This sixty-day study was performed to determine the effects of short-term starvation and refeeding cycles on growth, feeding performances and body composition of rainbow trout （Oncorhynchus mykiss）. Three hundred tr...This sixty-day study was performed to determine the effects of short-term starvation and refeeding cycles on growth, feeding performances and body composition of rainbow trout （Oncorhynchus mykiss）. Three hundred trout fingerlings with an average initial weight of 17.54-0.06 g were randomly distributed in 15 circular fiberglass tanks. The fish were exposed to 5 different feeding regimes; control： continuously fed twice daily to apparent satiation; T1： starved for 1 day and re-fed for 2 days; T2： starved for 1 day and re-fed for 4 days; T3： starved for 3 days and re-fed for 12 days; T4： starved for 4 days and re-fed for 16 days. At the end of the experiment, growth performance, feed utilization, whole body ash and moisture contents were not significantly （P〉0.05） different among the treatments. However, whole body protein content in T3 was significantly higher than other treatments （P〈0.05）. A significant difference in whole body fat content was observed between T3 and the control group at the end of the experiment （P〈0.05）. In conclusion this experiment suggests that feeding schedules involving starvation （1-4 days） and re-feeding cycles are a promising feed management tool for rainbow trout culture.展开更多
The effect of three stocking densities, ranging from 30 to 44 kg product per m2 on the performance, behaviour and welfare indexes in broiler chicken was investigated. Scan sampling for comparative behavior in all grou...The effect of three stocking densities, ranging from 30 to 44 kg product per m2 on the performance, behaviour and welfare indexes in broiler chicken was investigated. Scan sampling for comparative behavior in all groups was carried out at 2 min intervals during 2-20 min periods for five days each week. It was found that the most common behaviour in all densities was lying （resting）, lying and standing behaviour was tended to increase in H than L group of all experimental period. Pecking behaviour was not constantly changed by stocking density. Locomotion was not only reduced with increasing age but increase stocking density of all experimental period and all groups. Body weight gain and feed efficient were, tend to increase in L than H group of 2 to 3 weeks ages, higher in L than H group （P 〈 0.05） of 4 to 5 weeks ages and all experimental period. Other behaviours （dustbathing, preening, eating or drinking） were not influenced （P 〉 0.05） by stocking density. It seems that gait, foot pad and hock burn score were improved in L than H group of 35 days age （P 〈 0.05）. The claw length of 21 days age was not affected by stocking density, but it was significantly different by stocking density of 35 days age （P 〈 0.05）. The duration of tonic immobility （TI-reaction） was tended to decreased age of 21 than 35 days, but not effected by stocking density. These data indicate that stocking density can influence broiler behaviour and welfare indexes.展开更多
文摘This sixty-day study was performed to determine the effects of short-term starvation and refeeding cycles on growth, feeding performances and body composition of rainbow trout （Oncorhynchus mykiss）. Three hundred trout fingerlings with an average initial weight of 17.54-0.06 g were randomly distributed in 15 circular fiberglass tanks. The fish were exposed to 5 different feeding regimes; control： continuously fed twice daily to apparent satiation; T1： starved for 1 day and re-fed for 2 days; T2： starved for 1 day and re-fed for 4 days; T3： starved for 3 days and re-fed for 12 days; T4： starved for 4 days and re-fed for 16 days. At the end of the experiment, growth performance, feed utilization, whole body ash and moisture contents were not significantly （P〉0.05） different among the treatments. However, whole body protein content in T3 was significantly higher than other treatments （P〈0.05）. A significant difference in whole body fat content was observed between T3 and the control group at the end of the experiment （P〈0.05）. In conclusion this experiment suggests that feeding schedules involving starvation （1-4 days） and re-feeding cycles are a promising feed management tool for rainbow trout culture.
文摘The effect of three stocking densities, ranging from 30 to 44 kg product per m2 on the performance, behaviour and welfare indexes in broiler chicken was investigated. Scan sampling for comparative behavior in all groups was carried out at 2 min intervals during 2-20 min periods for five days each week. It was found that the most common behaviour in all densities was lying （resting）, lying and standing behaviour was tended to increase in H than L group of all experimental period. Pecking behaviour was not constantly changed by stocking density. Locomotion was not only reduced with increasing age but increase stocking density of all experimental period and all groups. Body weight gain and feed efficient were, tend to increase in L than H group of 2 to 3 weeks ages, higher in L than H group （P 〈 0.05） of 4 to 5 weeks ages and all experimental period. Other behaviours （dustbathing, preening, eating or drinking） were not influenced （P 〉 0.05） by stocking density. It seems that gait, foot pad and hock burn score were improved in L than H group of 35 days age （P 〈 0.05）. The claw length of 21 days age was not affected by stocking density, but it was significantly different by stocking density of 35 days age （P 〈 0.05）. The duration of tonic immobility （TI-reaction） was tended to decreased age of 21 than 35 days, but not effected by stocking density. These data indicate that stocking density can influence broiler behaviour and welfare indexes.
