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
Feed-animal balance is the key technique on the grassland ecosystem management,and attracts widespread attention in the world.Many studies have been conducted by former researchers,and most of their efforts were inten...Feed-animal balance is the key technique on the grassland ecosystem management,and attracts widespread attention in the world.Many studies have been conducted by former researchers,and most of their efforts were intended to keep the balance of feed-animal.However,there are still much more issue needed to be studied in details on the face of grassland degeneration and animal husbandry sustainable development.The author analyzed the feed-animal balance research progress,including the concept of stocking rate and its practical management techniques,especially on the stocking rate calculation methods.In addition,the social and economy effects on feed-animal balance were also discussed during the progress of improving the development of pastoral economy.In order to achieve feed-animal balance more effectively,it was concluded that the focus must be shift from only on animal number to the grassland quality,and it's necessary to strengthen market tax control.展开更多
In order to investigate the effect of meteorological factors on the yield and quality of special rice during the filling stage, an experiment was conducted with 10 special rice varieties which were planted in three di...In order to investigate the effect of meteorological factors on the yield and quality of special rice during the filling stage, an experiment was conducted with 10 special rice varieties which were planted in three different regions during spring 2017. The results showed that the quality traits and yields from different regions of the same variety were different, which reached up to a significant level in most varieties. Among the quality traits, the grain chalkiness rate and chalkiness degree were the most sensitive to different climatic factors, and changes were found among them in different regions, while minor variation was found between brown rice rate and white rice rate. The parameters that were severely affected by temperature were gel consistency, gelatinization temperature, brown rice rate and yield during the filling stage. The critically affected factors by heat were brown rice rate, protein content, essential amino acid and amylose content while brown rice rate, chalkiness rate and gelatinization temperature were substantially affected by water factors. Grain yield and quality were closely related to meteorological factors on different stages after heading. Our results revealed that yield and quality of special rice were significantly influenced by meteorological factors during the grain filling stage.展开更多
In order to solve the problem that the musk deer concentrated feed were easy to get rancidity in spring, summer, autumn and freezing in winter, high quality and palatability pellet feed of musk deer was researched and...In order to solve the problem that the musk deer concentrated feed were easy to get rancidity in spring, summer, autumn and freezing in winter, high quality and palatability pellet feed of musk deer was researched and developed to ensure the quality of musk deer＇s feed. Twenty-eight male musk deer （3 - 10 years old） （Moschus berezovskii） with normal body condition in the same culture conditions were chosen and were randomly divided into experimental group （fed pellets group） and control group （original feeding diet group）, the results show that musk deer was able to adapt to the pellet feed generally in 13 days and the duration varied with the palatability of pellet feed. During the trial period, the difference of the body weight, the average musk yield of producing musk deer and the producing musk incidence between the experimental group and the control group was not significant, the incidence of disease and mortality of experimental group deer was significantly lower than the control group.展开更多
Fifty Holstein cows (2.6 ± 1.0 lactations) in early lactation (52.6 ± 16.4 days in milk) calved in autumn and producing 34.3 (±4.4) kg milk per cow·day-1 were randomly assigned for 27 weeks to one ...Fifty Holstein cows (2.6 ± 1.0 lactations) in early lactation (52.6 ± 16.4 days in milk) calved in autumn and producing 34.3 (±4.4) kg milk per cow·day-1 were randomly assigned for 27 weeks to one of two treatments (feeding systems) in 10 groups (pens) of 5 animals each (5 groups/treatment). The confined treatment was a total mixed ration (TMR_100) whereas the supplemented grazing system was defined by a partially mixed ration (PMR_75) with 75% TMR and 25% oat pasture (Avena sativa L.) during the autum-winter (Period I) and alfalfa pasture (Medicago sativa L.) plus concentrate (7.0 kg per cow·day-1) (P + C) during the next spring (Period II). Milk production was daily and individually recorded throughout the trial while the chemical composition of milk was measured on individual samples every 2 weeks. Live weight (LW) and body condition score (BCS) using a scale of 1 to 5 were recorded every 3 weeks after the morning milking. Simultaneously, blood samples were taken for determinations of glucose, urea, non-esterified fatty acids (NEFA), insulin, somatotrophin (GH) and somatomedin C (IGF-I). Total DM intake was measured using the difference method four times per repetition in the months of July, August, September and October. The experimental herd was inseminated at fixed time at the start of the service (May-July) and on the return with estrus detection. The diagnosis of pregnancy was made by transrectal ultrasonography at 30 and 60 days after the start of the service. The productive data were analyzed according to a model with repeated observations in time adjusted by covariate with 2 periods and using the animal as the experimental unit. Data of DM intake were analyzed using ANOVA for 2 treatments with 5 repetitions. Cows from the TMR_100 group produced more milk (kg·cow-1·day-1) during Period I (33.7 vs. 32.3) and Period II (28.8 vs. 27.8) (P ·cow-1·day-1) in Periods I (1.33 vs. 1.24) and II (1.10 vs. 0.92) and for milk protein (1.19 vs. 1.13 and 0.99 vs. 0.93). The lower energy intake of grazing cows (45.0 vs. 43.1 and 40.9 vs. 38.9 Mcal per?cow·day-1 for TMR_100 vs. PMR_75 and TMR_100 vs. P + C) coupled to the extra energy cost associated with grazing activity would explain the difference in milk production. Milk protein content (%) resulted higher (P kg·cow-1·day-1) in the cows of the TMR_100 group in both periods (0.69 vs. 0.34 and 0.49 vs. -0.22) was consistent with the increase in the plasmatic levels of glucose and IGF-I and the reduction in the circulating levels of GH, but not with the lack of increases in plasma insulin concentration or decreases in circulating levels of NEFA, parameters that were not affected by treatments. Despite the positive effects of TMR_100 on parameters linked to energy balance, no significant differences were detected in any of the reproductive parameters evaluated and the final rate of pregnancy was 80.0 and 91.3% for the confined and grazing system with supplementation respectively. Free milk liters over feeding costs were higher in the grazing system with supplementation compared to the confined system (18.5 vs. 15.5 l, respectively). The results indicate that the grazing system with supplementation can be economically competitive compared to the confined system of milk production.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The National Special Research Fund for Non-Profit Sector."Carrying Capacity and Livestock in Different Places"(200903060)"Re-search and Demonstration of Resources Optimization in Family Farmland"(201003019)+1 种基金"Research and Demonstration of Nurture of Natural Grassland and Used Technology in Semi-arid Farmland"(201303060)National Forage Industry Technological System(CARS-35)
文摘Feed-animal balance is the key technique on the grassland ecosystem management,and attracts widespread attention in the world.Many studies have been conducted by former researchers,and most of their efforts were intended to keep the balance of feed-animal.However,there are still much more issue needed to be studied in details on the face of grassland degeneration and animal husbandry sustainable development.The author analyzed the feed-animal balance research progress,including the concept of stocking rate and its practical management techniques,especially on the stocking rate calculation methods.In addition,the social and economy effects on feed-animal balance were also discussed during the progress of improving the development of pastoral economy.In order to achieve feed-animal balance more effectively,it was concluded that the focus must be shift from only on animal number to the grassland quality,and it's necessary to strengthen market tax control.
文摘In order to investigate the effect of meteorological factors on the yield and quality of special rice during the filling stage, an experiment was conducted with 10 special rice varieties which were planted in three different regions during spring 2017. The results showed that the quality traits and yields from different regions of the same variety were different, which reached up to a significant level in most varieties. Among the quality traits, the grain chalkiness rate and chalkiness degree were the most sensitive to different climatic factors, and changes were found among them in different regions, while minor variation was found between brown rice rate and white rice rate. The parameters that were severely affected by temperature were gel consistency, gelatinization temperature, brown rice rate and yield during the filling stage. The critically affected factors by heat were brown rice rate, protein content, essential amino acid and amylose content while brown rice rate, chalkiness rate and gelatinization temperature were substantially affected by water factors. Grain yield and quality were closely related to meteorological factors on different stages after heading. Our results revealed that yield and quality of special rice were significantly influenced by meteorological factors during the grain filling stage.
基金Supported by Sci-tech Achievement Transformation Project from Sichuan Provincial Science and Technology Department([2007]33)
文摘In order to solve the problem that the musk deer concentrated feed were easy to get rancidity in spring, summer, autumn and freezing in winter, high quality and palatability pellet feed of musk deer was researched and developed to ensure the quality of musk deer＇s feed. Twenty-eight male musk deer （3 - 10 years old） （Moschus berezovskii） with normal body condition in the same culture conditions were chosen and were randomly divided into experimental group （fed pellets group） and control group （original feeding diet group）, the results show that musk deer was able to adapt to the pellet feed generally in 13 days and the duration varied with the palatability of pellet feed. During the trial period, the difference of the body weight, the average musk yield of producing musk deer and the producing musk incidence between the experimental group and the control group was not significant, the incidence of disease and mortality of experimental group deer was significantly lower than the control group.
文摘Fifty Holstein cows (2.6 ± 1.0 lactations) in early lactation (52.6 ± 16.4 days in milk) calved in autumn and producing 34.3 (±4.4) kg milk per cow·day-1 were randomly assigned for 27 weeks to one of two treatments (feeding systems) in 10 groups (pens) of 5 animals each (5 groups/treatment). The confined treatment was a total mixed ration (TMR_100) whereas the supplemented grazing system was defined by a partially mixed ration (PMR_75) with 75% TMR and 25% oat pasture (Avena sativa L.) during the autum-winter (Period I) and alfalfa pasture (Medicago sativa L.) plus concentrate (7.0 kg per cow·day-1) (P + C) during the next spring (Period II). Milk production was daily and individually recorded throughout the trial while the chemical composition of milk was measured on individual samples every 2 weeks. Live weight (LW) and body condition score (BCS) using a scale of 1 to 5 were recorded every 3 weeks after the morning milking. Simultaneously, blood samples were taken for determinations of glucose, urea, non-esterified fatty acids (NEFA), insulin, somatotrophin (GH) and somatomedin C (IGF-I). Total DM intake was measured using the difference method four times per repetition in the months of July, August, September and October. The experimental herd was inseminated at fixed time at the start of the service (May-July) and on the return with estrus detection. The diagnosis of pregnancy was made by transrectal ultrasonography at 30 and 60 days after the start of the service. The productive data were analyzed according to a model with repeated observations in time adjusted by covariate with 2 periods and using the animal as the experimental unit. Data of DM intake were analyzed using ANOVA for 2 treatments with 5 repetitions. Cows from the TMR_100 group produced more milk (kg·cow-1·day-1) during Period I (33.7 vs. 32.3) and Period II (28.8 vs. 27.8) (P ·cow-1·day-1) in Periods I (1.33 vs. 1.24) and II (1.10 vs. 0.92) and for milk protein (1.19 vs. 1.13 and 0.99 vs. 0.93). The lower energy intake of grazing cows (45.0 vs. 43.1 and 40.9 vs. 38.9 Mcal per?cow·day-1 for TMR_100 vs. PMR_75 and TMR_100 vs. P + C) coupled to the extra energy cost associated with grazing activity would explain the difference in milk production. Milk protein content (%) resulted higher (P kg·cow-1·day-1) in the cows of the TMR_100 group in both periods (0.69 vs. 0.34 and 0.49 vs. -0.22) was consistent with the increase in the plasmatic levels of glucose and IGF-I and the reduction in the circulating levels of GH, but not with the lack of increases in plasma insulin concentration or decreases in circulating levels of NEFA, parameters that were not affected by treatments. Despite the positive effects of TMR_100 on parameters linked to energy balance, no significant differences were detected in any of the reproductive parameters evaluated and the final rate of pregnancy was 80.0 and 91.3% for the confined and grazing system with supplementation respectively. Free milk liters over feeding costs were higher in the grazing system with supplementation compared to the confined system (18.5 vs. 15.5 l, respectively). The results indicate that the grazing system with supplementation can be economically competitive compared to the confined system of milk production.
