McLeod M N, Minson D J
CSIRO, Div. of Tropical Crops and Pastures, Cunningham Laboratory, St. Lucia, Queensland 4067, Australia.
J Anim Sci. 1988 Apr;66(4):992-9. doi: 10.2527/jas1988.664992x.
The proportion of large particles (LP) broken down to small, insoluble particles by primary mastication (eating), rumination, digestion and detrition (rubbing) was determined for separated leaf and stem fractions of perennial ryegrass (Lolium perenne) and alfalfa (Medicago sativa) fed to cattle cannulated at the esophagus. Large particles were defined as those particles retained during wet sieving on a screen with an aperture of 1.18 mm. Reduction in weight of particles caused by solubilizing or digestion was not considered to be particle breakdown per se, and particles were corrected for this loss in weight. The proportion of LP in the forage broken down by primary mastication was 25 +/- 1.9% (means +/- SE). Breakdown of LP by rumination was calculated from the weight of total particles regurgitated and the proportion of LP in the regurgitated and swallowed remasticated material. The weight of LP regurgitated was corrected for the dry matter lost by digestion using lignin ratio in the LP entering the rumen and of the regurgitated digesta. Rumination accounted for 50 +/- 1.5% of LP breakdown. Fecal loss accounted for 8 +/- .8% of the LP in forage. Breakdown of LP by digestion and detrition was calculated as 17 +/- 1.3% from the difference between the LP eaten and those broken down by primary mastication, rumination and passing out in the feces. The significance of these results for predicting voluntary intake from laboratory analysis is considered.
对于饲喂食管造瘘牛的多年生黑麦草（Lolium perenne）和苜蓿（Medicago sativa）分离出的叶片和茎部分，测定了通过初次咀嚼（采食）、反刍、消化和磨损（摩擦）分解为小的不溶性颗粒的大颗粒（LP）比例。大颗粒定义为在孔径为1.18毫米的筛网上湿筛时保留的颗粒。由溶解或消化引起的颗粒重量减少本身不被视为颗粒分解，并且对颗粒的这种重量损失进行了校正。通过初次咀嚼分解的饲草中LP的比例为25±1.9%（平均值±标准误）。反刍引起的LP分解是根据反刍的总颗粒重量以及反刍和吞咽再咀嚼物质中LP的比例计算得出的。使用进入瘤胃的LP和反刍消化物中的木质素比例，对反刍的LP重量进行了消化损失干物质的校正。反刍占LP分解的50±1.5%。粪便损失占饲草中LP的8±0.8%。通过消化和磨损引起的LP分解是根据采食的LP与通过初次咀嚼、反刍和随粪便排出而分解的LP之间的差异计算得出的，为17±1.3%。考虑了这些结果对于从实验室分析预测自愿采食量的意义。
