Comparative Anatomy Unit, Department of Biological and Pharmaceutical Veterinary Sciences, Hassan II Agronomy and Veterinary Medicine Institute, Rabat-Instituts, BP: 6202, 10101, Rabat, Morocco.
Medicine and Surgical Unit of Domestic Animals, Department of Medicine, Surgery and Reproduction, Hassan II Agronomy and Veterinary Medicine Institute, Rabat, Morocco.
Sci Rep. 2024 Nov 18;14(1):28387. doi: 10.1038/s41598-024-79586-7.
Rumination shows a nocturnal rhythmic pattern in day-active ruminants. Although feeding has been shown to quantitatively modulate rumination, it is not clear yet if feeding rhythm plays a causal role in rumination rhythm. The present study was carried out to determine whether the daily rhythm of rumination in goats under natural environmental conditions is food-dependent or not, and whether it is modulated by the season. Rumination and locomotor activity (LA) were continuously monitored in four male Moroccan goats, fed once daily every morning, and then fasted for 4 days. The same experimental design was carried out in two different seasons (summer and winter). The results show that normally fed goats ruminate on average 281 ± 37 min in both seasons. Rumination shows a rhythmic 24-h profile with a late nocturnal peak. During the four-day food deprivation, rumination persisted while its total amount duration was significantly reduced in both seasons. Our results also illustrate the clear phase-opposition between the diurnal rhythm of LA and the nocturnal rhythm of rumination. This study characterized the daily rhythm rumination in goats according to seasons and fed/fasted states, and provided clear evidence that this rhythm is not generated by feeding behavior. Further investigations are required to determine whether rumination has an endogenous origin and is driven by the central circadian clock.
反刍在日间活动的反刍动物中表现出夜间的节律性模式。虽然已经证明进食可以定量调节反刍，但进食节律是否在反刍节律中起因果作用尚不清楚。本研究旨在确定在自然环境条件下，山羊的反刍昼夜节律是否依赖于食物，以及是否受季节的调节。在两个不同的季节（夏季和冬季）中，对 4 只雄性摩洛哥山羊进行了连续监测，每天早上喂食一次，然后禁食 4 天。采用相同的实验设计。结果表明，在两个季节中，正常进食的山羊平均反刍 281±37 分钟。反刍呈现出具有夜间晚高峰的 24 小时节律性特征。在四天的禁食期间，反刍持续存在，但其总持续时间在两个季节均显著减少。我们的结果还表明，日间活动节律和夜间反刍节律之间存在明显的相位相反。本研究根据季节和进食/禁食状态描述了山羊的日常反刍节律，并提供了明确的证据表明，这种节律不是由进食行为产生的。需要进一步的研究来确定反刍是否具有内源性起源，并由中枢生物钟驱动。
