Mean Body Wt Research Articles

Effect of molasses based multi-nutrient herbal supplements on in vitro digestibility, serum enzymes and minerals profile in buffalo calves

Molasses based multinutrients herbal supplements (MMS) containing ground fenugreek seed and de-oiled mahua seed cake at two different ratios (1:1; MMS I or 1:3; MMS II) was evaluated under in vitro as well as in vivo conditions. For in vitro evaluation, concentrate mixture and wheat straw in 50: 50 ratio (on DM basis) was taken as substrate for the experiment. MMS I and MMS II were added at 2, 3 and 4% of the substrate, respectively. The total gas production (ml/g DM), partitioning factor (PF) and microbial biomass production (MBP) were found comparable in all the groups but significantly improved the IVDMD and IVOMD in supplemented groups. Under in vivo feeding trial, serum enzymes and minerals profile in buffalo calves were assessed during 9 months of experimental period. Fifteen male Murrah buffalo calves (10 to 15 months of age and mean body wt. 234.0±12.5 kg) were randomly distributed into 3 groups (5 in each group) according to randomized block design. All animals were fed with conventional concentrate mixture, available chopped green fodder (3-4 kg DM/d) and wheat straw ad lib to meet out nutrients requirement. While control group (C) were not fed supplements but groups T1 and T2 supplemented with MMS I and MMS II, respectively at 44 g/100 kg body weight or 200 g/100 kg metabolic body weight (kgW0.75). Serum AST, ALT activities and serum concentration of Ca, P, Fe, Mn, Cu and Co were comparable among 3 groups but serum concentration of Zn was significantly higher among supplemented groups. Thus, results show that supplementation of MMS improved IVDMD, IVOMD and serum Zn level resulting in to better health conditions of buffalo calves.

Effect of molasses based multi-nutrient herbal supplements on hematobiochemicals, serum lipid, antioxidants and hormonal profile in buffalo calves

Effect of molasses based multinutrients herbal supplements (MMS) containing ground fenugreek seed and deoiled mahua seed cake at two different ratios (1:1; MMS-I or 1:3; MMS-II) on hematobiochemicals, serum lipid, antioxidants and hormonal profile in male buffalo calves was assessed for 9 months. Fifteen male Murrah buffalo calves (10 to 15 months of age and mean body wt. 234–236 kg) were randomly distributed into 3 groups (5 each) according to Randomized Block Design (RBD). All animals were fed individually with conventional concentrate mixture, available green fodder (3–4 kg DM/d) and wheat straw ad lib. to meet out nutrients requirement. While animals in control group (C) were fed no supplement but animal’s diet in group T1 and T2 supplemented with MMS-I and MMS-II, respectively at 44 g/100 kg body weight or 200 g /100 kg metabolic body weight (kgW0.75). The values of Hb, PCV, RBC, WBC, platelets count, serum total protein, uric acid, creatinine, urea level, total cholesterol, triglyceride, high density lipoprotein (HDL) and T3 hormone level were comparable among 3 groups. Serum glucose, globulin, antioxidants and testosterone levels were significantly increased but serum albumin, A/G ratio, low density lipoprotein (LDL) and cortisol levels were significantly decreased among supplemented groups as compared to control group and hormone T4 was significantly higher in T1 group. The results showed that supplementation of MMS-I and MMS- II in the diet of buffalo calves improved serum glucose, globulin, antioxidants, T4 and testosterone levels but lower albumin, A/G ratio, LDL and cortisol.

Effect of molasses based multi-nutrient herbal supplements on the performance of buffalo calves

An experiment was conducted to study the effect of molasses based multi-nutrient herbal supplements (MMS) containing ground fenugreek seed and de-oiled mahua seed cake at two different ratios (1:1; MMS-I and 1:3; MMS-II) on growth performance, nutrient utilization and immune response of male buffalo calves. Fifteen male Murrah buffalo calves (10 to 15 months of age and mean body wt. 234–236 kg) were randomly distributed into 3 groups of 5 each. All animals were supplied with conventional concentrate mixture, green forages (3–4 kg DM/d) and wheat straw ad lib. to meet out nutrient requirement. Animals in control group were not fed supplement but animals in group T1 and T2 were fed MMS-I and MMS-II, respectively @ 200 g/100 kg metabolic body weight (kg W0.75). The intake and digestibility of DM, OM, EE, NDF, ADF, hemicelluloses, cellulose and purine derivatives in urine were comparable among 3 groups. Digestibility of crude protein (CP) was higher in supplemented groups (T1 and T2) than control. Total dry matter intake, body weight gain, average daily gain (ADG) and feed conversion ratio (FCR) during 270 days were comparable among 3 groups. Both cellular and humoral immune response improved in T1 and T2 groups. The results revealed that molasses based multi-nutrient herbal supplement containing fenugreek and DMSC improved the growth performance, nutrient utilization and immune responses.

혐기성 미생물로 제조한 synbiotics 혼합배양물의 첨가가 발효 TMR의 발효특성과 소실률에 미치는 영향

This study was conducted to estimate the in vitro fermentation characteristics and in situ degradabilities of total mixed rations fermented by the synbiotic co-cultures composed of various anaerobic microorganisms in the rumen of cow. Seventy two TMR bags (4 treatments × 6 fermentation days × 3 replications) were manufactured for in vitro and in situ experiments. The experiment was composed of four treatments including the control, the mould and bacteria synbiotics (T1), the mould and yeast synbiotics (T2) and the bacteria and yeast synbiotics (T3). Each treatment had six fermentation days (1, 3, 5, 7, 14, 21 day) with three replications. Two rumen cannulated Holstein cows (550 ㎏ of mean body wt) were used for in situ trial, and a total of 96 nylon bags were retrieved from the rumen according to eight fermentation times (1, 3, 6, 9, 18, 24, 48 and 72 hr). The mean fermentation temperatures of TMRs by supplementation of anaerobic micoorganism co-cultures ranged from 22.97℃ to 26.07℃, and tended to increase steadily during the entire period. pH values of the F-TMRs ranged from 4.39 to 4.98 and tended to decrease with the extension of the fermentation period, and decreased by supplementation of synbiotics (p＜0.05). The ammonia concentrations of F-TMRs were not affected by addition of synbiotic co-cultures during the early fermentation period (within 7 days), but was lowest (p＜0.05) in T3 during the late fermentation periods (after 14 days). Lactic acid concentration of F-TMR was lowest in T3 at 1 day of fermentation, but was not different from treatments in the other fermentation days. Microbial growth rates of F-TMR reached a peak at 7 days of fermentation, and afterward tended to decrease. In in situ experiment, the DM disappearance rates were higher in T1 than the control during early fermentation times (within 3 hours), but was vice versa at 48 hours of fermentation (p＜0.05). There was no significant difference in effective DM degradability among treatments. NDF and ADF disappearance rates in situ were similar to those of DM. From the above results, the supplementation of synbiotics, particularly the mould and bacteria synbiotics, resulted in improving the pH and concentration of lactic acid of F-TMR as parameters of fermentation compare to the control, and also had higher in situ disappearance rates of DM, NDF and ADF than the control at early fermentation time. However, effective DM degradability was not affected by supplementation of synbiotics.

Utilization of nutrients as influenced by different restriction levels of feed intake under sub-tropical conditions in crossbred calves

Twenty growing crossbred calves (mean body wt. 159.7 ± 3.94 kg) were randomly divided into 4 groups 5 in each following randomized block design. To assess the voluntary dry matter intake (VDMI) during preliminary feeding period, all the animals were fed concentrate mixture and wheat straw ad libitum. The lowest DMI amongst all animals fed ad libitum was defined as ‘VDMI’. The animals were fed at four fixed levels. The highest level of DMI was 95% of VDMI (group 1) as determined in preliminary period of feeding the other 3 levels were 80% (group 2), 60% (group 3) and 40% (group 4) of the VDMI. The experimental feeding was continued for a month followed by a metabolism trial. The dry matter intake through concentrate (crushed maize 33, deoiled-soya meal 32, wheat bran 32, mineral mixture 2 and common salt 1 part) and roughage (wheat straw) was 40:60. The DMI (kg/d) and percent of body weight ranged from 1.62 (group 4) to 4.06 (group 1) and 1.20 to 2.58, respectively. The CP intake (g/d) varied from 177 to 442 among 4 groups. The intake of DM, OM, CP, EE, NDF, ADF and hemi-cellulose (g/d or g/kg w 0.75) was also significantly ( P < 0.05) different among 4 groups. The digestibility of DM in groups 1, 2, 3 and 4 was 59.9, 61.7, 64.6 and 30.4%, respectively and was significantly ( P < 0.05) lower in group 4 as compared to the remaining 3 groups. The digestibility of other all nutrients viz. OM, CP, EE, NDF, ADF and HC was comparable among groups 1, 2 and 3. However, the digestibility of these nutrients was significantly ( P < 0.05) lower in group 4 (40% intake) as compared to the other 3 groups. Intake and balance of N was significantly ( P < 0.01) different among 4 groups, being the lowest in group 4. Animals of groups 1, 2 and 3 were in positive nitrogen balance, however, animals of group 4 were in negative N balance. The results revealed that nutrient utilization was unaffected up to 60% level but it was drastically reduced at 40% level of feed intake. It was also observed that calves maintained on 80 and 60% of feed intake lost body weight (250–300 g/d).

주정과 구연산 및 식이성 칼슘소재를 처리한 멸치분말이 흰쥐의 칼슘대사에 미치는 영향

본 연구는 주정과 구연산을 처리한 대멸분말과 함께 식이성 칼슘소재가 SD계 흰쥐의 칼슘대사에 미치는 영향을 조사하기 위하여 수행되었다. 실험식이는 대멸분말의 칼슘함량을 고려하여 식이중의 칼슘함량이 0.1%가 되도록 semipurified diet(AIN-diet, 1977)에 건조대멸분말을 첨가한 대조군(C), 주정-구연산처리군(EC), 주정-구연산＋CPPs처리군(ECC), 젖산칼슘첨가군(CL) 및 인산칼슘첨가군(CP)으로 처리하여 5주동안 실험한 결과는 다음과 같다. 증체량은 EC군이 ECC군과 일반적인 칼슘소재로 이용되는 젖산칼슘군 (CL)과 인산칼슘군(CP)에 비해 유의하게 높았고(p<0.05), 식이효율(FER)은 차이가 없었다. 생체내외(in vitro & invivo) 칼슘흡수율은 CPP를 처리한 ECC군이 각각 20.4%, 28.4%로 실험군중 가장 높았다(p<0.05). 혈당치는 CL군(105.7 mg/dL)이 대조군(89.5 mg/dL)보다 유의하게 높았고 (p<0.05), TC농도는 EC군(75.1 mg/dL)이 CP군(65.6 mg/dL)보다 높았으며, TG농도는 CP군(33.5 mg/dL)이 통계적으로 가장 낮았다(p<0.05). ALP활성과 OST농도는 실험군간 차이가 없이 CL군이 대조군보다 다소 높았다. 혈중 Ca농도는 칼슘흡수율이 가장 낮은 대조군(C)이 10.82 mg/dL로 유의하게 낮았고, EC군과 ECC군이 가장 높았다(p<0.05). 대퇴골무게는 CP군이 가장 낮았고(p<0.05), 길이는 ECC군이 가장 길었다(p<0.05). 골밀도는 CP군(0.1116 g/㎠)이 가장 낮았던 반면, ECC군(0.1149 g/㎠)이 가장 높았다. 이상의 결과에서 CPPs를 첨가한 ECC군이 생체내외 칼슘흡수율과 혈중 Ca농도 및 대퇴골의 길이와 밀도 등에 유의한 상승효과를 미친 것으로 나타났다. 향후 본 연구결과는 칼슘흡수율을 높이고 색택의 개선 및 관능이 향상된 기능성제품 개발의 기초자료로 활용될 수 있을 것으로 사료된다.

한우 육성 비육 시 보리 급여수준이 증체와 육질에 미치는 효과

본 연구는 보리의 급여수준이 한우수소의 성장과 육질에 미치는 효과를 조사하고자 실시되었다. 수송아지 20두(평균체중 99㎏)를 공시하여 한우수소의 육성비육 시 보리의 급여수준(육성기－비육전기－비육후기 보리 배합비; 0-0-40, FⅡ40; 0-0-60, FⅡ60; 0-20-40, F2040; 0-20-60, F2040)이 증체와 육질에 미치는 효과를 구명하였다. 시험기간 동안의 체중은 성장단계별 보리 급여수준 간 차이는 보이지 않았으나, FⅡ40구의 24개월령 체중이 591.5kg으로 606.2～614.6kg 내외의 다른 처리구에 비해 다소 감소된 경향이었다. 그러나 FⅡ60구는 비육후기에 보리 60% 첨가된 사료를 섭취하면서 증체가 개선되는 경향이 있었다(P<.19). 한우수소에 대한 보리위주 사료의 급여는 생체중, 도체중과 도체율, 정육률, 거래정육률 그리고 KPH 지방과 뼈의 비율 등의 도체특성에 있어 처리 간 차이는 없었으나, 보리를 비육전기에 20%, 비육후기에 60% 급여한 F2060구의 한우수소에서 정육률과 지방률이 각각 89.82, 20.28%로 다른 처리구에 비해 다소 높았으며, 이로 인해 거래정육률은 최대 5.5% 가량 낮게 나타났다. 근내지방도는 FⅡ40구 및 F2060구에서 각각 3.75, 3.60으로 다른 처리구에 비해 높은 편이었으며, 조직감 역시 FⅡ60구와 F2060구가 공히 1.6으로 다른 두 처리구에 비해 양호하였다. The present study was carried out to determine the effects of feeding levels of barley grain in diets of Hanwoo on the growth performance and carcass characteristics of Hanwoo. Twenty Hanwoo bull calves (initial mean body wt. 99kg) were randomly divided to examine the effects of 5 feeding levels of barley grains(addition levels: 0, 0 and 40% for FII40; 0, 0 and 60% for FII60; 0, 20 and 40% for F2040; and 0, 20 and 60% for F2060 during the growing, early fattening and late fattening periods, respectively) on growth performance and meat quality. Body weight was not affected by the feeding level of barley grains through the whole experimental period, although the body weight of Hanwoo bulls fed FII40 diet at 24 months old of age tended to be lower(591.5kg) than that of other animals(606.2～614.6kg). However, body weight gain in the bulls of the FII60 diet was slightly increased(P<.19). The feeding levels of barley grains did not influence on fasting body weight, carcass weight, carcass rate, lean meat, retailed cut, KPH fat and bone yield. The lean meat yield(89.82%) and fat yield(20.28%) tended to increase in Hanwoo bulls fed the F2060 compared with other treatments. Feeding of the diets of FII40 resulted in the higher marbling scores as 3.75, respectively than other diets.

Aerosol-derived airway dimensions of dog lungs in histamine-induced bronchoconstriction

The single-breath aerosol recovery technique has been demonstrated to facilitate non-invasive assessment of effective airway diameters in anesthetized mechanically-ventilated dogs with normal airway geometry. In order to test the sensitivity of the method for the detection of magnitude and site of airway constriction, effective airway diameters were determined in dogs with airways maintained in sustained constriction by intravenous histamine. Monodisperse di- (2-ethyl-hexyl) sebacate particles (mean aerodynamic diameter ± SD, 1.17 ± 0.13 μm) were applied by the single-breath technique in nine anesthetized, paralyzed and mechanically-ventilated dogs (mean body wt. ± SD, 15.2 ± 2.4 kg; mean total lung capacity ± SD, 1102 ± 346 ml) during control conditions and steady airway constriction achieved by continuous infusion of histamine (∼ 1.7 mg kg −1 h −1). The rate of aerosol recovery during post-inspiratory breath-holding (0–10 s) was determined from instantaneous particle concentration continuously recorded at the airway opening by a miniature in-line aerosol photometer. For comparison between control and histamine-induced airway narrowing, airway diameters determined as function of volumetric lung depth were referred to the actual volume of the dog's total lung capacity and expressed as % TLC. Narrowing of airway diameters by intravenous histamine was maximal (∼ 50%) in the proximal airways (corresponding to 8% TLC) and the effect was continually fading towards peripheral airways. For deeper lung regions, i.e. beyond a volumetric depth of 19% TLC, no significant differences from control values were detectable. Airway resistance during histamine challenge, determined simultaneously by an interrupter technique, was increased by a factor of 5.7 and would be expected to result mainly from constriction of proximal airways. The marked reduction of TLC (−25%) and static (−26%) and dynamic (−38%) lung compliances (along with an increasing difference between the two) is interpreted to suggest that a major fraction of peripheral airways was constricted but was not recovered by the aerosol technique. This finding may be attributed to presence of marked unequal distribution of peripheral airway constriction, in which case effective aerosol-derived airway diameters would represent not arithmetic means but volume-weighted averages according to the fractional contribution to total airway volume at a given volumetric depth.

Airway Dimensions of Dog Lungs by Aerosols: Comparison of Bolus and Single-Breath Techniques

ABSTRACT Monodisperse aerosols were used to determine airway dimensions as a function of volumetric lung depth in vivo. Two different techniques were compared in anesthetized mechanically ventilated dogs (mean body wt.± SD, 13.6 ± 0.9 kg). Monodisperse di-(2-ethyl-hexyl) sebacate particles (mean aerodynamic diameter±SD, 0.89±0.097 μm) were inhaled as bolus (half-width 8 ml) at 10-85% of the normalized (50% functional residual capacity, FRC) inspired volume (Bolus Technique). Alternatively, the total inspired volume contained the test aerosol, formally representing inspiration of a train of aerosol boluses of infinitesimal small volume (Single-Breath Technique). The particle concentration was continuously recorded at the airway opening by a miniaturized in-line aerosol photometer incorporating a 2 mW laser diode (λ = 820 nm) and a photodiode. The airway diameters determined at a given volumetric lung depth were related to the animal's total lung capacity (TLC) to account for lung volume differences between...

Alveolar slope and dead space of He and SF6 in dogs: comparison of airway and venous loading

Series (Fowler) dead space (VD) and slope of the alveolar plateau of two inert gases (He and SF6) with similar blood-gas partition coefficients (approximately 0.01) but different diffusivities were analyzed in 10 anesthetized paralyzed mechanically ventilated dogs (mean body wt 20 kg). Single-breath constant-flow expirograms were simultaneously recorded in two conditions: 1) after equilibration of lung gas with the inert gases at tracer concentrations [airway loading (AL)] and 2) during steady-state elimination of the inert gases continuously introduced into venous blood by a membrane oxygenator and partial arteriovenous bypass [venous loading (VL)]. VD was consistently larger for SF6 than for He, but there was no difference between AL and VL. The relative alveolar slope, defined as increment of partial pressure per increment of expired volume and normalized to mixed expired-inspired partial pressure difference, was larger by a factor of two in VL than in AL for both He and SF6. The He-to-SF6 ratio of relative alveolar slope was generally smaller than unity in both VL and AL. Whereas unequal ventilation-volume distribution combined with sequential emptying of parallel lung regions appears to be responsible for the sloping alveolar plateau during AL, the steeper slope during VL is attributed to the combined effects of continuing gas exchange and ventilation-perfusion inequality coupled with sequential emptying. The differences between He and SF6 point at the contributing role of diffusion-dependent mechanisms in intrapulmonary gas mixing.

An Infant Ventilator Technique for Resistive Unloading during Spontaneous Breathing. Results in a Rabbit Model of Airway Obstruction

The combined system of ventilator circuit, endotracheal tube, and lung commonly imposes a resistive load on spontaneous breathing efforts. It is possible to compensate for this positive resistance by a device generating a "negative ventilator resistance" (NVR), i.e. delivering a positive pressure during inspiration and a negative pressure during expiration in constant proportion to the instantaneous flow of the spontaneous breathing. The concept of NVR implies that there must not be any phase lag between flow and pressure signals. In eight anesthetized, intubated, spontaneously breathing rabbits (mean body wt 3570 g, range 2900-4600 g), challenged either by aerosolized histamine or an extrapulmonary resistive load, lung mechanical data were calculated from esophageal pressure and flow signals. Each animal served as its own control with and without NVR. In a total of 39 experiments, NVR was applied in amounts between 1 and 15 kPa.s/L. During both types of additional resistive load, NVR immediately reduced the resistive work of breathing. There was a strong linear correlation between the amount of NVR applied and the decrease in total resistance, where the total resistance equals the resistive load on the animal's respiratory muscles (sum of the resistances of all components of the combined respirator-lung system): r = 0.93, p less than 0.001. The relationship between NVR and the drop in resistive work per mL of tidal volume was similar: r = 0.85, p less than 0.001. Throughout the experiments, NVR operated in perfect synchronization with the animal's spontaneous breathing activity.

Pulmonary diffusing capacities for nitric oxide and carbon monoxide determined by rebreathing in dogs

Pulmonary diffusing capacities (DL) of NO and CO were determined simultaneously from rebreathing equilibration kinetics in anesthetized paralyzed supine dogs (mean body wt 20 kg) after denitrogenation (replacement of N2 by Ar). During rebreathing the dogs were ventilated in closed circuit with a gas mixture containing 0.06% NO, 0.06% 13C18O, and 1% He in Ar for 15 s, with tidal volume of 0.5 liter and frequency of 60/min. The partial pressures of NO, 13C18O, 16O18O, N2, Ar, CO2, and He in the trachea were continuously analyzed by mass spectrometry. Measurements were performed at various O2 levels characterized by the mean end-expired PO2 during rebreathing (PE'O2). In control conditions ("normoxia," PE'O2 = 67 +/- 8 Torr) the following mean +/- SD values were obtained (in ml.min-1.Torr-1): DLNO = 52.4 +/- 11.0 and DLCO = 15.4 +/- 2.9. In hypoxia (PE'O2 = 24 +/- 7 Torr) DLNO increased by 11 +/- 8% and DLCO by 19 +/- 10%, and in hyperoxia (PE'O2 = 390 +/- 26 Torr) DLNO decreased to 87 +/- 3% and DLCO to 56 +/- 8% with respect to values in normoxia. DLNO/DLCO of 3.24 +/- 0.06 (hypoxia), 3.38 +/- 0.31 (normoxia), and 5.54 +/- 1.04 (hyperoxia) were significantly higher than the NO/CO Krogh diffusion constant ratio (1.92) predicted for simple diffusion through aqueous layers. With increasing O2 uptake elicited by 2,4-dinitrophenol, DLNO and DLCO increased and DLNO/DLCO remained close to unchanged. The results suggest that the combined effects of diffusion and chemical reaction with hemoglobin limit alveolar-capillary transport of CO. If it is assumed that reaction kinetics of NO with hemoglobin (known to be extremely fast) are not rate limiting for NO uptake, the contribution of the slow chemical reaction with hemoglobin to the total CO uptake resistance (= 1/DLCO) was estimated to be 38% in hypoxia, 41% in normoxia, and 64% in hyperoxia. The various factors expected to restrict the validity of this analysis are discussed, in particular the effects of functional inhomogeneity.

Clearance of Calcium across in Situ Perfused Placentas of Intrauterine Growth-Retarded Rat Fetuses'

Maternofetal clearance of 45Ca and 51Cr-EDTA (diffusional marker) were simultaneously measured across in situ perfused placentas of intrauterine growth-retarded (IUGR) and control rat fetuses on d 20 of gestation. IUGR was induced by uterine artery and vein ligation on d 17 of gestation. Control fetuses and their placentas were taken from sham-operated dams. We hypothesized that calcium transfer would be impaired across placentas of IUGR fetuses. The mean body wt of IUGR fetuses was 42% lower, and the mean nose-anus length was 16% lower than those of control fetuses. The mean total calcium content of IUGR fetuses was significantly lower than that of control fetuses, but not when it was normalized to body wt. The mean maternal whole blood ionized calcium concentration was not significantly different in the two groups. The materno-fetal clearance of 45Ca across IUGR placentas was significantly lower than that across control placentas (IUGR = 35.2 +/- 1.9 micro L/min/g placenta, mean +/- SEM; control = 93.1 +/- 12 microliters/min/g placenta, p less than 0.002). In contrast, the maternofetal clearance of 51Cr-EDTA, the reference diffusional marker, was not significantly different across IUGR and control placentas. We conclude that maternofetal transfer of calcium is reduced across placentas of IUGR rat fetuses.

Pulmonary gas exchange in panting dogs

Pulmonary gas exchange during panting was studied in seven conscious dogs (32 kg mean body wt) provided with a chronic tracheostomy and an exteriorized carotid artery loop. The animals were acutely exposed to moderately elevated ambient temperature (27.5 degrees C, 65% relative humidity) for 2 h. O2 and CO2 in the tracheostomy tube were continuously monitored by mass spectrometry using a special sample-hold phase-locked sampling technique. PO2 and PCO2 were determined in blood samples obtained from the carotid artery. During the exposure to heat, central body temperature remained unchanged (38.6 +/- 0.6 degrees C) while all animals rapidly switched to steady shallow panting at frequencies close to the resonant frequency of the respiratory system. During panting, the following values were measured (means +/- SD): breathing frequency, 313 +/- 19 breaths/min; tidal volume, 167 +/- 21 ml; total ventilation, 52 +/- 9 l/min; effective alveolar ventilation, 5.5 +/- 1.3 l/min; PaO2, 106.2 +/- 5.9 Torr; PaCO2, 27.2 +/- 3.9 Torr; end-tidal-arterial PO2 difference [(PE' - Pa)O2], 26.0 +/- 5.3 Torr; and arterial-end-tidal PCO2 difference, [(Pa - PE')CO2], 14.9 +/- 2.5 Torr. On the basis of the classical ideal alveolar air approach, parallel dead-space ventilation accounted for 54% of alveolar ventilation and 66% of the (PE' - Pa)O2 difference. But the steepness of the CO2 and O2 expirogram plotted against expired volume suggested a contribution of series in homogeneity due to incomplete gas mixing.

Cardiorespiratory responses of the woodchuck and porcupine to CO2 and hypoxia

The burrow-dwelling woodchuck (Marmota monax) (mean body wt. = 4.45 +/- 1 kg) was compared to a similar-sized (5.87 +/- 1.5 kg) but arboreal rodent, the porcupine (Erithrizon dorsatum), in terms of its ventilatory and heart rate responses to hypoxia and hypercapnia, and its blood characteristics. VT, f, T1 and TE were measured by whole-body plethysmography in four awake individuals of each species. The woodchuck has a longer TE/TTOT (0.76 +/- 0.03) than the porcupine (0.61 +/- 0.03). The woodchuck had a higher threshold and significantly smaller slope to its CO2 ventilatory response compared to the porcupine, but showed no difference in its hypoxic ventilatory response. The woodchuck P50 of 27.8 was hardly different from the porcupine value of 30.7, but the Bohr factor, -0.72, was greater than the porcupine's, -0.413. The woodchuck breathing air has PaCO2 = 48 (+/- 2) torr, PaO2 = 72 (+/- 6), pHa = 7.357 (+/- 0.01); the porcupine blood gases are PaCO2 = 34.6 (+/- 2.8), PaO2 = 94.9 (+/- 5), pHa = 7.419 (+/- 0.03), suggesting a difference in PaCO2/pH set points. The woodchuck exhibited no reduction in heart rate with hypoxia, nor did it have the low normoxic heart rate observed in other burrowing mammals.

Induction of voluntary prolonged running by rats.

The rat is widely used in studies of the metabolic and physiological effects of physical exercise. The most commonly used form of exercise is running on treadmills or mechanically driven running wheels. Rats will not voluntarily run significant distances, under normal circumstances. If rats are exposed to running wheels with food freely available, only very limited activity normally occurs. When rats with access to a running wheel are restricted to a fixed amount of food, presented once per day, consistent running occurs. The running is spontaneous and very sensitive to the amount of food provided. Six 6-wk-old rats of 197 g mean body wt were induced to run for 139 days. The distance run increased rapidly over a 20-day initial period on a food supply of 15 g/day (vs. 19.5 g/day consumption by sedentary controls). From day 20 to day 139 the mean distance run was described by the regression equation distance (m/day) = 10,410 - 37.9 X days. Food provided was varied according to distance run, ranging from 15 to 18 g/day, and was normally 17.5 g/day. Thus a food deprivation of 10% of normal consumption will result in mean distances run of approximately 8,000 m/day. The use of pair-fed control animals without access to a wheel allows the conduct of experiments to test the effects of chronic long-distance running. The running is spontaneous; thus the technique avoids the complications accompanying techniques that force running.

Adipocyte blood flow: influence of age, anatomic location, and dietary manipulation.

Adipocyte blood flow in four distinct adipose tissue depots has been measured in conscious, unrestrained, male Sprague-Dawley rats by using the microsphere technique together with cellularity determinations. Blood flow was determined in young rats (90 days old, 387 g mean body wt), spontaneously obese rats (450 days old, 713 g mean body wt), and long-term calorically restricted rats (450 days old, 390 g mean body wt), therefore allowing the comparison of the relative effects of age and fat mass on adipose tissue blood flow. Results of these experiments indicate that while cardiac index remained constant, cardiac output increased in only the obese group, concomitant with increased body fat mass. Spontaneously obese rats exhibited increased adipose tissue depot weight, fat cell lipid, and fat cell size compared with young and restricted groups. Despite significant differences in cell volume, blood flow per cell was remarkably similar between young and obese rats. Long-term caloric restriction, however, was associated with decreased flow per cell. Interdepot comparisons of flow per unit surface area (mm2) or per unit volume (pl) indicate that mesenteric cells receive significantly more blood than cells of the other depots. Our results suggest that adipocyte blood flow is dependent in part on anatomic location, may be further influenced by age or dietary manipulation, and is not a limiting factor in the enlargement of adipocytes during the development of spontaneous obesity.

Cardiac output of dogs exercising in the heat.

We measured cardiac output and central blood temperature in five large dogs (27 kg mean body wt) running at 7.5 km/h for 30 min at two work loads and at low and high ambient temperature (Ta). Each animal ran on a level treadmill (O2 cost about 4 times that of resting) at 25 and 35 degrees C Ta and at a 20% slope (O2 cost about 10 times that of resting) at 25 and 35 degrees C Ta. Cardiac output (CO) was the same at 15 and 30 min of exercise at both work loads and both TaS. CO was higher at 35 degrees C Ta at both work loads. Blood temperature rose 0.6 degrees C during exercise on the level treadmill at 25 degrees C and stabilized after the 15th min of exercise. On the level treadmill at 35 degrees C, blood temperature increased by 1.9 degrees C after 30 min. During 30 min of running at 20% slope, blood temperature increased by 3.2 degrees C at 25 degrees C and by 4.6 degrees C at 35 degrees C. At these work loads the dog is able to increase CO during exercise in the heat. This response is similar to that of humans doing moderate exercise in the heat but is in contrast to that of humans doing heavy exercise in the heat, in whom CO shows a drop or no change compared with cool conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Estimation of pancreatic IRI output rate and its relations to glucose tolerance in normal anasthetized dogs.

The pancreaticoduodenal and portal venous blood flows were recorded electromagnetically in anaesthetized dogs. Blood glucose and IRI were measured in the arterial, portal, and peripheral venous as well as in the intestinal venous blood. By a mathematical model the actual net IRI output of the whole pancreas was estimated. Under basal conditions it is 10.2 +/- 2.4 mU/min (n = 30; 26 kg mean body wt.). After i.v. glucose injection, IRI output is rapidly enhanced. The biphasic nature of this reaction was unequivocally demonstrated by consideration of the ratio IRI output : blood glucose. Pancreaticoduodenal blood flow increases transiently in relation to the increased blood glucose concentration. The IRI secretion rate is well correlated with the blood glucose concentration and to the amounts of glucose or of blood reaching the whole pancreas. It is also correlated with the portal IRI Concentration. The overall peripheral venous or arterial IRI concentrations are correlated with the IRI secretion rate, but not in all individual experiments. The different phases of IRI output (basal rate, stimulated output 1-10 min and 10-60 min) show no influence on each other, nor are they correlated with the peripheral IRI concentration area. Basal IRI output is negatively correlated with the glucose assimilation constants. These constants or the peripheral BG areas, however, are independent of the stimulated IRI output rate. However, both the assimilation constants and the peripheral BG areas are related to the peripheral IRI concentration areas. Hepatic uptake of insulin and dynamics of pancreatic blood flow seem to contribute considerably to the estimated correlation pattern.

The effects of temperature on the metabolic rate and evaporative water loss of the sage sparrow Amphispiza belli nevadensis

1. 1. The thermoneutral zone of the sage sparrow, Amphispiza belli nevadensis, extended from ca. 28 to 37°C. The standard metabolic rate at 35°C was 7·41 kcal/day (mean body wt. = 18·6 g 2. 2. The temperature coefficient (5·8 per cent) and thermal conductance (3·96 kcal/m 2 per hr per °C) were relatively high, indicating poor insulation which is adaptive for desert existence. 3. 3. Between 10 and 35°C the rate of evaporative water loss was constant and averaged 6·7 mg H 2O/g per hr. Evaporative cooling began above 35°C. 4. 4. At high temperatures (43°C) and low humidities (25 per cent) sage sparrows dissipate up to 110 per cent of their metabolic heat production by evaporative cooling. 5. 5. The heat dissipating characteristics and evaporative cooling efficiency of the sage sparrow are somewhat less than in other desert birds.