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Biomedical subjects

W G Pond

Publications and source records attributed to W G Pond.

At least 91 records · Page 5Linked to original sources
PubMed1987

Effect of severe dietary protein, nonprotein calories or feed restriction during gestation on postnatal growth of progeny in swine.

Second-parity swine were assigned at breeding and continued through two reproduction-lactation cycles (second and third parities, phases one and two) on four dietary treatments as follows: Control (C), 1.8 kg of a standard gestation diet daily (6000 kcal DE daily) to parturition; "Protein-free" (PF), 1.8 kg of a semipurified diet containing less than .5% protein (6000 kcal DE daily) to parturition; Restricted control (R), 0.6 kg of a maize-soybean meal-based gestation diet (C) daily (2000 kcal DE daily) to d 70 of gestation and 1.8 kg daily (6000 kcal DE daily), from d 71 to parturition; Restricted nonprotein calories (RCal), 0.6 kg daily (2000 kcal DE daily) of a diet containing three times the concentrations of protein, vitamins and minerals present in the C diet to d 70 of gestation and 1.8 kg daily (6000 kcal DE daily) of the C diet to parturition. All sows were fed a 16% protein diet ad libitum from parturition to d 28 postpartum. Number of piglets born/litter was unaffected by gestation diet, but individual birth weight was less (P less than .01) in PF than in other progeny in both parities. Postweaning daily weight gain was less (P less than .01) in PF progeny than in other progeny and daily feed intake was less in PF than in C progeny (P less than .05) but intake of PF, R and RCal progeny did not differ. Body weight, chilled carcass weight, carcass length, and weights of trimmed wholesale cuts were less in PF than in other progeny at slaughter. It is concluded that severe protein restriction throughout pregnancy reduces postweaning weight gain of progeny, and that restricting nutrients other than protein and nonprotein calories to one-third of intake recommended by the National Research Council during the first two-thirds of pregnancy does not affect postweaning body weight gain of progeny of swine whose response to the nutritional insult does not result in reduced piglet birth weight.

Animals↗
PubMed1986

Comparative effects of dietary protein and cholesterol-fat content on genetically lean and obese pigs.

Interactions of a high fat-high cholesterol diet with low and high dietary protein levels were tested in genetically obese and lean growing pigs. Sixty-four growing swine (32 obese and 32 lean) were utilized in a 9-wk experiment in which four diets were fed in a 2 X 2 factorial arrangement with two levels of plant protein (8 and 16%) and two levels of fat and cholesterol (0 added or 11% beef tallow-3% dried egg yolk added). Daily gain and gain-to-feed ratio were significantly reduced by low protein (P less than 0.01) and increased by high fat-high cholesterol. Obese pigs gained weight faster than lean pigs but were less efficient in feed utilization (P less than 0.02) except when consuming low protein diets (P less than 0.001). Plasma cholesterol was increased by low protein (P less than 0.01) and by high fat-high cholesterol (P less than 0.02); highest values were in pigs fed low protein-high fat-high cholesterol. Lean pigs showed a greater rise than obese pigs in plasma cholesterol when fed low protein diets, reflecting a higher dietary protein requirement for lean pigs as indicated by plasma total protein, albumin and urea nitrogen (urea-N) responses to diet. Percentage of aortic surface area stained by Sudan IV tended to be higher in lean than in obese pigs but the difference was not statistically significant (P less than 0.25). The data show the hypercholesterolemic effect of dietary protein restriction in growing swine and establish that genetic differences related to body composition and quantitative protein requirement affect the response.

Animals↗
PubMed1986

Response of nonpregnant versus pregnant gilts and their fetuses to severe feed restriction.

Crossbred (Chester White X Landrace X Large White X Yorkshire) primiparous gilts were fed a standard gestation diet at 6,000 or 2,000 kcal calculated digestible energy (DE; 1.8 or .6 kg feed) daily for 84 or 108 (106 to 112) d after mating. Nonpregnant littermates were matched by body weight and assigned to the same diet treatments. Body weight and ultrasonic backfat measurements were made at 3-wk intervals. At 77 and 100 d, eight pregnant gilts (four control and four restricted) were fitted with indwelling jugular cannulas for frequent blood sampling (33 times over an 8-h period) to determine plasma glucose and growth hormone concentrations. At 84 and 108 d all gilts (eight pregnant and eight nonpregnant at d 84 and nine pregnant and nine nonpregnant at d 108 for each diet) were slaughtered and internal organs and reproductive tracts were removed and weighed. Fetal body and organ weights were recorded and an umbilical artery blood sample was removed from fetuses for plasma glucose, growth hormone, total protein and albumin measurements. The results demonstrated the ability of the primiparous gilt to maintain pregnancy through 106 to 112 d of gestation while consuming one-third (2,000 kcal DE daily) of recommended daily feed. Fetal weight at 84 and 108 d was reduced by about 13% without affecting litter size in gilts fed severely restricted intakes. Absolute and relative weights of maternal organs were affected by severe feed restriction, and backfat was reduced but there was no evidence of "pregnancy anabolism" in either adequately fed or restricted gilts. Fetal liver, kidney and gastrointestinal tract weights were reduced by maternal feed restriction; relative kidney weights were reduced while relative brain cortex weight was increased by maternal restriction. Maternal plasma glucose was unchanged by pregnancy or feed intake while plasma growth hormone peak amplitude, but not mean concentration or number of peaks, was increased by feed restriction. Fetal plasma glucose increased with time and in response to severe maternal feed restriction while plasma total protein and albumin decreased. Plasma growth hormone declined with time and was negatively correlated with fetal body weight.

Animals↗
PubMed1986

Effect of gestation-lactation diet calcium and zinc levels and of parenteral vitamins A, D and E during gestation on ewe body weight and on lamb weight and survival.

Data on ewe body weights and on lamb birth and weaning weights and survival rates were recorded on a total of 557 multiparous Rambouillet, Hampshire X Suffolk and Synthetic I (composite of Finnish Landrace, Rambouillet and Polled Dorset) ewes in two experiments started after the first trimester of gestation. In Exp. 1, a 2 X 2 factorial arrangement of treatments included all combinations of low (.24% in gestation and .48% in lactation), or high (.80%) dietary Ca and low (20 ppm) or high (74 ppm) dietary Zn. No effect of dietary Ca or Zn level and no Ca X Zn interaction with respect to number of lambs born or weaned, birth weight, weaning weight or survival rate of the lambs or body weight of the ewes was shown. Mean number of lambs born was 1.63 +/- .71 with a survival rate of 85.0 +/- .3% and a weaning weight (59 d) of 19.4 +/- 4.4 kg. Experiment 2 was a repeat of Exp. 1 except that two intramuscular injections of vitamins A, D and E (d 65 and 93 of experiment) were given to one-half of the ewes in each diet group. There was no effect of dietary Ca or Zn level or of vitamin administration on ewe body weight changes, number of lambs born (1.89 +/- .55), survival rate (86.6 +/- .3%), lamb birth weight 4.6 +/- 1.5 kg) or lamb weaning weight (23.2 +/- 7.2 kg). Blood plasma Ca, inorganic P and Mg concentrations of ewes in late pregnancy were unaffected by diet or vitamin injections.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Nutritional Physiological Phenomena↗
PubMed1986

Markers for estimating digesta flow in pigs and the effects of dietary fiber.

Effects of diluting the energy content of a corn-soybean meal diet with either alfalfa meal or corn cobs on nutrient digestibility and rate of passage of feed residues and particle markers were measured in crossbred (Yorkshire X Landrace X Chester White X Large White) barrows with a mean body weight of about 80 kg. The excretion pattern in the feces of Cr-mordanted diet and of rare earths initially bound individually to the mixed diet or to the corn or soybean meal suggested a model having a single age-dependent compartment with time delay. The compartmental turnover rate parameter (lambda 1) estimated by this model did not differ for the rare earths individually used to mark the corn-soybean meal diet (Yb), the corn (La) or the soybean meal (Sm). In contrast, lambda 1 for Cr was smaller (P less than .001) than that of the mean for the three rare earths. The residence time due to displacement flow (tau) did not differ among markers. These results were interpreted to indicate that the high specific gravity of Cr-mordanted feed slowed flow due to mixing but not due to displacement. Correlations between lambda 1 and tau were less than .71. These results suggested that the flow of rare earths initially bound to feed ingredients provides a reasonable estimate of the flow of their undigested residues through the gastrointestinal tracts of nonruminant animals. Inclusion of the fibrous feeds reduced digestibility of dry matter, cell contents, crude protein and acid detergent lignin and increased digestibility of cell walls, cellulose and acid detergent fiber. Digestibilities of cellulose and acid detergent fiber were greater with alfalfa than with corn cobs as the fiber source. Differences in digestibility of crude protein and acid detergent fiber existed due to litter in one replicate of the experiment. Variation in digestibility was not significantly related to variation in lambda 1 or tau within or among treatments and litters. This suggests that variations in lambda 1 and tau were not important causes of the observed variation in digestibility.

Animal Feed↗
PubMed1986

Heritability of plasma cholesterol and triglyceride concentrations in swine.

Three-hundred and eighteen female swine representing contemporary commercial swine breeds (34 Chester White, 43 Large White, 42 Landrace, 40 Yorkshire, and 159 four-breed crossbreeds) were used to evaluate genetic variation between and within breeds for levels of plasma cholesterol and plasma triglycerides. Blood was sampled from all pigs after a 16-hr fast at 154 days of age. Plasma cholesterol was measured in all pigs and triglycerides were measured in 232 pigs. Paternal half-sib heritabilities (h2) for plasma cholesterol and plasma triglycerides were 0.45 +/- 0.23 and 1.04 +/- 0.32, respectively. Breed differences were not apparent for either trait. Phenotypic and paternal half-sib genetic correlations between the two traits were 0.16 and 0.66, respectively. Neither body weight nor backfat depth were important in affecting the estimate of h2 for either trait. The relatively high h2 of total plasma cholesterol and of total triglycerides offers the possibility of developing, through selection, populations of hypercholesterolemic or hypertriglyceridemic swine useful as models for studies directed toward further understanding of human cardiovascular disease.

Animals↗
PubMed1986

Liver ornithine decarboxylase activity in suckling pigs after short term maternal deprivation.

Two female piglets from each of 23 litters were used to determine the effect of short term maternal deprivation on liver ornithine decarboxylase (ODC) activity at 3, 10, 17, 24, and 31 days of age. Data on body weight, liver weight and plasma glucose, catecholamine and growth hormone concentrations were also recorded. Liver ODC activity declined (P less than .01) with increasing age and was reduced (P less than .0001) at each age compared with control values after maternal deprivation for 16 h. Liver weight and plasma glucose were reduced (P less than .01) by maternal deprivation, while plasma catecholamines were unchanged and plasma growth hormone tended to be reduced, although the difference between means for deprived and control animals was not significant (P greater than .05). The design of the experiment did not permit separation of the relative contributions of sensory deprivation versus food deprivation of piglets in inducing the decline in liver ODC activity. The results indicate that maternal deprivation causes a marked decrease in liver ODC activity in neonatal swine as shown previously in neonatal rats (Schanberg et al., 1984).

Animals↗
PubMed1985

Severe feed restriction of pregnant swine and rats: effects on postweaning growth and body composition of progeny.

Rats and swine were restricted in feed during pregnancy to determine the effect on postnatal growth and development of the progeny. Restriction of rats to 50% of preconception feed intake during the first 2 wk of gestation was associated with higher body weight of the progeny at 21 wk postpartum than was ad libitum feeding throughout gestation. However, maternal intake during gestation had no effect on perirenal and gonadal fat weight or adipocyte size in male and female offspring at 160 d of age. Restriction of swine to one-third of recommended feed intake during the first 10 wk of pregnancy was associated in the progeny with less perirenal and subcutaneous backfat and smaller adipocytes in depot fat compared with progeny of adequately fed swine. It is concluded that feed restriction of pregnant rats to one-half of preconception intake for the first two-thirds of pregnancy results in increased weight gain in the resulting progeny while restriction of swine to one-third of the recommended feed allowance during the first two-thirds of pregnancy results in reduced postweaning weight gain and decreased fat accretion during young adulthood.

Animals↗
PubMed1985

Effect of carbadox on growth, fasting metabolism, thyroid function and gastrointestinal tract in young pigs.

Five experiments were done with 34 weanling and 24 growing crossbred gilts. Individually penned pigs were fed ad libitum (expt 1) or pair-fed (expt 2 through expt 5) for either 2 (expt 1 through expt 4) or 3 (expt 5) wk. Mean body weight gain and gain/feed values were significantly (P less than 0.05) greater in pigs fed carbadox (a synthetic antimicrobial). Fasting O2 consumption and CO2 production of pigs were measured during the 32- to 48-h (expt 1, 4 and 5) or during the 24- to 40-h (expt 2 and 3) postprandial periods with indirect open circuit calorimeters. Carbadox reduced O2 consumption significantly (P less than 0.05) in expt 2, but had no significant effect on CO2 production in any of the five experiments. The weight of thyroid gland and the plasma concentrations of L-3,3',5-triiodothyronine (T3) and thyroxine (T4) of pigs were not altered by carbadox. The mean weight, but not the length, of small intestine tended to be less in pigs fed carbadox. It is suggested that the growth-promoting effect of carbadox on young pigs may be associated with the weight of small intestine and its physiological processes such as metabolic rate. However, no definite effects of carbadox on whole-animal fasting metabolic rate and thyroid function could be demonstrated by the methods used in the present study.

Animals↗
PubMed1985

Enumeration and activity of cellulolytic bacteria from gestating swine fed various levels of dietary fiber.

Cellulolytic bacteria were enumerated and cellulase activity was determined over a 98-day period from fecal samples of gestating swine fed various levels and sources of fiber. The diets, each fed to five pigs, were a corn-soybean control, 20% corn cobs, and 40 and 96% alfalfa meal. Fecal samples were collected from all pigs on days 0, 5, 14, 21, 35, 49, 70, and 98. Overall, the most probable number of cellulolytic bacteria from pigs fed the control, 20% corn cobs, and 40 and 96% alfalfa meal was 23.3 X 10(8), 15.2 X 10(8), 45.1 X 10(8), and 52.5 X 10(8) per g (dry weight) of fecal sample, respectively. Enumeration of cellulolytic bacteria by counting zones of clearing in roll tubes, as compared with the most probable number procedure, accounted for only 1.1 and 17.0% of the cellulolytic bacteria, respectively, from pigs fed the control or 96% alfalfa meal diet. Cellulolytic bacteria (most probable number) on days 70 and 98 accounted for 4.1 and 10.0% of the viable count for the pigs fed the control and 96% alfalfa meal diets, respectively. The viable count was not different between pigs fed the control and 96% alfalfa meal diets. The overall mean cellulolytic activity (milligrams of glucose released from carboxymethyl cellulose per gram [dry weight] fecal sample per 30 min was 17.0, 19.9, 23.8, and 20.6, respectively, for the control, 20% corn cobs, and 40 and 96% alfalfa meal diets. The results indicate that the cellulolytic flora can be increased by prolonged feeding of high-fiber diets and may represent 10% of the culturable flora.

Animals↗
PubMed1985

Plasma thyroid hormones, growth and carcass measurements of genetically obese and lean pigs as influenced by thyroprotein supplementation.

A 2 X 2 factorial arrangement with two genotypes of pigs (genetically obese and lean) and two dietary treatments (basal, a 16% protein corn-soybean meal standard grower diet, and basal +220 ppm thyroprotein as iodinated casein) was used. The 28 gilts were housed individually and fed ad libitum from 121 d of age until slaughtered at 99 kg body weight. Compared with lean pigs, genetically obese pigs had significantly lower average daily gain and gain/feed, greater backfat thickness, smaller loin eye area, shorter carcass length and lower circulating plasma triiodothyronine (T3) concentration. However, both total plasma and free thyroxine (T4) concentrations were similar comparing obese and lean pigs. Supplementation with thyroprotein increased circulating plasma concentration of both total and free T4 and produced interactions with genotype in affecting daily gain and gain/feed of pigs. Thyroprotein reduced both daily gain and gain/feed in obese pigs, but increased daily gain and gain/feed in lean pigs. It is suggested, similar to the case with obese mice, that heat production of our genetically obese pigs may be more sensitive to thyroprotein administration compared with similar treatment of lean animals.

Animals↗
PubMed1985

Effect of obesity per se on plasma lipid and aortic responses to diet in swine.

Thirty-two genetically lean and obese Yorkshire X Duroc crossbred castrated male pigs were divided within genetic line into two groups at 7 weeks of age. Eight pigs within each line were fed a diet low in fat and cholesterol (maize-soybean meal diet fortified with minerals and vitamins). The other group was fed a similar diet containing added beef tallow (11%) and dried egg yolk (1%). All pigs were fed ad libitum for 4 months when one-half of each group was slaughtered. All other pigs were continued on their respective diets at a restricted level of intake for an additional 5 months at which time the protein source of two pigs in each diet group within each genetic line was changed from soybean meal to casein. After an additional 6 months on their respective diets (16 months total duration of experiment) these pigs were slaughtered. Blood samples were taken monthly or bimonthly for total plasma cholesterol and triglycerides. At slaughter, the aorta was opened, stained with Sudan IV, and the stained area traced and measured planimetrically. Only a moderate rise occurred in plasma cholesterol and triglycerides of pigs fed high fat-high cholesterol diets. Genetically obese pigs were no more susceptible to diet-induced hypercholesterolemia and to the percentage of the surface area of the aorta stained with Sudan IV than were lean pigs. It is concluded that obesity per se is not necessarily associated with development of atherosclerosis in pigs and that innate ability to metabolize high dietary cholesterol is of greater importance than body fatness in determining the response to diet.

Animals↗
PubMed1984

Responses of weanling pigs to dietary supplementation with vitamin C or carbadox.

A 2 X 2 factorial arrangement with two levels (0, 660 ppm) of vitamin C and two levels (0, 55 ppm) of carbadox supplementation was used in two experiments with 112 crossbred pigs weaned between 4 and 5 wk of age. An 18% protein corn-soybean meal-oats-dried whey starter diet was used as the basal diet. Each diet was fed ad libitum for a 4-wk period to three replicates of four pigs in Exp. 1 and to four replicates of four pigs in Exp. 2. Vitamin C supplementation produced a significantly higher plasma vitamin C concentration in weanling pigs, but, contrary to results of our previous study, failed to improve average daily gain of the pigs. Daily gain was, however, improved significantly by carbadox supplementation. Carbadox also produced a significantly higher plasma vitamin C concentration in pigs after a 7-d lag period. Plasma Fe concentration of pigs was not affected by supplemental vitamin C, but was significantly higher in those fed carbadox-supplemented diets. Plasma ceruloplasmin concentration increased significantly in all treatment groups from the initial sampling period (d 0) to subsequent periods. No interactions between supplemental vitamin C and carbadox were observed in daily gain, feed efficiency and the measured plasma constituents.

Animals↗
PubMed1984

Use of carbohydrate and fat as energy source by obese and lean swine.

Genetically obese and lean pigs were fed isonitrogenous-isoenergetic (digestible energy) amounts of a high or low fat diet from 25 kg body weight. Obese pigs gained less and required more feed per unit gain than lean pigs. Lean pigs were more muscular with less fat than obese pigs. Obese pigs utilized more dietary amino acids for energy (greater plasma urea N) than did lean pigs. Weight gain was similar at all intermediate periods in obese pigs fed the two diets. However, gain tended (P less than or equal to .10) to be greater and the ratio of dietary energy intake to gain tended (P less than or equal to .10) to be less in obese pigs fed high compared with low fat diets. Similar results were observed in lean pigs fed the two diets. The high fat diet produced more carcass adipose tissue deposition in both strains after 20 wk of feeding (detectable by ultrasound at 14, but not at 7 wk). Adipose tissue lipogenic rate (glucose incorporation) was similarly depressed by fat feeding in both obese and lean pigs. Obese and lean pigs both utilized dietary carbohydrate and fat differentially but there was no indication of genetic divergence regarding this utilization. In both strains of pigs, energy from the fat-enriched diet was preferentially partitioned into carcass adipose tissue.

Adipose Tissue↗
PubMed1984

Influence of dietary fiber on the performance and cellulase activity of growing-finishing swine.

Number of cellulolytic bacteria and their cellulase activity were determined from fecal samples of eight pairs of littermate pigs representing four litters (26 to 32 kg) fed a low or high fiber diet ad libitum (0 or 35% alfalfa meal, respectively) over a 70-d period. Fecal samples were obtained from all pigs on d 0, 5, 11, 18, 32, 53 and a final sample between d 67 to 70. Cecum and colon samples were obtained at slaughter. Growth and carcass data were also obtained during the study. Pigs fed the high fiber diet gained 17.3% less, had increased feed to gain ratio and less carcass weight at slaughter than those fed the low fiber diet (P less than .05). Overall, a larger number of cellulolytic bacteria (P less than .05) were found in the fecal samples from pigs fed the high fiber diet. The overall mean cellulolytic activity (mg glucose released X g dry weight fecal sample-1 X 30 min-1) was 27.7 compared with 33.8 (P less than .05) for the pigs fed the low and high fiber diet, respectively. A lower concentration of organic acids (P less than .05) was present in the fecal samples of the high fiber pigs. The overall mean acetate to propionate ratio was 1.92 and 2.48 (P less than .01), and ammonia-N was 2.27 and .98 mg/g dry weight (P less than .01) for the low and high fiber diet pigs, respectively. These data indicated that a 35% alfalfa meal diet significantly affects intestinal bacterial metabolism and number and activity of the cellulolytic population, along with performance and carcass characteristics.

Animals↗
PubMed1984

Effect of protein deficiency on growth and plasma zinc concentration in genetically lean and obese swine.

Thirty-two genetically lean and 32 genetically obese weanling (4 to 5 wk old) pigs from inter se matings of crossbreds produced by within-line matings of Duroc and Yorkshire breeds, selected for low or high backfat, were fed the following four diets for 8 wk (eight lean and eight obese pigs/diet): 10% protein -- 100 ppm Zn, 10% protein -- 200 ppm Zn, 18% protein -- 100 ppm Zn, 18% protein -- 200 ppm Zn. After 8 wk, all pigs were fed a standard 16% protein corn-soybean meal-type growing diet to a slaughter weight of about 87 kg. Lean pigs were more severely affected than obese pigs by low protein diets as measured by weight gain, plasma total protein and plasma albumin. Plasma Zn concentration was reduced in lean and obese pigs fed low protein diets. Supplemental Zn failed to increase plasma Zn in protein-deficient pigs. During repletion, weight gain of lean and obese pigs previously fed the 10% protein -- 100 ppm Zn diet was less than that of pigs previously fed other diets. The lower level (100 ppm) of Zn fed during protein depletion appeared to be associated with a negative effect on repletion weight gain of lean and obese pigs. Lean and obese pigs responded similarly during the repletion phase to earlier protein restriction. We conclude that supplementary dietary Zn does not maintain plasma Zn concentration in growing pigs fed protein-deficient diets and that repletion from dietary protein restriction is not associated with compensatory growth in genetically lean pigs.

Adipose Tissue↗