Interaction between melatonin and follicle-stimulating hormone promotes in vitro development of caprine preantral follicles     

R.M.P. Rocha  L.F. Lima  A.M.C.V. Alves  J.J.H. Celestino  M.H.T. Matos  I.B. Lima-Verde  M.P. Bernuci  C.A.P. Lopes  S.N. Báo  C.C. Campello  A.P.R. Rodrigues  J.R. Figueiredo 《Domestic animal endocrinology》2013

The aim of this study was to investigate the effects of melatonin and follicle-stimulating hormone (FSH) on the in vitro culture of goat preantral follicles. Ovarian fragments were cultured for 7 d in α-minimum essential medium (α-MEM⁺) containing melatonin (100, 250, 500, or 1,000 pM), FSH (50 ng/mL), or a combination of the 2 hormones and further analyzed by histology and transmission electron and fluorescent microscopy. The results showed that after 7 d of culture, tissues cultured in α-MEM⁺ alone or supplemented with FSH alone, melatonin (500 and 1,000 pM), or the combination of FSH and melatonin (1,000 pM) maintained percentages of normal preantral follicles similar to the fresh control. In contrast to the noncultured tissues, the percentage of developing follicles was increased under all culture conditions after 7 d (P < 0.05). The addition of 1,000 pM melatonin associated with FSH to the culture medium increased follicular and oocyte diameters compared with α-MEM⁺ alone after 7 d of culture (P < 0.05). Ultrastructural and fluorescent analyses confirmed the integrity of follicles cultured with 1,000 pM of melatonin plus FSH for 7 d. In conclusion, this study demonstrated that the interaction between melatonin and FSH maintains ultrastructural integrity and stimulates further growth of cultured caprine preantral follicles.  相似文献   

Production of dairy cows fed whole-crop cereals or ryegrass silages supplemented with a fixed amount of concentrate     

A. R. J. Cabrita  J. M. F. Abreu  M. F. S. Miranda  M. Cerca  C. Pinto  Z. M. C. Lopes 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(2-3):116-119

Abstract

Feed intake and milk production responses to whole-crop cereal silages and ryegrass silage (RGS) supplemented with a fixed amount of concentrate were measured in three 4×4 Latin square-designed experiment with three 17-day periods using 12 Holstein cows. Diets consisted of a fixed amount of concentrate (10 kg) and one of the following silages offered ad libitum: RGS, Mondego wheat silage (MWS), Alva wheat silage (AWS), and triticale silage (TS). Silage dry matter intake and milk yield were significantly higher for RGS. Milk composition was not affected by silage treatment. The whole-crop cereal silages tended to show higher milk concentrations of anteiso C15:0, iso C15:0, C16:1 and C18:1 and lower concentrations of C18:2 and C18:3. This study suggests better response of dairy cows to a single cut RGS than to whole-crop cereal silages harvested in an early stage of maturity.  相似文献   

Pathogenesis of reproductive failure induced by Trypanosoma vivax in experimentally infected pregnant ewes     

Taciana MF Silva  Roberio G Olinda  Carla MF Rodrigues  Ant?nio CL Camara  Francisco C Lopes  Wesley AC Coelho  Múcio FB Ribeiro  Carlos IA Freitas  Marta MG Teixeira  Jael S Batista 《Veterinary research》2013,44(1):1

The present study was aimed at investigating the effect of experimental infection by Trypanosoma vivax in different stages of pregnancy, determining the pathogenesis of reproductive failure, and confirming transplacental transmission. We used 12 pregnant ewes distributed into four experimental groups: G1, was formed by three ewes infected with T. vivax in the first third of pregnancy (30 days); G2 comprised three infected ewes in the final third of pregnancy (100 days); G3 and G4 were composed of three non-infected ewes with the same gestational period, respectively. Each ewe of G1 and G2 was inoculated with 1.25 × 10⁵ tripomastigotes. Clinical examination, determination of parasitemia, serum biochemistry (albumin, total protein, glucose, cholesterol, and urea), packed cell volume (PCV), serum progesterone, and pathological examination were performed. Placenta, amniotic fluid, blood and tissues from the fetuses and stillbirths were submitted to PCR. Two ewes of G1 (Ewe 1 and 3) presented severe infection and died in the 34^th and 35^th days post-infection (dpi), respectively; but both fetuses were recovered during necropsy. In G2, Ewe 5 aborted two fetuses on the 130^th day (30 dpi) of pregnancy; and Ewe 6 aborted one fetus in the 140^th day (40 dpi) of gestation. Ewes 2 and 4 delivered two weak lambs that died five days after birth. Factors possibly involved with the reproductive failure included high parasitemia, fever, low PCV, body score, serum glucose, total protein, cholesterol, and progesterone. Hepatitis, pericarditis, and encephalitis were observed in the aborted fetuses. The presence of T. vivax DNA in the placenta, amniotic fluid, blood, and tissues from the fetuses confirms the transplacental transmission of the parasite. Histological lesion in the fetuses and placenta also suggest the involvement of the parasite in the etiopathogenesis of reproductive failure in ewes.  相似文献   

15N-Urea Efficiency in Maize as Influenced by Humic Substances and Urease Inhibitors Treatments     

Luís Felipe Rinaldi  Pedro Lopes Garcia  Renata Alcarde Sermarini  Paulo Cesar Ocheuze Trivelin 《Communications in Soil Science and Plant Analysis》2019,50(2):198-208

Urea treated with urease inhibitors (UI) in association with humic substances (HS) is expected to improve urea efficiency by reducing ammonia losses and also provide the benefits of HS such as improve nitrogen (N) recovery by plants. Ammonia volatilization (AV), ¹⁵N recovery efficiency in the soil (NRE) and ¹⁵N use efficiency (NUE) were evaluated in maize (Zea mays L.) in a greenhouse pot trial. Treatments consisted of ¹⁵N-urea treated with UI (0, 0.4% boron (B) +0.15% copper (Cu), 0.64% B, and NBPT (N-(n-butyl) thiophosphoric triamide)) and three levels of HS (0%, 0.6%, and 1.2%). A control treatment (without N) was also included. N treatments were applied at V4 (vegetative leaf stage 4) on soil surface. HS was not efficient on AV reduction, NBPT had the greatest reduction in AV, and B had higher efficiency on AV reduction than Cu. At V8 (vegetative leaf stage 8), NBPT had the greatest NUE followed by B. At VT (tassel fully emerged), NUE from urea treated with NBPT reduced when increased levels of HS, and NBPT had the greatest NRE. UI in association with HS treated-urea does not reduce AV and it does not improve NUE by maize in vegetative stages.  相似文献   

Effect of increasing densities of Urochloa brizantha cv. Marandu on Eucalyptus urograndis initial development in silvopastoral system     

Michel Anderson Almeida Colmanetti  Allan Lopes Bacha  Pedro Luis da Costa Aguiar Alves  Rinaldo Cesar de Paula 《林业研究》2019,(2):537-543

In silvopasture system, the coexistence of eucalyptus seedlings with other species may result in growth reduction, especially during eucalyptus early development.Therefore, studies elucidating how forage species affect the eucalyptus growth can provide important information for their rational management aiming to obtain the maximum gain of the system. The aim of this work was to evaluate the effect of increasing densities of Urochloa brizantha cv.Marandu in the early development of Eucalyptus urograndis. An experiment was conducted in 20 L pots, in an open and semi-controlled area, during 90 days after planting of eucalyptus. A completely randomized design with four replications was used, in a 6 9 7 factorial system, meaning six evaluation periods and seven densities of U. brizantha: 0(control), 22, 33, 44, 67, 89 and111 plants m^-2. Fortnightly, eucalyptus height, stem diameter and chlorophyll fluorescence(Fv/Fm) were evaluated. At the end of experimental period, the net assimilation rate, stomatal conductance and transpiration rate of eucalyptus plants were determined, in addition to the dry matter of eucalyptus(leaves and stem) and U. brizantha (leaves). In coexistence with 111 plants m^-2, eucalyptus had reduction of 63.9% on total dry matter and 72.7% on leaf area, compared to the control. From the density of22 plants m^-2, U. brizantha negatively interfere significantly the growth of E. urograndis. Up to 8 plants m^-2 there are no reductions greater than 5% in eucalyptus height and stem diameter.  相似文献   

Productivity and nutritive value of Brachiaria decumbens and performance of dairy heifers in a long‐term silvopastoral system     

Marina A. Lima  Domingos S. C. Paciullo  Mirton J. F. Morenz  Carlos A. M. Gomide  Renato A. R. Rodrigues  Fernanda H. M. Chizzotti 《Grass and Forage Science》2019,74(1):160-170

Silvopastoral system (SPS) has been suggested to ensure sustainability in animal production systems in tropical ecosystems. The objective of this study was to evaluate the productive and nutritive value traits of Brachiaria decumbens and performance of dairy heifers in SPS and open pasture (OP) during the summer and autumn of two consecutive years in the SPS and OP (17th and 18th years after establishment). Experimental design was a randomized complete block with two treatments (SPS and OP) and three replications in subdivided plots with repeated measures in time. There was reduction in the tiller population density, total and green forage mass, and total and green forage bulk density in the SPS when compared to the OP in the summer. In the autumn, no difference was observed between the systems. Shading in SPS increased crude protein content of the grass pasture by 25% and 33% when compared to the OP during the first and second experimental years, respectively, and reduced neutral detergent fibre content. However, it did not change acid detergent fibre or lignin content. OP provided higher stocking rate and weight gain per area than the SPS. Average daily gain was higher in the OP in the second experimental year. Severe shading conditions should be avoided, because in the long ‐ term they may threaten the persistence and sustainability of pasture in the SPS. It is recommended to plant a low density of trees or implement management strategies of the tree component by either thinning or pruning over the years after planting.  相似文献   

Phenolic composition in grape (Vitis vinifera L. cv. Malbec) ripened with different solar UV-B radiation levels by capillary zone electrophoresis     

Berli F  D'Angelo J  Cavagnaro B  Bottini R  Wuilloud R  Silva MF 《Journal of agricultural and food chemistry》2008,56(9):2892-2898

The responses of Vitis vinifera L. cv. Malbec to different solar ultraviolet-B radiation (UV-B) levels were assessed in two contrasting situations, under sunlight with full UV-B (+UV-B) and filtered UV-B (-UV-B), in three different locations at 500, 1000, and 1500 m above sea level (asl). To evaluate the effects of radiation, a simple, accurate, and rapid method for the separation and simultaneous determination of representative phenolic compounds in grape berry skins by capillary zone electrophoresis was developed. Separation was carried out in less than 20 min with 20 mM sodium tetraborate buffer containing 30% methanol, pH 9.00. The procedure is fast and reliable, and extracted grape berry skins can be directly analyzed without prior sample cleanup procedure. Berry skins from the +UV-B treatment at 1500 m asl showed the highest levels of total polyphenols anthocyanins, and resveratrol, compared with the -UV-B treatment at this altitude.  相似文献   

Assessment and prediction of changes in the reserves of organic carbon in abandoned soils of European Russia in 1990–2020     

I. N. Kurganova  V. O. Lopes de Gerenyu 《Eurasian Soil Science》2008,41(13):1371-1377

Experimental studies and the analysis of published data have shown that carbon reserves in soils generally increase upon soil exclusion from agricultural use. The rate of carbon accumulation in the abandoned soils depends on the soil type, the time elapsed since the soil abandoning (the restoration period), and the thickness of the layer for which the rate of carbon accumulation is determined. For the upper 20-cm-thick layer, it varies from 66 to 175 g C/m² per year in dependence on the type of soil and averages 111 g C/m² per year. The highest rate is typical of the first 10–15 years of soil restoration. According to our calculations, the carbon sequestration in the upper 20-cm-thick layer of Russian soils due to changes in land use was 184–673 Mt C in 1990–2005 and may reach 282–1030 Mt C by 2020.  相似文献   

Secondary Stress Responses in Juvenile Brazilian Flounder,Paralichthys orbignyanus,throughout and after Exposure to Sublethal Levels of Ammonia and Nitrite     

Lucas C. Maltez  Luis A. L. Barbas  Marcelo H. Okamoto  Diogo L. de Alcantara Lopes  Luis A. Romano  Luís A. Sampaio  Luciano Garcia 《Journal of the World Aquaculture Society》2019,50(2):346-358

This study investigated the secondary stress responses of Paralichthys orbignyanus exposed to ammonia and nitrite and after recovery. Fish were exposed to 0.12, 0.28, and 0.57 mg NH₃‐N/L, or 5.72, 10.43, and 15.27 mg NO₂‐N/L for 10 d followed by the same time length for recovery. Ammonia‐ and nitrite‐free water was used as a control treatment. Blood samples were collected after 1, 5, and 10 d of exposure and after recovery. Fish exposed to ammonia presented lower and higher glucose levels after 10 d of exposure and recovery, respectively. Ammonia induced initial and transient ionic disturbances and metabolic alkalosis. Nitrite exposure caused hyperglycemia, increased plasma K⁺ levels, and respiratory alkalosis, whereas metabolic acidosis was observed after recovery. Increased proportion of monocytes and/or granulocytes and reduced number of lymphocytes were demonstrated in fish exposed to 0.28 mg NH₃‐N/L (Day 1) and 10.43 mg NO₂‐N/L (Day 5) and after recovery in the 0.28 and 0.57 mg NH₃‐N/L treatments. Exposure to ammonia decreased the proportion of granulocytes on Day 5. In conclusion, exposure to concentrations at 0.12 mg NH₃‐N/L and 5.72 mg NO₂‐N/L provoked physiological disorders in Brazilian flounder. Nonetheless, fish exposed to 5.72 mg NO₂‐N/L following a 10‐d recovery period showed complete resumption of homeostasis.  相似文献   

Dietary roughage sources affect lactating Holstein x Zebu cows under experimental conditions in Brazil: a meta-analysis     

Alessio  Dileta Regina Moro  Velho  João Pedro  Tambara  Antônio Augusto Cortiana  de Oliveira Gomes  Ivan Pedro  Knob  Deise Aline  Haygert-Velho  Ione Maria Pereira  Busanello  Marcos  Thaler Neto  André 《Tropical animal health and production》2020,52(1):185-193

Tropical Animal Health and Production - To reduce costs, lactating cows are often fed a higher proportion of roughage and alternative feeds; however, such protocols may not lead to optimal milk...  相似文献