De Gracia M, Ward J K
University of Nebraska, Lincoln 68583-0908.
J Anim Sci. 1991 Jun;69(6):2289-93. doi: 10.2527/1991.6962289x.
Two experiments, using Angus x Hereford spring-calving beef cows in mid- or late lactation nursing Simmental-sired calves, were conducted to evaluate the relative value of a corn gluten meal-blood meal mixture (CGM-BM; 50% of supplemental protein from each source). In Exp. 1 (78 d), cows in late lactation were assigned to one of three treatments: control at 8.2% CP (C), soybean meal at 10.4% CP (SBM), or CGM-BM at 10.3% CP. Diets were calculated to be isocaloric at 55% TDN. In Exp. 2 (65 d), cows in mid-lactation were assigned to four treatments: urea, SBM, low CGM-BM (LM), and high CGM-BM (HM). Diets in Exp. 2 were isonitrogenous (9.5% CP) and isocaloric (55% TDN). Diets in both experiments were based on ammoniated wheat straw and corn silage. Weight gains of cows and cow-calf pairs were greater (P less than .06) when protein was supplemented in Exp. 1. Gains were lower for cows fed urea (P less than .03) in Exp. 2 but were similar when cows were supplemented with SBM vs either the low or the high level of CGM-BM. Performance of calves did not differ among dietary treatments.
进行了两项试验，使用处于泌乳中期或后期的安格斯×赫里福德春季产犊肉牛，它们饲养着西门塔尔牛所生的犊牛，以评估玉米蛋白粉-血粉混合物（CGM-BM；每种来源提供50%的补充蛋白质）的相对价值。在试验1（78天）中，将处于泌乳后期的母牛分配到三种处理之一：8.2%粗蛋白的对照组（C）、10.4%粗蛋白的豆粕组（SBM）或10.3%粗蛋白的CGM-BM组。日粮计算为在总可消化养分（TDN）为55%时等热量。在试验2（65天）中，将处于泌乳中期的母牛分配到四种处理：尿素、豆粕、低水平CGM-BM（LM）和高水平CGM-BM（HM）。试验2中的日粮是等氮的（9.5%粗蛋白）且等热量的（55%TDN）。两个试验中的日粮均以氨化麦秸和玉米青贮为基础。在试验1中补充蛋白质时，母牛和母牛-犊牛对的体重增加更大（P小于0.06）。在试验2中，饲喂尿素的母牛增重较低（P小于0.03），但当母牛补充豆粕与低水平或高水平的CGM-BM时，增重相似。犊牛的性能在不同日粮处理之间没有差异。
