Haemonchus spp. in sheep farmed under resource-poor conditions in South Africa--effect on haematocrit,conjunctival mucous membrane colour and body condition

A longitudinal study was conducted on the differential faecal egg counts, haematocrits and body condition scores of sheep belonging to resource-poor farmers at Rust de Winter, Gauteng province, and Kraaipan, North West Province, South Africa. The animals were scored for level of anaemia using the FAMACHA method, an assay for the clinical evaluation of anaemia caused by Haemonchus spp. Periods of higher Haemonchus egg counts occurred from October to March for sheep at Rust de Winter and from September/October to February or April for sheep at Kraaipan. Lower haematocrit values were registered during these periods as was a higher incidence of anaemic conjunctival mucous membrane colour scores compared to the period April to September. No clear relationship between the faecal egg counts and the body condition scores was evident. Although wider application of the FAMACHA system in sheep raised by resource-poor farmers should be investigated, the present study indicates that this method may certainly prove to be a valuable worm control strategy for such livestock owners.     

Transpiration-induced axial and radial tension gradients in trunks of Douglas-fir trees

We determined the axial and radial xylem tension gradients in trunks of young Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees. Axial specific conductivity (k(s-a)) and sap flux density (Js) were measured at four consecutive depths within the sapwood at a stem height of 1 m. By definition, at a given position in the bole, Js is a function not only of k(s-a) but also of the driving force for water movement. The Js:k(s-a) ratio was therefore used to estimate axial tension gradients and the radial gradients at a stem height of 1 m were calculated from the differences in axial tension gradients at each depth. Tracheid lumen diameter and tracheid length were used to predict differences in k(s-a) and its divergence from the theoretical k(s-a) determined by the Hagen Poisseuille equation. The ratio of k(s-a) (determined in the laboratory) to Js (measured in the field) varied with depth in the sapwood, resulting in non-uniform axial and radial tension gradients from inner to outer sapwood. Transpiration-induced axial tension gradients were in the range of 0.006-0.01 MPa m(-1) excluding the gravitational tension gradient. At a stem height of 1 m, radial tension gradients were in the range of 0.15-0.25 MPa m(-1) and were lower in the middle sapwood than in the inner or outer sapwood. Axial tension gradients were 44-50% higher in the outer sapwood than in the inner sapwood. At a stem height of 1 m, radial Js, calculated on the basis of radial tension gradients and measured radial specific conductivity (k(s-r)), was about two orders of magnitude smaller than axial Js. Our findings indicate that large radial tension gradients occur in the sapwood and clarify the role played by xylem k(s-a) and k(s-r) in determining in situ partitioning of Js in the axial and radial directions.     

Hepatic tyrosine aminotransferase and glucocorticoid abuse in meat cattle

Bertarelli, D., Balbo, A., Carletti, M., Cannizzo, T., Girolami, F., Nebbia, C. Hepatic tyrosine aminotransferase and glucocorticoid abuse in meat cattle. J. vet. Pharmacol. Therap.  35 , 596–603. Besides being extensively applied as therapeutical remedies, glucocorticoids (GCs) – most notably dexamethasone or prednisolone – are also illegally used in livestock for growth‐promoting purposes. This study was designed to assess the suitability of liver tyrosine aminotransferase (TAT), a gluconeogenic enzyme known to be induced by GCs, to act as a reliable candidate biomarker to screen for GC abuse in cattle. Enzyme activity was measured spectrophotometrically in liver cytosols or in cell extracts, and TAT gene expression was determined by real‐time PCR. Compared with untreated veal calves, a notable scatter (20‐fold) and much higher median values (3‐fold) characterized TAT specific activity in liver samples from commercially farmed veal calves. A time‐related increase in both enzyme activity and gene expression was detected in rat hepatoma cell lines treated with dexamethasone concentrations (10^?8 or 10^?9 m ) in the range of those recorded in noncompliant samples from EU official controls. In experimental studies in which finishing bulls were administered GCs at growth‐promoting dosages, however, no such changes were recorded in dexamethasone‐treated animals; a statistically significant rise in liver TAT activity (+95%) only occurred in prednisolone‐treated bulls. Although further research is needed to characterize the GC‐mediated response in cattle liver, TAT does not appear to be a specific and sensitive biomarker of GC abuse in the bovine species.     

Indirect measurement of blood pressure as a guide to the efficacy of fluid therapy in equine shock: A case report

A case of acute circulatory failure in a horse is described. The response to intravenous fluid therapy was monitored by measurement of heart and respiratory rates, and arterial and central venous pressures. Heart rate was an unreliable guide to improved circulatory status. Central venous pressure and indirect arterial blood pressure were valuable guides to the efficacy of fluid therapy.     

Preliminary Studies on the Concentration of Na+,K+-ATPase in Skeletal Muscle of Draught Cattle in Mozambique: Effect of Sex,Age and Training

The effect of training on the potential for work in draught cattle was assessed by measuring the Na⁺,K⁺-ATPase in the muscle cell membrane and the elevation in the concentration of K⁺ in plasma during exercise. Biopsies of the semitendinosus muscle and venous blood samples were taken from the cattle used for draught work in Mozambique. No differences were found in the plasma ion or Na⁺,K⁺-ATPase concentrations in samples taken from Nguni, Africander and Angoni breeds. There were no significant differences in plasma ions (Na⁺, K⁺ and Cl^–) or muscle Na⁺,K⁺-ATPase concentrations between the Angoni males and females, although the males showed an increase in Na⁺,K⁺-ATPase with age, while the females showed a decrease. The increase in males might be attributed to their higher level of activity in the herds than that of females. After a training period of 15 days, a significant increase in Na⁺,K⁺-ATPase concentration in semitendinosus muscle was found in Angoni cattle. In females, this was significant after 8 days of training (about 30%); in males after 15 days of training (about 16%). On day 15, there was a reduction in the elevation of plasma K⁺ during the 2 h of draught work, indicating an increased capacity of the Na⁺,K⁺ pumps to maintain the extracellular K⁺ concentration in working muscles and a possible delay in the moment of fatigue.     

Serologic survey of domestic felids in the Petén region of Guatemala.

Blood samples were analyzed from 30 domestic cats (Felis domesticus) from the Petén region of Guatemala to determine the seroprevalence of common pathogens that may pose a potential risk to native wild felids. Eight of the cats had been vaccinated previously; however, owners were unable to fully describe the type of vaccine and date of administration. In addition, blood samples were obtained from two captive margays (Leopardus wiedii). Samples were tested for antibodies to feline immunodeficiency virus, Dirofilaria immitis, feline panleukopenia virus, feline herpesvirus, feline coronavirus, canine distemper virus, and Toxoplasma gondii and for feline leukemia virus (FeLV) antigen. Fifty percent or more of the cats sampled were seropositive for feline herpesvirus (22 of 30), feline panleukopenia (15 of 30), and T. gondii (16 of 30). Five cats were positive for FeLV antigen. Both margays were seropositive for feline coronavirus and one was strongly seropositive to T. gondii. All animals were seronegative for D. immitis. This survey provides preliminary information about feline diseases endemic to the Petén region.     

Early detection of viral excretion from experimentally infected goats with peste-des-petits ruminants virus

We observed 15 goats for 9 days after subcutaneous infection with 10(3) TCID(50) with isolates of peste-des-petits ruminants virus from Africa and India and five concurrent, uninfected control goats. Typical clinical signs of the infection were present in all 15 infected goats by day 8 and in most by day 6 and some signs were present by day 4. However, 6 out of 15 goats already have detectable virus shedding by day 3 and four more were shedding by day 4 and every goat had virus shedding for at least 1 day before the recognition of clinical signs. This experiment indicates that incubatory carriers therefore might play a role in the transmission of PPRV among small ruminants.     

Dietary n‐3 highly unsaturated fatty acids affect the biological and serum biochemical parameters,tissue fatty acid profile,antioxidation status and expression of lipid‐metabolism‐related genes in grass carp,Ctenopharyngodon idellus

A 95‐day feeding trial was conducted to determine the effects of n‐3 highly unsaturated fatty acids (n‐3 HUFA) on the growth, antioxidation and lipid metabolism in grass carp (Ctenopharyngodon idellus). Two isonitrogenous and isolipidic diets were formulated with either lard oil (LO) or fish oil (FO) as the main lipid source. The results showed that the intraperitoneal fat (IPF) ratio was significantly lower (P < 0.05) in FO group. The concentration of n‐3 HUFA in muscle, hepatopancreas and IPF was significantly higher in FO group (P < 0.05). The serum low‐density lipoprotein (LDL) content was significantly lower (P < 0.05), and glucose (GLU) content was significantly higher (P < 0.05) in FO group. The serum total superoxide dismutase (T‐SOD) activity was significantly higher (P < 0.05) in FO group, consistent with the serum malondialdehyde (MDA) content. The gene expression of IPF fatty acid synthase (FAS), acetyl‐CoA carboxylase (ACC), sterol regulatory element‐binding protein (SREBP‐1) and peroxisome proliferator‐activated receptor γ (PPARγ) was significantly lower (P < 0.05) and that of peroxisome proliferator‐activated receptor α (PPARα) was significantly higher (P < 0.05) in FO group compared with LO group. Similar trends were found in the hepatopancreas, except for PPARγ. It is suggested that n‐3 HUFA could inhibit lipid accumulation in grass carp by affecting the expression of lipid‐metabolism‐related genes.     

Plasmodium vivax and Plasmodium falciparum infection in Neotropical primates in the western Amazon,Brazil

The Brazilian Amazon is endemic for malaria and natural infections by Plasmodium spp. have been detected in Neotropical primates. Despite the diversity of primate species in the region, studies on infections by these agents are limited. The aim of the present study was to investigate the frequency of infection by Plasmodium vivax and P. falciparum in free‐born primates that were kept in captivity, in the western Amazon, Brazil. Blood samples were collected from 98 Neotropical primates. Detection of P. vivax and P. falciparum DNA was performed using a semi‐nested PCR, and the amplified products were sequenced. Plasmodium spp. DNA was detected in 6.12% (6/98) of the primates. P. vivax, and P. falciparum DNA was detected in 2.04% (2/98) and 4.08% (4/98) of these mammals, respectively. Sequencing and phylogenetic analysis confirmed the results obtained from the semi‐nested PCR. The presence of infected non‐human primates (NHP) can be auxiliary in the maintenance of P. falciparum and P. vivax and may have implications for the malaria surveillance and control in the Brazilian Amazon. It is necessary to structure an efficient surveillance system for the aetiological agents of malaria that infect NHP and humans to reduce the risk of Plasmodium spp. introduction into new areas, to protect all susceptible species.