Voluntary feed intake and leptin sensitivity in ad libitum fed obese ponies following a period of restricted feeding: a pilot study

The relation between plasma leptin and daily ad libitum roughage intake was evaluated during a 14‐day period in eight obese Shetland ponies. When the feeding strategy was changed from maintenance feeding to ad libitum feeding, feed intake increased the first day, decreased the second day and increased again during the following days to reach a constant level after 8 days. Plasma leptin concentration increased during the first 2 days, but remained constant afterwards. Although the same pattern was found in all ponies, the magnitude of the increase in leptin on day 1 and the resulting decrease in feed intake on day 2 differed between ponies. A lower anorectic effect was seen in ponies with higher initial leptin concentration, suggesting the presence of different degrees in leptin sensitivity in obese ponies. High leptin production in a attempt to compensate for the decrease in leptin sensitivity might explain large variations in plasma leptin among obese ponies with similar body condition score. Further research is necessary to clarify whether the reduced leptin sensitivity precedes obesity in equines or vice versa.     

Genetic connectedness between seven European countries for performance in jumping competitions of warmblood riding horses

The aim of this study was to evaluate the genetic connectedness between seven European populations of show jumping horses. Data on stallions bred for jumping and their pedigree up to three generations were provided by seven countries, including 6317 stallions and 22 324 different horses. Four different methods were used to estimate the genetic connectedness. Common stallions between countries varied from 0 to 308 and common horses from 130 to 1166. “Genetic similarities” were not the optimal measure of connectedness as number of progeny by country by stallion was not balanced. Correlation between estimates of country effects was computed in a mixed model including the genetic value of horses (h² = 0.20, all relationships included). For Germany, Belgium, France and The Netherlands, these correlations were 0.32 to 0.51 corresponding to a balanced scheme with 11 to 19 progeny per stallion per country. Other correlations ranged from 0.08 to 0.27. Another method to evaluate the connectedness was (i) to simulate a systematic difference between the true genetic level of countries, (ii) performing a BLUP and (iii) measuring the percentage of the initial difference that could be found between the estimated genetic levels of the corresponding countries. In 50% of the country pairs, 50% or more of the initial genetic difference was estimated. It was concluded that the genetic connectedness will allow the estimation of genetic correlations.     

The effect of oligofructose and inulin on faecal characteristics and nutrient digestibility in healthy cats

The effects on faecal characteristics of different concentrations of oligofructose (0, 3, 6 and 9%) were investigated. The 6 and 9% supplemented groups differed significantly compared with the control group in almost all faecal characteristics. There were no significant differences regarding the macroscopical and chemical aspects of the faeces between the control and the 3% supplemented group. There was a trend for a lower pH of the faeces in the 3% supplemented group, suggesting a substantial effect on the faecal composition. In a second experiment, the effects of oligofructose (3%) and inulin (3 and 6%) on digestibility parameters were tested. In the supplemented groups the apparent protein digestibility was lower but this was due to a higher bacterial nitrogen content of the faeces. There were no significant differences between 3% inulin and oligofructose, although oligofructose seemed to be more easily fermentable, because of a trend to a higher concentration of short chain fatty acids (SCFA) in the faeces of the oligofructose group.     

Digestibility of a complete ration in horses fed once or three times a day and correlation with key blood parameters

To determine the influence of feeding frequency on apparent digestibility and blood metabolites in horses, four geldings were fed a complete ration either once (at 08:00 h) or three times a day (at 08:00, 13:00 and 18:00 h). Horses were provided with a mixture of cereals and chopped alfalfa hay at maintenance level for energy supply, 344 kJ/kg BW(0.75) on a daily basis. After three weeks' adaptation, total amounts of faeces and urine were collected for five days, using collection harnesses. Serial blood samples were taken at -30, -15, 0, 5, 15, 30, 45, 60, 90, 120, 180, 240, 300, 360, 480 and 600 min after feeding and analysed for glucose, L-lactate, triglycerides (TG), non-esterified free fatty acids (NEFA) and triiodothyronine (T(3)). Apparent digestibility coefficients of dry matter (DM), crude protein (CP), ether extract (EE), crude fibre (CF), ash and nitrogen-free extract (NFE) were not significantly different (P>0.05) between the two feeding frequencies. Basal plasma glucose, plasma glucose curves and other plasma blood metabolites were not affected by meal frequency. The horses fed the whole ration in one morning feeding did not consume the entire meal at once, but spared feed for ingestion throughout the day, which may explain the lack of effect. Feeding frequency did not affect plasma glucose response (area under curve :AUC) (P=0.705), but AUC (glucose) was negatively correlated with CP (R(2)=0.76; P=0.005) and CF digestibility (R(2)=0.61; P=0.022). Further research is needed to clarify whether different endocrine responses or differences in passage rate can explain these correlations.     

Zinc distribution and speciation within rocket plants (Eruca vesicaria L. Cavalieri) grown on a polluted soil amended with compost as determined by XRF microtomography and micro-XANES

Zinc distribution and speciation within different organs (root, petiole, and leaf) of the edible plant Eruca vesicaria L. Cavalieri were determined using synchrotron microbeam X-ray techniques (XRF microtomography and mu-XANES) for plants grown in polluted soil with or without compost amendment. Data on soil derived from different extraction procedures and using mu-XANES analyses on rhizospheric soil indicated that compost amendment did not significantly influence the Zn speciation and availability in soil. However, major differences were observed within the plants. Plants grown in the presence of compost were able to partly block zinc immediately outside the root endodermis in the form of zinc-phytate, while a smaller Zn fraction was allowed to xylem transport as zinc-citrate. In the leaves, zinc was largely excluded from leaf cells, and about approximately 50% was in the form of phosphate precipitates, and the other 50% was complexed by cysteine and histidine residues. The reported data provide new information concerning the mechanisms of zinc tolerance in E. vesicaria L. Cavalieri, a very common edible plant in Mediterranean regions, and on the role of compost in influencing the molecular strategies involved in zinc uptake and detoxification.