Genetic associations between accumulated productivity, and reproductive and growth traits in Nelore cattle     

D.A. Grossi  O.G. Frizzas  C.C.P. Paz  L.A.F. Bezerra  R.B. Lbo  J.A. Oliveira  D.P. Munari 《Livestock Science》2008,117(2-3):139-146

The total meat yield in a beef cattle production cycle is economically very important and depends on the number of calves born per year or birth season, being directly related to reproductive potential. Accumulated Productivity (ACP) is an index that expresses a cow's capacity to give birth regularly at a young age and to wean animals of greater body weight. Using data from cattle participating in the “Program for Genetic Improvement of the Nelore Breed” (PMGRN — Nelore Brasil), bi-trait analyses were performed using the Restricted Maximum Likelihood method based on an ACP animal model and the following traits: age at first calving (AFC), female body weight adjusted for 365 (BW365) and 450 (BW450) days of age, and male scrotal circumference adjusted for 365 (SC365), 450 (SC450), 550 (SC550) and 730 (SC730) days of age. Median estimated ACP heritability was 0.19 and the genetic correlations with AFC, BW365, BW450, SC365, SC450, SC550 and SC730 were 0.33, 0.70, 0.65, 0.08, 0.07, 0.12 and 0.16, respectively. ACP increased and AFC decreased over time, revealing that the selection criteria genetically improved these traits. Selection based on ACP appears to favor the heaviest females at 365 and 450 days of age who showed better reproductive performance as regards AFC. Scrotal circumference was not genetically associated with ACP.  相似文献   

Minor corral changes and adoption of good handling practices can improve the behavior and reduce cortisol release in Nellore cows     

Maria Lúcia Pereira Lima  João Alberto Negrão  Claudia Cristina Paro de Paz  Temple Grandin 《Tropical animal health and production》2018,50(3):525-530

Inadequate corral facilities and improper handling are major causes of stress in beef cattle. The purpose of this study was to evaluate the effects of minor changes in the corral and adoption of good handling practices on the behavior, cortisol release, and time spent taking blood samples in Nellore cows. Minor corral changes included obstructing the cow’s vision when the handler walked deep into the animal’s flight zone and the elimination of bright objects, color contrasts, puddles, shadows, and darkness in the corral. Handling was improved by eliminating dogs, electric goads (prods), and yelling, as well as adopting a calm behavior. A total of 141 Nellore cows from two typical extensive livestock farms were studied. The cows were evaluated individually before and after the corral changes. Blood samples were collected in the restraint device for cortisol measurement. The minor corral changes and the adoption of good handling practices result in better results for all variables studied. The results showed differences in the interactions between treatment and ranch for chute score (P = 0.0091) and exit score (P < 0.0001). The cortisol release was lower (P < 0.001) and better for the improved methods, resulting in calmer cows compared to cortisol released before the minor changes (41.03 ± 2.9 vs 60.40 ± 3.8 ng/mL). Minor changes made in the corrals and the adoption of good handling practices were effective in improving cow behavior in the chute and in reducing exit velocity, cortisol released, and the time spent taking blood samples.  相似文献   

Redox cycling induces spermptosis and necrosis in stallion spermatozoa while the hydroxyl radical (OH•) only induces spermptosis          下载免费PDF全文

P Martín Muñoz  L Anel‐López  JM Ortiz‐Rodríguez  M Álvarez  P de Paz  C Balao da Silva  H Rodríguez Martinez  MC Gil  L Anel  FJ Peña  C Ortega Ferrusola 《Reproduction in domestic animals》2018,53(1):54-67

Oxidative stress is a major factor explaining sperm dysfunction of spermatozoa surviving freezing and thawing and is also considered a major inducer of a special form of apoptosis, visible after thawing, in cryopreserved spermatozoa. To obtain further insights into the link between oxidative stress and the induction of apoptotic changes, stallion spermatozoa were induced to oxidative stress through redox cycling after exposure to 2‐methyl‐1,4‐naphthoquinone (menadione), or hydroxyl radical formation after FeSO₄ exposure. Either exposure induced significant increases (p < 0.05) in two markers of lipid peroxidation: 8‐iso‐PGF_2α and 4‐hydroxynonenal (4‐HNE). While both treatments induced changes indicative of spermptosis (caspase‐3 activation and decreased mitochondrial membrane potential) (p < 0.01), menadione induced sperm necrosis and a dramatic reduction in motility and thiol content in stallion spermatozoa. Thus, we provided evidence that oxidative stress underlies spermptosis, and thiol content is a key factor for stallion sperm function.  相似文献   

Optimization of glycerol concentration and freezing rate in the cryopreservation of ejaculate from brown bear (Ursus arctos)     

de Paz P  Alvarez-Rodriguez M  Nicolas M  Alvarez M  Chamorro C  Borragán S  Martinez-Pastor F  Anel L 《Reproduction in domestic animals》2012,47(1):105-112

In order to establish a semen bank for the endangered Cantabrian brown bear, we tested five glycerol concentrations and three freezing rates for electroejaculated semen. Electroejaculation was performed on nine males. Semen was diluted in TES-Tris-Fructose (20% egg yolk, 2% EDTA, 1% Equex) with 2%, 4%, 6%, 8% or 10% glycerol and frozen at -10, -20 or -40°C/min. Before and after cryopreservation, samples were analysed for motility (CASA), viability and acrosomal status (flow cytometry). Pre-freezing results showed that glycerol concentration had no significant effect on total motility or progressive motility, but it significantly decreased VCL, ALH, viability and acrosomal status (p < 0.05). After thawing, sperm motility was higher at extender with 4%, 6% and 8% glycerol, but only at 4% and 6% glycerol for viability and acrosomal status. For 4% and 6% glycerol, freezing rates did not have significant effects. The curve fitting gave an estimate of the optimal glycerol concentration, with all the optimal values for every parameter between 6% and 7% glycerol falling. We propose using 6% glycerol and a freezing velocity of -20°C/min for freezing brown bear ejaculated spermatozoa.  相似文献   

Autochthonous Dirofilaria immitis infection in a ferret with aberrant larval migration in Europe     

V. Molnár  P. Pazár  D. Rigó  D. Máthé  É. Fok  R. Glávits  P. Vajdovich  O. Jacsó  L. Balogh  E. Sós 《The Journal of small animal practice》2010,51(7):393-396

A two-year-old male ferret (Mustela putorius furo) was presented to the Faculty of Veterinary Science, Szent István University, for investigation of somnolence. Following unsuccessful therapeutic attempts, the ferret was euthanased and a male Dirofilaria immitis worm was found in the pulmonary artery and a female D. immitis specimen in the subdural space of the cranial cavity. To the authors’ knowledge, this is the first European record of D. immitis infection in a ferret, and the first case in which aberrant larval migration and consequent central nervous system signs were observed in a ferret in the course of D. immitis infection.  相似文献   

Effect of high temperature on physiological parameters of Nelore (Bos taurus indicus) and Caracu (Bos taurus taurus) cattle breeds     

Lima  Sergio B. G. P. N. P.  Stafuzza  Nedenia Bonvino  Pires  Bianca V.  Bonilha  Sarah F. M.  Cyrillo  Joslaine N. S. G.  Negrão  João A.  Paz  Claudia C. P. 《Tropical animal health and production》2020,52(5):2233-2241

The climate-related problems that affect animal production in tropical countries have encouraged seeking solutions to increase herd productivity and one alternative is the use of breeds adapted to high-temperature environments. The objective of this study was to evaluate the effect of temperature on 77 Caracu and Nelore males submitted to three different environments: morning period (8:00 to 10:00 AM), afternoon in the sun, and afternoon in a shaded environment (11:00 AM to 1:00 PM). The following physiological parameters were measured in each treatment: heart and respiration rates, rectal and dorsal surface temperatures, and cortisol level. The data were analyzed with the MIXED procedure (SAS) and the model included the fixed effects of treatment (morning, sun, and shade), breed (Nelore and Caracu), month of measurement (December and February), and the interaction between effects. A higher dorsal surface temperature was observed in animals of both breeds in the sun treatment compared with the shade treatment. Caracu animals had a higher dorsal surface temperature than Nelore animals, which probably caused the higher rectal temperature observed in the sun treatment compared with the shade treatment in both breeds over the 2 months of the study. All physiological parameters measured in this study were efficient to detect the thermal stress in both breeds. Despite the variations in rectal temperature observed during the treatments, the animals of the two breeds exhibited no significant changes in heart rate, respiration rate, and cortisol level for the maintenance of thermal homeostasis. In conclusion, both breeds were considered tolerant to sun exposure, demonstrating adaptation of these animals to high-temperature environments, without evidence of harm to its health and welfare.

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Fine temporal resolution satellite sensors with global coverage: an opportunity for landscape ecologists     

Pazúr  Robert  Price  Bronwyn  Atkinson  Peter M. 《Landscape Ecology》2021,36(8):2199-2213

Landscape Ecology - Open data policies and accessible computation platforms allow efficient extraction of information from remote sensing data for landscape research. Landscape ecology is strongly...  相似文献   

An anti-inflammatory and immunomodulatory polysaccharide from Orbignya phalerata     

Bernadete Pereira da Silva  Jos Paz Parente 《Fitoterapia》2001,72(8)

A polysaccharide, a glucan with mean M_r of 1.0×10⁶ (MP1), was isolated from the mesocarp of fruits of Orbignya phalerata. Chemical and spectroscopic studies indicated that MP1 has a highly branched glucan type structure composed of α-(1→4) linked -glucopyranose residues with (3→4), (4→6), and with (3→6) branching points. MP1 enhanced phagocytosis in vivo and exhibited anti-inflammatory activity.  相似文献   

Maize ethanol feedstock production and net energy value as affected by climate variability and crop management practices     

Tomas Persson  Axel Garcia y Garcia  Joel Paz  Jim Jones  Gerrit Hoogenboom 《Agricultural Systems》2009,100(1-3):11-21

Ethanol from various plant resources, especially maize, is increasingly being used as a substitute for fossil fuels. The production potential of ethanol from maize varies with weather and climatic conditions and crop management practices. The merits and prospects of ethanol production have been evaluated based on its impact on greenhouse gas emissions, economic viability and national energy security. The net energy value (NEV), i.e. the output energy after all non-renewable energy inputs have been accounted for, is a measure of energy gain. At the same time, the NEV can be an indicator for the long-term sustainability of bio-ethanol production, regardless of other conditions e.g. climate change scenarios, global trade restrictions, or local variability in natural resources such as water availability. Crop management practices directly affect the NEV of ethanol. Moreover, both crop management practices and climate variability affect the NEV through the grain yield. The objective of this study was to assess the impact of crop management practices and climate variability on grain yield of maize for ethanol production and ethanol NEV for conditions that represent the southeastern USA. Maize grain yield was simulated with the dynamic crop growth model CSM–CERES–Maize and ethanol NEV was calculated using the simulated yield levels and crop management practices. The simulations were conducted for conditions representing Mitchell County, Georgia, USA, using weather data from 1939 to 2006 and local soil profile information. The impact of irrigation, nitrogen fertilizer, planting date and El Niño Southern Oscillation (ENSO) phases were determined for the maize cultivars DeKalb DKC 61-72 (RR2), Pioneer 31D58 and Pioneer 31G98. Crop management practices and ENSO phase had a significant impact on ethanol feedstock production and NEV. The NEV of ethanol produced from irrigated maize was more than two times higher and varied less than the NEV of ethanol from rainfed maize. NEV of ethanol produced from maize grown during La Niña years was significantly higher than maize grown during El Niño years, both under rainfed and irrigated conditions. This study showed the importance of crop management practices and climate variability on ethanol feedstock productivity and long-term energy sustainability as assessed by the NEV. We discuss methods of implementing the findings of this study in practical farming e.g. through market mechanisms and governmental initiatives.  相似文献   

Bipolar Mesoderm Cells in vitro Examined by Scanning Electron Microscopy     

C. A. Chamorro  P. de  Paz  J. G. Fernandez    M. Fernandez  J. M. Villar 《Anatomia, histologia, embryologia》1987,16(1):48-52

Head mesoderm cells from chick embryo at stage 10 were cultured onto coverslips. The mesoderm cells with bipolar aspect were studied by means of scanning electron microscopy. Several features of the filopodia and lamellipodia of these cells, as number, length and width were quantified and the results ire discussed in view of the role proposed for these projections in the cellular locomotion. Moreover, the morphological characterization here carried out permits to have comparison with other cellular types of the same culture or between cultured cells of different stages of chick embryo development.  相似文献