Biomedical subjects

C L Ferrell

Publications and source records attributed to C L Ferrell.

At least 55 records · Page 3Linked to original sources

PubMed1991

Level of nutrition and splanchnic metabolite flux in young lambs.

Splanchnic metabolite flux was measured in young lambs given access to a high-concentrate diet either ad libitum (ADLIB) or at a maintenance level (MAINT) for 21 d. Net fluxes of urea N (UN), ammonia N (NH3 N), alpha-amino N (AAN), amino acids, glucose (G), and lactate (L) across the liver and portal-drained viscera (PDV) were measured in 11 crossbred ram lambs (35 kg) surgically fitted with indwelling catheters in the portal, hepatic, and mesenteric veins and mesenteric artery. During the 21-d period, daily N and ME intakes were 24.6 and 10.7 g N/d and 3.02 and 1.28 Mcal/d, respectively, for ADLIB and MAINT lambs. Intakes, thus, were 42% lower for MAINT than for ADLIB lambs. Net portal fluxes of UN, NH3 N, AAN, and L in MAINT lambs were 46%, 84%, 50%, and 74%, respectively, of that in ADLIB lambs. Expressed as a percentage of N intake, the proportion of AAN absorbed by the PDV was higher in MAINT lambs (P less than .05) than in ADLIB lambs. There was no net portal glucose absorption in either group of lambs; however, net hepatic glucose production in MAINT lambs was 48% of that in ADLIB lambs. There was net utilization of glutamine by the PDV; net glutamine flux in MAINT lambs was 49% of that in ADLIB lambs. The liver utilized AAN and NH3 N and produced UN. Splanchnic tissues modulate metabolite flux following changes in feed intake in young ruminants.

Amino Acids↗

PubMed1991

Maternal and fetal influences on uterine and conceptus development in the cow: I. Growth of tissues of the gravid uterus.

Objectives of this study were to evaluate maternal and fetal influences on development of gravid uterine tissues of cows. Brahman cows with Brahman or Charolais fetuses and Charolais cows with Brahman or Charolais fetuses were used. Cows were killed 232 +/- .5 or 271 +/- .7 d after mating. The gravid uterus of each cow was weighed and dissected into its component parts. Weights of the fetus, fetal membranes, cotyledons, caruncles, and uterus were recorded as were weights of the fetal liver, heart, kidneys, spleen, lungs, stomach complex, intestines, and semitendinosus muscle. Ribonucleic acid, DNA, and protein concentrations in caruncles, cotyledons, liver, heart, kidney, and semitendinosus muscle were determined. Data were analyzed by analysis of variance; breed of cow (C), breed of fetus (F), day of gestation (D), and all interactions were included in the model as fixed effects. Fetal weights were influenced (P less than .003) by C, F, D, and C x D and tended (P = .07) to be influenced by C X F X D. Weight, RNA, DNA, and protein contents of selected fetal tissues followed similar patterns of significance. Thus, both maternal and fetal genotype influenced fetal growth. Greater influences of the maternal system and interrelationships between maternal and fetal systems were observed at the latter stage of gestation. Placentomal (caruncle + cotyledon) weights were greater for Charolais than for Brahman cows (P less than .02) or fetuses (P less than .001) and were greater (P less than .01) at 271 than at 232 d. Caruncular weights followed similar patterns; however, fetal genotype was the only significant source of variation in cotyledonary weight, RNA, DNA, or protein content.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

Maternal and fetal influences on uterine and conceptus development in the cow: II. Blood flow and nutrient flux.

Objectives of this study were to evaluate maternal and fetal influences on uterine and umbilical blood flows and nutrient fluxes of gravid uterine tissues of cows. Brahman cows with Brahman or Charolais fetuses and Charolais cows with Brahman or Charolais fetuses were used. Indwelling catheters were placed into a uterine artery and vein, an umbilical vein, and a fetal femoral artery and vein at 220 +/- .4 d after mating. Uterine and umbilical blood flows (liters/min) and net uptakes of oxygen, glucose, lactate, alpha-amino N, urea N, ammonia N, and estrone sulfate by the gravid uterus, fetus, and uteroplacenta were determined on d 227 +/- .4. Uterine blood flows in Brahman cows with Brahman (5.01) or Charolais (4.66) fetuses were similar but less (P less than .001) than in Charolais cows with Brahman (7.14) or Charolais fetuses (9.24), which differed (P less than .01). Umbilical blood flows of Charolais (3.78) were greater (P less than .01) than those of Brahman (2.29) fetuses. Rate of placental D2O clearance as well as net fetal uptake of oxygen, glucose, and alpha-amino N, gravid uterine uptake of alpha-amino N, and uteroplacental uptake of glucose and release of estrone sulfate were greater with Charolais than with Brahman fetuses. Gravid uterine oxygen uptake and estrone sulfate release and gravid uterine and uteroplacental lactate output were influenced by the interaction between cow and fetal breed. It is suggested that fetal growth may be limited by uterine blood flow and by function of the uteroplacenta, particularly in late gestation.

Animals↗

PubMed1991

Differences among breed crosses of cattle in the conversion of food energy to calf weight during the preweaning interval.

The objective of this study was to determine whether F1 cows that differ in genetic potential for weight at maturity and milk yield vary in the conversion of food energy to calf weight gain. Food intakes and weight change data were recorded by pen for cows and calves from approximately 45 d postpartum. Cows assigned to the study were 7- to 9-yr-old F1s produced by top-crossing Angus, Hereford, Brown Swiss, Chianina, Gelbvieh; Maine Anjou, and Red Poll sires to either Angus or Hereford dams. Calves were sired by Simmentals. Experimental units were pens (10 to 12 cow/calf pairs); pen was replicated within breed of sire in each of 2 yr (n = 24). Calf weight gain and energy consumed by the dams differed among the F1s, as did the ratio of calf weight gain to energy consumed by the calf and cow. Angus or Hereford (35.8), Red Poll (35.7), or Maine Anjou (35.6) F1s produced more calf weight per unit of energy consumed (g/Mcal) by the cow and calf than Chianina (33.1) or Gelbvieh (33.7) F1 females; Brown Swiss cows were intermediate (34.3). Differences in food conversion efficiency exist among breed crosses. These differences seem to be associated with breed cross differences in genetic potential for milk yield and mature weight; an exception to this trend was the Maine Anjou.

Analysis of Variance↗

PubMed1991

Evaluation of between- and within-breed variation in measures of weight-age relationships.

Variation between- and within-breeds was evaluated for accretion of weight from birth to 7 yr of age and hip height at 7 yr for 1,577 cows sired by Angus, Brahman, Brown Swiss, Charolais, Chianina, Gelbvieh, Hereford, Jersey, Limousin, Maine Anjou, Pinzgauer, Sahiwal, Simmental, South Devon, and Tarentaise and from either Angus or Hereford dams. Parameters from Wt = A (1 - Be-kt) were estimated by nonlinear regressions and provided estimates of mature body weight (A) and rate of weight accretion relative to change in age (k) for each cow. Actual weight at birth, linear adjusted weights at 200, 365, and 500 d of age, ratios of these weights to mature weight, and height at the hip at 7 yr were analyzed. Beyond 20 mo, weights were adjusted to a constant condition score within breed of sire. Variance and covariance components were derived for breed (sigma 2 b), sires within breed (sigma 2 s), and progeny within sire (sigma 2 w). For all traits, the sigma 2 b estimate of genetic variance ranged from two to four times greater than the variance component for sigma 2 s. Between-breed heritabilities were .91 +/- .27 and .54 +/- .17 for A and k, respectively. Estimates of within-breed heritability for these two traits were .61 +/- .11 and .27 +/- .09. Estimates, both between- and within-breed, of the genetic correlation between A and k were moderate to large and negative; those between A and weights at 200, 365, and 500 d and height at maturity were large and positive. Selection for immediate change in measures of growth would be most effective among breeds. Sufficient direct genetic variation exists between breeds to enhance breed improvement of growth characters through breed substitution. Greater opportunity to alter the shape of the growth curve exists through selection for within-breed selection than through breed substitution.

Aging↗

PubMed1991

Growth, body composition, and visceral organ mass and metabolism in lambs during and after metabolizable protein or net energy restrictions.

Three trials were conducted to assess effects of metabolizable protein and NE deficiencies on changes in body composition, organ mass and metabolism, and animal growth performance during restriction and realimentation. Growth of lambs was restricted to achieve no change in BW for periods of 5 to 6 wk by limiting intake of metabolizable protein or NE. In Trial 1, changes in body composition and visceral organ mass and metabolism during restriction were compared to unrestricted controls using 36 lambs. Trial 2 was designed to investigate changes in growth, body composition, and visceral organs during restriction and realimentation periods using 44 lambs. Trial 3 was limited to evaluation of differences in performance and carcass characteristics of previously restricted and unrestricted ram lambs (15 total). Results of Trial 1 indicated that liver weights were decreased with nutrient restrictions. Body protein mass was conserved in energy-restricted (ER) lambs and lost in protein-restricted (PR) lambs. Fat was mobilized at similar rates for PR and ER lambs. In Trial 2, liver and intestinal weights, as well as in vitro oxygen consumption by liver slices, were decreased with nutrient restrictions. The reductions persisted after 2 wk of realimentation, yet no compensatory growth was observed. Feed intakes were increased gradually during the first 2 wk of realimentation. Composition of gain during the realimentation period was similar to that of unrestricted lambs. In Trial 3, neither gain nor feed efficiency during realimentation was enhanced as a result of previous nutrient deficiencies. Absence of compensatory growth in Trial 3 is possibly attributable to differences in gastrointestinal fill. Lambs subjected to short-term PR and ER seem to have similar recuperative capacity.

Adipose Tissue↗

PubMed1990

Level of nutrition and visceral organ size and metabolic activity in sheep.

Thirty-two crossbred wether lambs (initial live-weight 31 kg) were fed on a diet (metabolizable energy (ME) 12.8 MJ/kg) ad lib. (ADLIB) or restricted to maintain body-weight (MAINT) for a 21 d period. On days 0, 7, 14 and 21, four lambs per treatment were slaughtered, visceral organs weighed and tissues sampled. During the 21 d period, ME intake in ADLIB lambs increased quadratically with an average rate of live-weight gain of 425 g/d. In MAINT lambs, live weight (30 kg) was maintained, and daily ME intake (kJ/kg empty body-weight (EBW)0.75) declined (P less than 0.01) quadratically with time. Weights of liver, stomach and small intestines as a percentage of EBW were increased in ADLIB lambs and decreased by 10-33% in MAINT lambs (treatment x day, P less than 0.01). In vitro liver oxygen consumption was not affected by level of feed intake. Estimates of whole-liver O2 consumption (mmol O2/d per kg EBW) increased in ADLIB lambs and were relatively constant in MAINT lambs. These findings suggest that level of feed intake changes the relative proportion of visceral organs to body mass. In addition, the effect of level of feed intake on changes in the relative contribution of visceral organs to whole-body metabolic rate appears to be primarily a result of differences in organ size rather than tissue-specific metabolic activity.

Animal Nutritional Physiological Phenomena↗

PubMed1990

Growth hormone, insulin and glucose concentrations in bovine fetal and maternal plasmas at several stages of gestation.

For cows on d 137 (n = 6), 180 (n = 8), 226 (n = 9) and 250 (n = 5) of gestation (Exp. 1), concentrations of insulin and glucose were two- to three-fold less (P less than .01) in fetal venous plasma than in uterine arterial plasma. Concentrations of growth hormone, conversely, were 10- to 20-fold greater (P less than .01) in fetal venous than in uterine arterial plasma. Concentrations of insulin and glucose in maternal and fetal plasmas and concentrations of growth hormone in maternal plasma did not vary with stage of gestation. Concentrations of growth hormone in fetal venous plasma, however, were greater on d 226 and 250 than on d 137 and 180. For cows (n = 6) on d 198 of gestation (Exp. 2), concentrations of insulin and glucose in maternal and fetal plasmas and of growth hormone in maternal plasma remained relatively constant in samples collected every 30 min for 3 h. In contrast, growth hormone concentrations in fetal venous plasma were highly variable and appeared to be episodic, with pulses of 10 to 60 ng/ml in amplitude. No significant correlations were found among concentrations of insulin, glucose and growth hormone in fetal venous plasma. When samples were collected every 15 min for 4 h from cows (n = 5) on d 198 of gestation (Exp. 3), episodes of growth hormone in fetal venous plasma were irregular in amplitude and frequency.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Effects of short term nutritional manipulation on organ size and fasting heat production.

Two studies were conducted to study the effects of short term nutritional manipulation on the organ size and the fasting heat production of pigs and sheep. The results of these studies indicate that fasting heat production can differ up to 40 per cent for animals of same age and weight, but with different nutritional backgrounds. Those animals on a higher plane of nutrition preceding measurements had higher fasting heat production, in spite of being the same age and body weight. At the same time, the weights of metabolically active organs such as the stomach, the small and large intestine, the liver and the kidneys are also very sensitive to the nutritional manipulation, in a parallel direction to that observed with fasting heat production. These findings provide strong evidence that the energy expenditures of the metabolically active tissues account for a significant amount of basal metabolic activity far in excess of the proportional weights of these tissues.

Animals↗

PubMed1989

Effect of level of nutrition on splanchnic blood flow and oxygen consumption in sheep.

The objective of the present study was to measure changes in splanchnic blood flow and oxygen consumption in sheep fed on a high-concentrate diet ad lib. (ADLIB) or an amount sufficient to maintain body-weight (MAINT) for 21 d. Eleven ram lambs were surgically implanted with chronic indwelling catheters in the portal, hepatic and mesenteric veins and mesenteric artery to measure blood flow and net O2 flux through the liver and portal-drained viscera (PDV). During the 21 d period, PDV (P less than 0.05) and liver (P less than 0.01) blood flow increased in ADLIB and decreased in MAINT lambs (treatment x day, linear). After 21 d, O2 consumptions in PDV and liver of MAINT lambs were 37 and 63% lower than in ADLIB lambs. In the control period, total splanchnic tissues represented an average of 52% of whole body O2 consumption. After 21 d, the relative contributions of PDV and liver to whole-body O2 consumption were 28 and 41% in ADLIB and 19 and 22% in MAINT lambs respectively. Allometric regression variables indicate that liver O2 consumption responds more rapidly to changes in metabolizable energy intake than portal O2 consumption. These results indicate that blood flow and O2 consumption in both PDV and liver are related to level of nutrition. Furthermore, splanchnic tissues represent a significant component of whole-body O2 consumption that is subject to manipulation by level of nutrition.

Animal Nutritional Physiological Phenomena↗

PubMed1988

Visceral organ size and hepatocyte metabolic activity in fed and fasted rats.

Changes in visceral organ mass and hepatocyte metabolic activity in response to nutrient deprivation were studied in male Sprague-Dawley rats. Forty-two rats (320 g) were given ad libitum access to feed or fasted for 72 h after which time visceral organ mass and metabolic activity were measured. Liver metabolic activity was measured in vitro by [14C]valine incorporation into acid-precipitable protein and oxygen consumption in isolated hepatocytes. Fasted rats had lower weights of liver and intestines and similar kidney and stomach weights relative to body weight than fed rats. Compared with fed controls, fasted rats had lower RNA and higher DNA concentrations in liver and intestines with decreased RNA and protein mass in all visceral organs. Nutrient deprivation generally resulted in reduced ratios of RNA/DNA and protein/DNA in visceral tissues. Nutrient deprivation had no effect on in vitro oxygen consumption or [14C]valine incorporation expressed per g tissue. However, in vitro oxygen consumption and valine incorporation expressed per unit DNA and estimated total liver oxygen consumption were reduced in fasted rats. These data suggest that nutrient deprivation reduced visceral organ mass of RNA and protein primarily through an apparent reduction in cell size. Nutrient deprivation resulted in decreased liver oxygen consumption because of decreased organ size rather than by tissue metabolic activity.

Animals↗

PubMed1988

Effects of dietary clenbuterol on metabolism of the hindquarters in steers.

The objective of this study was to measure acute (d 1) and chronic (d 9) effects of dietary clenbuterol on heart rate, blood flow, oxygen uptake, and net uptake/release of metabolites in the hindquarters of growing steers. The design was a single reversal with two 9-d periods of control or 8 mg clenbuterol/d with 5 d between periods. Within 2 h of initial consumption of 2 mg clenbuterol (d 1), heart rate and blood flow doubled and arterial plasma concentrations of glucose, L-lactate and nonesterified fatty acid (NEFA) increased, whereas alpha-NH2 N and NH3 concentrations decreased, demonstrating an acute response. Uptake of oxygen increased and net uptake of alpha-NH2 N decreased. Net release of both L-lactate and NEFA increased. On d 9, there were no acute responses to clenbuterol consumption; however, heart rate, blood flow, and NEFA concentration remained chronically elevated, and plasma concentrations of acetate and propionate decreased compared with control feeding. Net uptake of alpha-NH2 N, oxygen and release of L-lactate by the hindquarters chronically increased on d 9 of clenbuterol feeding. Changes in both blood flow and arteriovenous (AV) concentration difference contributed to changes in uptake/release. The chronic metabolic changes and oxygen uptake were consistent with increased N retention in the hindquarters through increased protein synthesis, decreased use of acetate and increased reliance on NEFA for cellular energy. In conclusion, the data show that the perturbation of homeostatic regulation by dietary clenbuterol on d 1 evolved to establishment of homeorhetic regulation by d 9 that is consistent with increased skeletal protein accretion in growing steers.

Animals↗

PubMed1987

Transplacental clearance and blood flows of bovine gravid uterus at several stages of gestation.

Rates of uterine and umbilical blood flows and transplacental clearance of deuterium oxide (D2O) were determined for cows on 137 +/- 1.0 (SE, n = 9), 180 +/- 0.5 (n = 8), 226 +/- 0.4 (n = 9), and 250 +/- 1.8 (n = 5) days of gestation. From days 137 to 250, rates increased 4.5-fold for uterine blood flow, 21-fold for umbilical blood flow, and 14-fold for clearance of D2O. Changes in rates of umbilical blood flow and D2O clearance paralleled increased rates of fetal growth and metabolism, which have previously been reported to occur during the last half of gestation. The regressions of D2O clearance on uterine and umbilical blood flows were significant (P less than 0.01) and explained 94-99% of the variation in placental clearance of D2O. Because the rate of D2O clearance was always less than that of uterine and umbilical blood flows, and because a relatively simple statistical model explained most of the variation in clearance, it was suggested that a concurrent or countercurrent arrangement of maternal and fetal placental microvasculatures is not adequate to explain clearance of highly diffusable substances across the bovine placenta. In addition, a placental exchange diagram of the data showed the existence of severe uneven distribution of maternal and fetal placental blood flows and/or significant shunting of maternal and fetal placental flows away from areas of exchange. Taken together, these data indicate that the placenta of the cow, like those of the sheep and goat, represents a relatively inefficient system of transplacental exchange.

Animals↗

PubMed1987

Blood flow to hindquarters of steers measured by transit time ultrasound and indicator dilution.

The objective was to compare blood flow to the hindquarters of steers measured by transit time ultrasound with blood flow determined by indicator (p-aminohippurate) dilution. Five Hereford steers had ultrasonic flow probes on the abdominal aorta and catheters in the abdominal aorta and inferior vena cava inserted through both sets of circumflex iliac vessels. Indicator was infused continuously into the abdominal aorta through both arterial catheters simultaneously, then through each of the arterial catheters in succession. Samples of blood from the inferior vena cava and jugular vein were taken during infusion for measurement of p-aminohippurate. Blood flow determined by the ultrasonic flow probe was averaged over each blood sampling interval. Compared with the ultrasonic flow probe there was no difference in mean blood flow measured by p-aminohippurate, regardless of method of infusion. Correlation of individual values between ultrasound and p-aminohippurate was .87 when p-aminohippurate was infused into both arterial catheters, .44 when p-aminohippurate was infused into the left arterial catheter, and .78 when p-aminohippurate was infused into the right arterial catheter. The respective ranges for ultrasonic measurements and p-aminohippurate were 3.62 to 10.99 L/min and 2.25 to 30.43 L/min. Although means by the two methods do not differ, there is a greater range and incidence of occasional high values with p-aminohippurate dilution.

Animals↗

PubMed1987

Dissecting aneurysm of the coronary artery.

Explore the source record for details and available documents.

Adult↗

PubMed1986

Effect of previous nutrition on body composition and maintenance energy costs of growing lambs.

1. Forty-eight intact male lambs (30 kg) were fed to gain 16 (H), 5 (M) or -6 (L) kg during a 42 d interval (period 1). Lambs from each of the H and M groups were fed to gain either 16 (HH, MH), 5 (HM, MM) or -6 (HL, ML) kg and lambs from the L group were fed to gain 27 (LS), 16 (LH) or 5 (LM) kg during the ensuing 42 d (period 2). 2. Fasting heat production (FHP) of four lambs from each treatment was determined at the end of period 2. 3. Weights and compositions of the carcass, offal and digesta-free body as well as weights of major internal organs were determined for four lambs of each treatment at the end of periods 1 and 2. 4. Within groups of lambs of similar weight at the end of period 2, body composition was, in general, similar, but FHP was greater in lambs that had been on higher planes of nutrition during period 2. 5. Within groups of lambs of similar weight, lambs that were fed at higher planes of nutrition during period 2 had greater weights or proportions of liver, small intestine, large intestine and stomach. 6. Neither weight of the liver, kidney, stomach, small intestine, large intestine nor daily fasting heat production were constant functions of body-weight. Relations of these traits to body-weight changed with rate of gain. 7. Regression analysis indicated that the feeding of lambs at higher planes of nutrition during period 1 resulted in higher maintenance requirements of those lambs during period 2.

Animal Nutritional Physiological Phenomena↗

PubMed1986

Influence of plane of nutrition on body composition, organ size and energy utilization of Sprague-Dawley rats.

Male (61) and female (53) Sprague-Dawley rats (31 d of age, 85 g) were used to evaluate the influence of plane of nutrition on body composition, internal organ size and energy utilization. Six male and nine female rats were sacrificed initially. The remaining animals were randomly assigned, within sex, and fed to gain either 105 g (H) or 40 g (M) or lose 25 g (L) during a 21-d period. Nine rats each from the H and M groups and six from the L group were then sacrificed. The remaining rats from the H (27) and M (27) groups were fed to gain at the H, M or L rate and rats from the L (12) group were fed to gain at the H or M level during a second 21-d period. All rats were sacrificed at the end of the second period. Body composition and weights of internal organs were determined and relationships between energy intake and energy gain were evaluated. Results indicated that at the end of period 2, body composition at equal age and body weight was influenced by nutritional treatment. At equal body weight, body protein weights were lower (P less than 0.05) and body fat, liver and gut weights higher (P less than 0.05) for rats on higher planes of nutrition. Feed required for maintenance of rats during period 2 tended to be lower and efficiencies of gain tended to be higher for rats fed the low level than for those fed the high level during period 1. Rats fed the medium level during period 1 had similar maintenance requirements but higher efficiencies of gain during period 2 than rats fed the high level during period 1. These results suggest that previous nutrition influenced energy utilization through adaptation of high energy expending internal organs as well as through alterations in body composition and composition of body weight gain.

Animal Nutritional Physiological Phenomena↗

PubMed1986

Growth, development and body composition in three genetic stocks of swine.

Differences in growth, chemical body composition and visceral organ development were evaluated in three genetic stocks: Beltsville Highfat (HF) and Lowfat (LF) Duroc-Yorkshire composites and a Hampshire X Large White cross (CX). Ten sets of littermate barrows were used from each stock. One pig from each set was slaughtered at 10, 17 and 24 wk of age. After slaughter, each pig was dissected into three fractions: carcass, head and feet, viscera and blood. Backfat was measured at three locations and visceral organs were weighed separately. Each fraction was frozen, ground, sampled and analyzed in duplicate for protein, fat, water and ash. The CX pigs were heaviest at all ages and contained the most fat-free mass (FFM). The HF pigs were smallest and contained the most fat, while LF pigs tended to be intermediate. The LF pigs deposited a greater proportion of weight in head and feet and a greater proportion of total FFM in the carcass than HF and CX pigs. Estimated allometric growth coefficients for non-fat chemical components relative to empty body weight (EBWT) were lower for HF than LF and CX, which were similar. Coefficients for fat were similar among stocks yet intercepts differed widely. Relative to total FFM, water increased at a faster rate and ash a slower rate in CX pigs compared to HF and LF. Growth coefficients were calculated for internal organs relative to EBWT. Coefficients for organs of the digestive tract were not different among stocks. However, significant differences among stocks were found for heart, lung, spleen and liver that were not explained by differences in body composition.

Animals↗