Department of Animal Sciences, Auburn University, Auburn, AL 36849-5415, USA.
J Anim Sci. 2011 Feb;89(2):571-80. doi: 10.2527/jas.2010-3102. Epub 2010 Oct 22.
Dallisgrass (Paspalum dilatatum) is well adapted to the Black Belt physiographic region of the southeastern United States, and information on its productivity and nutritive quality as influenced by grazing management is needed. In a 2-yr grazing experiment, replicate 0.40-ha paddocks in established dallisgrass pasture were continuously stocked, or replicate 0.40-ha paddocks were subdivided into two 0.20-ha (RS2), three 0.13-ha (RS3), or four 0.10-ha (RS4) cells and rotationally stocked with yearling beef steers. Individual cells within the RS2, RS3, and RS4 treatments were stocked for 7 d followed by 7, 14, or 21 d of rest, respectively. In 2007, 3 Angus × Simmental crossbred steers (initial BW, 354 ± 6 kg) were assigned randomly to each paddock on July 16; in 2008, 3 Angus × Simmental crossbred steers (initial BW, 310 ± 6 kg) were assigned randomly to each paddock on July 14. In 2007, there was no effect (P = 0.25) of stocking treatment on ADG. Steers grazing RS4, RS2, and continuously stocked paddocks had 106 (P = 0.01), 86 (P = 0.03), and 83 (P = 0.03) kg greater total BW gain per ha, respectively, than steers grazing RS3 paddocks. In 2008, there were no differences among treatments in ADG (P = 0.43) or total BW gain per ha (P = 0.90). Correlation and regression analyses revealed positive associations between steer performance and forage concentration of CP, areal mass (kg/ha) of forage DM, and areal mass of forage CP. Results indicate that productivity and quality of dallisgrass for stocker cattle production were comparable between continuous and rotational-stocking methods.
梯牧草(Paspalum dilatatum)广泛分布于美国东南部的黑土带,有关其在放牧管理条件下的生产力和营养品质的信息尚需进一步研究。本试验采用 2 年放牧试验,在已建立的梯牧草草地中设置重复的 0.40 公顷样地,其中连续放牧样地(0.40ha)和分栏放牧样地(0.40ha 分为 2 个 0.20ha 小区(RS2)、3 个 0.13ha 小区(RS3)和 4 个 0.10ha 小区(RS4)),后者采用轮流放牧方式,每小区放牧育肥牛 1 头。RS2、RS3 和 RS4 小区的每头育肥牛放牧 7 天后分别休牧 7、14 和 21 天。2007 年 7 月 16 日,每个小区随机分配 3 头安格斯×西门塔尔杂交公牛(初始体重 354 ± 6kg);2008 年 7 月 14 日,每个小区随机分配 3 头安格斯×西门塔尔杂交公牛(初始体重 310 ± 6kg)。2007 年,放牧处理对平均日增重(ADG)无显著影响(P = 0.25)。与 RS3 小区相比,RS4、RS2 和连续放牧小区的育肥牛每公顷总增重分别多 106(P = 0.01)、86(P = 0.03)和 83(P = 0.03)kg。2008 年,各处理间 ADG(P = 0.43)和每公顷总增重(P = 0.90)均无显著差异。相关和回归分析表明,育肥牛的性能与饲草 CP 浓度、饲草 DM 现存量(kg/ha)和饲草 CP 现存量之间存在正相关。结果表明,在连续和轮牧方式下,梯牧草的生产力和质量对育肥牛生产是等效的。