Hoffman P C, Brehm N M, Hasler J J, Bauman L M, Peters J B, Combs D K, Shaver R D, Undersander D J
Department of Dairy Science, University of Wisconsin, Madison 53706, USA.
J Dairy Sci. 1999 Apr;82(4):771-9. doi: 10.3168/jds.S0022-0302(99)75295-1.
Five trials were conducted to develop a system to estimate rumen-undegradable protein (RUP) of legume and grass silages using near infrared reflectance spectroscopy. In situ procedures were the reference method used to determine silage RUP content. Trials 1, 2, and 3 were devoted to improving in situ procedures. In trial 1, alfalfa silage with and without heat treatment was incubated ruminally in 30 cows. The standard deviation of in situ RUP attributable to cow and diet was 0.82 and 3.80 g/10(-1) kg of crude protein (CP) for the unheated and heated alfalfa, respectively. Based on trial 1, it was determined that 8 cows would be required to establish RUP standards. In trial 2, low (13.3 g/10(-1) kg of CP) and high (44.5 g/10(-1) kg of CP) RUP standards were developed using eight ruminally cannulated cows. In trial 3, 11 new RUP standards were developed by mixing trial 2 RUP standards together. The RUP standards were used to employ a calibration curve technique in ruminally cannulated cows. The technique was employed in four ruminally cannulated cows to estimate RUP contents of 121 silages, and RUP values were used for near-infrared reflectance spectroscopic analysis in trial 4. Trial 4 procedures yielded a calibration for RUP content of silages with an R2 of 0.84 and a standard error of calibration of 1.55 g/10(-1) kg of CP. In trial 5, the equation was tested on 300 silage samples. The mean predicted RUP content was 21.8 g/10(-1) kg of CP. Data suggest near-infrared reflectance spectroscopy can predict RUP content of silages.
进行了五项试验，以开发一种利用近红外反射光谱法估算豆科和禾本科青贮饲料瘤胃不可降解蛋白（RUP）的系统。原位法是用于测定青贮饲料RUP含量的参考方法。试验1、2和3致力于改进原位法。在试验1中，将经过和未经过热处理的苜蓿青贮饲料在30头奶牛的瘤胃中进行培养。未经加热和加热后的苜蓿青贮饲料，因奶牛和日粮导致的原位RUP标准差分别为0.82和3.80 g/10⁻¹ kg粗蛋白（CP）。基于试验1，确定需要8头奶牛来建立RUP标准。在试验2中，使用8头装有瘤胃瘘管的奶牛制定了低（13.3 g/10⁻¹ kg CP）和高（44.5 g/10⁻¹ kg CP）RUP标准。在试验3中，通过将试验2的RUP标准混合在一起，制定了11个新的RUP标准。这些RUP标准被用于在装有瘤胃瘘管的奶牛中采用校准曲线技术。该技术应用于4头装有瘤胃瘘管的奶牛，以估算121种青贮饲料的RUP含量，试验4中使用这些RUP值进行近红外反射光谱分析。试验4的程序得出了青贮饲料RUP含量的校准结果，R²为0.84，校准标准误差为1.55 g/10⁻¹ kg CP。在试验5中，该方程在300个青贮饲料样本上进行了测试。预测的RUP含量平均值为21.8 g/10⁻¹ kg CP。数据表明，近红外反射光谱法可以预测青贮饲料的RUP含量。
