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Biomedical subjects

W G Pond

Publications and source records attributed to W G Pond.

At least 109 records · Page 6Linked to original sources
PubMed1984

Factors affecting growth and survival of neonatal genetically obese and lean swine: cross fostering experiments.

Obese and lean lines of pigs were developed previously by genetic selection for thick and thin backfat thickness, respectively. A greater proportion of these obese than lean pigs survive to weaning. A cross-fostering experiment was designed to study neonatal piglet growth and to attempt to decipher some of the causes of the increased survival rate. At about 24 h postpartum, lean and obese sows were paired, the litters standardized to six pigs and three pigs from each sow transferred to a dam of opposite genetic line. The smaller birthweight of obese than lean piglets and the lesser growth of either obese or lean pigs raised on obese compared to lean sows were both observations that might support greater survival of lean rather than obese piglets. Positive factors that might contribute toward the greater survival of obese than lean piglets were the greater lipid content of milk from obese than from lean sows during the first 2 wk postpartum and possibly greater physiological maturity of obese than lean pigs at birth as reflected in greater hemoglobin, hematocrit, plasma protein and plasma albumin.

Animals↗
PubMed1983

Effect of gestation diet intake on plasma lipids and progeny birth and weaning weights of genetically lean, obese and contemporary swine.

Genetically obese (O), and lean (L) and contemporary (C) primiparous swine were assigned from day 30 to 40 of pregnancy to parturition to one of two dietary treatments: 1) 1.8 kg daily (6000 kcal DE) digestible energy, and 2) 0.6 kg daily (2000 kcal DE) of a standard corn-soybean meal-based diet. O gilts weighed less and were fatter at week 16 than L or C gilts. L and C gilts fed the low diet intake maintained constant body weight throughout pregnancy while O gilts gained approximately 10 kg. All gilts fed adequate energy gained weight. Plasma free fatty acids were higher and triglycerides were lower in pregnant gilts fed restricted energy. Plasma cholesterol and blood glucose appeared to be unaffected by genetic background, suggesting that genetic propensity to obesity is not necessarily associated with hypercholesterolemia or hyperglycemia. Pig birth weight was reduced by maternal feed restriction only in O and C pigs; survival was higher in progeny of O dams than in those of L and C dams. Maternal energy restriction had no effect on survival in L, C, or O pigs. Preweaning growth of C but not of L or O progeny was adversely affected by maternal feed restriction. The data illustrate the significance of genetic X gestation energy interactions in dam and progeny traits and suggest that a consideration of genetic background is essential in evaluating response criteria related to feed restriction during pregnancy.

Animals↗
PubMed1983

Response of swine to periparturient vitamin C supplementation.

Two experiments were conducted, involving 68 third-litter sows and 20 first-litter gilts in Exp. 1 and 82 first-litter gilts in Exp. 2. On d 108 of gestation, the dams were moved into individual crates, stratified by parity and breed, and randomly assigned within strata, to one of two treatments: (1) fed a basal 16% protein corn-soybean meal diet, 1.8 and 2.7 kg once daily before farrowing and for the first 7 d of lactation, respectively, and then ad libitum until pigs were weaned at 28 d of age, and (2) fed the basal diet plus 1 g of L-ascorbic acid (vitamin C)/dam daily from d 108 of gestation through d 7 of lactation and on the same feeding schedule as for treatment 1. In Exp. 1, no effect of vitamin C supplementation was observed in sows or gilts on total pigs born/litter, number of live pigs/litter or average live pig weight at birth, 7 or 28 d of age, or on plasma vitamin C concentration of dams at d 108 of gestation or d 7 of lactation or of pigs at birth, 7 or 28 d of age. However, there was a lower (P less than .01) plasma vitamin C concentration of the dams at d 7 of lactation than at d 108 of gestation. Plasma vitamin C concentration also declined (P less than .01) as pigs aged. In Exp. 2, with all gilts, vitamin C supplementation again showed no effect on any of the reproductive traits measured in Exp. 1. It is concluded that daily supplementation of 1 g of vitamin C to either sows or gilts from d 108 of gestation through d 7 of lactation has no beneficial effect on the reproductive or lactation performance of swine.

Animals↗
PubMed1983

Effect of dietary calcium and zinc levels on weight gain and blood and tissue mineral concentrations of growing Columbia- and Suffolk-sired lambs.

One hundred and sixty Columbia- and Suffolk-cross intact male and female growing lambs (8 wk of age) were used in an 84-d feeding trial to determine the effect of two levels dietary Ca and Zn on weight gain, feed utilization and several blood and tissue traits. Two levels of Ca (.5 and .8%) and two levels of Zn (20 and 100 ppm) were fed in a 2 X 2 factorial arrangement of dietary treatments. There was no effect of diet on performance or on blood traits. Columbia lambs had heavier fleeces at slaughter than Suffolks (P less than .01) and males had heavier fleeces than females (P less than .01). Based on the similarity in performance among lambs fed the four diets differing in Ca and Zn level, it is concluded that a dietary Ca level of .5% and a Zn level of 19 to 26 ppm is adequate for normal weight gain, feed utilization, liver and humerus ash concentrations and blood plasma concentrations of Ca, P, Zn, total protein, albumin, alkaline phosphatase and blood hemoglobin and hematocrit. Further, it appears that an elevated level of dietary Ca does not precipitate a clinical Zn deficiency in the growing lamb, in contrast to the general observation in growing swine.

Alkaline Phosphatase↗
PubMed1983

The effect of gastric loads of sugars and amino acids on milk intake of suckling pigs.

A 3 h fast of suckling pigs less than a week of age decreased plasma glucose (P less than .005), but did not affect plasma protein, osmolality or hematocrit. After fasting, solutions (40 ml/kg body weight) of 5% glucose, 5% fructose, 5% xylose, 5% mannitol, 5% sorbitol, 2.5% leucine, 2.5% phenylalanine (50 ml/kg), .9% NaCl, 5% lactose, 5% sucrose and a 50% egg yolk-distilled water mixture were administered by stomach tube and the piglet then returned to the sow. Weight gain was used as a measure of sow's milk intake. Milk consumption during the first 3 h after fasting was lower (P less than .05) for pigs given glucose than for sham-loaded controls, but no differences were observed between glucose and mannitol or sorbitol for the same period. Mannitol and sorbitol were more effective than NaCl (P less than .01) in lowering consumption for the 3 h after loading. Also during the first hour after loading, xylose caused lower (P less than .001) food intake than glucose. Egg yolk suppressed intake in comparison to sham-loaded controls (P less than .05). D-phenylalanine suppressed intake more than L-phenylalanine (P less than .05), but no differences were observed between the D and L isomers of leucine.

Amino Acids↗
PubMed1983

Protection by clinoptilolite or zeolite NaA against cadmium-induced anemia in growing swine.

Weanling Landrace X Yorkshire swine were fed a basal diet or a diet containing 3% clinoptilolite (a natural zeolite) with or without 150 ppm CdCl2 or 3% zeolite NaA (a synthetic zeolite) with or without 150 ppm CdCl2 for 31 days. Hematocrit and hemoglobin were depressed significantly in animals fed Cd in the absence of zeolites, but not in their presence. Liver Cd concentration was increased dramatically by added dietary Cd but was significantly lower in animals fed clinoptilolite with Cd than in those fed Cd alone (11.4 vs 16.5 ppm). Liver Fe and Zn were decreased by dietary Cd; liver Fe was not affected significantly by clinoptilolite or zeolite NaA, but liver Zn was increased by zeolite NaA. Kidney dry matter, Zn, and Cd concentrations were increased by dietary Cd; neither clinoptilolite nor zeolite NaA affected kidney Cd concentration. Zeolite NaA increased kidney dry matter both in the presence and in the absence of dietary Cd. Plasma urea-N, K, Na, and Mg were unaffected by Cd or by either zeolite. The data illustrate the different effects of dietary clinoptilolite compared with zeolite NaA on blood plasma, liver, and kidney concentrations of minerals and provide evidence that both zeolites offer some protection against Cd-induced Fe-deficiency anemia; the magnitude of this protection and the effects of each zeolite on tissue concentrations of Cd and other materials need further quantification.

Aluminum Silicates↗
PubMed1982

Influence of high-fiber diet on bacterial populations in gastrointestinal tracts of obese- and lean-genotype pigs.

Bacterial populations from gastrointestinal tracts of genetically lean and obese pigs fed a low- or high-fiber diet (0 or 50% alfalfa meal, respectively) were enumerated with rumen fluid media and specific energy sources. Total culture counts in rectal samples declined 56 (P greater than 0.05) and 63% (P less than 0.05) in lean and obese animals, respectively, 3 weeks after feeding the high-fiber diet. After 8 weeks, culture counts had risen and were similar to those obtained before alfalfa was fed (0 week). At slaughter, 12 to 17 weeks after feeding the high-fiber diet, total counts from rectal samples of lean pigs continued to rise and were 13% greater than the 0-week counts, whereas counts from obese animals declined 37% (P greater than 0.05). The number of cellulolytic bacteria in rectal samples of lean-genotype pigs fed the high-fiber diet increased 80 and 71% from 0 to 3 weeks and 3 to 8 weeks, respectively. This overall increases from 0 to 8 weeks in lean pigs was significant (P less than 0.05); however, these increases were not seen in obese pigs. These data suggest that the microflora is initially suppressed when exposed to a high-fiber diet and that later some adaptation takes place, apparently more so in lean than in obese pigs. When specific energy sources were used to delineate the distribution of different bacterial populations in the cecum, colon, and rectum, trends could be detected between high- and low-fiber diets. These data also support the concept that bacteria populations from different sites in the large bowel differ.

Adaptation, Physiological↗
PubMed1982

Bone lesions in growing swine fed 3% cement kiln dust as a source of calcium.

Cement kiln dust (CKD) samples of which have been reported to stimulate growth in cattle and sheep, was fed to weanling pigs in a 42-d experiment. CKD at levels of 1.5 and 3.0% was added to a corn-soybean meal-oats-whey-type diet containing inadequate amounts of Ca (.4% of the diet) to provide final dietary Ca levels of .85 and 1.3%. A diet containing 3% limestone (1.3% dietary Ca) served as a positive control. Body weight gain was depressed by 3.0% CKD, and histopathological lesions of the humerus, not typical of nutritional secondary hyperparathyroidism or rickets, were observed. The lesions detected were osteonecrosis, thinning of the cortex and reduction in the width of the epiphyseal cartilage. Width of the proximal epiphyseal plate and cortical index of the humerus (width of cortex divided by total diameter at narrowest point of diaphysis) were smaller in pigs fed 3% CKD than in pigs fed 3% limestone. CKD contained 2.3% A1, 15 ppm Cd and 110 ppm Pb, providing 690, .45 and 3.3 ppm of A1, Cd and Pb, respectively, in the diet containing 3% CKD. Kidney, liver and bone ash concentrations of these three minerals were not increased by CKD, and typical toxicity signs were absent. It is concluded that CKD may contain one or more factors that interfere with normal bone metabolism in growing pigs when the diet contains 3.0% CKD.

Animals↗
PubMed1982

Tissue glycogen levels in dams and fetuses as affected by fasting and refeeding pregnant sows.

Nineteen Landrace sows mated to Landrace boars were randomly assigned, on d 91 of pregnancy, to three groups: (1) control (six sows)--fed standard 13% protein corn-soybean meal gestation diet at 1.82 kg/d to d 112 of pregnancy; (2) 4-d fast (seven sows)--fed standard gestation diet to d 94 of pregnancy, fasted from d 95 to 98 of pregnancy and then refed a semipurified fat-free diet ad libitum until d 112 of pregnancy, and (3) 8-d fast (six sows)--treated the same as groups 2, except that the fast began on d 91 and extended through d 98 of pregnancy. The fat-free diet consisted of dextrose and soybean meal and was fortified with minerals and vitamins. On d 112 of pregnancy, all fetuses were removed by Caesarean section and determinations were made of fetal body and liver weights, fetal liver and gastrocnemius muscle glycogen concentrations, and maternal uterus and peritoneal adipose tissue glycogen levels. Sows in groups 2 and 3 consumed more (P less than .01) average daily feed during the refeeding period than did the control sows. Fasting and refeeding failed to affect maternal or fetal tissue glycogen concentration, or fetal body or liver weight. Average sow tissue glycogen concentrations were .23 and 3.0 mg/g tissue for peritoneal adipose tissue and uterus, respectively. Average fetal liver and gastrocnemius muscle glycogen concentrations were, 87 and 62 mg/g tissue, respectively. Average fetal body and liver weights were 1,287 and 39.5 g/fetus, respectively. We conclude that fasting followed by refeeding of a fat-free diet to pregnant sows during late gestation does not increase maternal or fetal tissue glycogen content and appears to be of no value in enhancing pig survival in early postnatal life.

Animal Feed↗
PubMed1982

Plasma glucose, insulin and lipids during growth of genetically lean and obese swine.

Female pigs were selected at birth from litters of genetically lean and obese and contemporary commercial-type pigs to quantify the biweekly changes in fasting concentrations of plasma glucose, immunoreactive insulin, triglyceride and cholesterol during the growing period (birth to 22 weeks of age). Pigs were weaned at 4 weeks of age to a standard corn-soybean meal type dry diet fed ad libitum. Four pigs from each genetic group were used at weeks 4 and 16 of age for a standard oral glucose tolerance test. Plasma concentrations of glucose, insulin, triglyceride and cholesterol were generally similar in all breed from birth to 22 weeks of age. Overall means (N = 306) were: glucose 93.2 mg/dl; triglyceride 37.5 mg/dL, cholesterol 101.8 mg/dL and insulin 10.8 micron Units/ml. There were significant breed differences in a given plasma variable at individual sampling periods, but most were not sustained at earlier or later ages. The genetically lean pigs had lower insulin and triglyceride levels, especially at older ages. Glucose clearance from the plasma at 4 and 16 weeks of age was similar in the three breed groups. It is concluded that these genetically obese pigs selected for fatness over many generations do not manifest their propensity to obesity through modifications in circulating glucose, insulin, triglyceride or cholesterol. Net differences in body fat accretion between these genetically lean and obese populations apparently reside in adipocyte metabolism and are not complicated by an inability to maintain homeostasis of plasma glucose or lipids as is the case with many animal models for obesity. This population of obese and lean swine selected for many generations from a common parental population appears to be a useful model for studies of the metabolic bases of obesity.

Aging↗
PubMed1981

Mature body weight and life span of male and female progeny of primiparous rats fed a low protein or adequate diet throughout pregnancy.

Sixty-one primiparous Sprague-Dawley female rats were fed an adequate diet containing 5% protein (experiment 1) or 8% protein (experiment 2) throughout gestation. Low dietary protein reduced individual pup birth weight in both experiments (P less than .01 in experiment 1 and P less than .10 in experiment 2) and drastically decreased early postnatal survival in experiment 1. Weaning weight of survivors was reduced by gestation protein deprivation in experiment 1 but no in experiment 2. Male and female progeny surviving to weaning in experiment 1 and randomly selected progeny from each maternal treatment in experiment 2 were caged individually and fed ad libitum and nutritionally adequate corn-soybean meal-type diet throughout the entire life span. Body weight were recorded monthly beginning in young adulthood and continuing until death. Life span (in days) was recorded for each rat. Mature body weight of male and female progeny of dams fed restricted protein during gestation was less in both experiments than that of offspring from dams fed an adequate diet (P less than .01). There was no effect of prenatal nutrition on life span in either experiment, but females lived significantly longer than males in both experiments (p less than .05). It is concluded that maternal protein restriction during gestation of a magnitude large enough to reduce pup birth weight causes a significant reduction in mature body size of the progeny without affecting longevity in the rat.

Animals↗
PubMed1981

Effect of doubling daily energy intake during the last two weeks of pregnancy on pig birth weight, survival and weaning weight.

Eighty-eight multiparous sows of four breeds -British Landrace (BL), Chester White (CW), Large White (LW) and Yorkshire(Y)-were mated to boars of their own breed or another breed-BL, Hampshire (H) or Y-to form eight breed groups. All sows were fed daily 1,8 kg of a standard 14% protein gestation diet based on corn-soybean meal through day 100 of pregnancy (6,000 kcal digestible energy/day). From day 100 of gestation to parturition, each sow received either the basal diet (6,000 kcal digestible energy/day) or the basal diet plus 1.82 kg corn starch (12,000 kcal digestible energy/day). All sows were fed a 16% protein corn-soybean meal-based diet ad libitum from day 1 to day 28 of lactation. Energy intake during gestation had no effect on individual pig birth weight, percentage survival or 28-day body weight. There were differences among breeds in pig birth weight (P less than .01) and 28-day weight (P less than .01), and a breed X gestation energy level interaction (P less than .05) was found, but the biological significance is questionable because of the small sample size. Pigs that nursed before blood samples were taken had lower (P less than .01) hematocrit than pigs not allowed to nurse before blood sampling. Energy intake of the dam had no effect on the magnitude of the difference between nursed and nonnursed pigs. We conclude than the normal pregnant dam maintains blood glucose homeostasis during hyperalimentation, thereby rendering ineffective this approach to increasing neonatal growth and survival.

Animals↗
PubMed1981

Effect of dietary vitamin C addition on performance, plasma vitamin C and hematic iron status in weanling pigs.

Each of 64 pigs weaned between 4 and 5 weeks of age was fed ad libitum one of four diets: (1) a basal 18% crude protein, corn-soybean meal-oats-dried whey starter diet or (2,3,4) the basal diet supplemented with 330, 660 or 990 ppm L-ascorbic acid (vitamin C). The pigs were kept in groups of four and housed in an environmentally regulated nursery with a raised, expanded metal floor. The room temperature was maintained at 21 C and floor allowance was .54 m2/pig. After 28 days, dietary vitamin C supplementation had improved daily weight gain and daily feed intake of pigs without altering gain to feed ratio. Plasma vitamin C concentration decreased during the 4 weeks period after weaning in pigs not fed supplemental vitamin C but not in those fed supplemental vitamin C. Plasma Fe was reduced at day 28 in pigs given supplemental vitamin C. Simple correlation indicated a positive (P less than .05) relationship between plasma vitamin C concentration and weight gain and a negative (P less than .05) relationship between plasma vitamin C and plasma Fe concentration. Results obtained suggest that, under the experimental conditions, young pigs weaned between 4 and 5 weeks of age require dietary vitamin C supplementation for maximum weight gain and that the benefit of vitamin C addition may be related to Fe metabolism.

Animal Feed↗