Springtime grazing by Arctic-breeding geese reduces first- and second-harvest yields on sub-Arctic agricultural grasslands

Long-term changes in herbivore community and vegetation impact of wild and domestic herbivores across Iceland

Changes in wild and domestic herbivore populations significantly impact extensive grazing systems, particularly in low productive environments, where increasing wild herbivore populations are perceived as a threat to farming. To assess the magnitude of these changes in Iceland, we compiled time series on herbivore populations from 1986 to 2020 and estimated changes in species densities, metabolic biomass, and consumption of plant biomass in improved lands and unimproved rangelands. We compared estimates of consumption rates to past and present net primary production. Overall, the herbivore community composition shifted from livestock to wildlife dominated. However, wild herbivores only contributed a small fraction (14%) of the total herbivore metabolic biomass and consumption (4-7%), and livestock dominated the overall herbivore biomass. These insights highlight the necessity of developing improved local integrated management for both wild and domestic herbivores where they coexist.

Comparison of growth performance, meat quality, and blood biochemical indexes of Yangzhou goose under different feeding patterns

The East China region is the main market for the breeding and consumption of meat geese in China, in order to provide data reference for small and medium-sized farms and farmers to choose breeding methods and growth performance. This study selected 300 Yangzhou geese as materials and determined the number of geese in each group according to different modes. The meat quality, blood biochemical indicators, and economic benefits of 4 common feeding methods (Group I: full concentrate feeding; Group II: concentrate feeding in the first stage + 3% fat addition in the later stage; Group III: concentrate feeding + pasture supplementation; Group IV: grazing feeding + concentrate) in East China were analyzed. The results are as follows: The average daily weight gain of Yangzhou geese in Group IV at 5 to 8 wk old was the highest, with the highest feed utilization rate. The body weight at 8 wk old was significantly higher than that of the group III (P < 0.05). The total mortality rate of Group I and II remained at a relatively low level, while the mortality rates of Group III and IV exceeded 17%. The SR, FECR, and FECW of female geese in Groups II, III, and IV were significantly higher than those in Control group I (P < 0.05). Different feeding methods have little effect on the quality of goose breast muscles, while in terms of leg muscles, Group II has the highest binding force, significantly higher than Group I (P < 0.05). The rate of chest muscle loss in group III was significantly higher than that in groups I and II (P < 0.05). However, the pH of leg muscles in groups I, II and III was significantly higher than that in group IV (P < 0.05). Group II has the highest protein and collagen content, and Group I has the highest fat content. Except for the significantly higher histidine content in Groups I And II compared to those in Groups III and IV (P < 0.05), there was almost no significant difference in amino acid content among the groups (P > 0.05). There was no significant difference in ALB/GLO content among the 3 groups of Groups II to IV, but they were all significantly higher than those of Group I (P < 0.05). There was no statistically significant difference in other indicators among the groups (P > 0.05). There was no significant difference in the content of Ca, Cu, Fe, P, Zn, and other elements in the muscles between the groups (P > 0.05). This study solved the problems of slow growth, poor meat performance, and low economic benefits in meat goose breeding, providing theoretical basis and data support for meat goose breeding enterprises and farmers to choose appropriate breeding modes.

Climate-related drivers of nutrient inputs and food web structure in shallow Arctic lake ecosystems

In order to predict the effects of climate change on polar ecosystems, disentangling mechanisms of nutrient transfer in food webs is crucial. We investigated sources of nutrients in tundra lakes, tracing their transfer through the food web and relating the observed patterns to runoff, snow coverage, and the presence of migratory geese in lake catchments. C and N content (elemental and isotopic) of several food web components including Lepidurus arcticus (Notostraca, at the top of the lake food webs) in 18 shallow Arctic lakes was compared. Terrestrial productivity and geese abundance were key biotic factors that interacted with abiotic variables (snow coverage, lake and catchment size) in determining the amount and origin of nutrient inputs, affecting the trophic interactions among aquatic species, food chain length and nutrient flow in Arctic lake food webs. Decreasing snow coverage, increasing abundance and expansion of the geese's range are expected across the Arctic due to climate warming. By relating nutrient inputs and food web structure to snow coverage, vegetation and geese, this study contributes to our mechanistic understanding of the cascade effects of climate change in tundra ecosystems, and may help predict the response of lakes to changes in nutrient inputs at lower latitudes.