Feed intake changes as animals age and grow. A constraint of most functional forms used to describe this relationship is that intake is maximum only once an animal reaches its mature weight. Often such is not the case and maximum intake is achieved earlier. Our aim was to describe a form unburdened by such a constraint and to determine its utility to describe the relationship between feed intake and liveweight across multiple species. Twelve data sets representing seven domestic animal species (cattle, chicken, dog, pig, rat, sheep, and turkey) with a wide range of mature weights were used. Average daily ad libitum feed intakes and liveweights were available on either a weekly or fortnightly basis. Rates of intake were scaled to mature intake. Within each set, the quadratic regression of scaled intake on the degree of maturity in weight was fitted. This form provided a very good description of the relationship between these variables (R² > 0.86) and, for all but one case, a realistic prediction of mature intake. With one exception, intake reached its maximum value at a liveweight below its mature value. Furthermore, by appropriately scaling the relationship between intake and liveweight, the data could be described by a function with a single parameter with general relevance across species. By expressing the rate of intake as a function of its value at maturity, a quadratic form provides a robust and general description of the relationship between feed intake scaled to mature intake and degree of maturity in weight.

中文翻译：

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饲料摄入量与家畜活重之间的关系。

饲料的摄入随着动物的年龄和成长而变化。用于描述这种关系的大多数功能形式的约束条件是，只有在动物达到其成熟体重后，摄入量才最大。通常情况并非如此，并且尽早达到最大摄入量。我们的目的是描述一种不受此类限制负担的形式，并确定其用途来描述多种物种的采食量与活重之间的关系。使用了十二种数据集，代表了具有广泛成熟权重的七个家畜物种（牛，鸡，狗，猪，大鼠，绵羊和火鸡）。每周或每两周获取平均每日自由采食量和活重。摄入量按比例调整为成熟摄入量。在每组中，拟合了按比例摄入量对体重成熟度的二次回归。R ² > 0.86），并且除了一种情况外，对于成熟摄入量的实际预测。除一个例外，在活重低于其成熟值时，摄入量达到最大值。此外，通过适当地缩放摄入量和活重之间的关系，可以通过具有单个参数的函数来描述数据，而该参数具有跨物种的一般相关性。通过将摄入率表示为其成熟度值的函数，二次形式可以对按成熟摄入量缩放的饲料摄入量与体重的成熟度之间的关系提供有力且一般的描述。