Comparison of techniques for estimating herbage intake of grazing dairy cows.

摘要: For estimating herbage intake during grazing, the traditional sward cutting technique was compared in grazing experiments 2002 and 2003 with recently developed n-alkanes net energy method. The first method estimates by difference between mass before after regrowth 2 points time. second ratio of a dosed even-chain synthetic n-alkane (C32) naturally occurring odd-chain (C31 or C33) feces. third calculated from animal's requirements for milk production maintenance. estimated highest coefficient variation had different results experimental years. yielded less variable results, whereas gave least results. In 2002, alkane C32:C33 were best related estimations 2003, C32:C31 related. estimate based on lower than one C32:C31. Therefore, considered to be better direct estimator lactating dairy cows.