Long‐Term Forage and Cow–Calf Relationships for Bermudagrass Overseeded with Arrowleaf Clover or Annual Ryegrass Managed at Different Stocking Rates
2018
Rouquette, Francis M., Jr | van Santen, Edzard | Smith, Gerald R.
Bermudagrass [Cynodon dactylon (L.) Pers.] pastures are often overseeded with annual ryegrass (Lolium multiflorum Lam.) and/or clovers to extend grazing. The bermudagrass pastures were stocked at three levels of forage mass to quantify cow and calf average daily gain (ADG, gain ha⁻¹) and its relationship with mass and allowance (forage dry matter/animal body weight [DM:BW]). From 2002 through 2013, ‘Coastal’ and common bermudagrass pastures were overseeded with either ‘Apache’ arrowleaf clover (Trifolium vesiculosum Savi.) without N fertilization or annual ryegrass plus N. Calf ADG was greater (P < 0.001) on arrowleaf clover and ryegrass from February to mid‐June (spring) compared with Coastal and common bermudagrass from mid‐June to late September (summer). Calf ADG was similar for bermudagrass pastures in spring, but different (P < 0.001) at all three stocking levels for low (1.42 kg d⁻¹), medium (1.22 kg d⁻¹), or high (0.90 kg d⁻¹) stocking rates. Cow ADG in spring was greater (P < 0.01) for ryegrass (0.41 kg d⁻¹) than for arrowleaf clover (0.22 kg d⁻¹), and at all three stocking levels. In summer, calf ADG was affected by stocking (P < 0.001) at low (1.05 kg d⁻¹), medium (0.81 kg d⁻¹), and high (0.58 kg d⁻¹) stocking rates. Cow ADG in summer varied by stocking level (P < 0.01), bermudagrass pasture (P < 0.04), and stocking level × bermudagrass pasture interaction (P < 0.04). Calf ADG was optimum at 2000 to 2500 kg ha⁻¹ mass in spring, and 3000 to 3500 kg ha⁻¹ mass in summer. Optimum allowance for calves was 1.2 to 1.5 (DM:BW) in spring and 1.5 to 2.0 in summer. A two‐phase linear relationship best fit mass and allowance with cow and calf ADG for the overall 11 yr.
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