Department of Biological Sciences, University of Limerick, Limerick V94 T9PX, Ireland.
Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA), Asturias, Spain.
Animal. 2022 Jul;16(7):100571. doi: 10.1016/j.animal.2022.100571. Epub 2022 Jun 22.
The assessment of feed intake in stabled horses is a difficult task to accomplish. Faecal markers, namely n-alkanes, have been used successfully for the estimation of this important nutritional parameter. This usually involves the dosing of synthetic n-alkanes via different matrices, a laborious task that may also influence the animal normal foraging behaviour. An experiment was conducted to evaluate a relative simple methodology to quantify feed intake in horses, based on the provision of measured amounts of a concentrate supplement labelled with beeswax and the utilisation of n-alkanes as faecal markers. Four Lusitano horses were used in three consecutive experimental periods. Animals were fed on cereal straw and different proportions of a previously prepared beeswax-labelled concentrate supplement (BLCS; 0.05, 0.10 and 0.20, DM basis). Beeswax labelling was performed to provide a distinct n-alkane profile for the concentrate feed. Prior to feed intake calculations, proportions of labelled concentrate supplement in the diets were estimated using n-alkanes C to C by least-square optimisation procedures. Results showed that the beeswax labelling resulted in high n-alkane concentrations in the concentrate feed, especially for the odd-chain n-alkanes. Estimates of diet composition did not differ from the measured values, except for the diet with highest BLCS incorporation, with an underestimation of 10%. DM intake was accurately estimated by the "labelled supplement method" in all diets. However, for the lowest BLCS incorporation, DM intake was underestimated by 16% whereas for the higher levels of BLCS in the diet, measured and estimated DM intake values were almost identical with a slight overestimation of only 0.7 and 0.2% (10 and 20% of BLCS, respectively). Results indicate that both diet composition and feed intake can be accurately estimated in horses using the "labelled supplement method", even when very low levels of the labelled concentrate supplement are included in the animals' diet. This method eliminates the need for daily dosing with external synthetic markers, providing advantages in terms of minimising animal management and interference with their normal foraging behaviour.
评估厩养马匹的采食量是一项艰巨的任务。粪中标记物，即正构烷烃，已成功用于估计这一重要的营养参数。这通常涉及通过不同基质给与合成正构烷烃进行剂量测定，这是一项繁琐的任务，也可能影响动物正常的觅食行为。本试验旨在评估一种相对简单的方法，基于提供定量的经蜂蜡标记的浓缩补充料，并利用正构烷烃作为粪中标记物来测定马匹的采食量。选用 4 匹葡萄牙温血马，在三个连续的试验期内进行试验。动物仅采食谷物秸秆和不同比例的预先制备的经蜂蜡标记的浓缩补充料（DM 基础，0.05、0.10 和 0.20）。蜂蜡标记是为了给浓缩饲料提供独特的正构烷烃图谱。在进行采食量计算之前，使用最小二乘优化程序，通过 C 至 C 的正构烷烃估计饲料中的标记浓缩补充料的比例。结果表明，蜂蜡标记使浓缩饲料中的正构烷烃浓度非常高，尤其是奇数链正构烷烃。除了高蜂蜡标记浓缩饲料添加比例的日粮外，日粮组成的估计值与实测值没有差异，估计值低估了 10%。在所有日粮中，“标记补充料法”都可以准确估计干物质采食量。然而，对于最低的蜂蜡标记浓缩饲料添加比例，干物质采食量估计值低估了 16%，而对于日粮中更高水平的蜂蜡标记浓缩饲料，实测和估计的干物质采食量值几乎相同，仅高估了 0.7%和 0.2%（分别为 10%和 20%的蜂蜡标记浓缩饲料）。结果表明，即使在动物日粮中包含非常低水平的标记浓缩补充料，“标记补充料法”也可以准确估计日粮组成和采食量。该方法消除了对外部合成标记物进行日常剂量测定的需要，在减少动物管理和干扰其正常觅食行为方面具有优势。
