匈牙利半湿润气候地区田间尺度下土壤侵蚀引起的土壤有机碳再分布     

Z. SZALAI  J. SZAB&#;  J. KOV&#;CS  E. M&#;SZ&#;ROS  G. ALBERT  C. CENTER  B. SZAB&#;  B. MADAR&#;SZ  D. ZACH&#;RY  G. JAKAB 《土壤圈》2016,26(5):652-665

Soil organic carbon(SOC) has primary importance in terms of soil physics, soil fertility and even of climate change control. One hundred soil samples were taken from an intensively cultivated Cambisol to quantify SOC redistribution triggered by soil erosion under a subhumid climate, by the simultaneous application of diffuse reflectance(240–1 900 nm) and traditional physico-chemical methods.The representative sample points were collected from the solum along the slopes at the depth of 20–300 cm with a mean SOC content of 12 g kg~(-1). Hierarchical cluster analyses were performed based on the determined SOC results. The spatial pattern of the groups created were similar, and even though the classifications were not the same, diffuse reflectance had proven to be a suitable method for soil/sediment classification even within a given arable field. Both organic and inorganic carbon distributions were found to be a proper tool for estimations of past soil erosion processes. The SOC enrichment was found on two sedimentary spots with different geomorphological positions. Soil organic matter composition also differed between the two spots due to selective deposition of the delivered organic matter. The components with low-molecular-weight reached the bottom of the slope where they could leach into the profile, while the more polymerised organic matter compositions were delivered and deposited even before on a higher segment of the slope in an aggregated form. This spatial difference appeared below the uppermost tilled soil layer as well, referring the lower efficiency of conventional ploughing tillage in soil spatial homogenisation.  相似文献   

Evidence of Damage in Cryopreserved and Fresh Bovine Embryos Using the Tunel Technique   总被引：1，自引：0，他引：1  

YC Márquez-Alvarado  CS Galina  B Castilla  H León  N Moreno-Mendoza 《Reproduction in domestic animals》2004,39(3):141-145

The objective of the present study was to evaluate the quality of bovine embryos cryopreserved in different years in Chiapas, Mexico. The embryos were obtained from a government institution (FIMEGEN) dedicated to promoting embryo transfer among dual-purpose cattle farmers. Forty-three embryos frozen in 1988, 1989, 2000 and 2002 were analysed with the Tunel technique to detect programmed cell death (apoptosis). Eleven fresh embryos were used as controls. Analysis of variance was used in embryos stored in the different years with averages tested using Tukey's test. Student's t-test was employed to compare fresh and frozen cells. Embryos with shorter storage time presented a lower number (p < 0.001) of Tunel-positive cells compared with embryos stored for longer time. On the contrary, when comparing the number of apoptotic cells between frozen and fresh embryos a higher number of positive cells (p < 0.05) were found in the former. The present results suggest that the cryopreservation per se caused damage that compromises the viability of the embryo. Another explanation for the lower pregnancy rate found in the tropics could be irreversible damage caused by poor storage technique in these large operations.  相似文献   

Synthesis and testing of novel alternative oxidase (AOX) inhibitors with antifungal activity against Moniliophthora perniciosa (Stahel), the causal agent of witches' broom disease of cocoa,and other phytopathogens     

Mario RO Barsottini  Brbara A Pires  Maria L Vieira  Jos GC Pereira  Paulo CS Costa  Jaqueline Sanit  Alessandro Coradini  Fellipe Mello  Cidnei Marschalk  Eder M Silva  Daniele Paschoal  Antonio Figueira  Fbio HS Rodrigues  Artur T Cordeiro  Paulo CML Miranda  Paulo SL Oliveira  Maurício L Sfora  Marcelo F Carazzolle  Silvana A Rocco  Gonalo AG Pereira 《Pest management science》2019,75(5):1295-1303

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Effects of Prolonged Exposure to Low‐Dose Fumonisin B1 in Pigs     

M. ZOMBORSZKY‐KOVCS  F. VETSI  P. HORN  I. REPA  F. KOVCS 《Zoonoses and public health》2002,49(4):197-201

From the point of view of human exposure, fumonisins (FB₁, FB₂, FB₃, FB₄), a relatively recently (1988) discovered and identified group of mycotoxins, represent one of the five most important mycotoxin groups causing human disease. In an earlier experiment studying the effects of relatively low doses (10, 20 and 40 p.p.m.) of FB₁ in weaned piglets, it was established that the 4‐week feeding of 10 p.p.m. (mg/kg feed) FB₁ produced mild pulmonary oedema. This suggested the importance of studies with even lower doses of the toxin to determine the tolerable limits. The objective of this experiment was therefore to study the effects of prolonged (8‐week) exposure to still lower concentrations (0, 1, 5 and 10 mg/kg feed) of FB₁. The 8‐week feeding of FB₁ in low concentrations (1–10 p.p.m.) did not cause clinical signs and significant performance impairment in pigs, but rendered irreversible the chronic changes that had already developed in the animals in a dose‐dependent manner. Dissection revealed pathological alterations of the lungs in one of the animals given 1 p.p.m. (n=4), in two animals exposed to 5 p.p.m. (n=5), and in three animals given 10 p.p.m. (n=4). In all three treatment groups, proliferation of the connective tissue fibres, primarily of those around the lymphatic vessels, in the subpleural and interlobular connective tissue of the lungs, extending to the peribronchial and peribronchiolar areas, was seen. The results of this experiment call attention to the risk of prolonged low‐dose toxin exposure, which has very important public health implications.  相似文献   

Experimental Leptospira borgpetersenii serovar hardjo infection of pregnant cattle     

CR SMITH  MR McGOWAN  CS McCLINTOCK  BG CORNEY  PJ KETTERER  L. SMYTHE  W. WARD 《Australian veterinary journal》1997,75(11):822-826

Objective To observe the effect upon the foetus of experimental infection of pregnant cattle with Leptospira borg-petersenii serovar hardjo .
Design A disease transmission study using pregnant cattle.
Procedure Fourteen heifers serologically negative to L hardjo were artificially inseminated and later challenged with a north-Queensland isolate of L hardjo by conjunctival inoculation. The heifers were serologically monitored and their urine examined for the presence of leptospires using culture and fluorescent-antibody tests at appropriate intervals. Elective caesarean sections were performed on pregnant heifers at 6.5 weeks after the challenge. Foetuses were examined using serological, histopathological, microbiological and fluorescent-antibody tests.
Results Ten of the heifers became pregnant, but three subsequently aborted before challenge. After challenge, all 14 heifers seroconverted and L hardjo was isolated from the urine of 6 of the 7 pregnant heifers. No evidence of foetal L hardjo infection was detected. Two of the foetuses had histopatho-logical lesions consistent with Neospora s p infection.
Conclusion It is likely that the isolate of L hardjo used in this study does not normally infect the foetus. Neospora s p may be a more significant cause of bovine reproductive wastage.  相似文献   

Resumption of Post-partum Ovarian Activity Monitored by Plasma Progesterone in Anoestrous Zebu (Bos indicus) Cattle Following Temporary Weaning and Progestogen Treatment     

JM Bolaños  CS Galina  S Estrada  M Forsberg 《Reproduction in domestic animals》1997,32(5):267-271

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Evaluation of an Artificial Insemination Programme in a Seasonal Breeding Dairy System through Milk Progesterone     

D Cavestany  & CS Galina 《Reproduction in domestic animals》2001,36(2):79-84

In order to evaluate an artificial insemination programme and reproductive efficiency of dairy herds in Uruguay, a survey was conducted with five dairy farms, utilizing a total of 768 lactating Holstein cows. Precision of oestrous detection was assessed by one milk progesterone sample taken on day of breeding and was 11.1%. Two additional samples taken at day 10 and 23 were used to confirm ovulation and early pregnancy. Accuracy of pregnancy estimation by milk progesterone was 70.4%. Reproductive efficiency was determined by the analysis of records. Average intervals from calving to first service were 101 days and to conception 132 days and these were affected by parity, body weight and body condition at calving, but not at breeding, or by milk production. Oestrous detection rates and pregnancy rates were 37.5 and 15.6%, respectively. It was concluded that losses in reproductive efficiency in dairy farms of Uruguay in a seasonal artificial insemination programme were mainly due to unobserved heats, rather than incorrect oestrous detection.  相似文献   

Relationship Among Follicular Growth, Oestrus, Time of Ovulation, Endogenous Estradiol 17β and Luteinizing Hormone in Bos Indicus Cows After a Synchronization Program     

M Maquivar  A Verduzco  CS Galina  A Pulido  S Rojas  K Forster  G Van der Laan  R Arnoni 《Reproduction in domestic animals》2007,42(6):571-576

To determine the pattern of follicular growth during oestrus and the relationship with estradiol and luteinizing hormone in ovulating and non-ovulating cows, three groups of (n = 10), thirty cyclic, Bos indicus cows were synchronized with CIDR, consecutively at 9-day intervals. Twenty-four hours after implant withdrawal, all cows synchronized in the same group with other cows displaying estrous behaviour after implant withdrawal were subjected to an intensive period of ultrasonographic observations (every 6 h for 120 h). Blood samples were taken to evaluate LH surge and 17-beta estradiol. No differences were observed in follicular growth, ovulatory diameter and growth average in the three groups of synchronized cows. Cows ovulating (CO) had a better growth average in comparison with the group of cows not ovulating (CNO) (1.4 +/- 0.7 mm vs 0.7 +/- 0.5 mm, p < 0.06). The average time from estradiol release to LH surge was 39.3 +/- 24.6 h. Differences were also observed between CO and CNO with respect to both the first concentration (27.7 +/- 5.2 vs 58.6 +/- 31.9, p < 0.004) and last concentration (79.3 +/- 23.3 vs 99.2 +/- 27.3, p < 0.05) of estradiol above 5 pg/ml. The average time from overt signs of oestrus to LH release was 8.4 +/- 7.7 h. In the CNO, the increase in LH concentration was never above two SD from the basal average. In conclusion, there is a wide variability in follicular growth and ovulatory diameter between CO and CNO, which can affect the intervals of LH release, estradiol peak and ovulation. Yet, LH surge might be a good marker for timing ovulation in Zebu cows.  相似文献   

Proteomic analysis of the hypothalamus of broiler‐type Taiwan country chickens in response to acute heat stress          下载免费PDF全文

Wei‐Lin Tu  Chuen‐Yu Cheng  Chao‐Jung Chen  Hong‐Lin Chan  Shih‐Han Wang  Pin‐Chi Tang  Chih‐Feng Chen  Hsin‐Hsin Chen  Yen‐Pai Lee  Shuen‐Ei Chen  San‐Yuan Huang 《Animal Science Journal》2018,89(10):1475-1485

The hypothalamus is a critical center for regulating heat retention or dissipation. This study investigated global protein changes in the hypothalamus of broiler‐type Taiwan country chickens (TCCs) after acute heat stress. Twelve TCC hens aged 30 weeks were allocated to groups subjected to acute heat stress at 38°C for 2 hr without recovery, with 2 hr of recovery, and with 6 hr of recovery; a control group was maintained at 25°C. Hypothalami were collected for protein expression analysis at the end of each time point. The results showed 114 protein spots differentially expressed after acute heat stress. Most of the differentially expressed proteins were involved in cellular processes, metabolism, transport, and cellular component organization. Functional annotation analysis suggested that these proteins were related to cellular defensive responses against heat and oxidative stress, detoxification and toxin export/delivery, cytoskeleton integrity, oxygen transport, and neural development. The results of this study suggest that acute heat stress damages the hypothalamus of broiler‐type TCCs through oxidative stress and provokes a series of responses to stabilize protein structures, degrade misfolded proteins, and remodel cytoskeletons for attenuating the detrimental effects by acute heat stress.  相似文献   

Raw beef bones as chewing items to reduce dental calculus in Beagle dogs          下载免费PDF全文

FR Marx  GS Machado  JG Pezzali  CS Marcolla  AM Kessler  Ø Ahlstrøm  L Trevizan 《Australian veterinary journal》2016,94(1-2):18-23

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