Health and Survival of Red Abalone Haliotis rufescens from San Miguel Island,California, USA,in a Laboratory Simulation of La Niña and El Niño Conditions

Abstract

The variability in Southern California's marine climate is dominated by the El Niño–Southern Oscillation, with cycling between El Niño events (characterized by warm water, low productivity, and frequent storms) and La Niña events (which exhibit the opposite conditions). Relative to the mainland and other Channel Islands, San Miguel Island (SMI) consistently maintains cooler water temperatures and supports significant populations of red abalone Haliotis rufescens, presumably owing to increased food production and diminished expression of the bacterial disease known as withering syndrome. We conducted a laboratory experiment to examine the effects of La Niña and El Niño conditions on the health and survival of red abalone from SMI. Six replicate tanks per treatment, each containing six abalone, were subjected to one of the following three temperature regimes (treatments): Bodega Bay, California ambient (AMB; mean, 11.4°C), SMI La Niña regime (LAN; mean, 13.8°C), and SMI El Niño regime (ELN; mean, 16.5°C). After 328 d, survival in the ELN treatment was significantly lower than in the AMB and LAN groups. A body condition index was significantly lower in the ELN group than in the AMB group, and the LAN group was in between. A visual score of body shrinkage was significantly higher in both the LAN and ELN groups than in the AMB group. Other clinical signs of withering syndrome and the prevalence and infection intensity of the causative agent, Candidatus Xenohaliotis californiensis, increased as temperature increased in the three treatment groups from AMB to LAN to ELN, although the differences were not statistically significant. Generally, we found that increased temperature resulted in elevated disease expression, although less than observed in previous studies that used farmed abalone and higher, less variable temperature regimes. Water temperature modulates the effect of withering syndrome in wild red abalone, and very strong El Niño events are predicted to result in significant mortality at San Miguel Island.

Received September 10, 2010; accepted December 16, 2010     

Effect of the El Niño phenomenon on the ovarian responsiveness and embryo production of donor cows

The effects of different Temperature Humidity Index (THI) values in cold, hot and El Ni?o (EN) climates on superovulation and embryo production were analysed on Holstein Friesian donor cows. There were significant differences in the THI among the three climates. The average temperature in the EN period was 6 degrees C higher than in the summer period of the previous 30 years. The number of corpora lutea (CL) and embryos were log- and back-transformed, Kolmogorov-Smirnoff test was used for normality and Lilliefors test was applied for significance. In the cold season THI was 70.74 +/- 1.35 and the average number of CL was 9.84 +/- 4.37. In the hot season the THI was 73.99 +/- 0.72 and the average number of CL was 9.70 +/- 4.49. When the THI, in the EN period, increased up to 79.74 +/- 4.01, the superovulation response was significantly (P < 0.01) reduced (average number of CL = 5.22 +/- 2.53). The embryo production result showed a similar tendency. In the hot period the average number of embryos obtained was 5.87 +/- 2.98. However, in the EN period it decreased to 4.21 +/- 2.05. Higher temperature reduced embryo quality. The proportion of live embryos (%) was 59.2 +/- 37.4 in the cold and 38.2 +/- 38.5 in the EN periods of the year (P < 0.01). However, ovarian sensitiveness showed adaptation to summer environment while the heat stress, which was more severe in the EN period, negatively affected the superovulation response and embryo production.     

East Coast fever and multiple El Niño Southern oscillation ranks

East Coast fever (ECF), a tick-borne disease of cattle, is a major constraint to livestock development in Africa in general and southern Zambia in particular. Understanding the transmission patterns of this disease complex is very difficult as shown by previous studies in southern and eastern Zambia due to the interplay of risk factors. In this long-term study, we investigated whether global weather changes had any influence on disease transmission in traditionally kept cattle in southern Zambia. The results from this study show a strong association between increased Theileriaparva contacts in cattle and the presence of El Niño, clearly linking a simple climatic index to disease outbreaks. We therefore propose that in southern Zambia, the simple and readily available multiple El Niño Southern oscillation index (MEI) ranks be used in planning ECF control programmes and early warning.     

Comparative pharmacokinetics and a clinical laboratory evaluation of intravenous acetaminophen in Beagle and Galgo Español dogs

Objective

To assess the pharmacokinetics (PK) and conduct a clinical laboratory evaluation of acetaminophen in Beagle and Galgo Español (GE) dogs.

Intestinal parasitism in the animals of the zoological garden "Peña Escrita" (Almuñecar, Spain)

Gastrointestinal parasites cause serious diarrhoea in captive animals. Therefore, we have undertaken this study to establish programmes to prevent, control, and treat intestinal parasitism in the animals of the zoological garden "Pe?a Escrita" of Almu?ecar (Granada). An annual survey was conduced to estimate the occurrence of gastrointestinal parasites and the seasonality of this parasitism. Between June 2006 and May 2007, 432 samples were collected from primates, carnivores, perissoodactyla, artiodactyla, rodentia, diprotodontia, galliformes, anseriformes and struthioniformes. One or more intestinal parasites were identified in 72.5% of the animals. The most frequent pathogenic endoparasites were Eimeria spp. (17.3%), Trichuris spp. (5.1%), Strongyloides spp. (4.5%), Cyclospora spp. (4.5%), Cryptosporidium spp. (3.2%) and Isospora spp. (2.6%). Iodamoeba butschlii, Parascaris equorum and Trichuris spp. did not vary with season and Cryptosporidium spp., Dicrocoelium dendriticum, Metastrongylus spp. and Cylicospirura spp. appeared exclusively in Artiodactyla. Multiple parasitic infections were common, 70% of animals presented with at least two parasites (maximum=6). The most frequent cases of multiple parasitism were Eimeria spp. plus Blastocystis spp. and Eimeria spp. plus Nematodirus spp., in the last case the animals presented explosive diarrhoea. In accord with our results, after each sampling, some of the affected animals were treated and the corresponding programmes of prevention and control were designed.     

Discovery and molecular characterization of a group A rotavirus strain detected in an Argentinean vicuña (Vicugna vicugna)

The wild vicuña (Vicugna vicugna) is one of the four species of native South American camelids (SACs) in addition to the wild guanaco, and their domesticated counterparts, alpaca and llama, respectively. Serological data have indicated the presence of group A rotaviruses (RVA) specific antibodies in all 4 members of the SAC, and so far, RVA has been detected from alpacas, llamas and guanacos. A total of 59 fecal samples from healthy wild newborn and juvenile vicuñas, raised in captivity in Jujuy, Argentina were collected and analyzed by ELISA to detect RVA antigen. Two samples (3%) were found to contain G8 RVA strains and one strain (RVA/Vicuña-wt/ARG/C75/2010/G8P[14]) was selected for further genome analyses, revealing the G8-P[14]-I2-R2-C2-M2-Ax-N2-T6-E3-Hx genotype constellation. Unfortunately, no sequence data could be obtained for NSP1 and NSP5. Except for the E3 NSP4 genotype, this partial genotype constellation is reminiscent to bovine RVA strains and bovine-like RVA strains isolated from sheep, guanaco, antelope and humans. This relationship was confirmed phylogenetically, providing further evidence of the widespread presence of this genotype constellation in animals belonging to the artiodactyls. In particular, a close phylogenetic relationship was found between C75 and guanaco RVA strain RVA/Guanaco-wt/ARG/Chubut/1999/G8P[14] for at least 5 gene segments, suggesting a partial conservation of the genotype constellation of RVA strains infecting different species of SACs, even though nowadays their natural habitats are not overlapping. The further monitoring of the sanitary health of wild newborn and juvenile vicuñas is essential to improve the management practices applied in their sustainable exploitation.     

Historical and Modern Disturbance Regimes,Stand Structures,and Landscape Dynamics in Piñon–Juniper Vegetation of the Western United States

Piñon–juniper is a major vegetation type in western North America. Effective management of these ecosystems has been hindered by inadequate understanding of 1) the variability in ecosystem structure and ecological processes that exists among the diverse combinations of piñons, junipers, and associated shrubs, herbs, and soil organisms; 2) the prehistoric and historic disturbance regimes; and 3) the mechanisms driving changes in vegetation structure and composition during the past 150 yr. This article summarizes what we know (and don't know) about three fundamentally different kinds of piñon–juniper vegetation. Persistent woodlands are found where local soils, climate, and disturbance regimes are favorable for piñon, juniper, or a mix of both; fires have always been infrequent in these woodlands. Piñon–juniper savannas are found where local soils and climate are suitable for both trees and grasses; it is logical that low-severity fires may have maintained low tree densities before disruption of fire regimes following Euro-American settlement, but information is insufficient to support any confident statements about historical disturbance regimes in these savannas. Wooded shrublands are found where local soils and climate support a shrub community, but trees can increase during moist climatic conditions and periods without disturbance and decrease during droughts and following disturbance. Dramatic increases in tree density have occurred in portions of all three types of piñon–juniper vegetation, although equally dramatic mortality events have also occurred in some areas. The potential mechanisms driving increases in tree density—such as recovery from past disturbance, natural range expansion, livestock grazing, fire exclusion, climatic variability, and CO₂ fertilization—generally have not received enough empirical or experimental investigation to predict which is most important in any given location. The intent of this synthesis is 1) to provide a source of information for managers and policy makers; and 2) to stimulate researchers to address the most important unanswered questions.     

A note on the population structure of the Avileña breed of cattle in Spain

The objective of this study was to describe the population structure of the Avileña breed considering the flow of genes between herds, effective number of herds and generation intervals. Characteristics of the breed which modify either the increase of level of inbreeding or the hierarchical structure of the population were also considered.     

Reversible chemical restraint of free-range cattle with a concentrated combination of tiletamine–zolazepam,ketamine, and detomidine

The aim of this study was to determine the efficacy of a concentrated combination of tiletamine–zolazepam [TZ, 0.53 mg/kg body weight (BW)], ketamine (Ket, 0.53 mg/kg BW), and detomidine (Det, 0.04 mg/kg BW) in the immobilization of free-range cattle for clinical procedures. The combination was administered intramuscularly to 53 animals. Anesthesia was reversed with the α₂-adrenoceptor antagonist atipamezole. Locoregional anesthesia was provided with lidocaine when required. The TZKD combination induced suitable immobilization for minor surgical procedures or medical treatments. Anesthetic onset was rapid, taking a mean of 6.1 min [standard deviation (SD) 2.8 min]. The duration of anesthesia depended on the time of administration of the antagonist; the animals recovered in the standing position in 12.9 ± 8.9 min after the administration of atipamezole. The quality of anesthesia and analgesia were satisfactory. In conclusion, this TZKD combination can be used for both immobilization and minor surgical procedures in free-range cattle.     

Expression of α-transducin,a chemoreceptive molecule,in endocrine and non-endocrine cells of the pig gastrointestinal tract

Veterinary Research Communications -     

Incidence and knowledge of bovine brucellosis in Kahuro district,Murang’a County,Kenya

Brucellosis in cattle is a zoonosis mainly caused by Brucella abortus. In Kenya, the disease is widespread, but its prevalence is largely unknown. The objective of this study was to investigate incidence rates of brucellosis and farmers’ knowledge on the disease in Kahuro district, Murang’a County. In this study, 150 pooled milk samples were collected from 75 milk collection centers and tested. Subsequently, 230 milk samples were collected from farmers in 16 collection centers in Wangu and Mugoiri divisions whose pooled samples gave positive results. Five cow owners in each of the 16 collection centers were interviewed using a questionnaire to assess their knowledge levels. Wangu division had the highest incidence rate 19% with positive samples observed from 14 collection centers. Mugoiri division recorded 3% with two collection centers having positive samples, while Murarandia had none. All respondents with no formal education were unaware of the causative agent of brucellosis. There was a significant difference in incidence between Mugoiri and Wangu divisions (p < 0.05). Knowledge levels were high in the young and educated farmers compared to the old and uneducated. Frequent screening for brucellosis to identify infected animals should be initiated thus prevent transmission to other animals and humans.     

Trichostrongyle worm infection in cattle: Ostertagiasis—Effect of a field outbreak on production,with a review of the disease syndromes,problems of diagnosis and treatment

Extract

The problem of parasitism in cattle in New Zealand has been largely neglected, except in acute disease outbreaks. Losses, apparently due to chronic or subclinical parasitic gastro-enteritis, have been either undiagnosed or ignored, or the measures required to prevent these losses have been considered uneconomic or impractical. This latter view can perhaps be attributed to the low efficacy of anthelmintics previously available. Now, at a time when greatly improved standards of prophylaxis and treatment are offered by the new broad-spectrum anthelmintics, new difficulties in control have become apparent.     

Age associated changes in sodium,potassium and moisture contents of Turkey skeletal muscles and a note on the effects of testosterone and 17‐β‐oestradiol

1. Sodium concentration declined and potassium concentration increased sharply in turkey skeletal muscles during the first 3 weeks of life.

2. Testosterone and 17‐β‐oestradiol implantation of 2‐d‐old male turkeys resulted in increased moisture and Na concentrations in leg muscle.

3. Testosterone but not 17‐β‐oestradiol implantation also increased the moisture content of breast muscle.     

Utilizing National Agriculture Imagery Program Data to Estimate Tree Cover and Biomass of Piñon and Juniper Woodlands

With the encroachment of piñon (Pinus ssp.) and juniper (Juniperus ssp.) woodlands onto sagebrush steppe rangelands, there is an increasing interest in rapid, accurate, and inexpensive quantification methods to estimate tree canopy cover and aboveground biomass. The objectives of this study were 1) to evaluate the relationship and agreement of piñon and juniper (P-J) canopy cover estimates, using object-based image analysis (OBIA) techniques and National Agriculture Imagery Program (NAIP, 1-m pixel resolution) imagery with ground measurements, and 2) to investigate the relationship between remotely-sensed P-J canopy cover and ground-measured aboveground biomass. For the OBIA, we used eCognition® Developer 8.8 software to extract tree canopy cover from NAIP imagery across 12 P-J woodlands within the Sagebrush Steppe Treatment Evaluation Project (SageSTEP) network. The P-J woodlands were categorized based on the dominant tree species found at the individual sites for the analysis (western juniper, Utah juniper, and mixed P-J community). Following tree canopy cover extractions, relationships were assessed between remotely-sensed canopy cover and ground-measured aboveground biomass. Our OBIA estimates for P-J canopy cover were highly correlated with ground-measured tree canopy cover (averaged across all regions r = 0.92). However, differences between methods occurred for western and Utah juniper sites (P < 0.05), and were more prominent where tree canopy cover was > 40%. There were high degrees of correlation between predicted aboveground biomass estimates with the use of remotely-sensed tree canopy cover and ground-measured aboveground biomass (averaged across all regions r = 0.89). Our results suggest that OBIA methods combined with NAIP imagery can provide land managers with quantitative data that can be used to evaluate P-J woodland cover and aboveground biomass rapidly, on broad scales. Although some accuracy and precision may be lost when utilizing aerial imagery to identify P-J canopy cover and aboveground biomass, it is a reasonable alternative to ground monitoring and inventory practices.     

Effects of tea saponins on rumen microbiota,rumen fermentation,methane production and growth performance—a review

Reducing methane emission from ruminant animals has implications not only for global environmental protection but also for efficient animal production. Tea saponins (TS) extracted from seeds, leaves or roots of tea plant are pentacyclic triterpenes. They have a lasting antiprotozoal effect, but little effect on the methanogen population in sheep. There was no significant correlation between the protozoa counts and methanogens. The TS decreased methanogen activity. It seems that TS influenced the activity of the methanogens indirectly via the depressed ciliate protozoal population. The TS addition decreased fungal population in the medium containing rumen liquor in in vitro fermentation, but no such effect was observed in the rumen liquor of sheep fed TS. Tea saponins had a minor effect on the pattern of rumen fermentation and hence on nutrient digestion. When added at 3 g/day in diets, TS could improve daily weight gain and feed efficiency in goats. No positive associative effect existed between TS and disodium fumarate or soybean oil on methane suppression. Inclusion of TS in diets may be an effective way for improving feed efficiency in ruminants.     

Enhanced expression of TGFβ protein in lymphoid organs and lung, but not in serum, of pigs infected with a European field isolate of porcine reproductive and respiratory syndrome virus

Transforming growth factor β (TGFβ) is an immunomodulatory cytokine which is able to modulate the host immune response eliciting an inefficient response against pathogens. In this sense, the role of this cytokine in porcine reproductive and respiratory syndrome (PRRS) has been poorly studied and the reported results are contradictory. Thus, in the present study, the expression of TGFβ was analysed both at tissue (lymphoid organs and lung) and serum level to study its correlation with the expression of PRRS virus (PRRSV). To carry out this study, 32 pigs were inoculated with the European PRRSV field isolate 2982 and sequentially killed from 0 dpi to the end of the study (24 dpi). Blood and tissue samples were collected to determine the expression of PRRSV and TGFβ. PRRSV was detected in inoculated animals from 3 dpi until the end of the study, however TGFβ was not detected in sera from inoculated animals. Contrary, an increase of TGFβ antigen was observed both in the lymphoid organs and in the lung of PRRSV-inoculated pigs when compared with control group. Since TGFβ play a role as an immunomodulatory cytokine of the immune response and also in the differentiation of regulatory T cells (Tregs), the upregulation of the TGFβ at tissue level may play a role in the impairment of the host immune response observed during PRRS, being observed a significant correlation between PRRSV and TGFβ expression at lung level.