利用血浆尿素氮作为快速反应标准来确定猪的赖氨酸需求量。

Use of plasma urea nitrogen as a rapid response criterion to determine the lysine requirement of pigs.

作者信息

Coma J, Carrion D, Zimmerman D R

机构信息

Department of Animal Science, Iowa State University, Ames 50011, USA.

出版信息

J Anim Sci. 1995 Feb;73(2):472-81. doi: 10.2527/1995.732472x.

DOI:10.2527/1995.732472x

PMID:7601781

Abstract

Five experiments were conducted to evaluate the potential use of plasma urea N (PUN) concentrations as a rapid response criterion to determine amino acid requirements. A preliminary experiment (Exp. 1) indicated that a 3-d feeding time was required to re-equilibrate PUN concentrations after a change in the dietary concentration of lysine. In Exp. 2, 3, and 4, PUN was used to estimate the lysine requirement of growing pigs at different specific BW. Thirty individually penned crossbred pigs weighing 32 and 44 kg in Exp. 2 and 3, respectively, were assigned to five dietary treatments (.60, .70, .80, .90, and 1.00% lysine) for 5 d. The PUN decreased quadratically (P < .05) to increasing dietary lysine. A two-slope, broken-line regression model estimated the requirement at .85% in Exp. 2 and at .76% in Exp. 3. In Exp. 4, 60 crossbred pigs (30 barrows and 30 gilts) weighing 70 kg were assigned to five dietary lysine concentrations: .50, .60, .70, .80, and .90% for 4 d. Increasing lysine caused PUN to decrease quadratically (P < .01). The estimated requirements were different (P < .05) between sexes: .69% for barrows and .75% for gilts. In Exp. 5, the validity of using PUN as a rapid response criterion was verified by comparing the estimated lysine requirement based on PUN with the requirement determined in a 7-d N balance. Twenty crossbred barrows averaging 19 kg were used. Dietary lysine concentrations were .60, .75, .90, 1.05, and 1.20%. A quadratic response was observed in PUN (P < .05) and N retention (NR) (P < .01) with increasing lysine. The estimated lysine concentrations that maximized rates of NR and minimized PUN (1.03 vs. 1.05) were not different (P > .10). Therefore, PUN concentrations can be used in short-term trials to accurately estimate the dietary lysine required to maximize total N utilization in pigs at a specific BW. In addition, the two-slope broken-line regression model had the highest R2 and the lowest mean square error compared with three other models as means for estimating lysine requirement from PUN concentrations.

摘要

进行了五项试验，以评估血浆尿素氮（PUN）浓度作为确定氨基酸需求的快速反应标准的潜在用途。一项初步试验（试验1）表明，赖氨酸日粮浓度改变后，需要3天的采食时间才能使PUN浓度重新达到平衡。在试验2、3和4中，使用PUN来估计不同特定体重生长猪的赖氨酸需求量。试验2和3中，分别将30头单独饲养的体重32千克和44千克的杂交猪分配到五种日粮处理（赖氨酸含量分别为0.60%、0.70%、0.80%、0.90%和1.00%），为期5天。随着日粮赖氨酸含量增加，PUN呈二次方下降（P<0.05）。两斜率折线回归模型估计试验2中的需求量为0.85%，试验3中的需求量为0.76%。在试验4中，将60头体重70千克的杂交猪（30头公猪和30头母猪）分配到五种日粮赖氨酸浓度：0.50%、0.60%、0.70%、0.80%和0.90%，为期4天。赖氨酸增加导致PUN呈二次方下降（P<0.01）。公母猪的估计需求量不同（P<0.05）：公猪为0.69%，母猪为0.75%。在试验5中，通过比较基于PUN估计的赖氨酸需求量与7天氮平衡确定的需求量，验证了使用PUN作为快速反应标准的有效性。使用了20头平均体重19千克的杂交公猪。日粮赖氨酸浓度分别为0.60%、0.75%、0.90%、1.05%和1.20%。随着赖氨酸增加，PUN（P<0.05）和氮保留率（NR）（P<0.01）呈二次方反应。使NR率最大化和PUN最小化的估计赖氨酸浓度（1.03对1.05）无差异（P>0.10）。因此，PUN浓度可用于短期试验，以准确估计特定体重猪最大化总氮利用率所需的日粮赖氨酸含量。此外，与其他三种从PUN浓度估计赖氨酸需求量的模型相比，两斜率折线回归模型的R2最高，均方误差最低。