Influence of pruning and the climatic conditions on acorn production in holm oak (Quercus ilex L.) dehesas in SW Spain

Acorn production by Quercus ilex L. ssp. ballota (Desf.) Samp. in SW Spain was assessed, and variations between years and the influence of pruning on it were examined. To this end, an experimental study was conducted at two different sites (Calañas and San Bartolomé, in the province of Huelva) where trees were subjected to traditional (light, moderate or heavy) pruning and also to a new (crown-regeneration) pruning method. Acorn yield was quantified over a period of 5 years in the Calañas plot and 4 in the San Bartolomé plot, and found to average at 95.61 ± 0.76 g DM/m², which is equivalent to 6.5 ± 0.05 kg DM/tree; however, yield figures varied markedly between years depending on the particular climatic conditions. The average acorn production was correlated with the water potential in mid summer (end of July); the annual, spring and autumn rainfall; and the actual evapotranspiration for the period from September (previous year) to August. No significant differences in acorn production between traditional pruning intensities were detected; in fact, there were only hints that heavy pruning might result in decreased acorn yields. The new pruning method used, crown-regeneration, seems promising with a view to increasing acorn yield; however, it should be tested on larger sample sizes before any final conclusions can be drawn in this respect. Based on the results, the present health status of holm oaks in southwestern Spain (a result of sustained decline) and the low value of firewood — which used to be a very important source of income from pruning a few decades ago -, the authors recommend reducing the frequency and intensity of pruning in the dehesas of the study area.     

Check dams and sediment control: final results of a case study in the upper Corneja River (Central Spain)

Journal of Soils and Sediments - The sediment yield and erosion rate in an area can be estimated by calculating the volume of sediment retained by check dams. However, results can show unrealistic...     

Characterization of Anaplasma phagocytophilum and A. ovis infection in a naturally infected sheep flock with poor health condition

Anaplasma species are transmitted by ticks and cause diseases in humans and animals. These pathogens infect sheep, an economically important domestic animal worldwide. The current study was designed to characterize in 200 animals the infection with Anaplasma phagocytophilum and Anaplasma ovis and the genetic diversity of A. ovis strains collected from a naturally infected sheep flock with poor health condition. Sheep had 98% seroprevalence to Anaplasma spp. antibodies. PCR results confirmed the presence of A. phagocytophilum and A. ovis DNA in 11.5% and 37% of the sheep, respectively. Concurrent infections were detected in 6.5% of the sheep. Seventy-one adult ticks were collected from 45 sheep with infestations ranging from one to 15 ticks per animal. The analysis of A. ovis msp4 sequences demonstrated a previously unreported polymorphism for this pathogen with 17 different haplotypes in infected sheep. These results demonstrated that, although A. ovis msp4 haplotypes may be less variable when compared with Anaplasma marginale and A. phagocytophilum strains on a global scale, genetic polymorphisms occur in this locus in strains obtained from an infected sheep flock with poor health condition.     

Characterization of pathogen-specific expression of host immune response genes in Anaplasma and Mycobacterium species infected ruminants

Anaplasma and Mycobacterium species are among the most prevalent bacterial pathogens in European red deer (Cervus elaphus) in south-central Spain and are known to modify gene expression in ruminants. In this study, we used microarray hybridization and real-time RT-PCR analyses to characterize global gene expression profiles in red deer in response to Anaplasma ovis and A. ovis/Mycobacterium bovis/Mycobacterium avium sub. paratuberculosis (MAP) infections, compare the expression of immune response genes between red deer infected with A. ovis, M. bovis and A. ovis/M. bovis/MAP, and characterize the differential expression of immune response genes identified in red deer in cattle infected with M. bovis and Anaplasma marginale. Global gene differential expression in A. ovis- and A. ovis/M. bovis/MAP-infected deer resulted in the modification of common and pathogen-specific cellular biological processes. The differential expression of host immune response genes showed pathogen and host-specific signatures and the effect of infection with multiple pathogens on deer immune response. These results suggested that intracellular bacteria from Anaplasma and Mycobacterium genera produce similar genes expression patterns in infected ruminants. However, pathogen and host-specific differences could contribute to disease diagnosis and treatment in ruminants.     

Development of a time-resolved fluorometry based immunoassay for the determination of canine haptoglobin in various body fluids

A time-resolved immunofluorometric assay (TR-IFMA) was developed for the determination of haptoglobin (Hp) in canine serum. Haptoglobin was purified from canine acute phase serum by ammonium sulphate precipitation followed by gel filtration. This isolated dog Hp was used as the standard to calibrate the assay. Intra- and inter-assay coefficients of variation of the assay were, respectively, 5.7% and 16.6% at 0.51 mg/mL, 2.4% and 10.6% at 2.1 mg/mL and 10.5% and 11.9% at 32.5 mg/mL. The dilution of serum samples with high Hp concentrations resulted in linear regression equations with R2 of 0.99 and 0.97. A high correlation was found in serum Hp measurements by TR-IFMA and a commercial assay based on peroxidase activity of haemoglobin bound to haptoglobin (R2 = 0.96). The limit of detection for the TR-IFMA method was 0.002 microg/mL. The addition of fresh haemolysate to serum samples did not affect the haptoglobin concentration (P = 0.694). Statistical differences (P < 0.003) were found between healthy dogs and dogs with different pathological processes. In whole blood, Hp concentrations were much lower than in serum but closely related (R2 = 0.84) whereas saliva Hp concentrations were poorly related with serum concentrations (R2 = 0.53). However, the concentration of Hp in saliva was significantly (P < 0.039) higher in dogs with pathological processes compared to healthy dogs. The assay sensitivity was adequate to also be applied to whole blood and saliva specimens.     

Assessment of some blood parameters as potential markers of hepatic copper accumulation in cattle.

The increasing frequency of copper (Cu) toxicosis episodes in cattle in recent years, mainly associated with excess Cu supplementation, underscores the need to identify animals in the clinically silent phase of hepatic Cu accumulation. The aim of the study reported here was to evaluate the suitability of various blood parameters as potential early markers of hepatic Cu accumulation in cattle. Paired liver and blood samples from 70 calves aged 6 to 10 months were obtained at slaughter in a region in northwestern Spain where animals usually have hepatic Cu concentration higher than safe values. Neither serum Cu concentration nor ceruloplasmin (CP) concentration, the 2 parameters most commonly used for diagnosis of Cu deficiency, were significantly associated with hepatic Cu concentration. However, whole-blood Cu concentration had a slight but significant correlation with hepatic Cu concentration (r = 0.269, P = 0.026). The use of calculated blood parameters, such as the serum or whole-blood non-CP Cu fraction, or the CP-to-serum Cu ratio, increased the correlation with the hepatic Cu concentration (r = 0.393, P = 0.001, in the case of whole-blood, non-CP Cu concentration), but the strength of the association remained insufficient for accurate prediction of hepatic Cu values. Likewise, hepatic enzyme (aspartate transaminase and gamma-glutamyltransferase) activities were significantly or nearly correlated significantly with hepatic Cu concentration, but the strength of the association remained too low for accurate prediction. It is concluded that direct analysis of Cu concentration in liver biopsy specimens--preferably postmortem liver samples obtained at slaughter--is the best technique currently available for detecting chronic subclinical Cu accumulation in cattle at risk for supraoptimal Cu exposure.     

The Productivity of Small Animal Species in Small-scale Mixed Farming Systems in Subtropical Bolivia

The productivity of the scavenging, small animal species (chickens, ducks, pigs, hair sheep and guinea-pigs) commonly found on small-scale farms at the forest margin in subtropical Bolivia was monitored over a full year. Chickens and guinea-pigs were kept mainly for home consumption, while ducks and pigs were kept mainly for sale. Sheep served both purposes, depending upon the family requirements. In the absence of veterinary treatment, the productivity varied greatly between farms. Pigs gave the greatest gross return, but received the largest amount of supplementary feed. Under the existing system, chickens, ducks and sheep all gave similar gross returns per breeding female, although chickens produced good returns and made a large contribution to the family diet where the reproductive efficiency was high and the chick mortality was low. Mortality resulting from disease was a major problem in poultry, while internal parasites appeared to be important limiting factors in pigs and sheep. Guinea-pigs showed no major problems apart from theft, and were an important dietary component for immigrant families from the highlands of the country. Small animal species have largely been ignored by agricultural research and development activities in Bolivia and elsewhere. They currently make significant contributions to the livelihoods of poor people in terms of both income and food security, and this could be greatly increased by simple improvements in animal husbandry.     

Development of a real-time SYBR Green PCR assay for the rapid detection of Dermatophilus congolensis

Methods such as real time (RT)-PCR have not been developed for the rapid detection and diagnosis of Dermatophilus (D.) congolensis infection. In the present study, a D. congolensis-specific SYBR Green RT-PCR assay was evaluated. The detection limit of the RT-PCR assay was 1 pg of DNA per PCR reaction. No cross-reaction with nucleic acids extracted from Pseudomonas aeruginosa, Mycobacterium tuberculosis, Staphylococcus aureus, or Austwickia chelonae was observed. Finally, the RT-PCR assay was used to evaluate clinical samples collected from naturally infected animals with D. congolensis. The results showed that this assay is a fast and reliable method for diagnosing dermatophilosis.     

Río de la Plata voyagers: Deciphering the migration ecology of a vulnerable marine catfish (Genidens barbus) in a large subtropical river (lower Uruguay River)

1. Genidens barbus is a vulnerable marine migrant catfish with low fecundity, a complex life cycle (i.e. mouth breeding), and is the target of industrial and artisanal fisheries of several countries. This species regularly migrates from marine to freshwater environments of the south-western Atlantic.
2. The aim of this work was to delve deeper into the migration ecology of G. barbus, characterizing both its timing and potential environmental drivers. Furthermore, aspects of the population structure and reproduction of migrants in the lower Uruguay River were studied and the presence of juveniles in the adjacent estuarine recruitment area was evaluated.
3. Data from 11 years (2008–2018) of records of adult G. barbus captured by artisanal fisheries were used alongside relevant environmental variables that were recorded monthly. Reproductive biology (i.e. sex ratio, gonadosomatic index, fecundity, and oocyte size) was analysed for a period of 3 years (2016–2018). The juvenile abundance in the Río de la Plata estuary was evaluated seasonally.
4. A total of 935 adult individuals of G. barbus were captured, representing a total biomass of 3,123 kg. The migration timing was from early spring to early summer. The abundance of migrants strongly increased with river discharge, suggesting that this variable regulates the upriver migration. Furthermore, pre- and post-spawn females and males displaying mouth breeding were recorded during the study period, confirming G. barbus reproduction in the lower Uruguay River.
5. The results obtained suggest that G. barbus ascend to spawn in the freshwater environments upstream from the mouth of the Uruguay River. Then, adult males incubate and carry the embryos downstream, releasing juveniles in the Río de la Plata estuary.
6. This relevant information will help with the implementation of effective management polices (e.g. fishing restrictions during the reproductive period) for the presently unregulated fishery of this vulnerable species in the lower Uruguay River.