The purpose of the study was to establish the structure of monitored animal farms and determine reproductive parameters of Sahelian goats in the Guera Region, in Central Chad. Data were collected through longitudinal ...The purpose of the study was to establish the structure of monitored animal farms and determine reproductive parameters of Sahelian goats in the Guera Region, in Central Chad. Data were collected through longitudinal survey in 27 observatory farms during three years using goats identified by numbered ear tags. The herds were composed on average of about 71% of females. The age pyramid covering all years showed a significant number of males aged between 0 - 1 year and perceptible fall thereafter. However, some stability was observed in the class of the 2 - 8 years old among females. The frequencies of accumulated kiddings showed that 44% of births occurred in the rainy season against 28% respectively in the cool dry and hot dry seasons. Obtained reproduction parameters were: a sex ratio of 0.51 in favor of males, a kidding interval of 10.6 months with significant differences (P < 0.05) according to the rank of birth, an age at first kidding of 16.5 months for females born in monitoring and an age of 20.3 months for all first-kidding, giving an apparent fertility rate of 145%, a fecundity rate of 116% and an abortion rate of 2%. The composition and structure of herds have highlighted the importance of females to ensure the reproducibility of goat production systems. The determined reproduction parameters are references for actions to improve goat rearing in this area.展开更多
The giant panda(Ailuropoda melanoleuca)is recognized worldwide as an icon for wildlife conservation.Since the introduction in 1992 of reliable methods for artificial insemination,the population of captive pandas has g...The giant panda(Ailuropoda melanoleuca)is recognized worldwide as an icon for wildlife conservation.Since the introduction in 1992 of reliable methods for artificial insemination,the population of captive pandas has grown to approximately 350 individuals in 2013.However,ca ptive panda populations are harmed by environmental pollution,diseases trans-mitted from domestic animals,and other anthropologenic activities.Although the Chinese government has proposed the creation of a Giant Panda National Park,there are at least three reasons that suggest that it is premature to reintroduce captive pandas into this proposed national park.First,habitat fragmentation remains the greatest threat to survival of giant pandas;second,most captive pandas are hybrids of the Sichuan and Qinling subspecies and release of hybrids may lead to further introgression between the two subspecies;and third,captive pandas may be competitively inferior to wild pandas in the region,and may not survive fights for food or mates.As an alternative,we suggest establishing a special con-servation zone in the Shennongjia National Nature Reserve for wild training of captive pandas prior to their reintroduction into the National Park.展开更多
文摘The purpose of the study was to establish the structure of monitored animal farms and determine reproductive parameters of Sahelian goats in the Guera Region, in Central Chad. Data were collected through longitudinal survey in 27 observatory farms during three years using goats identified by numbered ear tags. The herds were composed on average of about 71% of females. The age pyramid covering all years showed a significant number of males aged between 0 - 1 year and perceptible fall thereafter. However, some stability was observed in the class of the 2 - 8 years old among females. The frequencies of accumulated kiddings showed that 44% of births occurred in the rainy season against 28% respectively in the cool dry and hot dry seasons. Obtained reproduction parameters were: a sex ratio of 0.51 in favor of males, a kidding interval of 10.6 months with significant differences (P < 0.05) according to the rank of birth, an age at first kidding of 16.5 months for females born in monitoring and an age of 20.3 months for all first-kidding, giving an apparent fertility rate of 145%, a fecundity rate of 116% and an abortion rate of 2%. The composition and structure of herds have highlighted the importance of females to ensure the reproducibility of goat production systems. The determined reproduction parameters are references for actions to improve goat rearing in this area.
文摘The giant panda(Ailuropoda melanoleuca)is recognized worldwide as an icon for wildlife conservation.Since the introduction in 1992 of reliable methods for artificial insemination,the population of captive pandas has grown to approximately 350 individuals in 2013.However,ca ptive panda populations are harmed by environmental pollution,diseases trans-mitted from domestic animals,and other anthropologenic activities.Although the Chinese government has proposed the creation of a Giant Panda National Park,there are at least three reasons that suggest that it is premature to reintroduce captive pandas into this proposed national park.First,habitat fragmentation remains the greatest threat to survival of giant pandas;second,most captive pandas are hybrids of the Sichuan and Qinling subspecies and release of hybrids may lead to further introgression between the two subspecies;and third,captive pandas may be competitively inferior to wild pandas in the region,and may not survive fights for food or mates.As an alternative,we suggest establishing a special con-servation zone in the Shennongjia National Nature Reserve for wild training of captive pandas prior to their reintroduction into the National Park.
