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Biomedical subjects

D R Zimmerman

Publications and source records attributed to D R Zimmerman.

At least 55 records · Page 3Linked to original sources
PubMed1995

Interactive effects of feed intake and stage of growth on the lysine requirement of pigs.

We studied the effect of reduced feed intake on the lysine requirement of pigs at the early growing (G) and finishing (F) phases. Two sets of 40 individually penned crossbred barrows averaging 27.1 +/- .2 (G) and 92.6 +/- 1.1 kg BW (F) were fed five dietary treatments (G; .75, .90, 1.05, 1.20, 1.35%; and F: .45, .60, .75, .90, 1.05% lysine) at two feeding levels (equivalents to 100 and 80% ad libitum intakes) for 15 d. In both stages pigs on the 80% feeding level had lower ADG (P < 0.01) and lower plasma urea nitrogen (PUN) concentrations (P < .10) than pigs on the 100% feeding level. In all instances, increasing dietary lysine caused ADG to increase (P < .05) and PUN to decrease (P < .10) linearly. A tendency for an interaction was detected between the effects of growth stage and the effects of feeding level on the lysine requirements estimated by ADG (P < .19) and PUN (P < .10). In the F stage, pigs on the 80% feeding level required a greater dietary lysine concentration to maximize ADG and minimize PUN (.85 and .87%, respectively) than pigs on the 100% feeding level (.61 and .68%, respectively). In the G stage, however, the dietary lysine concentrations required to maximize ADG (.97 to 1.01%) and minimize PUN (1.05 to 1.09%) were not different (P > .20) between feeding levels. We conclude that the effect of a reduction in feed intake on the lysine requirement depends on the stage of growth of the pigs.

Aging↗
PubMed1995

Blood urea and amino acid concentrations in pigs of two breed combinations as affected by energy intakes.

Forty-eight barrows (61 kg), 24 Yorkshire x Landrace (YL) and 24 YL x Duroc x Hampshire (YLDH), were used to evaluate the effect of six dietary ME levels on concentrations of plasma urea nitrogen (PUN) and free amino acids. All pigs consumed equal amounts of each nutrient, except for energy. As energy intakes increased from 12.42 to 35.01 MJ/d of ME (34 to 97% of NRC recommendations), ADG increased linearly (P < .001) and concentrations of PUN decreased linearly (P < .01) and quadratically (P < .05). There was a tendency (P = .09) for an interaction of breed combinations and energy intakes on ADG. In general, increasing energy intake decreased plasma concentrations of essential amino acids and increased plasma concentrations of nonessential amino acids. Exceptions were a lack of change in plasma lysine and glutamic acid, an increase in histidine, and decreases in tyrosine and aspartic acid. Concentrations of most plasma amino acids were similar between the two breed combinations, but 9 of 27 amino acids that were measured were different (P < .05) between the breed combinations. The linear response of ADG was probably attained through a relatively constant lean-to-fat deposition ratio in the body over the levels of ME intakes. The curvilinear decline of PUN to increasing energy intakes was probably because at low energy intakes, amino acids were oxidized to furnish energy for maintenance and at increasing energy intakes there was increasing accretion of body proteins.

Amino Acids↗
PubMed1995

Effects of excess dietary leucine and leucine catabolites on growth and immune responses in weanling pigs.

Two experiments with weanling pigs were conducted to study the effects on growth and immune responses of excess dietary L-leucine (LEU) and dietary supplementation with the LEU catabolites, alpha-ketoisocaproic acid (KIC) and beta-hydroxymethyl butyrate (HMB). In Exp. 1, 80 pigs were randomly allocated according to initial BW and ancestry to five replications of four dietary treatments (four pigs/pen). The control diet contained wheat, oat groats, menhaden fish meal, and dried whey and provided 1.12% LEU. Treatment diets were the control plus 1.12% LEU, 1.12% KIC, or .4% HMB. The experiment lasted 6 wk. In Exp. 2, 36 pigs were randomly allocated to nine replications of four dietary treatments in a 2 x 2 factorial arrangement. Treatments consisted of two concentrations of dietary LEU and a daily i.m. injection of dexamethasone (DEX) or saline. Pigs were fed a control corn-soybean meal and dried whey diet (1.56% LEU) or the control diet plus 1.56% of crystalline LEU. Pigs were individually penned and the experiment lasted 4 wk. Growth performance, plasma free amino acids, plasma urea nitrogen, and humoral and cellular immune responses were measured. Results indicated that LEU concentrations in practical diets and supplementation with KIC and HMB (Exp. 1) did not detrimentally affect growth and immune response. The high LEU concentration and DEX injection used in Exp. 2, however, were detrimental to both growth and immune response.

3-Hydroxybutyric Acid↗
PubMed1995

Relationship of rate of lean tissue growth and other factors to concentration of urea in plasma of pigs.

The objectives of this study were 1) to investigate the relationship between plasma urea N concentrations (PUN) and lean tissue growth and 2) to compare the value of different variables, related to lean growth and renal function, to correct the relationship between dietary lysine concentration and PUN response for variation not related to amino acid adequacy. Forty-eight gilts (64.8 kg BW) were individually penned (blocks based on initial BW) for 50 d: a 10-d adjustment, a 35-d pretreatment, and a 5-d treatment period. During the pretreatment period, ADFI, urine specific gravity (SG), serum creatinine (SC), PUN, and daily fat-free carcass lean (DFFCL), empty body protein (DEBP), total carcass fat (DCF), and empty body lipid (DEBLI) depositions were measured. Partial correlation coefficients (ADFI effect removed) indicated a strong and inverse relationship between PUN and lean growth (DFFCL and DEBP) (r = -.88 and -.91, respectively, P < .01) and a positive relationship between PUN and fat deposition (DCF and DEBLI) (r = .66 and .54; respectively, P < .22). Treatments consisted of six dietary lysine concentrations (.475, .550, .625, .700, .775, and .850%). Initial and final BW in the treatment period were 103.3 and 107.7 kg, respectively. Pretreatment PUN (PUNO) was the pretreatment variable with the greatest R2 and the smallest MSE when used in the model describing the response of PUN (PUN1) to dietary lysine. The estimated lysine requirements from the PUN1 response corrected with either PUN0 or with the combination of PUN0, ADFI, DFFCL, DCF, SG, and SC were not (P > .05) different (.656 vs > 678%, respectively). We conclude that 1) PUN concentrations have a potential value as an indicator of the efficiency of lean tissue growth and 2) pretreatment PUN is a useful variable to correct treatment PUN for variation not related to amino acid adequacy.

Animal Feed↗
PubMed1995

Use of plasma urea nitrogen as a rapid response criterion to determine the lysine requirement of pigs.

Five experiments were conducted to evaluate the potential use of plasma urea N (PUN) concentrations as a rapid response criterion to determine amino acid requirements. A preliminary experiment (Exp. 1) indicated that a 3-d feeding time was required to re-equilibrate PUN concentrations after a change in the dietary concentration of lysine. In Exp. 2, 3, and 4, PUN was used to estimate the lysine requirement of growing pigs at different specific BW. Thirty individually penned crossbred pigs weighing 32 and 44 kg in Exp. 2 and 3, respectively, were assigned to five dietary treatments (.60, .70, .80, .90, and 1.00% lysine) for 5 d. The PUN decreased quadratically (P < .05) to increasing dietary lysine. A two-slope, broken-line regression model estimated the requirement at .85% in Exp. 2 and at .76% in Exp. 3. In Exp. 4, 60 crossbred pigs (30 barrows and 30 gilts) weighing 70 kg were assigned to five dietary lysine concentrations: .50, .60, .70, .80, and .90% for 4 d. Increasing lysine caused PUN to decrease quadratically (P < .01). The estimated requirements were different (P < .05) between sexes: .69% for barrows and .75% for gilts. In Exp. 5, the validity of using PUN as a rapid response criterion was verified by comparing the estimated lysine requirement based on PUN with the requirement determined in a 7-d N balance. Twenty crossbred barrows averaging 19 kg were used. Dietary lysine concentrations were .60, .75, .90, 1.05, and 1.20%. A quadratic response was observed in PUN (P < .05) and N retention (NR) (P < .01) with increasing lysine. The estimated lysine concentrations that maximized rates of NR and minimized PUN (1.03 vs. 1.05) were not different (P > .10). Therefore, PUN concentrations can be used in short-term trials to accurately estimate the dietary lysine required to maximize total N utilization in pigs at a specific BW. In addition, the two-slope broken-line regression model had the highest R2 and the lowest mean square error compared with three other models as means for estimating lysine requirement from PUN concentrations.

Animals↗
PubMed1995

True digestibility of amino acids and protein in pigs with 13C as a label to determine endogenous amino acid excretion.

The objective of this study was to determine whether differential labeling of 13C occurs in pigs fed diets with different 13C abundances and, if so, to use 13C as a label to determine true amino acid digestibility. Forty-eight pigs averaging 10.5 kg BW were fed dietary treatments consisting of a corn-corn gluten meal-crystalline amino acid diet (C-CGM) and a wheat-soybean meal diet (W-SBM). The 13C abundance of the amino acid fraction (AAF) of the C-CGM and W-SBM diets averaged delta 13C -14.19 and -26.36/1000, respectively. Three pigs/treatment group were killed when groups averaged 10.5 (initial), 22.9, and 46.6 kg BW, and AAF of organs were analyzed for 13C abundance. Carbon 13 in empty body AAF increased (-18.14, -13.98, and -12.66/1000) with increasing body weight in pigs fed the C-CGM diet and decreased (-18.06, -22.78, and -24.76/1000) in pigs fed the W-SBM diet. Liver, small intestine, and longissimus muscle tissues showed similar trends. Each tissue had dietary treatment effects (P < .001) and dietary treatment x weight group (P < .001) interactions. Ten pigs averaging 55.0 kg BW from each treatment group were assigned to metabolism cages and fed at 0700 and 1900. Six of these pigs from each treatment group were implanted with T-cannulas in the ileum and given a 17-d recovery period. At 1900 on d 0 of the collection phase, pigs were switched to the opposite diet that contained chromic oxide.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1995

Development and testing of nursing home quality indicators.

In this article, the authors report on the development and testing of a set of indicators of quality of care in nursing homes, using resident-level assessment data. These quality indicators (QIs) have been developed to provide a foundation for both external and internal quality-assurance (QA) and quality-improvement activities. The authors describe the development of the QIs, discuss their nature and characteristics, address the development of a QI-based quality-monitoring system (QMS), report on a pilot test of the QIs and the system, comment on methodological and current QI validation efforts, and conclude by raising further research and development issues.

Accidental Falls↗
PubMed1995

Homesickness and the use of a camp infirmary: a preliminary report.

Homesickness is a problem that is well known to parents but is little discussed in the medical literature. The goal of this study was to describe the prevalence of homesickness at one summer camp and to assess the hypothesis that children who are homesick are more frequent users of the camp infirmary than children who are not homesick. Homesickness was assessed by a questionnaire devised by the authors that was completed by the child's counselor at the end of camp. Homesickness was found in 20% of the campers. Two of three measures of homesickness derived from the questionnaire were significantly associated with multiple visits to the infirmary, and the third measure showed a trend in the same direction. Our findings led us to the conclusion that homesickness is a common problem and that multiple visits to a camp infirmary might be a warning signal of lack of adjustment to the camp environment.

Adaptation, Psychological↗
PubMed1994

Diurnal variation in concentrations of plasma urea nitrogen and amino acids in pigs given free access to feed or fed twice daily.

A repeated-measures experiment was conducted to test the effect of sampling times after feeding on concentrations of plasma urea nitrogen (PUN) and plasma free amino acids (PFAA) in pigs fed by two feeding methods. Seven castrated male pigs (mean weight of 65 kg) were randomly assigned to switchback treatments that were 3-d periods of either free access to feed or twice daily feeding. Blood was sampled at 2-h intervals (sampling points) during the day (0800 to 1800 h) and again during the night (2000 to 0600 h) on the last day of each of three 3-d feeding treatment periods. Concentrations of PUN and most PFAA were not affected by the feeding method and time of day (day and night), but they were affected by sampling points. The pigs fed twice daily had postprandial peak PUN at 4 h (32% increase over prepandial) and peak PFAA at 2 h after feeding during 12-h day and night periods. However, the pigs with free access to feed exhibited only a slight fluctuation of PUN during the day and night and almost constant concentrations of most PFAA during a 24-h period. The PFAA results suggest that concentrations of most plasma essential and nonessential amino acids varied relatively more than those of other amino acids in response to sampling times.

Amino Acids↗
PubMed1994

Colostral milk fat percentage and pig performance are enhanced by feeding the leucine metabolite beta-hydroxy-beta-methyl butyrate to sows.

Three trials were conducted to test whether feeding the leucine metabolite beta-hydroxy-beta-methyl butyrate (HMB) would increase fat content of sows' milk and pig weight gain. All sows received a basal diet and were assigned at random to receive either 2 g of CaCO3/d (control) or 2 g of Ca(HMB)2/d (HMB), which was top-dressed to the basal diet. Treatment began 3 to 4 d before farrowing. In Trials 1, 2, and 3 there were 4, 19, and 11 pairs of sows, respectively. In a combined analysis that included all three trials, milk fat at d 1 was increased by 41% (P = .01) and pig weight at d 21 was increased by 7% (P = .01) for sows fed diets containing HMB compared with sows fed control diets. Sows fed HMB lost more backfat (P = .03); however, sows receiving HMB had more (P < .05) backfat depth at farrowing than control sows. At weaning there was no difference in backfat depth between the treatment groups. Sows fed HMB tended to consume less feed (P = .07) than control sows. In Trials 2 and 3, data were collected on the subsequent reproductive cycles of the sows. A combined analysis of the data revealed no differences in sow performance when sows previously fed the diet containing HMB were compared with sows previously fed the control diet. In conclusion, beta-hydroxy-beta-methyl butyrate, when fed to sows at 2 g/d, resulted in an increase in fat percentage of sow's milk and pig performance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1994

Evaluation of a DUR intervention: a case study of histamine antagonists.

Drug Utilization Review (DUR) programs aim to control inappropriate prescribing and drug costs, but there are few rigorous studies of their impact. This paper presents the evaluation results of a DUR intervention (excessive duration of full-dose histamine-2 receptor antagonists) using a quasi-experimental design. We observe a greater reduction of H2RA use in the intervention group than in the comparison group, and a reduction in drug expenditures which exceeded the cost of targeting and notifying prescribers. The success of DUR programs depends on both their efficiency and the drug issues under consideration; the use of a comparison group is critical in the evaluation of their impact.

Ambulatory Care↗
PubMed1993

Effect of administration of porcine follicular fluid to gilts during the luteal phase of the estrous cycle on plasma gonadotropins, follicular development, and ovulation rate.

Eighty gilts were assigned randomly to receive twice daily i.v. injections of either 5 mL of steroid-reduced porcine follicular fluid (pFF) or .15 M saline (S) to evaluate the effects of suppression of FSH before, during, and 1 d after induced luteolysis on d 13 (d 0 = onset of estrus) on development of medium and large follicles during the follicular phase and subsequent ovulation rate. Ovaries were recovered and assessed for numbers of corpora albicantia (CA) and medium (NMF, 3 to 6.9 mm) and large (NLF, > 6.9 mm) follicles on d 13, 15, and 17 of the estrous cycle and number of corpora lutea (CL) in the group assigned to be examined after ovulation. Gilts assigned to the postovulatory group were bled at 12-h intervals from d 9.5 through 17. Administration of pFF suppressed concentrations of FSH during treatment with pFF (pFF, .38 +/- .02 vs S, .52 +/- .02 ng/mL, P < .05) and reduced NMF on d 13 (pFF, 17.3 +/- 4.0 vs S, 45.8 +/- 4.0, P < .01) and d 15 (28.1 +/- 4.0 vs 38.7 +/- 4.2, P < .05). The NMF declined markedly between d 15 and 17 in control gilts but not in pFF-treated gilts; pFF and S gilts had achieved similar NMF on d 17 (pFF, 23.1 +/- 4.0 vs S, 21.3 +/- 4.2). Large follicles were first observed on d 17 and were reduced substantially by prior treatment with pFF (pFF, 6.7 +/- 1.4 vs S, 12.4 +/- 1.5, P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Quality of pediatric care at a freestanding emergency facility.

The last decade has seen the introduction of freestanding emergency facilities, which provide an alternative to hospital emergency departments. The contribution made by these facilities to the clinical welfare of patients depends on their availability to deliver quality medical care without the need for frequent referral. This study describes the clinical experience of one such facility with pediatric patients and attempts to assess the quality of their care.

Ambulatory Care Facilities↗
PubMed1991

Follicle-stimulating hormone (FSH) during the secondary surge in gilts as influenced by administration of porcine follicular fluid (pFF).

The effect of volume and frequency of administration of porcine follicular fluid (pFF) on FSH concentration was determined in mature gilts during the period of the secondary FSH surge (d 0 to 5; d 0 = onset of estrus) and following withdrawal of pFF (d 5.5 to 9). Crossbred gilts (n = 14) were randomized in a 3 x 2 factorial treatment design involving three doses of pFF (0, 5, or 10 ml) and once- vs twice-daily pFF administration. Porcine FF was aspirated from medium and large follicles and treated with 5 mg of activated charcoal per milliliter of pFF to remove steroids. Once-daily administration of pFF, regardless of dose, failed to suppress mean concentrations of FSH during the secondary FSH surge. Treatment of gilts twice daily with 10 ml of pFF suppressed (P less than .05) area under the FSH curve during the secondary FSH surge compared with gilts given saline. Gilts treated twice daily with 5 ml pFF showed comparable suppression of plasma FSH from d 0 to 3 but began to overcome FSH inhibition after d 3. As a result, FSH release only tended to be lower than controls for the entire treatment period (P less than .1). Mean FSH concentrations were increased (P less than .05) during the post-treatment period (d 5.5 to 9) by treatment with intermediate (5 ml pFF, two times daily and 10 ml pFF, one time daily) and high (10 ml pFF, two times daily) doses of pFF. Neither ovulation rate nor interestrous interval was affected by pFF administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Direct responses to selection for increased litter size, decreased age at puberty, or random selection following selection for ovulation rate in swine.

Nine generations of selection for high ovulation rate were followed by two generations of random selection and then eight generations of selection for increased litter size at birth, decreased age at puberty, or continued random selection in the high ovulation rate line. A control line was maintained with random selection. Line means were regressed on generation number and on cumulative selection differentials to estimate responses to selection and realized heritabilities. Genetic parameters also were estimated by mixed-model procedures, and genetic trends were estimated with an animal model. Response to selection for ovulation rate was about 3.7 eggs. Response in litter size to selection for ovulation rate was .089 +/- .058 pigs per generation. Average differences between the high ovulation rate and control lines over generations 10 to 20 were 2.86 corpora lutea and .74 pigs (P less than .05). The regression estimate of total response to selection for litter size was 1.06 pigs per litter (P less than .01), and the realized heritability was .15 +/- .05. When the animal model was used, the estimate of response was .48 pigs per litter. Total response in litter size to selection for ovulation rate and then litter size was estimated to be 1.8 and 1.4 pigs by the two methods. Total response to selection for decreased age at puberty was estimated to be -15.7 d (P less than .01) when data were analyzed by regression (realized heritability of .25 +/- .05) and -17.1 d using the animal model. No changes in litter size occurred in the line selected for decreased age at puberty. Analyses by regression methods and mixed-model procedures gave similar estimates of responses and very similar estimates of heritabilities.

Age Factors↗
PubMed1990

Long-term effects of corn gluten feed on the reproductive performance and weight of gestating sows.

Corn gluten feed (CGF) was evaluated as the primary energy and protein source for gestating sows. Eighty gravid multiparous Yorkshire x Landrace sows were assigned randomly to three treatment groups for the entire three-parity trial. The gestation treatment diets were 1) corn-soybean meal fed at 1.8 kg/d (control), 2) CGF plus soybean meal fed at 2.3 kg/d (CGF-low) and 3) CGF plus soybean meal fed at 2.6 kg/d (CGF-high). The CGF diets contained 92.2% and 93.7% CGF, respectively. Feeding levels of Diets 2 and 3 were based on the assumption that CGF had 80% and 70% of the net energy value of corn, respectively. All sows had ad libitum access to a conventional corn-soybean meal diet during lactation and were fed 3.2 kg/d during breeding. Intakes of gestation treatment diets were increased 25% during winter months. Based on litter size and weight, the performance of sows fed CGF did not differ from that of the sows fed the control diet. Mean number of pigs at birth and 21 d (weaning) for the three parities were: (control) 10.16, 7.65; (CGF-low) 11.30, 8.44; (CGF-high) 10.73, 8.13, respectively. Pigs from CGF-fed sows were smaller at birth (P less than .05), but subsequent pig weights did not differ. Mean pig birth and 21-d weights for the three parities were: (control) 1.44, 5.18; (CGF-low) 1.30, 4.84; (CGF-high) 1.31, 5.01 kg, respectively. CGF-low sows weighed less (P less than .01) at d 109 of gestation than did the control and CGF-high sows, which did not differ in weight.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1990

The Quality Assessment Index (QAI) for measuring nursing home quality.

There have been few detailed evaluations of measures of quality of care in nursing homes. This is unfortunate because it has meant that much research on factors affecting nursing home quality has used measures of questionable reliability and validity. Moreover, some measures currently in use have been developed using methodologies not based on solid conceptual grounds, offering little reason to expect them to have much internal or external validity. In this article we suggest characteristics that should be present in measures of nursing home quality, propose a methodology for the development of such measures, propose a specific nursing home quality measure (the Quality Assessment Index or QAI), and report the results of several tests of its validity and reliability.

Abstracting and Indexing↗