Self-feeding device is extensively used in aquaculture farms, but for salmonids the individual feeding behavior has seldom been continuously observed. In this article, the individual self-feeding behavior of 10 rainbo...Self-feeding device is extensively used in aquaculture farms, but for salmonids the individual feeding behavior has seldom been continuously observed. In this article, the individual self-feeding behavior of 10 rainbow trout was continuously monitored with a PIT tag record for 50 days with three replicates. The?sh fell into three categories according to their feeding behavior, i.e. high triggering ?sh(trigger behavior more than 25% of the group, HT), low triggering ?sh(1%–25%, LT) and zero triggering ?sh(less than1%). The results showed that in a group of 10 individual 1–2 HT ?sh accounted for most of the self-feeding behavior(78.19%–89.14%), which was far more than they could consume. The trigger frequency of the?sh was signi?cantly correlated with the initial body weight( P <0.01), however, no signi?cant dif ference in growth rate among the HT, LT, and ZT ?sh was observed( P >0.05). Cosinor analysis showed that the two HT ?sh in the same group had similar acrophase. Though some of the HT ?sh could be active for 50 d, there were also HT ?sh decreased triggering behavior around 40 d and the high trigger status was then replaced by other ?sh, which was ?rst discovered in salimonds. Interestingly, the growth of the group was not af fected by the alternation triggering ?sh. These results provide evidence that in the self-feeding system the HT ?sh didn't gain much advantage by their frequent self-feeding behavior, and high trigger status of the HT ?sh is not only an individual character but also driven by the demand of the group. In the self-feeding system, the critical individual should be closely monitored.展开更多
Although it has been hypothesized that a predictable feeding regime in animals allows physiological variables to be adjusted to maximize nutrient utilization and,hence,better growth performance,the assumption has rare...Although it has been hypothesized that a predictable feeding regime in animals allows physiological variables to be adjusted to maximize nutrient utilization and,hence,better growth performance,the assumption has rarely been tested.This study compares the effects of time-restricted versus free access self-feeding on the growth,feeding behavior and daily digestive enzyme rhythms of Atlantic salmon(Salmo salar).In an experiment that lasted 6 weeks,fish(109.9 g) were divided into two groups:group 1 had free access to a self-feeder(FA);group 2 received three meals per day(2 h per meal) at dawn,midday and dusk via a time-restricted self-feeder(TR).At the end of the experiment,the fish were sampled every 3 h over a24-h period.The results showed that the TR fish quickly synchronized their feeding behavior to the feeding window and their blood glucose showed a significant postprandial increase,while FA fish displayed no statistically significant rhythms(P>0.05).Pepsin activity of TR fish also showed a significant daily rhythm(P<0.05) with the acrophase at the second feed and a decrease over the next 12 h.Average daily trypsin,lipase and amylase levels of FA fish were significantly lower than those of TR fish(P<0.01);however,the growth performance of both groups was similar(P>0.05).In conclusion,the study failed to confirm a link between the entrainment of daily digestive enzyme profiles and growth performance,with the TR group showing comparatively poor blood glucose regulation.展开更多
基金Supported by the National Natural Science Foundation of China(No.31602208)the K.C.Wong Magna Fund in Ningbo Universitythe Qingdao Post-doctoral Application Research Project(No.Y6KY01110N)
文摘Self-feeding device is extensively used in aquaculture farms, but for salmonids the individual feeding behavior has seldom been continuously observed. In this article, the individual self-feeding behavior of 10 rainbow trout was continuously monitored with a PIT tag record for 50 days with three replicates. The?sh fell into three categories according to their feeding behavior, i.e. high triggering ?sh(trigger behavior more than 25% of the group, HT), low triggering ?sh(1%–25%, LT) and zero triggering ?sh(less than1%). The results showed that in a group of 10 individual 1–2 HT ?sh accounted for most of the self-feeding behavior(78.19%–89.14%), which was far more than they could consume. The trigger frequency of the?sh was signi?cantly correlated with the initial body weight( P <0.01), however, no signi?cant dif ference in growth rate among the HT, LT, and ZT ?sh was observed( P >0.05). Cosinor analysis showed that the two HT ?sh in the same group had similar acrophase. Though some of the HT ?sh could be active for 50 d, there were also HT ?sh decreased triggering behavior around 40 d and the high trigger status was then replaced by other ?sh, which was ?rst discovered in salimonds. Interestingly, the growth of the group was not af fected by the alternation triggering ?sh. These results provide evidence that in the self-feeding system the HT ?sh didn't gain much advantage by their frequent self-feeding behavior, and high trigger status of the HT ?sh is not only an individual character but also driven by the demand of the group. In the self-feeding system, the critical individual should be closely monitored.
基金Supported by the Qingdao Postdoctoral Application Research Project(No.Y6KY01110N)the National Natural Science Foundation of China(Nos.31472312,41306152,31402283)+2 种基金the Qingdao Innovation Talents Program(No.13-CX-16)the National Key Technologies R&D Program of China(No.2014BAD08B09)the Earmarked Fund for Modem AgroIndustry Technology Research System(No.CARS-48)
文摘Although it has been hypothesized that a predictable feeding regime in animals allows physiological variables to be adjusted to maximize nutrient utilization and,hence,better growth performance,the assumption has rarely been tested.This study compares the effects of time-restricted versus free access self-feeding on the growth,feeding behavior and daily digestive enzyme rhythms of Atlantic salmon(Salmo salar).In an experiment that lasted 6 weeks,fish(109.9 g) were divided into two groups:group 1 had free access to a self-feeder(FA);group 2 received three meals per day(2 h per meal) at dawn,midday and dusk via a time-restricted self-feeder(TR).At the end of the experiment,the fish were sampled every 3 h over a24-h period.The results showed that the TR fish quickly synchronized their feeding behavior to the feeding window and their blood glucose showed a significant postprandial increase,while FA fish displayed no statistically significant rhythms(P>0.05).Pepsin activity of TR fish also showed a significant daily rhythm(P<0.05) with the acrophase at the second feed and a decrease over the next 12 h.Average daily trypsin,lipase and amylase levels of FA fish were significantly lower than those of TR fish(P<0.01);however,the growth performance of both groups was similar(P>0.05).In conclusion,the study failed to confirm a link between the entrainment of daily digestive enzyme profiles and growth performance,with the TR group showing comparatively poor blood glucose regulation.
