Portugal Thales Baggio, Szymczak Leonardo Silvestri, de Moraes Anibal, Fonseca Lidiane, Mezzalira Jean Carlos, Savian Jean Víctor, Zubieta Angel Sánchez, Bremm Carolina, de Faccio Carvalho Paulo César, Monteiro Alda Lúcia Gomes
Department of Crop Production and Protection, Federal University of Paraná, Curitiba 80035-050, Brazil.
CONSIPA-Consulting on Integrated Crop-Livestock Systems, Ponta Grossa 84015-500, Brazil.
Animals (Basel). 2021 Dec 22;12(1):13. doi: 10.3390/ani12010013.
We assessed the effects of high-intensity and low-frequency (HILF) vs. low-intensity and high-frequency (LIHF) grazing on herbage production and performance of beef cattle grazing sorghum pastures. The experimental design was a complete randomized block with two treatments and four replicates (paddocks), carried out in 2014/15. The management target of 50 and 30 cm for pre- and post-grazing, respectively, a LIHF grazing management strategy oriented to maximize beef cattle herbage intake per unit time, was compared with a HILF grazing management strategy of 80 and 20 cm for pre- and post-grazing, respectively, aiming to maximize herbage accumulation and harvest efficiency. Sixteen Brangus steers of 15-month-old and 265 ± 21 kg of live weight (LW) were randomly distributed to paddocks (experimental units). The LIHF resulted in shorter rest periods when compared with the HILF. The greater leaf lamina mass in LIHF allowed greater sward light interception at post-grazing, resulting in greater total herbage production than HILF (7581 and 4154 kg DM/ha, respectively). The average daily gain (ADG) of steers was greater for the LIHF than for the HILF treatment (0.950 and 0.702 kg/animal, respectively); however, even with a greater stocking rate in the HILF, there was no difference for LW gain per ha, with an average of 4 kg LW/ha/day. Our findings demonstrated that the LIHF strategy that is based on offering to the animals an optimal sward structure to favor the maximum herbage intake rate fosters greater herbage production, harvesting efficiency, and ADG without compromising LW gain per area of beef steers, despite the lower herbage harvested per stocking cycle.
我们评估了高强度低频(HILF)放牧与低强度高频(LIHF)放牧对肉牛在高粱牧场上的牧草产量及生产性能的影响。实验设计为2014/15年进行的具有两种处理和四个重复(围场)的完全随机区组设计。分别以放牧前50厘米和放牧后30厘米为管理目标的LIHF放牧管理策略,旨在使肉牛单位时间内的牧草摄入量最大化,将其与放牧前80厘米和放牧后20厘米的HILF放牧管理策略进行比较,后者旨在使牧草积累量和收获效率最大化。16头15月龄、体重265±21千克(活重,LW)的婆罗门牛被随机分配到各围场(实验单元)。与HILF相比,LIHF导致的休牧期更短。LIHF中更大的叶片质量使得放牧后草地对光的截获量更大,从而使总牧草产量高于HILF(分别为7581和4154千克干物质/公顷)。LIHF处理的肉牛平均日增重(ADG)高于HILF处理(分别为0.950和0.702千克/头);然而,尽管HILF的载畜率更高,但每公顷的体重增加量并无差异,平均为4千克体重/公顷/天。我们的研究结果表明,基于为动物提供最佳草地结构以促进最大牧草摄入率而制定的LIHF策略,能提高牧草产量、收获效率和ADG,且不会影响肉牛单位面积的体重增加,尽管每个放牧周期收获的牧草较少。