Optimal stocking densities were investigated for the sea cucumber Apostichopus japonicus Selenka under feed-supplement and non-feed-supplement regimes in net enclosures for 333 d. Substantial weight loss occurred duri...Optimal stocking densities were investigated for the sea cucumber Apostichopus japonicus Selenka under feed-supplement and non-feed-supplement regimes in net enclosures for 333 d. Substantial weight loss occurred during the aestivation phase (AE). Decreased growth rates were also observed during the winter phase (WT). In contrast, sea cucumbers showed rapid growth during the spring (SP) and autumn (AU) phases. Feeding regimes considerably influenced the growth performance, i.e., sea cucumbers grew faster under feed-supplement regime than under non-feed-supplement regime (P < 0.05). The average survival rates of sea cucumbers under feed-supplement regime were higher than those under non-feed-supplement regime for both the autumn phase and spring phase, but the differences were only significant for the latter phase (P < 0.05). The fitted B-N curves showed that the optimal stocking densities, in terms of net production, were 22.3 ind. m-2 for feed-supplement regime and 14.1 ind. m-2 for non-feed-supplement regime.展开更多
[Objective] The experiment was conducted to investigate the growth performance of graze cattle fed on non-protein nitrogen （NPN） supplement. [ Method] The experiment was conducted in late spring and early summer bef...[Objective] The experiment was conducted to investigate the growth performance of graze cattle fed on non-protein nitrogen （NPN） supplement. [ Method] The experiment was conducted in late spring and early summer before grazing. Thirty Chinese SimmentaI-Taihang taxa bulls at the age of 9-10 months weighing 150-170 kg were divided into the control group, experimental group 1 and experimental group 2, 10 in each group, Each cattle in the experimental group 1 fed on the basal diet supplemented 1.0 kg cornmeal every day. Each cattle in the experimental group 2 fed on the basal diet supplemented 1.0 kg cornmeal and 0.25 kg NPN supplement every day. Those in the control group were fed on the basal di- et. The experiment was performed for 100 d. [Result] The average daily gain of the experimental group I was 217 g larger than that of the control group, while the average daily gain of the experimental group 2 was 429 g larger than that of the control group. The differences in the average daily gain were significant between the three groups. [ Conclusion ] The growth performance of cattle grazed in northern slopes was obviously improved by supplementing a small amount of concentrate in feed. The improvement was more remarkable if a small amount of NPN supplement was also added in feed.展开更多
基金supported by the National Project of Scientific and Technical Supporting Programs (Grant Nos. 2006BAD09A01, 2006BAD09A06)the Hi-Tech Research and Development Program of China funded by Ministry of Science & Technology of China (Grant No. 2006AA10Z409)the National Natural Science Foundation of China (Grant No. 30871931)
文摘Optimal stocking densities were investigated for the sea cucumber Apostichopus japonicus Selenka under feed-supplement and non-feed-supplement regimes in net enclosures for 333 d. Substantial weight loss occurred during the aestivation phase (AE). Decreased growth rates were also observed during the winter phase (WT). In contrast, sea cucumbers showed rapid growth during the spring (SP) and autumn (AU) phases. Feeding regimes considerably influenced the growth performance, i.e., sea cucumbers grew faster under feed-supplement regime than under non-feed-supplement regime (P < 0.05). The average survival rates of sea cucumbers under feed-supplement regime were higher than those under non-feed-supplement regime for both the autumn phase and spring phase, but the differences were only significant for the latter phase (P < 0.05). The fitted B-N curves showed that the optimal stocking densities, in terms of net production, were 22.3 ind. m-2 for feed-supplement regime and 14.1 ind. m-2 for non-feed-supplement regime.
基金funded by the National Key Technology R&D Program for the 11th Five-Year Plan (2006BAD29B05 and 2006BAD56B04)Achievements Conversion Fund of Shanxi Science and Technology Department,Animal Breeding Fund of Shanxi Academy of Agricultural Sciences,Shanxi Natural Science Foundation (2010011040-4)Doctor Research Fund of Shanxi Academy of Agricultural Sciences (YBSJJ0901)
文摘[Objective] The experiment was conducted to investigate the growth performance of graze cattle fed on non-protein nitrogen （NPN） supplement. [ Method] The experiment was conducted in late spring and early summer before grazing. Thirty Chinese SimmentaI-Taihang taxa bulls at the age of 9-10 months weighing 150-170 kg were divided into the control group, experimental group 1 and experimental group 2, 10 in each group, Each cattle in the experimental group 1 fed on the basal diet supplemented 1.0 kg cornmeal every day. Each cattle in the experimental group 2 fed on the basal diet supplemented 1.0 kg cornmeal and 0.25 kg NPN supplement every day. Those in the control group were fed on the basal di- et. The experiment was performed for 100 d. [Result] The average daily gain of the experimental group I was 217 g larger than that of the control group, while the average daily gain of the experimental group 2 was 429 g larger than that of the control group. The differences in the average daily gain were significant between the three groups. [ Conclusion ] The growth performance of cattle grazed in northern slopes was obviously improved by supplementing a small amount of concentrate in feed. The improvement was more remarkable if a small amount of NPN supplement was also added in feed.
