Could the breed composition improve performance and change the enteric methane emissions from beef cattle in a tropical intensive production system?
Could the breed composition improve performance and change the enteric methane emissions from beef cattle in a tropical intensive production system?
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DOI：
10.1371/journal.pone.0220247
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发表时间：
2019-07-26
期刊：
影响因子：
3.7
通讯作者：
Quintao Lana, Angela Maria
中科院分区：
文献类型：
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作者：
de Faria Maciel, Isabella Cristina;Barbosa, Fabiano Alvim;Quintao Lana, Angela Maria
杂交育种已被用于改善肉牛的生产性能，但品种组成对热带集约化和综合系统饲养的牛的甲烷(CH4)产量、产量和强度的影响尚不清楚。为了评估品种组成对生产性能和甲烷排放的影响，比较了尼洛尔(Nel；Yr1：BW=171.5+/-19.4 kg；n=10；Yr2：BW=215.8+/-32.3 kg，n=25)和安格斯×Nellore杂交(an；Yr1：BW=214.2+/-26.4 kg，n=10；Yr2：BW=242.5+/-32.2 kg，n=25)。在生长期(放牧率2452 kg BW/ha，牧草质量4884 kg干物质(DM)/ha，饲料限额5.9 kg DM/100 kg BW)上放牧，然后在饲养场饲养。在每个阶段，从每个品种的成分中随机选择8头牛，用六氟化硫(SF6)示踪技术测量甲烷产量，用二氧化钛测量DM采食量(DMI)。与NEL相比，AN在放牧期的总增重和平均日增重(ADG)均优于NEL。饲养场日增重越大，育肥期越短，屠体产量和屠体日增重越高。NEL的甲烷产生量(千克/周期)比放牧低19%(P<；0.01)，饲养场的差异不显著。与AN相比，NEL在放牧时CH4强度(CH4/BW)较低，但在饲养场单位日增重CH4较高。品种组成对两个阶段的CH4产量(CH4/DMI)没有影响，尽管饲养场DMI(kg/d)存在差异。总之，在热带气候条件下，杂交可能是提高生产性能和降低每只日增重甲烷排放量的一种选择，从而降低每公斤肉的甲烷排放量。
Crossbreeding has been used to improve performance in beef cattle, however the effects of breed composition on methane (CH4) production, yield and intensity from cattle raised in tropical intensive and integrated systems remain unknown. To assess the impact of breed composition on performance and methane emissions, Nellore (NEL; yr 1: BW = 171.5 +/- 19.4 kg; n = 10; yr 2: BW = 215.8 +/- 32.3 kg, n = 25) and Angus x Nellore crossbred (AN; yr 1: BW = 214.2 +/- 26.4 kg, n = 10; yr 2: BW = 242.5 +/- 32.2 kg, n = 25) were compared. The animals grazed on integrated crop-livestock system in the growing phase (stocking rate 2452 kg BW/ha, herbage mass 4,884 kg dry matter (DM)/ha, forage allowance 5.9 kg DM/100kg BW) and then were finished in a feedlot. Steers (n = 8) from each breed composition were randomly selected in each phase to measure CH4 production using a sulfur hexafluoride (SF6) tracer technique and DM intake (DMI) using titanium dioxide. Compared with NEL, AN had both superior total gain and average daily gain (ADG) in the grazing period. The AN presented greater ADG in the feedlot with a shorter finishing period and resulted in greater carcass yield and carcass ADG. Methane production (kg/period) was lower in NEL (19% less) than AN in grazing (P< 0.01), and no difference was observed in feedlot. The NEL had less CH4 intensity (CH4/BW) in grazing but greater CH4 per unit of ADG in the feedlot compared to AN. Breed composition did not influence the CH4 yield (CH4/DMI) in either phase, despite the difference in feedlot DMI (kg/day). In conclusion, crossbreeding may be an option to improve performance and reduce the CH4 per ADG in tropical climate conditions, resulting in lower methane emission per kg of meat produced.