In vitro gas production kinetics and short-chain fatty acid production from rumen incubation of diets supplemented with hop cones (Humulus lupulus L.).

The aim of this study was to assess the effects of hop cones (Humulus lupulus L.) from two varieties Aurora and Dana, differing in their α- and ß-acid contents, on rumen microbial activity measured with in vitro gas production kinetics and short-chain fatty acids (SCFA) production. Hop cones were added to the total mixed dairy cow ration (CONT) in concentrations simulating a cow's daily intake of 50, 100 and 200 g of hop cones - the concentrations of hop cones expressed on a substrate basis were 43, 82 and 153 mg/g of substrate. Substrates were anaerobically incubated in glass syringes, and gas production kinetic parameters were determined by fitting data with the Gompertz model. Gas produced after 24 h (Gas24), maximum fermentation rate (MFR) and time of maximum fermentation rate (TMFR) were calculated from the estimated gas production kinetic parameters. After 24 h of incubation, the fermentation liquids of each substrate were taken for the determination of SCFA. Increasing the hop cone concentration decreased the total potential gas production, Gas24, MFR and shortened TMFR. The highest hop cone concentration significantly decreased acetic and butyric acid productions and total SCFA production after 24 h of incubation, but not propionic acid production, resulting in a decreased ratio between acetic acid and propionic acid.

Use of milk fatty acids composition to discriminate area of origin of bulk milk.

The fatty acid composition of cow milk, collected in a survey from 19 dairy farms in the border area between Italy and Slovenia, was investigated for 2 consecutive years (2005 and 2006) to assess the possibility of discriminating the area of the origin of the milk. Farms were selected based on diet, animal breed, and farm management to represent the local variability of the systems. In Slovenian farms, grass silage and hay prevailed over corn silage and concentrate feeds, whereas in Italian farms, hay and concentrates were the predominant components of the diet. Fifty-three fatty acids were separated and quantified in Italian and Slovenian milks. Saturated fatty acids represented the most abundant class, followed by monounsaturated and polyunsaturated fatty acids. Significant differences were observed between Italian and Slovenian milks for the concentration of 40 fatty acids, whereas significant differences were observed between years of production for 15 fatty acids. Discriminant analysis was used to identify a classification criterion of milk, using country and year of production as grouping variables. Considering statistical results and the scatter plot of the scores of the first 2 functions, the best discriminant criteria were those based on unsaturated fatty acids and on fatty acids with several carbon atoms >or=18.

The effect of rabbit age on in vitro caecal fermentation of starch, pectin, xylan, cellulose, compound feed and its fibre.

In vitro gas production kinetics of six different substrates, pectin (PEC), xylan (XYL), starch (STA), cellulose (CEL), commercial compound feed (FEED; 201 g crude protein per kg, 155 g crude fibre per kg, 334 g neutral-detergent fibre (NDF) per kg and 190 g acid-detergent fibre (ADF) per kg) and an NDF prepared from commercial compound feed (NDFFEED) were determined using the caecum contents of weaned rabbits (36 days of age) and of rabbits at slaughter age (78 days of age) as inoculums. The cumulated gas production over 96 h of incubation was modelled with Gompertz model, and the kinetic parameters compared. The total potential gas production (parameter 'B' of the Gompertz model) was not affected (P>0.05) by the inoculum source, except with STA, where rabbits at slaughter weight had significantly higher total potential fermentability (314 ml/g dry matter (DM)) than those at weaning age (189 ml/g DM). Intensities of fermentation (maximum fermentation rate; MFR) of PEC (32.2 ml/h) and XYL (24.4 ml/h) were significantly greater in rabbits at weaning, while that of STA (45 ml/h) was significantly lower than at slaughter age (23.0, 14.3 and 14.0 ml/h for PEC, XYL and STA, respectively). The MFRs of CEL and NDFFEED were very similar between inoculum sources. In the first 10 h of fermentation which correspond to the normal retention time of the substrates in the caecum, the highest amount of gas was produced from PEC, followed by FEED and XYL. These substrates had a time of maximum fermentation rate (TMFR) at both rabbit ages short enough (8.0 and 9.5 h for PEC, 9.5 and 6.6 h for FEED, 13.7 and 14.2 h for XYL at weaning and at slaughter age, respectively) to be almost completely fermented in vivo.

Physical training improves flow-mediated dilation in patients with the polymetabolic syndrome.

Endothelial dysfunction that can be detected as impaired flow-mediated dilation by ultrasonography is an early event in atherogenesis and has been demonstrated in healthy subjects with risk factors for atherosclerosis many years before the appearance of atheromatous plaques. We examined the influence of physical training on flow-mediated dilation in patients with the polymetabolic syndrome. Twenty-nine asymptomatic men aged 40 to 60 years with the polymetabolic syndrome were randomly divided between the control group and the training group, which trained 3 times a week for 12 weeks. On high-resolution ultrasound images, the diameter of the brachial artery was measured at rest, after reactive hyperemia (causing flow-mediated, endothelium-dependent dilation), and after sublingual glyceryltrinitrate (causing endothelium-independent vasodilation) in all subjects before and after the training period. The training program induced an increase of 18% in physical fitness. Flow-mediated dilation increased from 5.3+/-2.8% to 7.3+/-2.7% (P<0. 05). There was no change in body mass index, blood pressure, insulin resistance, lipids, and big endothelin-1 in either group. Flow-mediated dilation measured before training was negatively correlated with resting heart rate, waist-to-hip ratio, and insulin resistance. Resting heart rate emerged as the only independent determinant, which explained 22% of the variation in flow-mediated dilation. In conclusion, our findings suggest that a 3-month physical training program, which improved maximal exercise capacity, enhances flow-mediated dilation in patients with the polymetabolic syndrome.

Carotid intima-media thickness in young patients with familial hypercholesterolaemia.

OBJECTIVE: To assess the extent of early atherosclerotic changes of the carotid arteries in young patients with familial hypercholesterolaemia (FH) detected as increased intima-media thickness (IMT), and to determine the relations between IMT and some clinical and blood variables such as lipid and lipoprotein(a) (Lp(a)) concentration and haemostatic factors. DESIGN: The IMT of the carotid bifurcation, the proximal 1 cm of the internal carotid artery, and the distal 1 cm of the common carotid artery was determined in all subjects using B mode ultrasonography. Blood lipids, fasting glucose, and several haemostatic variables were also analysed. SUBJECTS: 28 patients with FH (12 males and 16 females aged 11 to 27 years, one homozygote, 27 heterozygotes) and 28 sex and age matched normolipidaemic healthy subjects. RESULTS: The mean carotid IMT (the average of six measurements of the maximum far wall IMT in the three carotid segments on each side) was significantly greater in patients with FH than in controls (mean (SD) 0.71 (0.15) v 0.49 (0.08) mm, P < 0.001). In all subjects, the mean IMT was significantly correlated with total cholesterol (r = 0.59), low density lipoprotein (LDL) cholesterol (r = 0.60), triglycerides (r = 0.27), and systolic blood pressure (r = 0.47). No correlation was found between the mean IMT and Lp(a), fibrinogen, tissue plasminogen activator, and plasminogen activator inhibitor 1. CONCLUSIONS: The majority of young patients with FH have a greater intima-media thickness of the carotid arteries than healthy subjects. Since the individual susceptibility of patients with FH to increased LDL cholesterol is different, B mode ultrasonography could provide a useful tool to identify those who are more likely to develop premature atherosclerotic disease.