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51.
Leonardo José Assis de Barros Marcelo de Andrade Ferreira Julio César Vieira de Oliveira Djalma Cordeiro dos Santos Juana Catarina Cariri Chagas Adryanne Marjorie Souza Vitor Alves Aghata Elins Moreira da Silva Wandemberg Rocha Freitas 《Tropical animal health and production》2018,50(1):149-154
This study aims to evaluate the effect of the Tifton 85 hay (Cynodon dactylon L. Pers) replacement by Orelha de Elefante Mexicana spineless cactus (Opuntia stricta [Haw.] Haw) on the nutrient intake and digestibility, growth performance, microbial protein synthesis, and efficiency of dietary nitrogen compound utilization in the diets of Girolando heifers. Twenty-four (3.5 months and 100 kg ± 3.5 kg) Girolando heifers (5/8 Holstein x Gyr) were used and arranged in a completely randomized design. Dry matter, organic matter, crude protein, and neutral detergent fiber decreased linearly as a function of the levels of Tifton hay (TH) replacement by Orelha de Elefante Mexicana spineless cactus (OEM). The non-fiber carbohydrate intake and coefficient of dry matter digestibility increased, while the neutral detergent fiber (NDF) digestibility decreased linearly with the OEM inclusion. After evaluating the growth performance by observing weight gain and morphometric measurements, there were no significant alterations. The urinary volume, nitrogen balance as well as the efficiency of nitrogen retention had increased, while the urinary and plasma urea concentrations had decreased linearly with the OEM inclusion. The results obtained in this study show that Orelha de Elefante Mexicana spineless cactus should replace Tifton hay in post-weaned heifer diets. 相似文献
52.
Helena M. Amaro Rita Barros Tnia Tavares Raquel Almeida Isabel Sousa Pinto Francisco Xavier Malcata Ana Catarina Guedes 《Marine drugs》2021,19(11)
Bioactive lipidic compounds of microalgae, such as polyunsaturated fatty acids (PUFA) and carotenoids, can avoid or treat oxidation-associated conditions and diseases like inflammation or cancer. This study aimed to assess the bioactive potential of lipidic extracts obtained from Gloeothece sp.–using Generally Recognized as Safe (GRAS) solvents like ethanol, acetone, hexane:isopropanol (3:2) (HI) and ethyl lactate. The bioactive potential of extracts was assessed in terms of antioxidant (ABTS•+, DPPH•, •NO and O2•assays), anti-inflammatory (HRBC membrane stabilization and Cox-2 screening assay), and antitumor capacity (death by TUNEL, and anti-proliferative by BrdU incorporation assay in AGS cancer cells); while its composition was characterized in terms of carotenoids and fatty acids, by HPLC-DAD and GC-FID methods, respectively. Results revealed a chemopreventive potential of the HI extract owing to its ability to: (I) scavenge -NO• radical (IC50, 1258 ± 0.353 µg·mL−1); (II) inhibit 50% of COX-2 expression at 130.2 ± 7.4 µg·mL−1; (III) protect 61.6 ± 9.2% of lysosomes from heat damage, and (IV) induce AGS cell death by 4.2-fold and avoid its proliferation up to 40% in a concentration of 23.2 ± 1.9 µg·mL−1. Hence, Gloeothece sp. extracts, namely HI, were revealed to have the potential to be used for nutraceutical purposes. 相似文献
53.
Cortisol and testosterone accumulation in a low pH recirculating aquaculture system for rainbow trout (Oncorhynchus mykiss) 
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下载免费PDF全文 Vasco C Mota Catarina I M Martins Ep H Eding Adelino V M Canário Johan A J Verreth 《Aquaculture Research》2017,48(7):3579-3588
Steroids accumulate in recirculating aquaculture system (RAS), although explanatory factors for such accumulation are still poorly explored. This study investigated the effect of water exchange rate and pH in six replicated RAS on the concentration of the stress hormone cortisol in rainbow trout blood plasma and in the holding water and of the sex steroids testosterone, 11‐ketotestosterone (11‐KT) and 17,20β‐dihydroxypregn‐4‐en‐3‐one (17,20β‐P) over a 70‐day experimental period. Three combinations of water exchange rate and pH were used each treatment, with two replications: (i) high water exchange rate (±1700 L kg?1 feed) and neutral pH (±7.3), (ii) low water exchange rate (±500 L kg?1 feed) and neutral pH (±7.3) and (iii) low water exchange rate (±500 L kg?1 feed) and low pH (±5.8). Plasma cortisol concentrations at day 70 were higher (24.4 ± 9.5 ng mL?1) for fish kept at low pH when compared to fish kept at neutral pH (12.0 ± 0.1 and 8.7 ± 0.2 ng mL?1). Water cortisol and testosterone concentrations at day 35 were higher at low pH than at neutral pH, whereas water 11‐KT and 17,20β‐P did not differ among treatments. At day 70, there were no significant differences between low and high pH. These results demonstrate that low pH contributes to increased plasma cortisol concentrations and to its accumulation in water, possibly indicating a stress response to low pH. The higher concentration of testosterone but not of the other sex hormones point to unspecified reproductive effects that need further investigation. 相似文献
54.
Guilherme Lobato Menezes Alan Figueiredo de Oliveira Frederico Patrus Ananias de Assis Pires Lúcio Carlos Gonçalves Rafael Araújo de Menezes Pamella Grossi de Sousa Paulo Henrique Arruda de Medeiros Matheus Morais de Pinho Ângela Maria Quintão Lana Vânia Eloisa de Araújo Diogo Gonzaga Jayme 《Grass and Forage Science》2023,78(1):1-22
The effects of different additives on farm-scale silage quality and beef cattle performance are inconsistent. This study aimed to carry out a systematic review and meta-analysis to evaluate the efficacy of chemical and microbial additives to silage on beef cattle performance. Systematic searches were performed using databases and scientific journals, and 42 articles were selected. Data for all variables were grouped into subgroups according to the additive type. For dry matter intake and average daily gain, the data were also grouped by forage type due to greater comparison numbers. The treatment mean differences and 95% confidence intervals (p < 0.05) were analysed using a random-effects model. The use of homo- and heterofermentative microbial inoculant mixtures and chemical additives (Ch) increased the average daily gain of beef cattle fed maize/sorghum silage. Homofermentative microbial inoculant (Ho), Ch, and a mixture of microbial inoculant and chemical additives also increased the average daily gain of beef cattle fed temperate grasses. Only Ch increased dry matter intake. Ch increased feed efficiency, and Ch and Ho increased carcass weight. The evaluated additives improved the silage fermentation process mainly via pH and ammonia nitrogen reduction. Overall, this meta-analysis demonstrated that silage additives improved the ensiling process and beef cattle performance, with better results with Ch use. Due to the aerobic stability and microbiological profile analyses being carried out more in laboratory-scale silos, more studies are needed to determine these silage parameters after opening the silo at the farm scale. 相似文献
55.
Background, aim, and scope
Soil quality has been threatened by intensive agricultural practises, namely those relying on the application of pesticides, such as herbicides. Among the non-target terrestrial organisms exposed to such scenarios, earthworms are key ecological receptors widely used in ecotoxicological studies. As such, this work aims to assess the effects of two herbicide active ingredients (a.i.)—sulcotrione and penoxsulam—and their respective commercial formulations—MIKADO® and VIPER® (referred as Mikado and Viper)—on the avoidance behaviour of Eisenia andrei. In an attempt to enhance the ecological relevance of the generated toxicity data, the avoidance tests were run with standard (LUFA 2.2; L) and natural soils (from corn and rice fields), as long as their habitat function did not constrain the earthworm behaviour.Methodology
Earthworms were bred in the lab before test conductance. The natural soils used as substrates were collected before the cropping season on corn (C) and rice (R) fields, which are integrated in a wide area exploited for agriculture. Their physico-chemical characterization evolved the determination of pH (H2O, KCl), conductivity, organic matter (OM) and clay/silt contents, and water-holding capacity (WHC). The avoidance tests intended to ascertain (1) the random distribution of earthworms in the natural soils C and R (dual-control tests), (2) the habitat function of natural soils against each other and against L soil, (3) the effect of active ingredients and formulated herbicides on E. andrei behaviour. Avoidance tests with the a.i.s were only performed in L soil. Data evaluation followed ISO (2005) guidelines.Results
C and R soils presented higher OM (5.1% and 4.5%, respectively) and clay/silt (53.3 and 43.1, respectively) contents and WHC (107.2 and 109.9%, respectively) than L soil (4.1, 21.4 and 48.0%, correspondingly). Earthworms distributed randomly in dual-control tests, but preferred R soil significantly, relative to L or C soils. The LOEC and EC50 values calculated for sulcotrione (>1,000.0 and 1,263.3 mg a.i. kg-1, respectively) and Mikado (1,012.8 and 1,301.3 mg a.i. kg-1, respectively) were much higher than those calculated for penoxsulam (100 and 80.6 mg a.i. kg-1, respectively) or Viper (52.7 and 51.5 mg a.i. kg-1, respectively), when L soil was used as substrate. Moreover, the habitat function of L soil contaminated with the formulated herbicide Viper was more constrained relative to that of the a.i. penoxsulam. Viper induced higher % avoidance on E. andrei exposed to the contaminated L soil compared to that under the R soil.Discussion
The response of earthworms to R (attraction) and C (avoidance) soils could be related, not only to the quantity of OM content, but also to the quality of organic and inorganic fractions of soil, beyond other intrinsic properties of soils. Both Mikado and sulcotrione impacted the behaviour of E. andrei only slightly. This endpoint was more affected under penoxsulam or Viper exposures on L soil, being the latter-formulated product even more repellent for E. andrei than the a.i. The effect of adjuvants added to the commercial formulation of Viper, may have increased the toxicity of the a.i. Thereby, our results reinforce the need for a careful assessment of the impacts of formulated products. Furthermore, since there was a reduction in earthworm % avoidance under Viper exposures on the natural soil R, it was possible that pesticide bioavailability had been reduced by its sorption to OM and clay mineral sorption sites.Conclusions
Though the standard L soil should be used for reproducibility and comparison means, other natural soils should be added to the assessment of chemicals, for sake of ecological relevance. Both herbicides induced avoidance behaviour on E. andrei, albeit stronger effects were denoted by penoxsulam and its respective formulated product, Viper. Overall, avoidance tests provided a sensitive, valuable and feasible response either to compare the habitat function of different standard and agricultural natural soils or to test the effect of herbicides.Recommendations and perspectives
An effort should be made to enlarge the terrestrial ecotoxicological database as a way to fulfil the huge lack of information available for this ecosystem. In this context, additional research congregating a potential linkage between physiological activities sustaining the regular metabolism of earthworms and their avoidance behaviour or even their reproductive effects would be welcomed, especially in what regards formulated pesticides. Such approach would provide a robust and comprehensive understanding of chemical effects. Furthermore, it is encouraged that natural soils should be used to improve the reliability of chemical testing. 相似文献56.
Evolution by natural selection is driven by the continuous generation of adaptive mutations. We measured the genomic mutation rate that generates beneficial mutations and their effects on fitness in Escherichia coli under conditions in which the effect of competition between lineages carrying different beneficial mutations is minimized. We found a rate on the order of 10(-5) per genome per generation, which is 1000 times as high as previous estimates, and a mean selective advantage of 1%. Such a high rate of adaptive evolution has implications for the evolution of antibiotic resistance and pathogenicity. 相似文献
57.
Catarina Pereira Fernando Caldeira Jorge Mark Irle José Maria Ferreira 《Journal of Wood Science》2006,52(4):318-324
It is already known by the scientific and industrial communities that lignocellulosic substrates are, to a certain extent,
inhibitors of the hydration reaction of cement. The extent to which and how they influence such reactions is still a matter
of debate. Several techniques, such as calorimetry, i.e., the measurement of the heat evolved or obtaining temperature profiles
during the hydration, the determination of extractive contents of lignocellulosic substrates and their relation with the characteristics
of the hydration curves, or even testing of the mechanical properties of the wood-cement composites, have been used in previous
research. This study complements past research using two techniques that have been used in the analysis of cement hydration
but are not usually applied to lignocellulose-cement mixes, namely X-ray diffraction (XRD) and differential thermal analysis
(DTA). The raw materials for this study were three lignocellulosic materials of Portuguese origin: cork (the bark of Quercus suber L.), blue gum (Eucalyptus globulus Labill.), and maritime pine (Pinus pinaster Ait); and Portland cement. The two techniques allowed tracking of the evolution of the main cement constituents during hydration.
It was found that all the lignocellulosic substrates had detrimental effects on cement hydration. The blue gum exhibited the
fastest hydration kinetics in the initial stage of reaction, but was then overtaken by cork, which at the end gave the highest
hydration conversion amongst the three lignocellulosic substrates. Although pine caused the slowest initial hydration kinetics,
with the passage of time its effect approached that of blue gum. At the end of the hydration period, specimens containing
either species had similar quantities of hydration reaction products. The DTA and XRD results were consistent and are in good
agreement with the temperature profiles and compatibility indexes reported in a previous work. 相似文献
58.
Associations between rearing conditions and the risk of culling in dairy cows were studied by survival analysis. Data were collected from 1039 Swedish Red cows, 1029 Swedish Holsteins, and 56 cows of other milk or cross-breeds, representing all female animals born in 109 Swedish herds during 1998. Length of productive life was defined as the number of days from 1st calving to culling. The applied Weibull proportional hazards model included time-independent effects of breed, housing from 3 to 7 months of age, number of housing changes before calving, grazing before 1st calving, herd median age at 1st calving, age at 1st calving, cow housing, herd lactational incidence risk of veterinary-reported clinical mastitis, and the random effect of herd. Time-dependent effects were year, month, the interaction year by month, parity, number of breedings, pregnancy status, the interaction parity by pregnancy status, herd mean milk-production level, relative milk yield within breed-parity, and veterinary-reported clinical mastitis. The lactation was divided into six stages in which pregnancy status was assumed to be known by the farmer and culling could occur. Median productive life time in culled cows was 780 d and 14% of the records were censored due to terminated data collection. An individual calving age of 28.2–30.9 months was associated with the highest culling risk, 1.2-fold higher than calving at ≤25.3 months, whereas the risk decreased almost linearly with a higher herd median age at 1st calving. Housing in slatted pens with >7 calves from 3 to 7 months was associated with a 1.7-fold increase in risk, relative to litter pens. If a cow had changed housing system 4 times before 1st calving it increased the risk of culling 1.4 times, relative to two housing changes. These results show that rearing factors affect the productive life time of dairy cows in Swedish family operations. 相似文献
59.
Catarina I M Martins Johan W Schrama & Johan A J Verreth 《Aquaculture Research》2005,36(15):1509-1516
Individual variation in growth, feed intake and feeding behaviour has been previously recognized in several fish species. However, there is a lack of information regarding the consistency of such individual differences, which is important to understand the probability of a certain individual trait to be inherent, i.e. genetically linked. The goal of this study is to quantify the consistency of individual differences in growth, feed intake/efficiency and feeding behaviour in African catfish Clarias gariepinus (Burchell 1822). Forty‐eight juvenile fish (58.9±0.4 g) were housed individually for 47 days and weighed every second week. The consistency of growth, feed efficiency (residual feed intake (RFI)) and feeding behaviour (total feeding time (TFT)) was determined using repeatability estimates. Fish exhibited pronounced individual variation in growth (CV=52.8%), feed intake (34.3%) and in the TFT (>100%). The repeatability estimates were 0.55 for growth, 0.70 for feed intake, 0.49 for RFI and 0.81 for TFT. Individual differences in growth were mainly explained by individual differences in feed intake (～80%). Individual differences in feeding behaviour contributed to explain differences in feed intake by affecting the RFI. With increasing TFT, the maintenance levels also increased suggesting that slow eaters were less efficient in feed/energy utilization. The results of this study indicate that individual differences in growth, feed intake/efficiency and feeding behaviour are consistent over time and therefore probably inherent. Moreover, this study may have implications on the use of feeding behaviour as a predictor of feed efficiency in juveniles of African catfish. 相似文献
60.
Marcelo D. Catarino Catarina Maral Teresa Bonifcio-Lopes Dbora Campos Nuno Mateus Artur M. S. Silva Maria Manuela Pintado Susana M. Cardoso 《Marine drugs》2021,19(7)
Recent studies indicate that plant polyphenols could be pointed as potential prebiotic candidates since they may interact with the gut microbiota, stimulating its growth and the production of metabolites. However, little is known about the fate of brown seaweeds’ phlorotannins during their passage throughout the gastrointestinal tract. This work aimed to evaluate the stability and bioaccessibility of Fucus vesiculosus phlorotannins after being submitted to a simulated digestive process, as well as their possible modulatory effects on gut microbiota and short-chain fatty acids production following a fermentation procedure using fecal inoculates to mimic the conditions of the large intestine. The stability of phlorotannins throughout the gastrointestinal tract was reduced, with a bioaccessibility index between 2 and 14%. Moreover, slight alterations in the growth of certain commensal bacteria were noticed, with Enterococcus spp. being the most enhanced group. Likewise, F. vesiculosus phlorotannins displayed striking capacity to enhance the levels of propionate and butyrate, which are two important short-chain fatty acids known for their role in intestinal homeostasis. In summary, this work provides valuable information regarding the behavior of F. vesiculosus phlorotannins along the gastrointestinal tract, presenting clear evidence that these compounds can positively contribute to the maintenance of a healthy gastrointestinal condition. 相似文献