Soil loss in an olive grove in Central Spain under cover crops and tillage treatments,and farmer perceptions

Journal of Soils and Sediments - Soil erosion is a threat for the sustainability of the grove production all over the world, and olive groves are where the highest erosion is achieved. This study...     

Social behaviour of buffalo heifers during the establishment of a dominance hierarchy

This study investigated the social behaviour of buffalo heifers during the establishment of a dominance hierarchy under conditions that differed in space availability (pen, small pasture and large pasture), food competition and in the presence or absence of an intact bull. The herd consisted of 21 Mediterranean–Murrah crossbreed buffalo heifers and one bull. During the establishment of dominance hierarchy, one observer recorded all of agonistic interactions occurring in the pen, in the small pasture and in the large pasture. For the food competition test, the females were first separated into groups (G) of seven animals and the behavioural interactions within these groups were observed. The group levels were determined by the sociometric parameters (h′: Landau linearity index and DCI: directional consistency index). The percentage of unknown, one-way and two-way dyadic relationships; a social index, hierarchical position and correlations among feeding duration, latency, social index and hierarchical position were calculated. In the large pasture, the DCI value was 55.24% of the dyadic relationships were one-way and 36.19% were unknown; whereas in the small pasture and pen most of the dyads were unknown (54–63%) or one-way (33-41%). The social indexes observed were low (0.004 and 0.122). In the food competition test, h′ values were not significant for groups G1, G2, G3 and G6, and significant for Groups G4 and G5. The percentages of two-way dyadic relationships were high in G4 (80.95%) and G6 (100%) groups. Correlations among feeding duration and latency, social position and social index were all negative and significant. There were no significant correlations between body weight and social index or hierarchy position. This study showed that buffalo heifers established social dominance relationships among several of the herd members, but because there were several unknown dyads, the hierarchy is classified as semi-linear hierarchy. Two factors seemed to affect the establishment of social dominance and a hierarchy: adjusting to a new environment and the presence of an adult intact male, and the dominant females had advantage over the subordinate females during feeding in a trough. To reduce agonistic encounters between buffalo heifers suggest provide more space in the trough during feeding.     

Characterization of a pigeon paramyxovirus (PPMV-1) isolated from chickens in South Africa

A paramyxovirus with a thermostability of 60 min (typical of velogenic viruses) and a mean death time of > 90 h (typical of lentogenic viruses) was isolated from layers near Mooi River, South Africa. Our results, based on comparative nucleotide sequence data indicated that the virus is pigeon paramyxovirus 1 (PPMV-1), a variant of Newcastle disease virus. The F0 cleavage site contains a 112RRKKRF117 motif, and the virus had 98% sequence identity with PPMV-1 strains from the Far East. PPMV-1 was last reported in South Africa during the 1980s, with this being the first report of PPMV-1 isolated from chickens in South Africa.     

Seasonal changes in plasma concentrations of cecum-derived amines in clinically normal ponies and ponies predisposed to laminitis

OBJECTIVE: To measure concentrations of amines formed in the cecum of clinically normal ponies, determine amine concentrations in plasma samples collected in spring and winter, and compare concentrations of amines and serotonin in plasma samples obtained from clinically normal ponies and ponies predisposed to laminitis. SAMPLE POPULATION: Cecal contents obtained from 10 ponies euthanatized at an abattoir and blood samples obtained from 42 adult ponies. PROCEDURE: Cecal contents were assayed for amines by high-performance liquid chromatography (HPLC). Blood samples were collected at various times of the year from 20 ponies predisposed to acute laminitis and 22 clinically normal ponies. Plasma serotonin concentration was measured by HPLC, and tryptamine (TRP), tyramine (TYR), phenylethylamine (PEA), and isoamylamine (IAA) were measured by liquid chromatography-mass spectrometry. RESULTS: 15 amines were identified in cecal contents. Plasma TRP, TYR, PEA, and IAA concentrations ranged from 10pM to 100nM in both groups of ponies. Plasma concentrations of serotonin or other amines did not differ between clinically normal ponies and those predisposed to laminitis; however, significantly higher concentrations of TRP, PEA, and IAA were found in samples obtained in the spring, compared with winter samples. CONCLUSIONS AND CLINICAL RELEVANCE: Various amines are found in the cecum of ponies, several of which can be detected in the plasma. Concentrations increase significantly in the spring and may reach concentrations close to the threshold for causing vasoconstriction. Release of amines from the cecum into the systemic circulation may contribute to hemodynamic disturbances in horses and ponies with acute laminitis.     

Digital blood flow and plasma endothelin concentration in clinically endotoxemic horses

OBJECTIVE: To measure plasma endothelin-1 (ET-1) concentrations and digital blood flow in clinically endotoxemic horses. ANIMALS: 36 adult horses that underwent emergency celiotomy for primary gastrointestinal tract disease. PROCEDURE: On days 2 and 5 following surgery, Doppler ultrasonographic digital arterial blood flow measurements were obtained. Hematologic and biochemical analyses were performed, and plasma concentrations of ET-1 and endotoxin (lipopolysaccharide) were determined. A scoring system based on 9 clinical variables was used to assign horses to group B (quartile with greatest cumulative score) or group A (remaining 3 quartiles). Follow-up at 2.5 years was obtained by telephone questionnaire. RESULTS: For all horses on day 2, median (interquartile values) plasma ET-1 concentrations were 1.4 (0.8, 1.7) pg/mL, whereas on day 5, plasma ET-1 concentrations were 1.0 (0.5, 1.6) pg/mL. On day 2, digital blood flow was 0.057 (0.02, 0.07) mL/min in group A horses and 0.035 (0.02, 0.03) mL/min in group B horses. On day 5, plasma ET-1 concentration was significantly (73%) higher in group B horses, compared with group A horses. Thirty of 36 horses were alive at 2.5 years; group A horses were more likely to have survived (odds ratio, 25; 95% confidence interval, 2.4 to 262). Significant associations were found between an increase in digital pulses, hoof wall temperatures, or both and increased digital blood flow (0.14 vs 0.04 mL/min) on day 2 and increased digital arterial diameter (0.32 vs 0.23 cm) on day 5. CONCLUSIONS AND CLINICAL RELEVANCE: Horses with more severe endotoxemia had decreased digital blood flow, increased plasma ET-1 concentrations, and decreased long-term survival.     

Contamination of dog hair with eggs of Toxocara canis

Toxocara canis, the common intestinal nematode of dogs and foxes, is the parasite responsible for human toxocarosis. It has recently been shown that dogs may harbour eggs of the parasite in their fur. To further investigate this claim a population of 100 stray dogs was examined to establish the prevalence and intensity of adult toxocaral worm infection in the intestines and eggs harboured in the hair. A novel method of washing the eggs from the hair was used. Sixty-seven percent of dogs were found to have T. canis eggs on their hair with a mean egg retrieval of nearly 584 eggs per gram from positive dogs. The age of the dog was found to be the only significant factor to influence the prevalence and intensity of eggs, with 95% of all the eggs recovered found on puppies. Thirty-nine percent of dogs were found to have adult T. canis worms in their intestine, although a significantly higher percentage of puppies (80%) were infected with worms than adults (22.5%). Puppies also had more worms per infection than adults and have a strong positive correlation between egg and worms numbers whereas adults did not. These studies show that stray dogs, particularly puppies, potentially harbour considerable numbers of eggs on their hair, at densities far higher than those reported in the soil or the general environment.