Animal and Poultry Nutrition Department, Desert Research Center, Cairo, Egypt.
Animal Production Department, Faculty of Agriculture, Ain Shams University, Cairo, Egypt.
BMC Vet Res. 2024 Aug 13;20(1):364. doi: 10.1186/s12917-024-04199-1.
It was proposed that camels are more effective than other livestock species in selecting plants for their nutritional value. They may self-regulate their voluntary feed intake to satisfy their nutritional needs. This study was designed to investigate camels' feeding selectivity and ability to cover nutritional requirements when grazing alfalfa (high in protein) and/ or barley (high in energy) in a desert climate.
Eighteen lactating camels were equally divided into three feeding treatments. They grazed daily on alfalfa, barley, or a mixed pasture of both, for two periods of one month each. The concentrate supplement was individually administered at 40 g/kg BW, divided into two equal parts, in the morning and in afternoon. Total energy expenditure (EE) was estimated by heart rate (HR) monitors for 48 h after being calibrated by oxygen consumption using an upgraded face mask open-circuit respiratory system.
During the first period, camels had a greater forage intake and digestibility when they grazed barley rather than alfalfa, while those grazing mixed pasture performed intermediately. In the second period, camels had a similar forage intake and digestibility among treatments due to a decline in barley intake and digestibility compared to the first period, which was expected since the preferred plant part gradually shifted from barley grains to predominantly straw as a function of time. Similar HR and EE were found across periods and treatments. As a result of greater gross and digestible energy intake in period 1, a better energy balance in period 1 was observed compared to period 2. Camels better utilize barley than alfalfa. Grazing on barley had a higher energy balance than grazing alfalfa alone or in combination with barley. However, camels grazing barley produced lower milk yield and energy than those grazing alfalfa alone or in combination with barley, with no interaction detected between period and treatment.
Lactating camels are able to self-regulate their voluntary intake to cover their energy requirements when they are grazing barley and/or alfalfa supplemented with a concentrate supplement at 40 g/kg BW. Grazing barley is better utilized by camels than alfalfa. The chemical and physical properties of plant species play an important role in the selectivity of foraging camels. It also impacts their intake and digestibility, which is negatively associated with the proportion of cell wall content consumed.
有人提出，骆驼在选择具有营养价值的植物方面比其他牲畜更有效。它们可能会自我调节自愿进食量以满足其营养需求。本研究旨在调查骆驼在沙漠气候下放牧苜蓿（高蛋白）和/或大麦（高能量）时的采食选择性和满足营养需求的能力。
将 18 头泌乳骆驼等分为 3 个饲养处理组。它们每天在苜蓿、大麦或两者的混合牧场上放牧，每个月各放牧 2 个周期。浓缩饲料以 40g/kgBW 的量单独给予，分为两份，上午和下午各一份。通过使用升级后的面罩开路呼吸系统测量耗氧量来校准后，通过心率（HR）监测器在 48 小时后估计总能量消耗（EE）。
在第一个周期中，与苜蓿相比，骆驼采食和消化大麦的饲料量更大，而采食混合牧草的骆驼则处于中间水平。在第二个周期中，由于与第一个周期相比，大麦的摄入量和消化率下降，因此所有处理组的骆驼的饲料摄入量和消化率相似，这是预料之中的，因为随着时间的推移，首选植物部分逐渐从大麦粒转移到主要是秸秆。各个时期和处理组的 HR 和 EE 相似。由于第一周期中总可消化和可消化能量的摄入量增加，因此与第二周期相比，第一周期的能量平衡更好。骆驼比苜蓿更能利用大麦。与单独放牧苜蓿或与大麦混合放牧相比，放牧大麦具有更高的能量平衡。然而，与单独放牧苜蓿或与大麦混合放牧相比，放牧大麦的骆驼产奶量和能量较低，并且在时期和处理之间未检测到相互作用。
泌乳骆驼在以 40g/kgBW 的量补充浓缩饲料并放牧大麦和/或苜蓿时，能够自我调节其自愿摄入量以满足其能量需求。与苜蓿相比，骆驼更能利用大麦。植物物种的化学和物理特性在骆驼的觅食选择性中起着重要作用。它还影响它们的摄入量和消化率，而摄入量和消化率与消耗的细胞壁含量比例呈负相关。
