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Biomedical subjects

L M Crocker

Publications and source records attributed to L M Crocker.

7 recordsLinked to original sources
PubMed1998

Influence of processed corn grain in diets of dairy cows on digestion of nutrients and milk composition.

Five primiparous Holstein cows (55 d in milk) that were fitted with ruminal and duodenal cannulas were used in a 4 x 5 incomplete Latin square to determine the effects of blends of steam-flaked and dry-rolled corn on site and extent of nutrient digestion and milk yield and composition. Diets were fed as total mixed rations and consisted of 45% forage and 55% concentrate; each diet contained 27% corn grain. Dietary treatments were composed of blends of dry-rolled and steam-flaked corn in ratios of 100:0, 67:33, 33:67, and 0:100. Intake of dry matter; digestibilities of dry matter, organic matter, acid detergent fiber, cellulose, neutral detergent fiber, fatty acids, and N; and microbial efficiency were unaffected by diet. Ruminal, postruminal, and total tract digestion of starch increased linearly, and starch passage to the duodenum decreased linearly, as the proportion of dry-rolled corn in the diet decreased. Ruminal propionate and valerate increased linearly, and acetate, butyrate, isovalerate, and the acetate to propionate ratio decreased linearly, as proportions of dry-rolled corn in the diet decreased; however, no changes in total volatile fatty acid concentrations in ruminal fluid were observed. Ruminal fluid pH was similar across diets. A decrease in dry-rolled corn decreased ruminal ammonia N and plasma urea N linearly. Milk yield and composition, as well as milk N fractions, were similar across diets. Although changes in fatty acid composition of milk fat were small, linear decreases in percentages of trans-C16:1 and cis-9- and cis-10-C18:1, as well as a linear increase in the percentage of C18:2 occurred as the proportion of dry-rolled corn in the diet decreased. An increased proportion of dry-rolled corn in the diet decreased digestion of starch in the rumen, and patterns of volatile fatty acid concentrations shifted accordingly. However, no effects on lactational parameters were observed.

Ammonia↗
PubMed1998

Ash content of detergent fibers in feeds, digesta, and feces and its relevance in fiber digestibility calculations.

The influence of insoluble ash in diet, digesta, and fecal samples was evaluated. Ash-free values of neutral detergent fiber (NDF) and acid detergent fiber (ADF) for feed, digesta, and fecal samples were compared with uncorrected values of NDF and ADF in two digestibility experiments. Six feed samples were selected at random along with four duodenal and two fecal samples; the latter two were a part of two digestion studies. The silica composition of feed samples was low with the exception of oat hay and rice straw. Ash-free values of NDF and ADF for digesta and fecal samples were lower than uncorrected values of NDF and ADF, and silica accounted for the majority of the differences. The use of ash-free values of NDF and ADF in both digestibility experiments with dairy cows resulted in more realistic digestibility estimates and reduced the amount of variability associated with the calculation of the digestibility of NDF and ADF in the rumen and total digestive tract. The source of the insoluble ash was not identified but could have come from individual feedstuffs or the consumption of sand. Sample contamination by silica and other ash components may influence NDF and ADF composition if the fiber residues are not ashed prior to calculation of NDF and ADF.

Animal Feed↗
PubMed1977

Linking research to practice: suggestions for reading a research article.

Although researchers and editorial review boards are obligated to communicate research information in readable fashion, journal readers also must assume responsibility for interpreting and evaluating research articles. The general format for reporting research results is described. In addition, seven major questions to be asked by cirtical readers are presented. These questions are designed to help readers identify the purpose of a study; assess its importance; evaluate the research design, sampling and data collecting procedures; interpret the results of data analyses; and form implications for practice.

Humans↗
PubMed1976

Field work experience ratings and certification examination scores as predictors of job performance and satisfaction in occupational therapy.

The American Occupational Therapy Association's certification instruments, the Certification Examination for Occupational Therapists Registered and the Field Work Performance Report, were examined in terms of their ability to predict future job performance and satisfaction of occupational therapists. A job satisfaction questionnaire was administered to 208 occupational therapists, and their supervisors rated them on a job performance instrument. The resulting correlations between these work adjustment variables and the previously administered certification instruments failed to reveal any predictive ability. Some plausible reasons for these negative results and possible directions for further research into this professional screening process were explored.

Certification↗
PubMed1976

Validity of certification measures for occupational therapists.

Major factors that can affect the results of validation studies are identified and include reliability, homogeneity of sample, and criterion contamination. An overview and a description of content, predictive, concurrent, and construct validities are presented as well as a review of the recent studies of the validity of the Field Work Performance Report and the Certification Examination for Occupational Therapists. Adequate evidence of content and concurrent validity has been established for the Field Work Performance Report, although evidence for long-range predictive validity is lacking. Content validity alone has been established for the Certification Examination for Occupational Therapists. The evidence indicates that the instruments should not be abandoned, that they are better than no measures at all. The directions research might take in the future are given and the implications of continued use of the instruments are evaluated.

Certification↗
PubMed1975

A performance rating scale for evaluating clinical competence of occupational therapy students.

This study was conducted to assess the effectiveness of a 53-item rating scale, the Field Work Performance Report (FWPR), developed to evaluate the performance of occupational therapy students during field work. University faculty and field work supervisors from five different geographic regions in the United States participated in instrument construction. The FWPR was field-tested on a standardization group of 934 student affiliates. An item-analysis and cross-validation design was used to investigate instrument reliability and validity. When FWPR ratings were correlated with other supervisor ratings of student performance, validity coefficients for this scale ranged from .62 to .83. The tests of reliability yielded an inter-rater correlation coefficient of .75, where the consistency coefficient was .97. The FWPR has now been adopted as the official instrument of the AOTA for evaluation of field work performance.

Achievement↗