Impacts of past abrupt land change on local biodiversity globally

Abrupt land change, such as deforestation or agricultural intensification, is a key driver of biodiversity change. Following abrupt land change, local biodiversity often continues to be influenced through biotic lag effects. However, current understanding of how terrestrial biodiversity is impacted by past abrupt land changes is incomplete. Here we show that abrupt land change in the past continues to influence present species assemblages globally. We combine geographically and taxonomically broad data on local biodiversity with quantitative estimates of abrupt land change detected within time series of satellite imagery from 1982 to 2015. Species richness and abundance were 4.2% and 2% lower, respectively, and assemblage composition was altered at sites with an abrupt land change compared to unchanged sites, although impacts differed among taxonomic groups. Biodiversity recovered to levels comparable to unchanged sites after >10 years. Ignoring delayed impacts of abrupt land changes likely results in incomplete assessments of biodiversity change

Global lake responses to climate change

Climate change is one of the most severe threats to global lake ecosystems. Lake surface conditions, such as ice cover, surface temperature, evaporation and water level, respond dramatically to this threat, as observed in recent decades. In this Review, we discuss physical lake variables and their responses to climate change. Decreases in winter ice cover and increases in lake surface temperature modify lake mixing regimes and accelerate lake evaporation. Where not balanced by increased mean precipitation or inflow, higher evaporation rates will favour a decrease in lake level and surface water extent. Together with increases in extreme-precipitation events, these lake responses will impact lake ecosystems, changing water quantity and quality, food provisioning, recreational opportunities and transportation. Future research opportunities, including enhanced observation of lake variables from space (particularly for small water bodies), improved in situ lake monitoring and the development of advanced modelling techniques to predict lake processes, will improve our global understanding of lake responses to a changing climate

Effects of different dietary copper sources on laying hen performance and egg yolk cholesterol

An experiment was conducted using a total of 120 Lohmann Brown hens, 16 wk of age, to compare 3 different supplemental dietary Cu sources incorporating supraoptimal amounts of Cu (250 mg/kg) on layer performance, egg yolk cholesterol, and blood parameters. Layers were randomly allocated to 4 dietary treatments with 10 replications of 3 birds each for each treatment. Layers were fed diets containing 0 (control) or 250 ppm of Cu from Cu sulfate, Cu proteinate, or Cu lysine for 24 wk. No differences were observed among Cu sources for BW, egg mass, feed conversion, egg specific gravity, egg yolk cholesterol, plasma total cholesterol, high-density lipoprotein cholesterol, triglycerides, or glutathione peroxidase. Supplementation with 250 ppm of Cu sulfate improved egg production but decreased egg weight (P < 0.05) and feed intake (P < 0.01) as compared with the other diets. Supplementation with Cu proteinate resulted in decreased feed intake (P < 0.01), but egg production, egg mass, and egg weight were not changed as compared with the controls. Eggshell thicknesses of layers fed the Cu sulfate and Cu lysine diets were lower than the eggshell thickness of layers fed the control diet (P < 0.001). Copper contents of eggs and excreta were significantly (P < 0.001) increased regardless of Cu source as compared with birds fed the control diet. The results of this trial did not confirm the finding that Cu alters lipid metabolism and decreases cholesterol in the egg yolk. We conclude that increasing the dietary Cu intake through the use of different Cu compounds did not affect layer performance and cholesterol content of the egg yolk

Live performance, digestive tract features, and ileal nutrient digestibility in broilers fed diets containing soy hulls

This study aimed at determining the impact of dietary soy hulls (SH) addition on growth performance, digestive tract attributes, and apparent ileal digestibility of dry matter (DM), nitrogen, and phosphorus (P) in broiler chickens. Male broilers (Ross 308, n = 224) were assigned to one of four diets, including 0, 20, 40, or 60 g/kg SH, with eight replications per treatment from 0 to 21 d of age in a completely randomised design. Dietary chromic oxide was the indigestible marker for determining the apparent ileal digestibility. Data were subjected to orthogonal polynomial contrasts using the Proc GLM of SAS. Growth performance and small intestine weight and length, and gizzard content pH were not influenced (p > .05) by increasing levels of dietary SH. Increasing the dietary SH level resulted in a linear increase (p  .05) by dietary SH inclusion. However, apparent ileal digestibility of DM and P increased linearly (p < .01) with increasing dietary SH levels. In conclusion, the addition of SH up to 60 g/kg improved the ileal digestibility of DM and P and increased gizzard weight without affecting the proportionate small intestine morphology and live performance of broiler chickens at 21 d of age.HIGHLIGHTS Soy hulls did not have any effect on growth Soy hulls increased the digestibility of P Soy hulls increased gizzard weigh

True phosphorus digestibility of camelina meal in broiler chickens

This study was conducted to determine the true digestibility of phosphorus (P) in two different cold-pressed camelina meals using regression method. Six semi-purified experimental diets containing 120, 240, or 360 g of camelina meal (CM) per kilogram from camelina meal 1 (CM1) and camelina meal 2 (CM2) were formulated. A total of 384 male Ross 708 broilers were allocated to six dietary treatments with eight cages per treatment from day 18 to day 23 post hatching in a randomized complete block design. The result showed that body weight gain, gain: feed ratio, ileal dry matter (DM) digestibility, DM and nitrogen (N) retention decreased (linear, P < 0.001) with increasing levels of CM1 and CM2. Apparent ileal digestibility of P and Ca decreased (P < 0.01) with increasing dietary levels of CM. From the regressions of ileal and excreta P output against intake of P from CM1 or CM2, true ileal P digestibility and true P retention were determined to be 35% and 15%, and 24% and 21% for CM1, and CM2, respectively. Results from the current experiment showed that high level of dietary CM inclusion resulted in a significant reduction in utilization of P in diets, and there was a considerable range in P utilization between the two camelina meal samples

Effects of dietary supplementation of citric acid, copper, and microbial phytase on growth performance and mineral retention in broiler chickens fed a low available phosphorus diet

An experiment was conducted to study the effects of microbial phytase (PHY), citric acid (CA), and Cu proteinate supplementation in broilers (13 to 42 d of age) fed a low available P diet (0.25%) on growth performance, carcass characteristics, blood parameters, and mineral retention. A 2 x 2 x 2 factorial arrangement of treatments was used to evaluate 2 levels of PHY (0 and 750 phytase units/kg of diet), Cu (0 and 250 ppm), and CA (0 and 3%). The CA and Cu supplementation as well as their interaction significantly affected BW and BW gain (P < 0.05), with birds fed supplemental CA having better BW gain when fed the Cu-supplemented diet. A significant Cu x CA interaction (P < 0.05) was observed for tibia weight, in which CA supplementation resulted in increased tibia weight when birds were fed a diet not supplemented with Cu. Interaction effects between PHY and Cu were noted for tibia ash (P < 0.01) and tibia P (P < 0.05), with Cu + PHY supplementation being superior to the other treatments for tibia ash. However, tibia P was greater for the individual effects of both Cu and PHY compared with the combined effect of both additives. There was a significant interaction (P < 0.01) of PHY and CA supplementation with tibia ash percentage, in which the tibia ash (%) increased with combinations of PHY and CA. Supplementation with Cu also resulted in significantly lower cholesterol levels in the thigh muscle (P < 0.05) and serum of birds (P < 0.05). Regarding the main effects of microbial phytase (P < 0.01) and CA (P < 0.05), supplementation increased the P retention with both additives. Therefore, when a low available P diet is used after 13 d, supplementing these additives in the formulation should be considered