Flying Slower: Floor Pattern Object Size Affects Orthokinetic Responses During Moth Flight to Sex Pheromone

Previous studies with Oriental Fruit Moth (OFM, Grapholita molesta) and Heliothis virescens males flying upwind along a pheromone plume showed that they increased their upwind flight speed as they flew higher above striped floor patterns and, for OFM, to a similar degree over dotted floor patterns. This response pattern has been demonstrated in another moth species, Epiphyas postvittana and in a beetle, Prostephanus truncatus. In all cases the role played by the change in angular size of the wind tunnel’s ventral floor pattern was not assessed. In the present study we specifically addressed this question with a systematic examination of moths’ flight control over different sizes of transverse stripes and dot patterns ranging down by halves from 5 to 0.625 cm and a blank white floor as a control, and showed that OFM males fly faster upwind and along their flight paths over floor patterns of decreasing size. Increased speeds over striped patterns were evident as stripe width decreased below 2.5 cm, whereas moths did not increase their flight speed over dot patterns until dot size had decreased to less than 1.25 cm. Another flight component that the moths can actively control, their course angles, was unchanged above both patterns, except for moths flying over 5 cm stripes. Turning frequency and interturn distances were mostly unchanged or offset each other, negating any effects on upwind progress. As in an earlier study examining flight speeds at three heights above floor patterns of three densities, the moths’ changes in speed appear to be exclusively affected by changes in their orthokinetic response to the size of the floor pattern objects.     

Flying Beetles Respond as Moths Predict: Optomotor Anemotaxis to Pheromone Plumes at Different Heights

The current level of understanding of orientation mechanisms used by flying insects responding to pheromone sources, based almost entirely on studies of moths and flies, allows clear predictions to be made of how other, hitherto little-studied insect taxa, such as beetles (Coleoptera), should behave if the same mechanisms are used. Results are presented of the first test of such set of predictions, the effect of flight height on ground speed, on a beetle, Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae). The beetle P. truncatus flew upwind toward the source of horizontal pheromone plumes and responded to the movement of visible patterns on the floor of a sustained flight tunnel. Beetles flying at a greater height from the floor were less responsive to moving floor patterns. The flight speeds of P. truncatus increased with flight altitude, as found with moths, suggesting that they use orientation mechanism similar to those of moths.     

Flight paths of night-flying moths to light

The terminal portion of the flight paths of the corn earworm moth, Heliothis zea, to blacklights were studied on a moth flight pond and in the field. It was found that moths did not spiral into a lamp or fly directly at the light, but flew towards a region next to the lamp. It is suggested that near-the-light moths perceive a dark Mach band next to the lamp and fly towards this region in an effort to escape.     

Effect of Dietary Supplementation with Copper Sulfate or Tribasic Copper Chloride on the Growth Performance, Liver Copper Concentrations of Broilers Fed in Floor Pens, and Stabilities of Vitamin E and Phytase in Feeds

An experiment was conducted using a total of 840, 1-day-old, Arbor Acres commercial male broilers to compare copper (Cu) sulfate and tribasic Cu chloride (TBCC, Cu₂(OH)₃Cl) as sources of supplemental Cu for broilers fed in floor pens. Chicks were randomly allotted to one of seven treatments for six replicate pens of 20 birds each, and were fed a basal corn–soybean meal diet (10.20 mg/kg Cu) supplemented with 0, 100, 150, or 200 mg/kg Cu from either Cu sulfate or TBCC for 21 days. Chicks fed 200 mg/kg Cu as TBCC had a higher (P?<?0.05) average daily gain (ADG) than those consuming other diets. Liver Cu contents of broilers fed diets supplemented with TBCC were numerically lower (P?>?0.05) than those of broilers fed diets supplemented with Cu sulfate. The vitamin E contents and the phytase activities in the feed fortified with TBCC were higher (P?<?0.01) and numerically higher (P?>?0.05) compared with those in the feeds fortified with Cu sulfate stored at room temperature, respectively. The vitamin E contents in liver and plasma of broilers fed diets supplemented with TBCC were higher (P?<?0.05) than those of birds fed diets supplemented with Cu sulfate. This result indicates that TBCC is more effective than Cu sulfate in improving the growth of broilers fed in floor pens, and it is chemically less active than Cu sulfate in promoting the undesirable oxidation of vitamin E in feeds.     

Use of Radio Telemetry for Studying Flight Movements of <Emphasis Type="Italic">Paysandisia archon</Emphasis> (Lepidoptera: Castniidae)

The moth Paysandisia archon is an invasive species that infests palm trees in the Mediterranean Basin. The immature stages occur exclusively inside the palm crown, whereas adults fly to mate and locate a new host plant. Here, we describe the use of small radio transmitters (0.27 g) for tracing the movements of P. archon adults. We report the first successful use of radio telemetry to track flight distances and space use of a flying moth. Our study was carried out using 11 tagged moths released on the Maguelone Peninsula in southern France. Although the males were successfully tracked within a restricted area, estimated at 4 ha, most of the tagged females immediately flew distances over 500 m, disappearing beyond the maximum detection range of the 30 ha study area. Flights for mating, resting and, likely, oviposition covered distances of 11.6 m to 224 m in males and 16.8 m to >500 m in females. We found evidence that both sexes are active during the warmer temperatures of the day. In contrast, the moths were inactive when the relative humidity was high. Moreover, the P. archon moths do not seem to reside on the host palm trees. Our data show a high mobility of females, which may be responsible for the spread of the first recorded Castniidae in France by laying eggs far from the palm trees where they emerged.     

Passive heat exposure induced by hot water leg immersion increased oxyhemoglobin in pre-frontal cortex to preserve oxygenation and did not contribute to impaired cognitive functioning

This study investigated the effects of passive heat exposure on pre-frontal cortex oxygenation and cognitive functioning, specifically to examine whether the change in pre-frontal cortex oxygenation coincided with cognitive functioning during heat exposure. Eleven male students who participated in this study immersed their lower legs to the knees in three different water temperatures, 38 °C, 40 °C, and 42 °C water in an air temperature of 28?º C and 50 % relative humidity for 60 min. After 45 min of leg immersion they performed cognitive functioning tasks assessing their short-term memory while immersing their lower legs. There were higher rectal temperature (P?<?0.05) and higher increase of oxyhemoglobin in both left (P?<?0.05) and right (P?<?0.05) pre-frontal cortex at the final stage of 45-min leg immersion in the 42 °C condition with unaltered tissue oxygenation index among the three conditions (P?>?0.05). No statistical difference in cognitive functioning among the three conditions was observed with a higher increase of oxyhemoglobin during the cognitive functioning in the 42 °C condition for the left (P?=?0.05) and right (P?<?0.05) pre-frontal cortex. The findings of this study suggest, first, passive heat exposure increases oxygen delivery in the pre-frontal cortex to maintain pre-frontal cortex oxygenation; second, there is no evidence of passive heat exposure in cognitive functioning in this study; and third, the greater increases of oxyhemoglobin in the pre-frontal cortex during cognitive functioning at the hottest condition suggests a recruitment of available neural resources or greater effort to maintain the same performance at the same level as when they felt thermally comfortable.     

Flight duration and flight muscle ultrastructure of unfed hawk moths

Flight muscle breakdown has been reported for many orders of insects, but the basis of this breakdown in insects with lifelong dependence on flight is less clear. Lepidopterans show such muscle changes across their lifespans, yet how this change affects the ability of these insects to complete their life cycles is not well documented. We investigated the changes in muscle function and ultrastructure of unfed aging adult hawk moths (Manduca sexta). Flight duration was examined in young, middle-aged, and advanced-aged unfed moths. After measurement of flight duration, the main flight muscle (dorsolongitudinal muscle) was collected and histologically prepared for transmission electron microscopy to compare several measurements of muscle ultrastructure among moths of different ages. Muscle function assays revealed significant positive correlations between muscle ultrastructure and flight distance that were greatest in middle-aged moths and least in young moths. In addition, changes in flight muscle ultrastructure were detected across treatment groups. The number of mitochondria in muscle cells peaked in middle-aged moths. Many wild M. sexta do not feed as adults; thus, understanding the changes in flight capacity and muscle ultrastructure in unfed moths provides a more complete understanding of the ecophysiology and resource allocation strategies of this species.     

Litterfall production, decomposition and nutrient use efficiency varies with tropical forest types in Xishuangbanna, SW China: a 10-year study

Litterfall production, decomposition and nutrient use efficiency in three different tropical forest ecosystems in SW China were studied for 10 years. Annual mean litterfall production in tropical seasonal forest (TSF) (9.47?±?1.65 Mg ha^?1) was similar to that in man-made tropical forest (MTF) (9.23?±?1.29 Mg ha^?1) (P?>?0.05) but both were significantly lower than that in secondary tropical forest (STF) (12.96?±?1.71 Mg ha^?1) (P?<?0.05). The annual variation of litterfall was greater in TSF (17.4%, P?<?0.05) than in MTF (14.0%) or STF (13.2%). The annual mean decomposition rate of litterfall increased followed the order of MTF (2.72)?<?TSF (3.15)?<?STF (3.50) (P?<?0.05), which was not correlated with annual precipitation or annual mean temperature, but was rather related to litter quality. The nutrient use efficiency was found to be element-dependent and to vary significantly among the three forest types (P?<?0.05). These results indicate that litterfall production and decomposition rates in different tropical forest systems are related to plant species composition and are influenced strongly by coexisting species and their life stage (age) but less so by the species richness. Constructing multi-species and multistory man-made tropical forest is an effective way to enhance biological productivity and maintain soil nutrients on degraded tropical land.     

The Effect of Enriched Milk with Selenium and Vitamin E on Growth Rate, Hematology, Some Blood Biochemical Factors, and Immunoglobulins of Newborn Goat Kids

Thirty male and female (n?=?15 for each one) Markhoz newborn goat kids (aged 7?±?3 days) were distributed in a randomized block design in a 2?×?2?+?1 factorial arrangement: two levels of sodium selenite as a source of selenium (0.2 or 0.3 ppm Se), two levels of α-tocopherol acetate as a source of vitamin E (150 or 200 IU Vit E), and one control treatment with six repetitions per treatment (each replicate included three male and three female kids). Animals were fed daily by Se-Vit E-enriched milk (Se-Vit E treatments) or non-enriched milk (control treatment). Growth rate, hematology, and serum biological parameters were measured. The levels of serum albumin (P?<?0.01), serum globulin (P?<?0.05), total serum protein levels (P?<?0.01), erythrocyte counts (RBC) (P?<?0.001), hemoglobin (P?<?0.001), hematocrit (P?<?0.001), leukocyte counts (WBC) (P?<?0.001), IgA (P?<?0.05), IgG (P?<?0.01), and IgM (P?<?0.01) significantly differed among treatments, while no significant differences were observed for calcium, lymphocyte, neutrophil average daily gain and body weight among treatments. Kids feeding by enriched milk with 0.3 ppm Se and 200 IU Vit E had significantly higher serum total protein, globulin, RBC, IgA, IgG, and IgM compared to control and those fed by enriched milk to 0.2 ppm Se and 200 IU Vit E had significantly higher WBC counts.     

Effects of dietary selenium and vitamin E on immune response and biological blood parameters of broilers reared under thermoneutral or heat stress conditions

A study was conducted using 360 broiler chickens to evaluate the effects of dietary vitamin E (0, 125 and 250 mg/kg), selenium (Se, 0, 0.5 and 1 mg/kg), or their different combinations on immune response and blood biological parameters of broilers raised under either thermoneutral (TN, 23.9 °C constant) or heat stress (HS, 23.9 to 37 °C cycling) conditions. Humoral immunity was assessed by intravenous injection of 7 % sheep red blood cell (SRBC) followed by evaluation of serum for antibody titers in primary and secondary responses. Heterophil to lymphocyte (H/L) ratio also determined as an indicator of stress. Furthermore, at the end of the experiment, birds were bled for determination of some biological parameters. There was a significant reduction in body weight and feed intake, but the feed conversion ratio increased when the birds were exposed to HS (P?<?0.05). Body weight and feed intake were not influenced significantly by dietary vitamin E and Se (P?>?0.05), whereas feed conversion was improved significantly by 125 mg/kg vitamin E (P?<?0.05). The liver and lymphoid organ weights as well as IgM and IgG, antibody titers for primary and secondary antibody responses to SRBC were reduced significantly under HS (P?<?0.05). Heat stress also resulted in a significant increase in H/L ratio (P?<?0.05). Dietary vitamin E resulted in improvement of primary and secondary antibody responses both in TN and HS broilers (P?<?0.05). The HS birds also showed an improved antibody titer in secondary response with high concentration of Se (P?<?0.05). Vitamin E and Se had interactive effects on anti-SRBC titers; however, no consistent differences were found between dietary levels during the study. The H/L ratio decreased by feeding vitamin E at both levels either under HS or TN conditions (P?<?0.05). The serum concentrations of glucose, triglycerides, total cholesterol, and LDL-cholesterol were increased but serum HDL-cholesterol decreased in HS broilers (P?<?0.05).     

Effectiveness of Maifanite in Reducing the Detrimental Effects of Cadmium on Growth Performance, Cadmium Residue, Hematological Parameters, Serum Biochemistry, and the Activities of Antioxidant Enzymes in Pigs

This study was conducted to investigate the toxicity of cadmium and to evaluate the effectiveness of maifanite in preventing cadmium-induced adverse effects. Thirty-two crossbred pigs (Duroc × Landrace × Large white, sex balanced, 17.25?±?0.07 kg average body weight) were randomly allotted to one of four dietary treatments in a 2?×?2 factorial arrangement, with eight replicates per treatment and one pig per replicate. The dietary treatments included two cadmium (as CdCl₂) doses (0.32 and 30.49 mg/kg) and two maifanite doses (0 and 1 %). The results showed that pigs treated with cadmium decreased their average daily feed intake (P?<?0.05) and increased (P?<?0.05) the feed/gain ratio. Cadmium was found in the tissues of pigs that were fed with cadmium-contaminated diets, but the level of cadmium was much lower when maifanite was added to the cadmium-contaminated diets. Ingestion of diets that were artificially contaminated with cadmium (30.49 mg/kg of cadmium) reduced (P?<?0.05) the number of lymphocytes, the total erythrocyte count, the hemoglobin level, and the hematocrit. However, the activities of serum aspartate aminotransferase and gamma glutamyltransferase were increased (P?<?0.05). The total protein level was lower (P?<?0.05) in pigs fed with cadmium-contaminated diets. The contents of malondialdehyde increased (P?<?0.05), while the total antioxidant capacity and the activities of total superoxide dismutase, glutathione peroxidase, glutathione S-transferase, and catalase decreased (P?<?0.05) in pigs fed with cadmium-contaminated diets. Dietary addition of maifanite can, to some extent, prevent the negative effects associated with feeding cadmium diets (30.49 mg/kg of cadmium) to pigs.     

A zebrafish (danio rerio) model for high-throughput screening food and drugs with uric acid-lowering activity

With co-treatment of potassium oxonate (PO) and xanthine sodium salt (XSS), a zebrafish larva model of acute hyperuricemia has been constructed for the first time. The results show PO 200 μM + XSS 10 μM, PO 300 μM + XSS 15 μM, and PO 400 μM + XSS 20 μM can significantly increase the level of uric acid in the zebrafish larvae (P?<?0.05), the concentrations as described above can be used to construct the zebrafish larvae model of acute hyperuricemia. At the same time, treatment of allopurinol (APL, one of the hyperuricemia drugs) at 2000?μM?(P?<?0.001) and treatment of anserine (ASE) at 200?μM?(P < 0.05) could significantly decrease the level of uric acid in the model group which received PO 200 μM + XSS 10 μM, which demonstrate that such model could offer a new robust approach for high-throughput screening of food and drugs with uric acid-lowering activity.     

Visual ground pattern modulates flight speed of male Oriental fruit moth Grapholita molesta

Insects flying in a horizontal pheromone plume must attend to visual cues to ensure that they make upwind progress. Moreover, it is suggested that flying insects will also modulate their flight speed to maintain a constant retinal angular velocity of terrestrial contrast elements. Evidence from flies and honeybees supports such a hypothesis, although tests with male moths and beetles flying in pheromone plumes are not conclusive. These insects typically fly faster at higher elevations above a high‐contrast ground pattern, as predicted by the hypothesis, although the increase in speed is not sufficient to demonstrate quantitatively that they maintain constant visual angular velocity of the ground pattern. To test this hypothesis more rigorously, the flight speed of male oriental fruit moths (OFM) Grapholita molesta Busck (Lepidoptera: Tortricidae) flying in a sex pheromone plume in a laboratory wind tunnel is measured at various heights (5–40 cm) above patterns of different spatial wavelength (1.8–90°) in the direction of flight. The OFM modulate their flight speed three‐fold over different patterns. They fly fastest when there is no pattern in the tunnel or the contrast elements are too narrow to resolve. When the spatial wavelength of the pattern is sufficiently wide to resolve, moths fly at a speed that tends to maintain a visual contrast frequency of 3.5 ± 3.2 Hz rather than a constant angular velocity, which varies from 57 to 611° s^?1. In addition, for the first time, it is also demonstrated that the width of a contrast pattern perpendicular to the flight direction modulates flight speed.     

Effect of Organic Selenium Supplementation on Growth, Se Uptake, and Nutrient Utilization in Guinea Pigs

Forty weaned male guinea pigs (Cavia porcellus) of 152.6?±?7.96 g mean body weight were divided into four equal groups and fed a common basal diet comprised of 25% ground cowpea (Vigna unguiculata) hay, 30% ground maize (Zea mays) grain, 22% ground gram (Cicer arietinum) grain, 9.5% deoiled rice (Oryza sativa) bran, 6% soybean (Glycine max) meal, 6% fish meal, 1.5% mineral mixture (without Se), and ascorbic acid at 200 mg/kg to meet their nutrient requirements along with 0, 0.1, 0.2, and 0.3 ppm of organic selenium (Se) in groups I, II, III, and IV, respectively. Experimental feeding lasted for a period of 10 weeks, during which, daily feed intake and weekly body weights were recorded. Intake and digestibility of dry matter, organic matter, ether extract, crude fiber, and nitrogen-free extract as well as uptake of calcium and phosphorus were similar (P?>?0.05) among the four groups. Feed:gain ratio was also similar (P?>?0.05) in the four groups. However, digestibility of crude protein was significantly (P?<?0.001) higher in group II supplemented with 0.1 ppm organic Se as compared to other three group. Intake and absorption of Se was significantly (P?<?0.001) higher in all the Se supplemented groups as compared to control group. Average daily gain (ADG) was significantly (P?<?0.05) higher in group II (3.16 g/day) and III (3.38 g/day) as compared to group I (2.88 g/day). However, ADG in group IV (supplemented 0.3 ppm organic Se) was significantly (P?<?0.05) lower (2.83 g/day) than group II and III, but comparable (P?>?0.05) to group I. Findings of the present experiment suggests that Se requirements of guinea pigs are ≥0.2 ppm, as supplementation of 0.1 ppm organic Se in the diet (having 0.1 ppm Se) not only enhanced their growth rate but also improved the protein utilization.     

Effect of Lead on Lipid Peroxidation, Phospholipids Composition, and Methylation in Erythrocyte of Human

Lead (Pb) is one of the most abundant heavy metals on earth considered as number one environmental persistent toxin and health hazard affecting millions of people in all age groups. After entering bloodstream, 99 % of Pb is accumulated in erythrocytes and causes poisoning. Toxic Pb effects on erythrocytes membrane’s composition of phosphatidyl serine (PS), phosphatidyl ethanolamine (PE), phosphatidyl choline (PC), and sphingomyelin (SM), and phospholipids transmethylation were determined. Lipid peroxidation in Pb-exposed erythrocytes was evaluated as malondialdehyde (MDA) formation in presence of Fe and vitamin E to understand severity of Pb toxicity and its mitigation. Pb (0.5–5.0 μM) degraded PS (12 to 31 %, P?<?0.05–0.001) and elevated SM (19–51 %, P?<?0.05–0.001). Composition of PC and PE were diminished (22 %) and elevated (29 %), respectively, with higher Pb exposure (5.0 μM, P?<?0.001). Pb toxicity suppressed (P?<?0.001) transmethylation of phospholipids in membranes (34, 41, and 50 %, respectively, with 0.5, 2.5, and 5.0 μM). Pb-induced dose-related MDA production (P?<?0.05–0.001) in erythrocytes was obtained, which was accentuated in presence of Fe (P?<?0.05–0.001). The vitamin E mitigated (P?<?0.05–0.01) the severity of Pb-induced lipid peroxidation. The ratio PS/SM showed maximum change of ?27 (P?<?0.01), ?30 (P?<?0.01), and ?54 % (P?<?0.001), respectively at 0.5, 2.5, and 5.0 μM Pb exposures. Ratios PC/SM and PS/PE were at the second, whereas PE/PS at the third order. The study suggests that the mechanisms underlying distortion of compositional phospholipids, inhibition of transmethylation, and exasperated phospholipid peroxidative damage are the active phenomena of Pb toxicity in erythrocytes.

Combining Effect of Microbial Transglutaminase and Bambara Groundnut Protein Isolate on Gel Properties of Surimi from Sardine (Sardinella albella)

Effects of protein isolate from bambara groundnut (BGPI) at different levels (0–6 %, w/w) in combination with microbial transglutaminase (MTGase) at different concentrations (0, 0.3 and 0.6 U g^?1surimi) on gels properties of sardine (Sardinella albella) surimi were investigated. In the absence of MTGase, the increases in breaking force and deformation of gels were obtained when BGPI at levels of 1.5–3 % was incorporated (P?<?0.05). The further increases in BGPI levels (4.5–6 %) resulted in the decrease in breaking force and deformation (P?<?0.05). When MTGase (0.3 and 0.6 U g^?1surimi) was added, the increase in breaking force and deformation were noticed, regardless of BGPI levels, and the strengthening effect was in dose-dependent manner. The increases in hardness, gumminess and chewiness were also observed when surimi gel was added with BGPI and MTGase (P?<?0.05). Water-holding capacity of gels was improved with increasing level of BGPI, and MTGase incorporated (P?<?0.05). Whiteness of gels slightly decreased with increasing BGPI levels, however the addition of MTGase had no impact on whiteness (P?>?0.05). Based on electrophoretic study, myosin heavy chain decreased with addition of MTGase, indicating the formation of cross-links. More compact structure was observed in gel added with MTGase (0.6 U g^?1surimi) and 6 % BGPI, and was accompanied by an increased gel strength.     

ELISA examining urinary angiotensinogen as a potential indicator of intrarenal renin–angiotensin system (RAS) activity: a clinical study of 128 chronic kidney disease patients

In the current study, we measured urinary angiotensinogen (AGT) through enzyme-linked immunoadsordent assay (ELISA) and analyzed its correlation with intrarenal renin–angiotensin system (RAS) activity in 128 chronic kidney disease (CKD) patients. Urinary and plasma renin activity, AGT, angiotensin II (Ang II) and aldosterone levels were also measured by radioimmunoassay (RIA) or ELISA in these participants. Further, the expression level of intrarenal renin, AGT, Ang II and Ang II receptors were examined by immunohistochemistry staining (IHCS) in 72 CKD patients. Their correlations with urinary AGT were also analyzed. We found that the urinary AGT level was positively correlated with hypertension (ρ = 0.28, P < 0.01), urinary protein (r = 0.38, P < 0.01), urinary Ang II (r = 0.29, P < 0.05), urinary type IV collagen (Col IV) (r = 0.56, P < 0.01), and was negatively correlated with estimated glomerular filtration rate (eGFR) (r = ?0.28, P < 0.01), urinary sodium (r = ?0.22, P < 0.05) and serum AGT (r = ?0.27, P < 0.01). Multiple regression analysis indicated low serum AGT (P < 0.01), high urinary protein (P < 0.01), high urinary Ang II (P < 0.05) and high urinary Col IV (P < 0.01) were correlated significantly with high urinary AGT. Urinary AGT level was positively correlated with intrarenal expression level of AGT (ρ = 0.46, P < 0.01), Ang II (ρ = 0.56, P < 0.01) and Ang II type 1 receptor (ρ = 0.32, P < 0.01), as detected by IHCS. Together, these data suggest that urinary AGT might be a potential biomarker of intrarenal RAS and Ang II activities in CKD patients.     

Effect of Chromium Picolinate Supplementation on Growth Performance and Meat Characteristics of Swine

The purpose of this study was to evaluate the effect of supplemental chromium (Cr) in the form of chromium picolinate (CrPic) on swine growth performance, meat quality, and protein deposition in skeletal muscle. Forty-eight piglets were divided into three groups randomly, fed with three different dietary levels of Cr (common basal feedstuff supplemented with a dose of 1.61 μg/g or 3.22 μg/g CrPic, which corresponded to 0.2 and 0.4 μg/g Cr). Results indicated that during the growing period (1–35 days), pigs fed with the diet supplemented with CrPic showed no improvement in body mass, average daily gain (ADG), feed consumption, or feed conversion rate (FCR) (P?>?0.05). During the finishing period, a supplementary dose of 0.2 μg Cr/g improved daily weight gain significantly (P?<?0.05), while the situation had no significance with 0.4 μg Cr/g (P?>?0.05) supplemented. For the entire growing-finishing period, body mass increased by 3.86%, ADG rose by 6.08%, and the FCR decreased by 3.30%; levels of total muscular pigment and that in the ribeye areas significantly improved (P?<?0.05) when supplementation with 0.2 μg Cr/g (P?<?0.05) was employed. However, there were no significant changes when supplemented with 0.4 μg Cr/g. While there were no changes in yield of carcass, back fat, water holding capacity, or levels of muscular crude protein and fat (P?>?0.05) in treatment, the ratio of fat-lean and RNA/DNA increased significantly supplemented with 0.2 μg Cr/g (P?<?0.05), but there were no significance with 0.4 μg Cr/g supplementation. In addition, the muscular levels of cholesterol had slightly decreased and the content of DNA in skeletal muscle showed no marked changes with 0.2 or 0.4 μg/g Cr supplementation. In conclusion, the present results suggested that dietary Cr supplementation in the dose of 0.2 μg/g could promote the growth performance, carcass characteristics, and protein deposition.     

Performance,Egg Quality Traits,and Serum Metabolite Concentrations of Laying Hens Affected by Dietary Supplemental Chromium Picolinate and Vitamin C Under a Heat-Stress Condition

A 3?×?2 factorial experiment consisting three levels (0, 200, and 400 μg/kg) of chromium (chromium picolinate) and two levels (0 and 250 mg/kg) of vitamin C was employed to evaluate the effects of these dietary supplements on performance, egg quality traits, and serum biochemical parameters of heat-stressed laying hens (Lohmann LSL-Lite) from 66 to 74 weeks of age. Feed intake increased when birds were given either 400 μg/kg chromium or 250 mg/kg vitamin C (P?<?0.05), but the birds that received both chromium and vitamin C consumed feed similar to those that received only chromium. Dietary treatments had no effect on egg production, egg mass, egg volume, feed conversion ratio, and body mass (P?>?0.05). The birds that fed on diet with chromium or vitamin C produced eggs with higher shell mass and thickness compared to the control. Both eggshell mass and thickness decreased when vitamin C and chromium were supplemented simultaneously, and birds given the diet supplemented with 400 μg/kg chromium and 250 mg/kg vitamin C had eggshell mass and thickness similar to those of the control group. The serum concentration of chromium increased due to increasing level of dietary chromium (P?<?0.05). The birds that received diet with chromium and vitamin C had higher serum concentrations of chromium compared to those that received only chromium (P?<?0.05). Similarly, the hens that received chromium and vitamin C had higher serum concentrations of calcium and phosphorus compared to the hens fed with other treatments (P?<?0.05). The birds given with supplemental chromium exhibited lower serum glucose, total cholesterol, and triglycerides concentrations but higher serum albumin and total protein concentrations compared to the other groups (P?<?0.05).     

Litter- and soil carbohydrate-carbon stocks in 2-, 4- and 10-year-old improved fallows in eastern Zambia

This study evaluated the effects of tree species and sites on soil carbohydrates, litterfall, and litter chemistry in 2-, 4- and 10-year-old improved fallows at three sites in eastern Zambia. Between April 2002 and August 2003, litter was collected in 2-year-old tree fallows at Kalichero, Kalunga and Msekera for chemical analyses. Soil samples collected at 0–30 cm from all experiments were analysed for total soil organic carbon (SOC), but only those from 4- and 10-year-old fallows were analysed for carbohydrates. Soil arabinose- and mannose-C stocks, and carbohydrate-C percentages of SOC (7.7–20.6 %) significantly (P < 0.05) differed across tree species in 10-year-old coppicing fallows at Msekera. Converting M + F to improved fallows resulted in a decline in monosaccharide-C, carbohydrate-C stocks and carbohydrate-C percentage of SOC. There were significant (P < 0.05) variations in litterfall (0.7–2.3 t ha^?1 year^?1) and litter C contents (0.3–1.1 t ha^?1 year^?1) across 2-year-old coppicing tree fallows at Msekera. Litter production and C contents were significantly greater on sandy soils at Kalunga than on fine-textured soils at Msekera. Litter chemical contents (C, N, AUR and polyphenols) and ratios (C:N, P:N, AUR:N, and (AUR + P):N) for litter in fallows differed significantly (P < 0.05) across species and sites. In this study, the role of litter in carbon cycling in improved fallows depended on tree species and site conditions.