摘要
This experiment was conducted with lactating Chinese Holstein cows to study the nutritional value of local protein feed resources.A three-step method(TSP)and a modifed three-step method(MTSP)were used to measure the in vitro digestibility of rumen undegraded protein(RUP)for 11 feedstufs and correlation.Eleven experimental feeds were chosen and air-dried to investigate the efects of diferent growth periods and varieties on nutrition value and RUP digestibility.The small intestinal digestibility of RUP by TSP in concentrated feed was determined to be higher than that of roughage,approximately 65%.The highest concentrate(79%)was SBM(soybean mean),while the lowest was corn(65%).The proportions of DDGS(with soluble wine lees)and SFM(sunfower meal)were 70.9 and 74.9%,respectively.ASS(alfalfa mowed at the squaring stage)had the highest small intestinal digestibility of RUP(55%)among roughages,and WCS(whole-plant corn silage)had the lowest digestibility(40.5%).When the small intestinal digestibility of RUP was determined using the MTSP method,it exhibited similar results to the TSP method.Nevertheless,the values were generally higher,and there was a strong signifcant correlation between them(R2=0.967,P<0.01).The comparative study of these two methods help us have a better understanding of small intestine digestibility of diferent feeds,make a reasonable feed formula to efectively prevent diseases.
基金
Inner Mongolia Health Science and Technology Project(202201108)
Inner Mongolia Medical University Youth Training Project(YKD2021QN006).