warm seasons. Goats in the mixed pasture obtained the highest (100 g per day) and the grass-only pasture goats the lowest ADG (27 g per day) during the low rainfall year (year×pasture interaction P=0.05). The animals in both the shaded mixed and grass-only paddocks had greater ADG whereas mixed pasture animals were unchanged the second, higher rainfall year, indicating that there was competition for moisture between the herbaceous forages and the pecan trees when rainfall was low and that crabgrass monocultures require more soil moisture to maintain animal gains. Grass percentage composition increased over time for all treatments in both years. Legume percentage composition decreased over time for both mixed pasture treatments in both years, indicating goat selection for this component. Forbs tended to survive longer in mixed pasture than in the shaded mixed pasture while the grass component tended to increase in both paddocks with time. Herbage analyses indicated that crude protein (CP) tended to decrease over time while acid detergent fiber (ADF) and lignin increased, at least partially due to animal selection.