Colony cages for natural mating have been applied on many layer breeder farms.However,feather pecking and cloacal cannibalism are considered as prominent problems for these systems.This study aimed to investigate the ...Colony cages for natural mating have been applied on many layer breeder farms.However,feather pecking and cloacal cannibalism are considered as prominent problems for these systems.This study aimed to investigate the effects on feather pecking and vent pecking behaviors by providing layer breeders with nest boxes(0.90 m L×0.40 m W×0.60 m H)in colony cages for natural mating(4.80 m L×1.20 m W×0.71 m H).Video recording and artificial observation were adopted.The results showed that the usage of nest boxes gradually increased from the beginning of nest boxes providing at the age of 37 weeks to the end of the experiment at the age of 55 weeks.The utilization rates of nest boxes were 36.75%,44.75%and 50.38%at the ages of 41 weeks,47 weeks and 53 weeks,respectively.The hens in the cages without nest boxes showed significantly more frequent gentle feather pecks(both given and received)than hens in the cages with nest boxes at the ages of 41 weeks,47 weeks and 53 weeks.A decreasing trend of gentle feather pecking frequency(both given and received)was found with the increasing age for both the two groups.No significant difference was found in the number of given or received severe feather pecks at the age of 41 weeks.The hens in the cages without nest boxes showed a significantly higher frequency of given and received severe feather pecks than hens in the cages with nest boxes at the ages of 47 weeks and 53 weeks(p<0.05).Both cannibalistic injury occurrence and mortality rate in the cages with nest boxes were significantly lower than those in the cages without nest boxes.In conclusion,providing nest boxes in colony cages for natural mating could decrease abnormal pecking behaviors and improve animal welfare conditions of layer breeders.展开更多
Zirconia(ZrO_(2))ceramic material has been widely applied to various fields due to its unique properties of high strength,high hardness,and excessive temperature resistance.However,the high-quality micro-hole machinin...Zirconia(ZrO_(2))ceramic material has been widely applied to various fields due to its unique properties of high strength,high hardness,and excessive temperature resistance.However,the high-quality micro-hole machining of zirconia ceramic material remains a significant challenge at present.In this study,experiments on peck drilling of 0.2 mm and 0.5 mm micro-holes in zirconia ceramics using diamond-coated drills are conducted.The characteristics of the force signal during the drilling process,the influence of drilling parameters on the drlling force and the chipping size at the hole exit,and features of the tool wear stages of the diamond coated drill are analyzed.Experimental results suggest that when machining micro-holes in zirconia ceramics,there is a positive correlation between the axial force and the size of the chipping at the exit.The axial force increases with the increase of the feed rate and the step distance,and it shows a trend of first increasing and next decreasing with the increase of the spindle speed.The wear of the drll bit has a significant impact on the quality of the hole exit.It is found that with the continuous drilling of seven holes,the axial force increases by 144.2%,and the size of edge chipping at the exit increases from about 20μm to more than 130μm.This study can provide some valuable references for improving the micro-hole processing quality of material.展开更多
基金This research was funded by China Agricultural Research System(CARS-40)Beijing Science&Technology Committee Special Project(Z171100002217018).
文摘Colony cages for natural mating have been applied on many layer breeder farms.However,feather pecking and cloacal cannibalism are considered as prominent problems for these systems.This study aimed to investigate the effects on feather pecking and vent pecking behaviors by providing layer breeders with nest boxes(0.90 m L×0.40 m W×0.60 m H)in colony cages for natural mating(4.80 m L×1.20 m W×0.71 m H).Video recording and artificial observation were adopted.The results showed that the usage of nest boxes gradually increased from the beginning of nest boxes providing at the age of 37 weeks to the end of the experiment at the age of 55 weeks.The utilization rates of nest boxes were 36.75%,44.75%and 50.38%at the ages of 41 weeks,47 weeks and 53 weeks,respectively.The hens in the cages without nest boxes showed significantly more frequent gentle feather pecks(both given and received)than hens in the cages with nest boxes at the ages of 41 weeks,47 weeks and 53 weeks.A decreasing trend of gentle feather pecking frequency(both given and received)was found with the increasing age for both the two groups.No significant difference was found in the number of given or received severe feather pecks at the age of 41 weeks.The hens in the cages without nest boxes showed a significantly higher frequency of given and received severe feather pecks than hens in the cages with nest boxes at the ages of 47 weeks and 53 weeks(p<0.05).Both cannibalistic injury occurrence and mortality rate in the cages with nest boxes were significantly lower than those in the cages without nest boxes.In conclusion,providing nest boxes in colony cages for natural mating could decrease abnormal pecking behaviors and improve animal welfare conditions of layer breeders.
基金supported by the National Natural Science Foundation of China(Nos.51805242,52475463).
文摘Zirconia(ZrO_(2))ceramic material has been widely applied to various fields due to its unique properties of high strength,high hardness,and excessive temperature resistance.However,the high-quality micro-hole machining of zirconia ceramic material remains a significant challenge at present.In this study,experiments on peck drilling of 0.2 mm and 0.5 mm micro-holes in zirconia ceramics using diamond-coated drills are conducted.The characteristics of the force signal during the drilling process,the influence of drilling parameters on the drlling force and the chipping size at the hole exit,and features of the tool wear stages of the diamond coated drill are analyzed.Experimental results suggest that when machining micro-holes in zirconia ceramics,there is a positive correlation between the axial force and the size of the chipping at the exit.The axial force increases with the increase of the feed rate and the step distance,and it shows a trend of first increasing and next decreasing with the increase of the spindle speed.The wear of the drll bit has a significant impact on the quality of the hole exit.It is found that with the continuous drilling of seven holes,the axial force increases by 144.2%,and the size of edge chipping at the exit increases from about 20μm to more than 130μm.This study can provide some valuable references for improving the micro-hole processing quality of material.
