The use of ultrasonography in the reproductive evaluation of boars          下载免费PDF全文

RO Pinho  BS Camilo  DMA Lima  FAC Villadiego  JCM Vergara  HH Shiomi  RE Cardoso  PS Lopes  JD Guimarães 《Reproduction in domestic animals》2018,53(2):393-400

The objective was to study the use of ultrasound as a complementary test in the breeding soundness evaluation in male pigs and study the pattern of echogenicity of the testicular parenchyma in boars of different racial groups. Twenty‐six adult boars from four different racial groups were used, 10 from the Piau breed (group 1), four from the commercial and finishing group (group 2), six Pietrain breed (group 3) and six from the Duroc breed (group 4). All animals were evaluated for breeding soundness evaluation and the ultrasound examination of the testicles. The groups of animals that were evaluated showed no difference in the main semen parameters that were evaluated, except for the sperm volume, concentration of the ejaculated sperm and the supravital staining; the lowest figures were for the animals from the Piau breed (group 1). In relation to the testicular biometrics, Duroc animals (group 4) had a greater scrotal width compared to the other groups. But when we assessed the intensity of pixels of the testicles, there was a difference between groups. The groups 2 (finishing animals), 3 (Pietrain) and 4 had no difference between themselves. Group 3 had greater pixel intensity in relation to group 1. Of the 26 animals studied, five showed an abnormality during ultrasound evaluation, like hydrocele, hyperechoic mass in the testicular parenchyma, cyst in the head of the epididymis and the presence of fluid in the head and tail of the epididymis. The various animal groups studied did not differ in the principal reproductive parameters evaluated, showing that despite the great variability of reproductive traits between breeds and within the same breed, the breeding soundness evaluation, the more complete it is, is essential for the selection of breeders and the ultrasonography of the reproductive system becomes an important addition in this examination.  相似文献   

Occupancy pattern of a long-horned beetle in a variegated forest landscape: linkages between tree quality and forest cover across spatial scales     

Pablo M. Vergara  Luis O. Meneses  Audrey A. Grez  Madelaine S. Quiroz  Gerardo E. Soto  Christian G. Pérez-Hernández  Paola A. Diaz  Ingo J. Hahn  Andrés Fierro 《Landscape Ecology》2017,32(2):279-293

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Identification of emesis-causing Bacillus cereus strains by polymerase chain reaction: preliminary results     

Colavita G  Rotili M  Leone A  Vergara A  Sammarco ML  Ripabelli G 《Veterinary research communications》2007,31(Z1):351-353

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Amelioration of Drought-Induced Transplanting Shock in Rice by an Abscisic Acid Analog in Combination with the Growth Retardant Tetcyclacis     

A. A. Flores-Nimedez  K. Dörffling  B. S. Vergara 《Journal of Agronomy and Crop Science》1995,174(3):145-150

The protective effect of a synthetic terpenoid analog of abscisic acid (ABA), coded LAB 173711, on transplant shock in rice was investigated under field conditions. Rice seedlings (Fujisaka 5 and IR 20) were taken from a seed bed and their roots were immersed in aqueous solutions of the growth regulators for 24 h. Afterwards they were drought-stressed for 3 or 6 h by exposing them to direct sunlight before they were transplanted to the field. A pretreatment with either LAB 173711 alone or in combination with the growth retardant tetcyclacis reduced the loss of water during the exposure to sunlight, increased the percentage of survival of the seedlings in the field, and increased the percentage of grain filling of the plants which had survived. The combined application of growth regulators was most effective and may be useful for minimizing transplant shock in rice and other crops.  相似文献   

Behaviour of Listeria monocytogenes in anchovies during marination     

Vergara A  Ianieri A  Colavita G  Paparella A 《Veterinary research communications》2003,27(Z1):319-321

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In vitro and in vivo efficacy of lasalocid for treatment of experimental cryptosporidiosis   总被引：3，自引：0，他引：3  

Castro Hermida JA  Freire Santos F  Oteiza López AM  Vergara Castiblanco CA  Ares-Mazás ME 《Veterinary parasitology》2000,90(4):265-270

In vitro viability of purified Cryptosporidium parvum oocysts, exposed for 30, 60, 90 and 120 min to 0.27 mg/ml lasalocid suspension was evaluated by inclusion or exclusion of two fluorogenic vital dyes and an excystation technique. Continuously, preventive and curative efficacies at different doses (9, 6.75, 5.625 and 4.5 mg/kg body weight) and regimens of lasalocid against cryptosporidial infection were evaluated on an experimental neonatal mice model. In vitro assays demonstrated a decrease in the oocyst viability related to an increase in exposure time for exposure to the lasalocid suspension. The infection was eradicated when the suspension was administered with a dose of ≥6.75 mg/kg body weight. No apparent toxic effects were observed.  相似文献   

Responses of Chilean forest birds to anthropogenic habitat fragmentation across spatial scales   总被引：1，自引：1，他引：0  

Pablo M. Vergara  Juan J. Armesto 《Landscape Ecology》2009,24(1):25-38

Although it is recognized that anthropogenic forest fragmentation affects habitat use by organisms across multiple spatial scales, there is uncertainty about these effects. We used a hierarchical sampling design spanning three spatial scales of habitat variability (landscape > patch > within-patch) and generalized mixed-effect models to assess the scale-dependent responses of bird species to fragmentation in temperate forests of southern Chile. The abundances of nine of 20 bird species were affected by interactions across spatial scales. These interactions resulted in a limited effect of within-patch habitat structure on the abundance of birds in landscapes with low forest cover, suggesting that suitable local habitats, such as sites with dense understory cover or large trees, are underutilized or remain unused in highly fragmented landscapes. Habitat specialists and cavity-nesters, such as tree-trunk foragers and tapaculos, were most likely to exhibit interactions across spatial scales. Because providing additional sites with dense understory vegetation or large habitat trees does not compensate the negative effect of the loss of forest area on bird species, conservation strategies should ensure the retention of native forest patches in the mixed-use landscapes.  相似文献   

Depletion of serum alternative complement pathway activity in gilthead seabream caused by α-tocopherol and n-3 HUFA dietary deficiencies     

D. Montero  L. Tort  M.S. Izquierdo  L. Robaina  J.M. Vergara 《Fish physiology and biochemistry》1998,18(4):399-407

Studies on the alternative complement pathway (ACP) activity in fish have suggested the particular relevance of this pathway as a non-specific immune mechanism being its activation directly related with the availability of certain nutrients. In the present study ACP activity in gilthead seabream fed different dietary levels of a-tocopherol and n-3 HUFA deficiencies was studied under different stress conditions (overcrowding and repetitive chasing).A reduction in ACP activity was found when diets with deficiencies in -tocopherol and n-3 HUFA were assayed at any of the experimental conditions assayed. Levels of plasma cortisol were similar to those of fish after crowding stress subjected to dietary deficiencies at low stocking density, suggesting that dietary deficiencies produced a chronic elevation of cortisol. When fish were subjected to repetitive chasing, plasma cortisol from fish fed control diet showed a progressive increase whereas plasma cortisol levels from both dietary deficient groups showed a transitory peak 4 days after the beginning of the repetitive chasing. However, ACP activity levels of fish fed deficient diets remained lower than the control group and constant during chasing period. These results suggest that both a-tocopherol and n-3 HUFA nutritional deficiencies rather than stress are an important determinant of fish complement activity.  相似文献   

Alteration of liver and muscle fatty acid composition in gilthead seabream (Sparus aurata) juveniles held at high stocking density and fed an essential fatty acid deficient diet   总被引：2，自引：0，他引：2  

D. Montero  L.E. Robaina  J. Socorro  J.M. Vergara  L. Tort  M.S. Izquierdo 《Fish physiology and biochemistry》2001,24(1):63-72

The aim of the present study was to determine the combined effect of both stress and EFA deficiency on several biological and biochemical parameters. Fish were fed during 15 weeks two isocaloric and isoproteic diets: a control diet based on fish oil and formulated to meet the n-3 HUFA requirements for this species (1.5% of n-3 HUFA) and a deficient diet containing beef tallow and formulated to be deficient in n-3 HUFA. Each experimental diet was evaluated both at high and low stocking densities (10 and 3.2 kg m^–3 of initial density, respectively).High stocking density produced a chronic stress situation with elevation of plasma cortisol levels. It also caused a reduction in hepatosomatic index and liver lipid contents, increasing the oleic acid/n-3 HUFA ratios in the polar lipids. Fish fed the EFA deficient diet at low stocking density showed common deficiency symptoms. High stocking density in fish fed the EFA deficient diet induced a higher degree of EFA deficiency symptoms leading to mortality, liver steatosis, liver lipid deposition, reduced muscle lipid and reduced n-3 HUFA contents, which particularly affected EPA, but not DHA, suggesting a preferential retention of the latter fatty acid, specially in the phosphoglycerides fraction.  相似文献   

The genetic structure of Mytilus chilensis (Hupé 1854) populations along the Chilean coast based on RAPDs analysis     

Jorge E Toro  Johana A Ojeda  & Ana M Vergara 《Aquaculture Research》2004,35(15):1466-1471

The Chilean blue mussel Mytilus chilensis is an important commercial species. However, little has been published on the population genetics of this species, despite the need to implement management and conservation policies. Randomly amplified polymorphic DNA‐polymerase chain reaction analysis was used to estimate genetic variation within and between eight natural populations along the whole range of its Chilean natural distribution (ca. 1900 km from Arauco (VIII Region) to Punta Arenas (XII Region)). The values of Nei's unbiased genetic distance, D (0.030–0.107), among populations were small, despite the large geographic separation. A mantel test using 50 000 randomizations showed evidence for a significant correlation (r=0.74, P<0.05) between genetic and geographic (coastal) distance. Punta Arenas population was the most genetically differentiated from the others, although the scale of differentiation was not large (D=0.076–0.107). The levels of gene flow (Nm=1.55) found in this study prevent differentiation among populations by genetic drift. This is the result of the long‐lived planktotrophic larvae of M. chilensis, which provides this species with considerable dispersal ability throughout its range, which is favoured by the ocean currents along the Chilean coast. A restricted larval dispersal towards the north due to the Cape Horn Current derived from the West Wind Drift could be the cause of the higher genetic differentiation of Punta Arenas population from the northern populations. For management purposes of the M. chilensis fishery, the results provide no evidence for discrete stocks, with the possible exception of the Punta Arenas population. The present study provides the baseline data in order to continue further characterization of these mussel populations, considering the great increase in aquaculture of this species.  相似文献