Li Zhongqiu
The State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China.
PLoS One. 2013 Jun 18;8(6):e66261. doi: 10.1371/journal.pone.0066261. Print 2013.
Extensive studies have been conducted on the rumination behavior of domestic herbivores. However, studies on wild animals are limited, particularly wild animals with specific ruminating parameters. In this study, Père David's deer, a previously extirpated species, was observed to analyze the effects of sex-age, feeding habitat, and rainfall on rumination behavior in the Dafeng Nature Reserve, China. Rumination behavior was investigated based on four parameters: proportion of bedding time spent chewing, bolus processing time (s/bolus), chewing frequency (chews/bolus), and chewing rate (chews/s). Results showed that all three factors affect rumination behavior. The extent of their effects varied based on the four rumination parameters. Chewing rate and frequency decreased based on sex-age levels, i.e., from fawns to juvenile female, juvenile male, adult female, stag, and harem holder. Therefore, body size played a major role in shaping rumination behavior. Deer found in grasslands could chew faster compared with deer found in woodlands. This result might be caused by the effects of dietary composition and sunlight intensity. A deer spends a longer time ruminating while bedding during rainy days compared with rainless days to maximize energy and nutrition intake and compensate for the loss of feeding time during rainy days. Therefore, rumination behavior is plastic and is shaped by intrinsic and extrinsic factors.
人们已经对家养食草动物的反刍行为进行了广泛研究。然而，对野生动物的研究却很有限，尤其是对具有特定反刍参数的野生动物。在本研究中，我们观察了麋鹿（一种曾一度灭绝的物种），以分析性别年龄、觅食栖息地和降雨对中国大丰自然保护区内反刍行为的影响。我们基于四个参数对反刍行为进行了调查：卧息时咀嚼时间的比例、食团处理时间（秒/食团）、咀嚼频率（咀嚼次数/食团）和咀嚼速率（咀嚼次数/秒）。结果表明，这三个因素都会影响反刍行为。它们的影响程度因四个反刍参数而异。咀嚼速率和频率随着性别年龄水平的变化而降低，即从幼鹿到幼年雌性、幼年雄性、成年雌性、雄鹿和群主。因此，体型在塑造反刍行为方面起着主要作用。与林地中的鹿相比，草原上的鹿咀嚼速度更快。这一结果可能是由饮食组成和阳光强度的影响所致。与无雨日相比，鹿在雨天卧息时反刍的时间更长，以便最大限度地摄入能量和营养，并弥补雨天觅食时间的损失。因此，反刍行为具有可塑性，是由内在和外在因素塑造的。
