Stocker Cattle Performance from Grazed Mixtures of Triticale and Wheat with Ryegrass
Type of Degreethesis
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Previous research indicates that beef production from winter grazing in the lower Gulf Coast region is typically greater from monocultures of ryegrass (Lolium multiflorum) and wheat (Triticum aestivum) than triticale (× Triticosecale); how-ever, little information is available on beef production from mixtures of these species. For this reason, we conducted a 2-yr experiment to evaluate triticale (T; var. ‘Tri-cal 2700’), wheat (W; var. ‘SS 8641’) and ryegrass (RG; var. ‘Marshall’) in mixtures as winter forage for grazing beef cattle. Replicate 1.42-ha paddocks of T + RG, W + RG and T + W + RG (2 paddocks/ treatment) were planted on November 30, 2012 (Yr 1) and November 4, 2013 (Yr 2), and were initially stocked with 4 yearling crossbred steers (mean initial BW, 357 kg) per paddock on January 29, 2013 (Yr 1) and December 16, 2013 (Yr 2). Forage allowance was maintained at a target value of 1 kg DM/kg steer BW utilizing an adjustable stocking density by the put-and-take method. Forage mass and nutritive value were determined by clipping eight 0.25-m2 quadrats per paddock prior to grazing and at subsequent 2-wk intervals throughout the duration of the experiment. Grazing was discontinued in Yr 1 on May 24, 2013 (116 d) and in Yr 2 on May 5, 2014 (141 d) when forage mass and quality were no longer able to support an ADG 0.90 kg. Data were analyzed as a completely randomized design by the PROC MIXED procedure of SAS 9.2, and forage metrics and chemical composition determined at each sampling period were treated as repeated measures. Suboptimal early-season growing conditions in Yr 2 contributed to decreased mean for-age mass (P < 0.001) and stocking density (P = 0.003) compared with Yr 1. Across both yr, mean forage mass (1,093 kg DM/ha), forage allowance (0.89 kg DM/kg steer BW) and grazing-d/ha (375) did not differ (P > 0.10) among treat-ments, and there were no differences (P > 0.10) among treatments in steer ADG (1.45, 1.49 and 1.39 kg/d for T + RG, W + RG and T + W + RG, respectively). Mean forage IVDMD (90.9%) and concentrations of CP (19.5%) and ADL (1.2%) were not different (P > 0.10) among treatments. Results indicate that binary mixtures of W and T with RG were comparable, and the ternary mixture offered no advantage over binary mixtures, for beef production from winter-grazing of these forage species.
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