Renal excretion of urea in a small east African antelope, the dik-dik (Rhynchotragus kirkii)

1. A study on the renal handling of urea by the dik-dik antelope (Rhynchotragus kirkii) was conducted. 2. Plasma and urine samples were analysed for osmolality, urea and creatinine concentrations during dehydration and intra-ruminal loading of potassium and sodium solutions. 3. The glomerular filtration rate (GFR) of the dik-dik was found to be 182.6 +/- 11.7 ml/min/100 kg body mass. 4. Dehydration was observed to increase tubular urea reabsorption and increase plasma and urine osmolalities, but had no effect on the amount of urea filtered at the glomerulus. 5. Potassium loading increased both GFR and urine flow rate.     

Comparison of voluntary food and water consumption and digestion in Kirk's dikdik and suni

Voluntary food and water consumption of Kirk's dikdik (Madoqua kirki) and suni (Nesotragus moschatus) was determined under controlled laboratory conditions. Both species consumed large amounts of dried matter (lucerne hay leaves) per day. Dry matter consumption of dikdik accounted for 3.8 ± 0.5% and of suni for 3.5 ± 0.2% of body weight. Dry matter intake in one immature dikdik and one female dikdik during late pregnancy and lactation was considerably higher. Dikdik drank very little water (278 ml/day, equalling 83 ml/kg^0.82) which is further proof of their adaptation to arid environment. Suni drank about twice as much (401 ml/day, equalling 155 ml/kg^0.82), but individual variation of water con sumption was high. Thus, the forest-dwelling suni seems to be less adapted to de hydration than the dikdik. There was no difference in the digestibility of dry matter and gross energy of lucerne hay leaves for dikdik and suni. The fraction of N-free extracts which consists mainly of soluble carbohydrates was digested very well (84% and 81%, respectively), whereas fibre and cellulose digestibility was poor. Suni digested crude protein, minerals and cellulose significantly better than dikdik.     

Aspects of digestion and in vitro fermentation in the caecum of some East African herbivores

Caecal digestive functions were compared in 22 species of East African herbivores. Comparisons were made between ruminant pseudo-ruminant, and non-ruminant herbivores to assess the relative in vitro fermentation rate and composition of caecal contents from these species observed in their natural habitat. Measurements were made of caecal fermentation rate, organic acid composition, osmolality, pH and dry matter content. The data were compared by foregut structure, feed preference and body weight of the herbivores.     

Cannabinoid-1 receptor antagonists reduce caloric intake by decreasing palatable diet selection in a novel dessert protocol in female rats

Although many feeding protocols induce obesity, few use multiple foods to analyze diet selection within a single group of animals. To this end, we describe a protocol using time-limited access to a dessert that induces hyperphagia and body weight gain while allowing simple analysis of diet selection. Female retired breeder Sprague-Dawley rats were provided with ad libitum access to standard moist chow (1.67 kcal/g) and daily 8-h nocturnal access to either a sugar gel (SG; 0.31 kcal/g) or sugar fat whip (SFW; 7.35 kcal/g) for 15 days, and food intake and body weight were measured daily. Rats given SFW reduced moist chow intake but not enough to compensate for the large amount of calories consumed from SFW, and thus gained weight. We use this SFW overconsumption protocol to investigate the hypothesis that cannabinoid (CB)1 receptor antagonists reduce caloric intake by selectively decreasing consumption of palatable foods. In two experiments, female retired breeder Sprague-Dawley rats were injected with either Rimonabant (1 mg/kg ip) or vehicle (equal parts polyethylene glycol and saline, 1 ml/kg ip) for 7 days, or one of three doses of AM251 (0.3, 1.0, or 3.0 mg/kg ip), or vehicle for 15 days; food intake and body weight were measured daily. Both Rimonabant and AM251 decreased 24-h caloric intake, but the reduction was specific to a decrease in SFW consumption. This supports the hypothesis that these CB1 receptor antagonists impact feeding by modulating the perception of palatability.     

Adaptability of the digestive function according to age at weaning in the rabbit: I. Effect on feed intake and digestive functionality

The functional adaptability of the digestive system to the level of feed intake was investigated in the young rabbits by comparing two groups of 12 litters each, weaned at 21 (W21) or 35 (W35) days of age. From 14 days onwards, rabbits were fed a pelleted feed (NDF: 332 g/kg, CP: 177 g/kg, starch: 98 g/kg, as-fed basis). Until 49 days of age, the profile of digestive enzymes was weekly determined in the small intestinal content and mucosa, as well as caecal fermentation traits and fibrolytic activities. In the W21 group, the solid feed intake was increased by 57% between 21 and 35 days (P < 0.01), while the daily body growth was lower from 21 till 42 days (-17%, P < 0.05) when compared with the W35 group. Activities of enzymes of pancreatic origin were only scarcely influenced by the weaning age. In the W21 group, amylase activity tended to be lower at 28 days of age (-36%, P = 0.064), and trypsin activity was decreased by 31% at 49 days of age (P < 0.01). Lipase activity was similar in both weaning groups. Duodenal and jejunal activities of maltase and aminopeptidase N (APN) were higher on day 28 in the W21 group as compared with the W35 group (×1.4 to ×2.4, respectively, P < 0.05). On day 35, duodenal APN activity was twice as higher in the W21 group than in the W35 group (P < 0.01). In caecum, major differences between both weaning groups were observed at 28 days of age with a decrease in ammonia concentration (-43%, P < 0.01) in W21 compared with W35 rabbits. Conversely, the acetate proportion was 5% higher in the W21 group (P < 0.01) on day 28. In conclusion, the digestive tract of early-weaned rabbits showed some adaptative properties in response to nutritional environment changes, but they were insufficient to maintain their growth rate.     

Effects of the level of feed intake and ergot contaminated concentrate on ruminal fermentation and on physiological parameters in cows

The aim of the present study was to examine the effects of ergot contaminated feed concentrate at differing levels of feed intake on ruminal fermentation, and on various physiological parameters of dairy cows. Twelve double fistulated (in the rumen and the proximal duodenum) Holstein Friesian cows were fed either a control diet (on a dry matter (DM) base: 60% maize silage, 40% concentrate) or a diet containing ergot alkaloids (concentrate contained 2.25% ergot resulting in an ergot alkaloid concentration of the daily ration between 505 and 620 (μg/kg DM) over a period of four weeks. Daily feed amounts were adjusted to the current performance which resulted in a dry matter intake (DMI) variation between 6.0 and 18.5 kg/day. The resulting ergot alkaloid intake varied between 4.1 and 16.3 (μg/kg body weight when the ergot contaminated concentrate was fed. Concentrations of isovalerate, propionate and ammonia nitrogen in the rumen fluid were significantly influenced by ergot feeding, and the amount of ruminally undegraded protein, as well as the fermentation of neutral detergent fibre, tended to increase with the ergot supplementation at higher levels of feed intake, which might indicate a shift in the microbial population. Other parameters of ruminal fermentation such as ruminai pH, fermented organic matter as a percentage of intake, or the amount of non-ammonia nitrogen measured at the duodenum were not significantly influenced by ergot feeding. The activities of liver enzymes (aspartate aminotransferase, γ-glutamyltransferase, glutamate dehydrogenase, creatine kinase) in the serum were not affected by ergot feeding. The rectal measured body temperature of the cows significantly increased after ergot administration (p=0.019). Thus, body temperature can be regarded as a sensitive parameter to indicate ergot exposure of dairy cows.     

In Vitro Study and Comparison of Caecal Methanogenesis and Fermentation Pattern in the Brown Hare (Lepus europaeus) and Domestic Rabbit (Oryctolagus cuniculus)

The brown hare and the domestic rabbit are mid-sized herbivorous mammals and hindgut fermenters, though their digestive physiologies differ in some traits. The objective of this study was to estimate and compare the caecal microbial activity in hares and rabbits via an analysis of the following end-products of in vitro caecal fermentation: methane, total gas production, short chain fatty acids and ammonia concentration. Hare caecal methanogenesis occurred at a much lower level (0.25 mmol/kg for samples incubated without substrate and 0.22 mmol/kg for samples incubated with substrate) than that of the rabbit (15.49 and 11.73 mmol/kg, respectively) (P<0.001). The impact of the substrate’s presence on caecal methanogenesis was not significant, though its presence increased the total gas production during fermentation (P<0.001). Hare caecal microflora produced a lower short chain fatty acids concentration than did rabbit microorganisms (P<0.05). In unincubated hare samples, the short chain fatty acids concentration was 28.4 mmol/kg, whereas in unincubated rabbit samples, the short chain fatty acids concentration was 51.8 mmol/kg. The caecal fermentation pattern of the hare was characterised by higher propionate and isobutyrate molar proportions compared with those observed in rabbit caecum (P<0.01). No significant changes in the ammonia concentration in either rabbit or hare caecum were found. The results obtained indicate some differences in the activity of the microbial populations colonising the hare and rabbit caecum, particularly in regards to methanogenic Archaea.     

Randomised double blind trial of single dose doxycycline for treating cholera in adults.

OBJECTIVE--To compare the efficacy of a single dose of doxycycline (200 or 300 mg) with the standard multiple doses of tetracycline in patients with cholera. DESIGN--Randomised double blind controlled trial. Patients were given a single 200 mg dose of doxycycline, a single 300 mg dose of doxycycline, or multiple doses of tetracycline (500 mg, six hourly intervals). SETTING--Hospital in Bangladesh treating diarrhoea. PATIENTS--261 Patients aged over 15 admitted to the hospital with severe dehydration due to acute watery diarrhoea associated with Vibrio cholerae. All vibrios isolated from the stools and rectal swabs of patients, including those patients with prolonged excretion of vibrios, were sensitive to tetracycline. The stools of all patients at admission were negative for shigella and salmonella. INTERVENTIONS--All patients received rapid intravenous acetate solution for the first four hours after admission to hospital. They were then entered in the study and randomised. Oral rehydration was started immediately after the intravenous treatment. If signs of severe dehydration reappeared during oral treatment patients were given rapid intravenous acetate solution until dehydration was fully corrected. MAIN OUTCOME MEASURES--Stool output in first 24 hours and till diarrhoea stopped, total intake of oral rehydration fluid, duration of diarrhoea, and excretion of vibrio after receiving antibiotic treatment. RESULTS--The median stool outputs during the first 24 hours (275 ml/kg body weight) and till diarrhoea stopped (296 ml/kg body weight) were significantly higher in patients receiving 200 mg doxycycline as a single dose than in patients receiving either standard tetracycline (242 ml/kg body weight and 254 ml/kg body weight) or 300 mg doxycycline (226 ml/kg body weight and 255 ml/kg body weight). Similarly, median consumption of oral rehydration solution (18.45 l) was significantly higher in patients receiving 200 mg doxycycline than in patients receiving either 300 mg doxycycline (16.10 l) or standard tetracycline (14.80 l). Almost equal numbers of patients in each group required unscheduled intravenous acetate solution to correct dehydration during antibiotic treatment. Patients treated with doxycycline (low or high dose), however, had more prolonged excretion of bacteria. CONCLUSIONS--A single 300 mg dose of doxycycline is as effective as the standard multiple dose tetracycline treatment for cholera in terms of stool output, duration of diarrhoea, vomiting, and requirement for oral rehydration solution.     

Oxygen uptake capacity of gills and skin in relation to body weight of the air-breathing siluroid fish, Clarias batrachus (Linn.).

Oxygen consumption through gills and skin in relation to body weight was estimated in the air-breathing catfish, Clarias batrachus, under two experimental conditions, viz., (i) when access to air was allowed and (ii) when air-breathing was prevented. There was a positive correlation between VO2 (ml/hr) and body weight in both experimental conditions. Oxygen consumption (ml/hr) increased by a power of 0.869 when access to air was allowed whereas the power was slightly less (b = 0.841) when air-breathing was prevented. As the values for exponent (b) were less than 1.0, the weight specific VO2 (ml/kg/hr) decreased with increasing body weight. The decrease was more marked (b = - 0.180) in fishes which were not allowed air than in those where access to air was allowed (b = - 0.148). Under normal conditions of water and air-breathing the rate of VO2 (ml/kg/hr) via gills and skin from water ranged from 39.7 +/- 3.21 to 76.7 +/- 9.01 and this increased to 42.17 +/- 6.2 to 105.9 +/- 8.33 when air-breathing was prevented. The increase in the rate of VO2 was perhaps associated with the increase in the volume of water irrigating the gills per unit time.     

Hyperhydration with glycerol solutions

Glycerol was tested as an agent to promote hyperhydration of male and female subjects. Series I experiments involved ingesting 0.5, 1.0, or 1.5 g glycerol/kg body wt and within 40 min drinking 0.1% NaCl, 21.4 ml/kg. In series II, 1.0 g glycerol/kg body wt was ingested at time 0, and 25.7 ml/kg of 0.1% NaCl was ingested over a 3.5-h period. Experiments were of 4-h duration and included controls without glycerol as each subject served as his/her control. Blood samples were taken at 40- or 60-min intervals for hemoglobin (Hb), hematocrit (Hct), plasma osmolality, glycerol, and multiple blood chemistry analyses. Urine was collected at 60-min intervals. Glycerol ingestion increased plasma osmolality for 2 h and reduced the total 4-h urine volume. There were no significant changes in Hb or Hct as a result of the glycerol or excess fluid intake. This study demonstrates that glycerol plus excess fluid intake can produce hyperhydration for at least 4 h.     

Combined stimulation of glucagon-like peptide-1 receptor and inhibition of cannabinoid CB1 receptor act synergistically to reduce food intake and body weight in the rat

Pharmacological activation of the glucagon-like peptide-1 (GLP-1) receptor and inhibition of the cannabinoid CB1 receptor were found to reduce food intake and body weight in humans and animals. Since earlier studies revealed that endocannabinoids may interact with other neurotransmitters to affect feeding behavior, we have examined whether a stable GLP-1 agonist, exendin-4 and a CB1 receptor antagonist, AM 251, may reciprocally enhance their inhibitory effects on food consumption in the rat. Additionally, we have tested whether the blockade of the GLP-1 receptor by exendin (9-39) modifies AM 251-dependent effects on energy balance. In a dose-response study, male Wistar rats were injected intraperitoneally with either 1.5-6.0 μg/kg exendin-4, 0.5-2 mg/kg AM 251, 80-320 μg/kg exendin (9-39) or their vehicle and the daily food and water intake as well as body weight changes were monitored two days before and two days after the injection. Exendin-4 at a dose of 3.0 and 6.0 μg/kg and AM 251 at a dose 2 mg/kg decreased significantly 24-hour food intake and body weight. Therefore, in the next study, the effects of lower doses of exendin-4 (1.5 μg/kg) and AM 251 (1.0 mg/kg) administered alone or together on food consumption were compared. As opposed to being injected alone, the co-administration of the two resulted in a marked decrease in both daily food intake and body weight. Exendin (9-39) did not modify the suppressory effect of the highest AM 251 dose on food consumption. Apparently, the effect of AM 251 on the appetite is not mediated by GLP-1. The concomitant stimulation of GLP-1 receptor and blockade of CB1 receptor, however, may act synergistically to inhibit appetite in the rat.     

Ticarcillin administration to the equine: Intrauterine and intramuscular

Serum levels of ticarcillin disodium, a semi-synthetic penicillin (Beecham Laboratories, Bristol, Tennessee, 37620), were measured at various time intervals up to and including 24 h after intrauterine and intramuscular administration in adult female horses. Three separate studies were conducted in Part I: in the first and second studies, serum levels were measured after intrauterine administration of 1 and 3 g of ticarcillin, respectively, and in the third study, levels were measured after intramuscular administration of 6 g of ticarcillin. In Part II, serum levels of ticarcillin were measured after intramuscular administration of ticarcillin at dosages based on body weight: 10 mg/lb (22 mg/kg) of body weight, 15 mg/lb (33 mg/kg) of body weight and 20 mg/lb (44 mg/kg) of body weight. Results showed little if any absorption of the antibiotics into the systemic circulation after intrauterine administration. All serum levels measured after administration of both intrauterine dosages of 1 and 3 g were less than 4.0 ug/ml. Peak serum concentrations, after intramuscular administration of 6 g of ticarcillin, occurred between 20 and 45 min after administration and averaged 15.97 +/- 5.0 ug/ml. Average peak serum concentrations, after intramuscular administration of 10 mg/lb (22 mg/kg) of body weight, 15 mg/lb (33 mg/kg) of body weight, 15 mg/lb (33 mg/kg) and 20 mg/lb (44 mg/kg) of body weight, were 16.12 ug/ml, 25.75 ug/ml and 50.25 ug/ml, respectively. After intramuscular administration of 6 g of ticaracilin, average serum half-life was determined to be 2.9 h.     

Effects of recovery beverages on glycogen restoration and endurance exercise performance

The restorative capacities of a high carbohydrate-protein (CHO-PRO) beverage containing electrolytes and a traditional 6% carbohydrate-electrolyte sports beverage (SB) were assessed after glycogen-depleting exercise. Postexercise ingestion of the CHO-PRO beverage, in comparison with the SB, resulted in a 55% greater time to exhaustion during a subsequent exercise bout at 85% maximum oxygen consumption (VO(2)max). The greater recovery after the intake of the CHO-PRO beverage could be because of a greater rate of muscle glycogen storage. Therefore, a second study was designed to investigate the effects of after exercise CHO-PRO and SB supplements on muscle glycogen restoration. Eight endurance-trained cyclists (VO(2)max = 62.1 +/- 2.2 ml.kg(-1) body wt.min(-1)) performed 2 trials consisting of a 2-hour glycogen-depletion ride at 65-75% VO(2)max. Carbohydrate-protein (355 ml; approximately 0.8 g carbohydrate (CHO).kg(-1) body wt and approximately 0.2 g protein.kg(-1) body wt) or SB (355 ml; approximately 0.3 g CHO.kg(-1) body wt) was provided immediately and 2 hours after exercise. Trials were randomized and separated by 7-15 days. Ingestion of the CHO-PRO beverage resulted in a 17% greater plasma glucose response, a 92% greater insulin response, and a 128% greater storage of muscle glycogen (159 +/- 18 and 69 +/- 32 micromol.g(-1) dry weight for CHO-PRO and SB, respectively) compared with the SB (p < 0.05). These findings indicate that the rate of recovery is coupled with the rate of muscle glycogen replenishment and suggest that recovery supplements should be consumed to optimize muscle glycogen synthesis as well as fluid replacement.     

Metabolism and evaporative heat loss in the dik-dik antelope (Rhynchotragus kirki)

1. Under controlled conditions, the rate of oxygen consumption (VO2) respiratory frequency, evaporative water loss, heat balance, rectal (Trec) and surface temperatures were determined in the dik-dik antelopes at ambient temperatures (Ta) ranging from 1 to 44 degrees C. 2. The thermal neutral zone was found to be between 24 and 35 degrees C. 3. Respiratory frequency ranged between 27 and 630 breaths/min. 4. At a Ta of 44 degrees C, 95% of the heat produced by the dik-dik was lost via respiratory evaporation. Despite an increase in Trec, cutaneous evaporation did not increase. 5. During panting, VO2 increased in accordance with the expected Q10 effect, contrary to earlier findings. 6. Measurements of circadian rhythm [LD 12:12 (7-19) CT26 degrees C] in VO2 showed that the minimum VO2 (0.42 ml O2/g/hr) occurred at midnight while the maximum (0.78 ml O2/g/hr) occurred at midday. The 24 hr mean VO2 was 0.61 ml O2/g/hr. 7. These measurements suggest that in nature, determinants other than light may be responsible for triggering the variations observed in VO2.     

Fluid and particle retention in the digestive tract of the addax antelope (Addax nasomaculatus)--adaptations of a grazing desert ruminant.

Retention time of food in the digestive tract is a major aspect describing the digestive physiology of herbivores. Differences in feed retention times have been described for different ruminant feeding types. In this study, a dominantly grazing desert ruminant, the addax (Addax nasomaculatus), was investigated in this respect. Eight animals with a body weight (BW) of 87+/-5.3 kg on an ad libitum grass hay (Chloris gayana) diet were available. Co-EDTA and Cr-mordanted fibers (<2 mm) were used as pulse-dose markers. Mean retention time (MRT) in the digestive tract was calculated from faecal marker excretion. Average daily intake of the addax was found to be 1.7 kg dry matter (DM) or 60+/-8.3 g DM/kg BW(0.75). The MRT of fluid and particles in the reticulo-rumen (MRT(fluid)RR and MRT(particle)RR) were quantified to be 20+/-5.8 and 42+/-7.0 h respectively. When compared to literature data, MRT(fluid)RR was significantly longer than in cattle species, and MRT(particle)RR was significantly longer than in 11 taxa of all feeding types. The ratio of MRT(particle)RR/MRT(fluid)RR (2.3+/-0.5) was found to be within the range described for grazing ruminants. The long retention times found in the addax can be interpreted as an adaptation to a diet including a high proportion of slow fermenting grasses, while the long retention time of the fluid phase can be interpreted as a consequence of water saving mechanisms of the desert-adapted addax with a potentially low water turnover and capacious water storing rumen.     

Fluid and particle retention in the digestive tract of the addax antelope (Addax nasomaculatus)--adaptations of a grazing desert ruminant

Retention time of food in the digestive tract is a major aspect describing the digestive physiology of herbivores. Differences in feed retention times have been described for different ruminant feeding types. In this study, a dominantly grazing desert ruminant, the addax (Addax nasomaculatus), was investigated in this respect. Eight animals with a body weight (BW) of 87+/-5.3 kg on an ad libitum grass hay (Chloris gayana) diet were available. Co-EDTA and Cr-mordanted fibers (<2 mm) were used as pulse-dose markers. Mean retention time (MRT) in the digestive tract was calculated from faecal marker excretion. Average daily intake of the addax was found to be 1.7 kg dry matter (DM) or 60+/-8.3 g DM/kg BW(0.75). The MRT of fluid and particles in the reticulo-rumen (MRT(fluid)RR and MRT(particle)RR) were quantified to be 20+/-5.8 and 42+/-7.0 h respectively. When compared to literature data, MRT(fluid)RR was significantly longer than in cattle species, and MRT(particle)RR was significantly longer than in 11 taxa of all feeding types. The ratio of MRT(particle)RR/MRT(fluid)RR (2.3+/-0.5) was found to be within the range described for grazing ruminants. The long retention times found in the addax can be interpreted as an adaptation to a diet including a high proportion of slow fermenting grasses, while the long retention time of the fluid phase can be interpreted as a consequence of water saving mechanisms of the desert-adapted addax with a potentially low water turnover and capacious water storing rumen.     

Effects of fibre level and dietary mannanoligosaccharides on digestibility,caecal volatile fatty acids and performances of growing rabbits

The current experiment with 3 trials aimed to study the effect of two levels of dietary fibre – high fibre (HF; 323 g aNDFom/kg) and low fibre (LF; 248 g aNDFom/kg) – and the effect of mannanoligosaccharides (MOS) addition (1 g/kg) to the LF diet (LFM) on the performances and health status of growing rabbits, digestibility and caecal fermentative characteristics. In the growth trial 132 rabbits of both sexes were used (11 cages with 4 rabbits per treatment) from weaning (32 days of age) to slaughter (67 days of age). Rabbits fed HF diet showed a significantly higher weight gain and live weight at 67 days than rabbits fed LF diet (2032 g vs. 1935 g) (P<0.05). Feed and digestible energy intake increased with dietary fibre level (P<0.05). During the growing period rabbits fed HF diet had a feed intake 26% higher than those fed LF diet. Feed efficiency ratio was worse in HF animals (0.334 vs. 0.385; P<0.05). Addition of MOS to LF diet did not affect growth performance parameters (P>0.05). Mortality and morbidity rate were not affected by treatments. In the digestibility 24 rabbits from 46 to 51 days of age trial were used. The HF diet resulted in a significant (P<0.05) decrease in digestibility of dry matter, organic matter and protein while the aNDFom digestibility was not significantly different between diets (P>0.05). Supplementation with MOS had no effects on digestibility (P>0.05). In the 3rd trial the caecal traits were measured in 30 rabbits with 46 days of age that received the experimental diets in the previous 14 days. Caecal production of total volatile fatty acids (VFA), acetate and propionate were significantly higher (P>0.05) on rabbits fed HF diets than on rabbits fed LF diets. The total VFA concentration increased 64% (from 5.01 to 8.20 mmol/100 ml) and acetate increased 73% (from 3.73 to 6.44 mmol/100 ml). Butyrate production was not different between diets (P>0.05). Fibre level did not affect proportions of VFA and caecal contents and caecal weights. Addition of MOS to LF diet did not affect any caecal trait (P>0.05). It was concluded that the reduction of dietary fibre level increases feed digestibility but worsens rabbit growth performances. Supplementation of low fibre diet with 1 g MOS/kg is not enough to reduce its negative effects on growth performances.     

Liquid supplementation of grazing cows and calves

One hundred and one Angus cows (average weight 614 kg) and their bull calves (average weight 213 kg) grazing improved summer pastures were used to determine cow and calf intake of liquid supplement, and its effect on forage intake and performance. Forty-seven pairs had access to a 410 g CP/kg DM molasses-based liquid supplement in an open feeder and 54 pairs were not supplemented. The study was conducted in southwestern Montana from July 28 to October 3, 1997. Cows consumed significantly more supplement (0.3 kg/day) than calves (0.1 kg/day) but both consumed 0.5 g/kg bodyweight per day. Supplemented cows gained 0.12 kg/day more (p<0.05) than unsupplemented cows; however, there was no difference (p>0.10) in body condition score change. Average daily gain by supplemented calves was 30% greater (p<0.01) than average daily gain by unsupplemented calves. Forage intake (g/kg body weight) by both supplemented cows and calves was 64% greater (p<0.01) than forage intake by unsupplemented cows and calves. There was no difference (p>0.10) in milk intake between supplemented and unsupplemented calves. There was no difference (p>0.10) in time spent at the supplement feeder between cows and calves, averaging 5.0 min/day. Time at the feeder was lowest for 7-year-old cows, intermediate for 6- and 8-year-old cows, and highest for 9-year-old cows (p<0.10). There was no difference (p>0.10) in supplement feeding bouts/day between age groups of cows. Calf liquid supplement intake (g/kg body weight) and time spent at the supplement feeder were similar to intake and time spent at the feeder by cows. Liquid supplementation increased forage intake and average daily gain by cows and calves grazing improved forages in late summer. The cost for additional weight gained by the supplemented calves was US$ 0.33/kg and October cattle prices in Montana were US$ 1.64/kg. Liquid supplementation was cost effective under the conditions of this study.     

Plasma volume expansion in humans after a single intense exercise protocol.

We used intense intermittent exercise to produce a 10% expansion of plasma volume (PV) within 24 h and tested the hypothesis that PV expansion is associated with an increase in plasma albumin content. The protocol consisted of eight 4-min bouts of exercise at 85% maximal O2 uptake with 5-min recovery periods between bouts. PV, plasma concentrations of albumin and total protein (TP), and plasma osmolality were measured before and during exercise and at 1, 2, and 24 h of recovery from exercise. During exercise, PV decreased by 15%, while plasma TP and albumin content remained at control levels. At 1 h of recovery, plasma albumin content was elevated by 0.17 +/- 0.04 g/kg body wt, accounting for the entire increase in plasma TP content. PV returned to control level at 1 h of recovery without fluid intake by the subjects, despite a 820 +/- 120-g reduction in body weight. At 2 h of recovery, plasma TP content remained significantly elevated, and plasma TP and albumin concentration were significantly elevated. At 24 h of recovery, PV was expanded by 4.5 +/- 0.7 ml/kg body wt (10 +/- 1%), estimated from hematocrit and hemoglobin changes, and by 3.8 +/- 1.3 ml/kg body wt (8 +/- 3%), measured by Evans blue dye dilution. Plasma albumin content was increased by 0.19 +/- 0.05 g/kg body wt at 24 h of recovery. If 1 g of albumin holds 18 ml of water, this increase in plasma albumin content can account for a 3.4-ml/kg body wt expansion of the PV. No significant changes in plasma osmolality occurred during recovery, but total plasma osmotic content increased in proportion to PV.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dietary intake of platinum and gold by children from Germany using duplicate portion sampling

The dietary intake of platinum and gold by 84 small children, 42 boys and 42 girls at the age of 14 to 83 months, with different food consumption behaviour living in urban and rural areas of Germany was measured by the duplicate method with a seven day sampling period from May to September 1998. The levels in the food duplicates were in the range of < 0.01 to 450 ng Pt/kg (dry weight) (median: 22) and < 0.14 to 28 microg Au/kg (dry weight) (median: 0.645). Related to the body weight, Pt was in the range of < 0.81 to 32 ng/(kg (body weight) x week) (median: 2.3) and Au was < 0.015 to 2.6 microg/(kg (body weight) x week) (median: 0.068). Children consuming exclusively products from the super market showed slightly higher Pt concentrations in the food duplicates and a higher dietary intake per body weight than children with food consumption including products from the family owned vegetable gardens or the surrounding area and/or products from domestic animals of the surrounding area. No influence of the food consumption behaviour was found for the concentrations in the food duplicates or the dietary intake of Au.