Fisher D S
USDA-ARS, College of Agriculture and Life Sciences, North Carolina State University, Raleigh 27695-7620, USA.
J Anim Sci. 1996 Dec;74(12):3076-81. doi: 10.2527/1996.74123076x.
Little progress has been made in modeling intake regulation in spite of the many mechanisms identified as important. A model with relatively simple inputs was developed that included compartments for protein, soluble carbohydrate, digestible fiber, and very slowly digesting fiber. Distention and chemostatic feedbacks were combined using a previously published equation. The ratio of current ruminal fill to a modulating parameter for ruminal fill represented distention feedback. The ratio of the current flow of available energy to a modulating parameter for chemostatic demand represented chemostatic feedback. The modulating parameter for ruminal fill was based on literature reports of ruminal contents. Intake was adjusted based on current fill and energy flow relative to modulating parameters for fill and chemostatic feedback. The effect of the digestible organic matter (DOM) to CP ratio on DOM intake was modeled to adjust rates of digestion, rates of passage, and the chemostatic feedback. The model tested an integrated concept of intake regulation with only CP, IVDMD, and NDF as inputs. In spite of relatively simple inputs, the model behavior in response to variation in protein, digestibility, and fiber was similar to observations of animal responses.
尽管已确定许多重要机制，但在建立采食量调节模型方面进展甚微。开发了一个输入相对简单的模型，该模型包括蛋白质、可溶性碳水化合物、可消化纤维和极缓慢消化纤维的区室。使用先前发表的方程将扩张反馈和化学稳态反馈结合起来。当前瘤胃充盈度与瘤胃充盈度调节参数的比值代表扩张反馈。当前可用能量流量与化学稳态需求调节参数的比值代表化学稳态反馈。瘤胃充盈度调节参数基于瘤胃内容物的文献报道。根据当前充盈度和相对于充盈度调节参数及化学稳态反馈的能量流量来调整采食量。对可消化有机物（DOM）与粗蛋白（CP）比值对DOM采食量的影响进行建模，以调整消化率、通过率和化学稳态反馈。该模型仅以CP、体外干物质消化率（IVDMD）和中性洗涤纤维（NDF）作为输入，测试了采食量调节的综合概念。尽管输入相对简单，但该模型对蛋白质、消化率和纤维变化的响应行为与动物反应的观察结果相似。
