A promising strategy to support broiler health and performance in a sustainable way is the enhancement of microbial fibre fermentation in broilers.This fermentation mainly occurs in the caeca,but the actual particle s...A promising strategy to support broiler health and performance in a sustainable way is the enhancement of microbial fibre fermentation in broilers.This fermentation mainly occurs in the caeca,but the actual particle size range that allows caecal influx has not yet been described.This study aimed to understand the physical limitations of caecal influx as a function of broiler age by using both solid and soluble markers.In the first trial,the caecal filter mechanism was studied by microscopically visualising the caecal entrance and measuring caecal lobe development and digesta particle size as a function of age(d 8-36)for 44 broilers(Ross 308)receiving a conventional wheat-based diet.In two consecutive trials,microcrystalline cellulose beads(100-700 mm)and a combination of fluorescent polystyrene beads(5-30 mm)and chromium-ethylenediamine tetraacetic acid(Cr-EDTA)were administered to 176 and 189 broilers,respectively,at different ages(d 8-36).Results showed that the actual caecal entrance diameter is significantly reduced due to a dense villi network acting as a filter for digesta inflow.This explains the size gap between the average digesta particle size(D50)of the ileum(451-322 mm)and caeca(5-19 mm),and the outer diameter of the caecal entrance(2000-4000 mm)on d 8 to 36.In contrast to the caecal D50,cellulose beads of 700 mm already entered the caeca at 8 d of age,even though the general caecal influx of digesta particles larger than 100 mm seemed very limited.The caecal influx of the markers further exhibited large individual variation among birds.A maximum of 13.2%(d 9)and 4.3%(d 29)of the total administered soluble marker(Cr-EDTA)was detected in the caeca,5 h after bolus administration.Both solid and soluble markers showed a larger concentration in the caeca at a young age compared to older ages(P<0.01),possibly related to the limited caecal functioning early in life.These findings highlight the importance of carefully selecting the physical properties of fibres to be added as a function of age to further improve caecal fibre fermentation in broilers.展开更多
应用石蜡切片技术和显微测量法，对从孵化后到变态完成（55～60d，day post hatching，dph）的条斑星鲽（Verasper moseri Jordan et Gilbert）仔稚幼鱼早期发育中消化道的结构变化进行了观察，描述了个体发育过程中的组织学结构特征。...应用石蜡切片技术和显微测量法，对从孵化后到变态完成（55～60d，day post hatching，dph）的条斑星鲽（Verasper moseri Jordan et Gilbert）仔稚幼鱼早期发育中消化道的结构变化进行了观察，描述了个体发育过程中的组织学结构特征。结果表明，在13～15℃，7dph的仔鱼开口时，消化道已经分化为口咽腔、食道、肠和直肠，消化器官肝脏和胰腺出现。从7dph到14～17dph（卵黄囊消失）为混合营养期，形态上肠道进一步弯曲、盘旋；功能上中肠空泡样结构和后肠嗜伊红颗粒的出现，预示着肠上皮细胞在胃功能成熟前有吸收蛋白的作用。形态学上胃以及幽门盲囊的分化出现在26～29dph，与稚鱼刚开始附底的时期相吻合。而功能性胃的分化则出现在35dph左右，与稚鱼变态期相一致。条斑星鲽作为中国新近养殖品种，关于其早期发育的报道还是空白，作者对其消化系统进行系统的研究，旨在为该鱼种的商业化养殖提供相关的科学数据，同时也为海水鱼类早期营养和发育生物学的深入研究提供理论依据。展开更多
To obtain baseline information on the size distribution of individuals in the population and reproductive features of sea star Asterias amurensis, monthly surveys of the population were carried out from May to Decembe...To obtain baseline information on the size distribution of individuals in the population and reproductive features of sea star Asterias amurensis, monthly surveys of the population were carried out from May to December 2010 and March to May 2015 in coastal waters off Yantai, China. Spawning period was predicted by gonad and pyloric caeca indices as well as anatomical and histological methods. In the A. amurensis population, both large individuals（〉143 mm） and small ones（〈42 mm） were present in all sampling months. The population size structure was driven by the appearance of big cohorts of individuals less than 55 mm from May to August. The appearance of small individuals in all months suggested a prolonged spawning period at other sites in this bay or sea stars growing slowly because of food shortage. An arm length is a good predictor to wet body weight for A.amurensis. The development of gonad was relative slow from May to September but rapidly reached a peak of20.95 in October 2010, and then dropped remarkably, indicating its spawning lasted from October to November.The same phenomenon was found from March to May 2015, suggesting another spawning during March to May,which was also verified by the results of histologic analysis on ovary. The gonad index（GI） and pyloric caeca index（PCI） tended to show a negative relationship. Due to the poor food availability, the reproductive characteristics of sea star were most likely affected by the shellfish mariculturein Yantai coastal waters.展开更多
文摘A promising strategy to support broiler health and performance in a sustainable way is the enhancement of microbial fibre fermentation in broilers.This fermentation mainly occurs in the caeca,but the actual particle size range that allows caecal influx has not yet been described.This study aimed to understand the physical limitations of caecal influx as a function of broiler age by using both solid and soluble markers.In the first trial,the caecal filter mechanism was studied by microscopically visualising the caecal entrance and measuring caecal lobe development and digesta particle size as a function of age(d 8-36)for 44 broilers(Ross 308)receiving a conventional wheat-based diet.In two consecutive trials,microcrystalline cellulose beads(100-700 mm)and a combination of fluorescent polystyrene beads(5-30 mm)and chromium-ethylenediamine tetraacetic acid(Cr-EDTA)were administered to 176 and 189 broilers,respectively,at different ages(d 8-36).Results showed that the actual caecal entrance diameter is significantly reduced due to a dense villi network acting as a filter for digesta inflow.This explains the size gap between the average digesta particle size(D50)of the ileum(451-322 mm)and caeca(5-19 mm),and the outer diameter of the caecal entrance(2000-4000 mm)on d 8 to 36.In contrast to the caecal D50,cellulose beads of 700 mm already entered the caeca at 8 d of age,even though the general caecal influx of digesta particles larger than 100 mm seemed very limited.The caecal influx of the markers further exhibited large individual variation among birds.A maximum of 13.2%(d 9)and 4.3%(d 29)of the total administered soluble marker(Cr-EDTA)was detected in the caeca,5 h after bolus administration.Both solid and soluble markers showed a larger concentration in the caeca at a young age compared to older ages(P<0.01),possibly related to the limited caecal functioning early in life.These findings highlight the importance of carefully selecting the physical properties of fibres to be added as a function of age to further improve caecal fibre fermentation in broilers.
文摘应用石蜡切片技术和显微测量法，对从孵化后到变态完成（55～60d，day post hatching，dph）的条斑星鲽（Verasper moseri Jordan et Gilbert）仔稚幼鱼早期发育中消化道的结构变化进行了观察，描述了个体发育过程中的组织学结构特征。结果表明，在13～15℃，7dph的仔鱼开口时，消化道已经分化为口咽腔、食道、肠和直肠，消化器官肝脏和胰腺出现。从7dph到14～17dph（卵黄囊消失）为混合营养期，形态上肠道进一步弯曲、盘旋；功能上中肠空泡样结构和后肠嗜伊红颗粒的出现，预示着肠上皮细胞在胃功能成熟前有吸收蛋白的作用。形态学上胃以及幽门盲囊的分化出现在26～29dph，与稚鱼刚开始附底的时期相吻合。而功能性胃的分化则出现在35dph左右，与稚鱼变态期相一致。条斑星鲽作为中国新近养殖品种，关于其早期发育的报道还是空白，作者对其消化系统进行系统的研究，旨在为该鱼种的商业化养殖提供相关的科学数据，同时也为海水鱼类早期营养和发育生物学的深入研究提供理论依据。
基金The Strategic Priority Research Program of the Chinese Academy of Sciences under contract Nos XDA11020403 and XDA1102702the Key Research Program of the Chinese Academy of Sciences under contract No.KZZD-EW-14+1 种基金the Science and Technology Service Network Initiative Program under contract No.KFJ-EW-STS-127the self-deployment project of Yantai Institute of Coastal Zone Research,Chinese Academy of Sciences under contract No.YICY755021012
文摘To obtain baseline information on the size distribution of individuals in the population and reproductive features of sea star Asterias amurensis, monthly surveys of the population were carried out from May to December 2010 and March to May 2015 in coastal waters off Yantai, China. Spawning period was predicted by gonad and pyloric caeca indices as well as anatomical and histological methods. In the A. amurensis population, both large individuals（〉143 mm） and small ones（〈42 mm） were present in all sampling months. The population size structure was driven by the appearance of big cohorts of individuals less than 55 mm from May to August. The appearance of small individuals in all months suggested a prolonged spawning period at other sites in this bay or sea stars growing slowly because of food shortage. An arm length is a good predictor to wet body weight for A.amurensis. The development of gonad was relative slow from May to September but rapidly reached a peak of20.95 in October 2010, and then dropped remarkably, indicating its spawning lasted from October to November.The same phenomenon was found from March to May 2015, suggesting another spawning during March to May,which was also verified by the results of histologic analysis on ovary. The gonad index（GI） and pyloric caeca index（PCI） tended to show a negative relationship. Due to the poor food availability, the reproductive characteristics of sea star were most likely affected by the shellfish mariculturein Yantai coastal waters.
