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Biomedical subjects

C R Long

Publications and source records attributed to C R Long.

62 records · Page 4Linked to original sources

Production characters of first-generation cows of a five-breed diallel: reproduction of young cows and preweaning performance of inter se calves.

Data from cows of a five-breed diallel involving Angus, Brahman, Hereford, Holstein and Jersey were analyzed. Females were used in inter se matings to produce three second-generation parturitions per cow. Crossbred (CB) cows were 43 d younger (P less than .05), 14 kg heavier (P less than .05) and 2 cm taller (P less than .05) at first calving than straightbred (SB) cows; however, no differences were detected (P greater than .10) between the two groups for pelvic measurements. Although large differences among breed types existed for gestation length, crossbreds generally did not differ from straightbreds for this character. Crossbred cows exhibited a 7.5 d shorter (P less than .05) interval from parturition to first service, but did not exhibit a shorter interval from parturition to conception (P greater than .10). The dairy breeds (Holstein and Jersey) and their crosses exhibited similar postpartum and calving intervals as Angus, while Brahman and their crosses had longer intervals. Crossbred calves were 1.3 kg heavier (P less than .01) and had greater (P less than .01) shoulder and hip dimensions at birth than SB calves, but no difference in the amount of calving difficulty was detected (P greater than .10) between the two groups. Higher (P less than .01) rates of survival to 24 h (3.7%) and to weaning (8.7%) were observed for CB calves compared with SB calves. Heterotic effects for weaning weight (15.2 kg), weaning height (2 cm) and preweaning average daily gain (68 g) were large and illustrate the importance of individual and maternal heterosis for these characters. These results suggest that substantial amounts of heterosis may be retained for survival and weaning characters of calves in early generations of inter se mating of CB.

Analysis of Variance↗

Characterization of cattle of a five-breed diallel. III. Puberty in bulls and heifers.

Pubertal characters of bulls and heifers produced in a diallel mating of Angus, Brahman, Hereford, Holstein and Jersey cattle were analyzed. Ninety-one heifers and 138 bulls in individual pens adn 286 bulls in drylots were fed a 72% TDN diet ad libitum; another 384 heifers were placed on pasture with supplemental feed. Puberty in heifers was defined as time of first ovulatory estrus; in bulls, as first detection of sperm cells in an electroejaculate. Breed type least-squares means, adjusted for birth month, were estimated within sex-nutrition-management groups and then decomposed into breed effects, average heterosis (h), general combining ability (GCA) and specific combining ability (SCA) by diallel analysis techniques. Breed effects were a significant source of variation for all characters studied. Heterosis (h, GCA, SCA) was not significant for pubertal age of bulls or heifers receiving complete diets in pens, a rather high nutritional plane. However, on pasture, crossbred heifers reached puberty at a younger age (P less than .05) than straightbreds. Average heterosis was significant (P less than .05) for increased weight and hip height at puberty and ratios involving these characters for both sexes. Specific combining abilities were not statistically significant for the majority of the pubertal characters, yet large differences among estimates of combining abilities were expressed. Ad libitum feeding of the penned heifers tended to decrease pubertal age and increase pubertal size as compared to pubertal age and size of pastured heifers. The breed type x management interactions within both sexes indicated a different ranking of the breed types for each management regimen.

Animals↗

Living in two worlds: Native American women and prenatal care.

The purpose of this qualitative study was to explore traditional beliefs and practices related to pregnancy and childbirth among Native American women and examine the relationship of these beliefs and practices to current use of prenatal care. Focus groups of elders and young women were held and the data analyzed with the Ethnograph software. The central theme was the breakdown in transmission of cultural wisdom among Native American women. The major causes described by women were federal assimilation policies and deaths of elders. Major factors influencing young women's nonutilization of prenatal care were this breakdown, the "Western model" of prenatal care, substance abuse, and domestic violence. Recommendations for improving the use of prenatal care are grounded in the reality that Native American women live in two different worlds. Prenatal care should be reconceptualized as traditional cultural wisdom, with the majority of care provided by natural helpers in the Native American community, including tribal elders, grandmothers, and aunts in collaboration with licensed providers.

Adult↗

The early effects of dietary restriction on the pathogenesis of chronic renal disease in Sprague-Dawley rats at 12 months.

This study evaluated the effects of different diets and dietary regimens on the pathogenesis of chronic renal disease (CRD) in Sprague-Dawley rats at 52 wk and correlated these data with survival at 106 wk. A commercial diet (5002) was compared to a modified diet (5002-9) with less protein, fat, and energy and more fiber. Both diets were fed by ad libitum (AL) or dietary restriction (DR) regimens. The glomerular area (GA), glomerular sclerotic index (GSI), tubulo-interstitial index (TII), and tubular labeling index (tubular LI) were measured. The 5002-9 diet fed AL did not decrease the severity of CRD or increase survival, nor did the 5002 diet fed 6.5 hr/day. Both diets fed by DR did improve CRD and survival. Both AL groups had higher indices, and the 5002 AL males had the highest GA and GSI. These data indicate that the initial events in CRD occur as glomerular hypertrophy. Because the TII and tubular LI were only increased with advanced CRD, tubulo-interstitial damage did not occur until the glomerular changes were established. The 52-wk glomerular indices correlated with survival at 106 wk. Increased GA at 52 wk predicted low survival rates at 106 wk. These findings support a hypothesis that glomerular sclerosis and tubulo-interstitial damage occur secondary to early initial glomerular hypertrophy that is mitigated by caloric restriction.

Animals↗

Prevalence of nonmusculoskeletal complaints in chiropractic practice: report from a practice-based research program.

OBJECTIVE: To identify patient and practice characteristics that might contribute to people's seeking chiropractic care for nonmusculoskeletal complaints. DESIGN: This was a cross-sectional study conducted through the methods of practice-based research. SETTING: Data were collected in 1998--1999 in chiropractic offices in the United States, Canada, and Australia; data were managed by a practice-based research office operating in a chiropractic research center. POPULATION: The subjects were new and established patients of all ages who visited the participating offices during a designated data collection week. DATA ANALYSIS: Multiple logistic regression was used to examine factors associated with patients' presenting for nonmusculoskeletal chief complaints. Pearson's chi(2) test was used to examine associations among practice variables and the proportion of patients with nonmusculoskeletal chief complaints. RESULTS: A total of 7651 patients of 161 chiropractors in 110 practices in 32 states and 2 Canadian provinces participated; data from 2 Australian practices were included in the totals but not in the analysis. Nonmusculoskeletal complaints accounted for 10.3% of the chief complaints. The following characteristics made patients more likely to present with nonmusculoskeletal chief complaints: being less than 14 years of age (adjusted odds ratio [AOR], 6.9; 95% CI, 5.2--9.1); being female (AOR, 1.5; CI, 1.3--1.8); presenting in a small town/rural location (AOR, 1.9; CI, 1.3--2.7); reporting more than 1 complaint, especially nonmusculoskeletal complaints (AOR, 4.9; CI, 3.9--6.0); having received medical care for the chief complaint (AOR, 3.4; CI, 2.9--4.1); and having first received chiropractic care before 1960 (AOR, 1.7; CI, 1.1--2.4). Practices with the highest proportion of patients with nonmusculoskeletal chief complaints (>17%) were less likely to accept insurance and more likely to be in locations with populations greater than 100,000. They used the most common chiropractic adjustive techniques less frequently and used more nonadjustive procedures, especially diet/nutrition counseling, nutritional supplementation, herbal preparations, naturopathy, and homeopathy. CONCLUSIONS: Drawing on practices with the patient and practice characteristics identified in this study to conduct outcomes studies on nonmusculoskeletal conditions is a possible direction for future research.

Adolescent↗

Development of a practice-based research program.

OBJECTIVE: To establish an infrastructure to collect accurate data from ambulatory settings. DESIGN: The program was developed through an iterative model governed by a process of formative evaluation. The three iterations were a needs assessment, feasibility study and pilot project. Necessary program components were identified as infrastructure, practitioner-researcher partnership, centralized data management and standardized quality assurance measures. SETTING AND PARTICIPANTS: Volunteer chiropractors and their staff collected data on patients in their practices in ambulatory settings in the U.S. and Canada. OUTCOME MEASURES: Evaluative measures were counts of participants, patients and completed forms. Standardized, validated and reliable measures collected by patient self-report were used to assess treatment outcomes. These included the SF-36 or SF-12 Health Survey, the Pain Disability Index, and the Global Well-Being Scale. For characteristics for which appropriate standardized instruments were not available, questionnaires were designed and and pilot-tested before use. RESULTS: Information was gathered on practice and patient characteristics and treatment outcomes, but for this report, only those data concerning process evaluation are reported. Through the three program iterations, 65 DCs collected data on 1360 patients, 663 of whom were new patients. Follow-up data recorded by doctors were obtained for more than 70% of patients; a maximum of 50% of patient-completed follow-up forms were collected in the three iterations. CONCLUSIONS: This program is capable of providing data for descriptive epidemiology of ambulatory patients, and, with continued effort to maximize follow-up, may have utility in providing insight into utilization patterns and patient outcomes.

Algorithms↗