עוד דף שלא העתקתי
66 H.Hirakawa ©2001 Mammal Society,Mammal Review,31,61–80 of the dark phase (Jilge,1982),as is observed in the wild European Rabbit (Southern,1942; Watson,1954;Meyers,1955). Despite the aforementioned studies,understanding of the caecotrophy rhythm in the Domestic Rabbit has been in confusion,from the initial studies through to today.For example,Eden (1940b)called soft faeces ‘night faeces’and Cheeke (1987)included this as one of the names for soft faeces.The cause of this confusion is probably the daily care routine, in that food is often provided first in the morning and in such an amount that none is left over to the next morning (Taylor,1940a).Under this practice,the Domestic Rabbit probably becomes accustomed to start eating at the provision of food and continue eating until food is depleted.As a result,the feeding rhythm is reversed and soft faeces are excreted during the night after the food is depleted (for example,see Fig.1 in Thacker &Brandt,1955). Ebino et al.(1993)reported frequent reingestion of hard faeces in the Domestic Rabbit, but did not clearly indicate the rhythm of reingestion. Passage and recycling of food particles The passage rate of large food particles is quite fast in leporids (Olsen &Madsen,1944; Hirakawa &Okada,1995).In the Japanese Hare,large particles ingested early in the evening are almost completely eliminated by the end of that night (the minimum passage time is 2 hours and the mean retention time (MRT)is 4–5 hours)(Hirakawa &Okada,1995).As ingested later on,however,they are increasingly eliminated in the daytime faeces (both in soft and hard faeces)and hence reingested.Of the reingested particles,those that still remain large after remastication are eventually discarded in hard faeces during the following night.The fate of large food particles thus varies depending on the time at ingestion (Fig.3). Fig.3.Excretion of particulate markers in relation to the time at ingestion.The upper graph shows the excretion rates of particulate markers by the end of the first and second night.The lower graph shows their minimum passage time, mean retention time,and 98%excretion time.(Modified from Fig.4 in Hirakawa &Okada 1995.) יש לי את התוכנה שמתרגמת. אני שלחתי לכמה אנשים שיתרגמו. בלי נדר אני אתקשר לרב יעקב סגל שיתן שיאמר לי היכן מדובר על הקנגרו.