Effect of fat supplementation on leptin, insulin-like growth factor I, growth hormone, and insulin in cattle

We investigated the effect of fat supplementation on plasma levels of hormones related to metabolism, with special attention to leptin, in cows in early lactation and in feedlot steers. In experiment 1, 34 lactating cows received no fat or else 0.5 or 1.0 kg of partially hydrogenated oil per day in addition to their basal diet from day 20 before the expected calving date to day 70 postpartum. In experiment 2, part of the corn in the basal concentrate was replaced with 0.7 kg of the same oil such that the diets were isocaloric; 18 cows received the fat-substituted diet and 18 a control diet from day 20 before the expected calving date to day 75 postpartum. In experiment 3, calcium salts of fatty acids were added to the basal diet of 14 feedlot steers for 80 d; another 14 steers received a control diet. The basal plasma levels of leptin were higher in the cows than in the steers. Dietary fat supplementation did not affect the leptin levels in the lactating cows but lowered the levels in the feedlot steers despite greater energy intake and body fatness (body weight) in the steers receiving the supplement than in those receiving the control diet. The levels of insulin-like growth factor I and insulin were decreased with dietary fat supplementation in the lactating cows but were unaffected in the steers, suggesting that responses to fat ingestion depend on the physiological state of the animal, including age and sex. Finally, no effects of supplementary fat on the level of growth hormone were demonstrated in any of the models.     

The effects of two dosages of midazolam on short-duration anesthesia in the harp seal (Phoca groenlandica).

The purpose of this study was to provide safe anesthesia for bronchoalveolar lavage and assess the utility of premedication with i.m. midazolam for short-duration anesthesia with isoflurane in harp seals (Phoca groenlandica). Fourteen yearling harp seal pups were anesthetized three times each as part of a prospective, cross-over, blinded study. Each animal received i.m. premedication with saline, low-dose, or high-dose midazolam (respectively 0.1 and 0.2 mg/ kg). Following premedication, anesthesia was induced with 4% isoflurane in oxygen delivered through a mask and connected to a Bain non-rebreathing system. A significantly longer time was taken from the end of general anesthesia to head movement in the high-dose group compared with the saline group (P = 0.002). A significantly longer time was taken from the end of general anesthesia to ambulation in the high-dose group compared with the saline group (P = 0.006). There were no significant differences between groups in the subjective assessment of anesthetic quality or ease of intubation. Premedication with i.m. midazolam at the dosages used did prolong recovery from anesthesia, although to a degree unlikely to be significant clinically.     

Long-term evaluation of compliance with refuge requirements for Bt cotton

The success of the refuge strategy for delaying pest resistance to Bt crops depends on compliance by farmers. However, the accuracy of previous estimates of compliance has been questioned. We have applied a novel approach based on the use of Geographical Information System (GIS) technology to measure compliance with refuge requirements for Bt cotton in six Arizona regions from 1998 to 2003. Although compliance varied among regions, overall compliance was above 88% in five of six years. With the cooperation of farmers, our approach allows precise and economical assessment of compliance with the refuge strategy.     

Palatal sclerotherapy: a potentially useful treatment of intermittent dorsal displacement of the soft palate in juvenile standardbred racehorses

This study was aimed at evaluating the tolerability and the efficacy of palatal sclerotherapy in juvenile standardbred racehorses with easily audible "snoring-like" respiratory noises suspected to be the result of intermittent dorsal displacement of the soft palate. The palate of 8 horses was injected with sodium tetradecyl sulfate under videoendoscopic guidance. Palatal sclerotherapy resulted in resolution of the respiratory noise in 7 horses, improvement of performance in 6 horses, and mild side effects in only 3 horses. This preliminary study suggests that palatal sclerotherapy is a safe, repeatable, inexpensive, and promising technique that should be considered as an alternative to existing treatments of intermittent dorsal displacement of the soft palate.     

Plasma leptin, feed intake and body fat accumulation in fattening castrated male and female lambs

The main objective of this study was to investigate the relationships between changes in plasma leptin concentration and feed intake or bodyweight in female and castrated male lambs with fattening. Four female and four castrated male lambs were used and were fed roughage and concentrate supplemented with beef tallow ad libitum for 28 weeks. Although the feed intake and bodyweight increased with fattening in both the castrated male and female lambs, they decreased at 24–28 weeks in the female lambs. At the end of fattening, the crude fat content in the muscle (loin) of the female lambs was significantly higher than in the castrated male lambs (P < 0.05), while the crude protein content in the loin and fillet meat was higher in the castrated male than in the female lambs (P < 0.05). The plasma leptin concentration showed high values at a later stage of fattening (P < 0.05). In the female lambs the plasma insulin concentration increased at a later stage of fattening (P < 0.05) and was positively correlated (P < 0.0001, r = 0.78) with plasma leptin. Plasma metabolites (glucose, nonesterified fatty acid, total cholesterol and triglyceride) concentrations were also changed with fattening. Plasma total cholesterol was positively related to plasma leptin, more closely in the female than in the castrated male lambs (in females, r = 0.63, P < 0.001; in males, r = 0.38, P < 0.01). The accumulation of body fat was probably accelerated by the consumption of a lot of concentrate feed supplemented with treated beef tallow and by the stimulation of insulin with fattening. Consequently, the plasma leptin concentration increased, especially toward the end of the fattening period. The decrease in feed intake and bodyweight after the 24th week of fattening was possibly caused by an increase in leptin that is involved in the homeostatic regulation of body energy by regulating appetite.     

Impact of Paris Waste Upon the Chlorinated Solvent Concentrations of the River Seine (France)

The occurrence of twelve chlorinated and brominated volatile compounds was investigated by a HRGC (High Resolution Gas Chromatography) device with a dynamic purge (PTI, Chrompack) in the water of the river Seine under dry conditions and under contrasting hydrological regimes, according to three longitudinal profiles from upstream to downstream of the Paris urban centre. Our results showed an obvious rise of the solvent concentrations in the river Seine water along the profiles. The total chlorinated solvent concentration, which was below 1 μg L^-1 upstream of Paris, reached a maximum value of 8 μg L^-1 dowstream of the urban centre in December 1994. This corresponded to a flux of around 300 kg d^-1. This contamination originated in successive waste inputs, both domestic and industrial, from the Paris main sewers. The losses by evaporation from the river were taken into account for the estimation of the waste. The waste inputs represented about 85 to 97% of the total chlorinated solvent flux observed downstream of Paris. During the two first sampling sessions, dichloromethane represented 67% of the inputs. Though the hydrological regime plays a part both in the waste dilution and in the losses by evaporation processes, other factors such as the industrial activities or the ambient temperature may have a major influence upon the river contamination.     

Intra- and interspecific diversity in the response to waterlogging of two co-occurring white oak species (Quercus robur and Q. petraea)

Quercus robur L. and Quercus petraea (Matt.) Liebl. are sympatric oak species with different ecological requirements. Quercus robur is more tolerant to waterlogging than Q. petraea. This ecological divergence may play a role in the maintenance of the two species despite the absence of an insurmountable reproductive barrier between them. We predicted that the genetic architecture of traits related to waterlogging tolerance differs between the species. To gain insight into this architecture in the absence of genetic markers for waterlogging tolerance, we compared populations of seedlings of each species for diversity in the expression of quantitative phenotypic traits induced by severe hypoxia. To determine the capacity for hypertrophied lenticel formation, we applied gas-impermeable mastic to stems of seedlings. Two months after application, the mastic treatment had induced the formation of 3 (+/- 2) cm(-2) hypertrophied lenticels in the absence of root hypoxia. Leaf epinasty during root hypoxia was an early predictor of seedling mortality. Four weeks of waterlogging resulted in greater epinasty in Q. petraea than in Q. robur, but fewer hypertrophied lenticels (16 +/- 6 versus 21 +/- 9 cm(-2)) and adventitious roots (2.7 +/- 4.7 versus 5.2 +/- 5.9). Differences between species in these traits were associated with differences in the frequencies of extreme phenotypes rather than with a generally higher tolerance to waterlogging in Q. robur seedlings.