Biomedical subjects

J B Morgan

Publications and source records attributed to J B Morgan.

At least 37 records · Page 2Linked to original sources

PubMed1997

Nutritional composition of home-prepared baby meals in Madrid. Comparison with commercial products in Spain and home-made meals in England.

The nutritional value of 50 home-prepared meat-based baby meals for infants of 7 and 8 months old in Madrid was evaluated. Chemical analysis showed the meals to have a low energy density (mean 50 kcal 100 g-1), mainly due to the low fat content of the meals (mean 2.5 g 100 kcal-1). Protein content was high in proportion to the energy provided (mean 9.1 g 100 kcal-1). The addition of fat would have considerably improved the relation between the three macronutrients. About 20% of the meals had a higher than desired sodium level (> 200 mg 100 kcal-1) when assessed against guidelines for commercial baby meals. The English home-made baby meals had a higher energy density, a lower protein content, the same low fat content, and a wider range between minimum and maximum values observed for each nutrient compared to the Spanish home-prepared meals. The commercial baby meals had a higher energy density, a better ratio between the macronutrients and a smaller variation in the nutrient content.

Cooking↗

PubMed1997

Dietary advice in the management of diabetes mellitus--history and current practice.

Diet has been recognised for over three thousand years as being vital to the overall management of diabetes mellitus (DM). Today dietary advice for the person with diabetes continues to play just as an important role, not just as regards the day to day control but also in respect of the prevention of complications. The history of dietary advice for diabetes is examined as well as current dietary advice.

Adult↗

PubMed1997

Anabolic implant effects on visceral organ mass, chemical body composition, and estimated energetic efficiency in cloned (genetically identical) beef steers.

Six sets of four genetically identical Brangus steers (n = 24; X BW 409 kg) were used to determine the effect of different anabolic implants on visceral organ mass, chemical body composition, estimated tissue deposition, and energetic efficiency. Steers within a clone set were randomly assigned to one of the following implant treatments: C, no implant; E, estrogenic; A, androgenic, or AE, androgenic + estrogenic. Steers were slaughtered 112 d after implanting; visceral organs were weighed and final body composition determined by mechanical grinding and chemical analysis of the empty body. Mass of the empty gastrointestinal tract (GIT) was reduced approximately 9% (P < .10) in steers implanted with estrogen alone or in combination with an androgen. Liver mass was increased (P < .10) from 6 to 14% by implants. Steers implanted with the AE combination had greater (P < .10) daily protein accretion (163.4 g/d) than either E (128.8 g/d) or A (137.1 g/d), and, because the combination improved gain above C (101.1 g/d), this demonstrates the additive effects of a combination implant on protein deposition. Anabolic implants did not alter (P > .10) the efficiency of ME utilization. In general, estrogenic implants decreased GIT, androgenic implants increased liver, and all implants increased hide mass. Steers implanted with an AE combination had additive effects on protein deposition compared with either implant alone. The NEg requirements for body gain are estimated to be reduced 19% by estrogenic or combination implants.

Anabolic Agents↗

PubMed1997

Vitamin E supplementation of cattle and shelf-life of beef for the Japanese market.

Feeder steers (n = 84) were stratified into four weight groups to provide slaughter groups so that product that had been in vacuum packages at 0 to 2 degrees C for 40, 60, 80, or 100 d postmortem could be simultaneously evaluated. Each of the four groups was randomly divided into three subgroups so that vitamin E could be supplemented in the diet at rates of 0, 1,000, or 2,000 (E0, E1000, and E2000, respectively) IU.steer-1.d-1 for 100 d. After slaughtering, chilling, and fabricating, one ribeye-roll and one strip loin from each carcass was transported to the university laboratory for analyses, whereas the paired subprimals were transported to Japan. Based on metmyoglobin formation and lipid oxidation, strip loin steaks deteriorated at a faster rate during retail-display than did ribeye steaks. Steaks from subprimals that were stored for 100 d had inferior (P < .05) retail-display characteristics and a shorter (P < .05) caselife than steaks from the other storage periods. alpha-Tocopherol levels in longissimus muscle were lower (P < .05) for E0 than for E1000 and E2000 (3.51, 5.54, and 6.10 micrograms/g of tissue, respectively). Supplementing cattle with vitamin E resulted in steaks that exhibited superior lean color, less surface discoloration, more desirable overall appearance, and less lipid oxidation during retail display than control steaks; minimal differences were observed between E1000 and E2000 steaks. Steaks from cattle supplemented with vitamin E were preferred over control steaks by 91% of Japanese survey participants (n = 10,941), and 58% of all participants identified muscle color as the most important factor in selecting beef products.

Animals↗

PubMed1997

Anabolic implant effects on steer performance, carcass traits, subprimal yields, and longissimus muscle properties.

Crossbred steers (n = 140; 353 kg) were implanted as follows: (C) control, no implant; (S) Synovex-S (20 mg estradiol benzoate + 200 mg progesterone); (R) Revalor (20 mg estradiol + 140 mg trenbolone acetate [TBA]; international dosage); (ST) S + finaplix-S (140 mg TBA); (STT) S + finaplix-S with finaplix-S reimplanted on d 58. Steers were harvested after 119 to 126 d on feed. Left sides of 40 carcasses were fabricated into boneless subprimals for two s.c. fat levels: 2.5 and .64 cm. Steers administered an estrogen (estradiol benzoate or estradiol) plus TBA gained more rapidly (P < .05) than C or S steers. Feed efficiency was improved (P < .05) with an estrogen plus TBA. No differences (P > .05) were noted among treatments for carcass s.c. fat thickness, percentage internal fat, or lean color. Carcasses from steers receiving TBA had larger (P < .05) longissimus areas and tended to have lower (P < .10) marbling scores and yield grades than C or S steers. Steers implanted with R had a lower (P < .05) percentage of U. S. Choice carcasses (51.8%) than C, S, and ST steers (82 to 86%). Shear force values for implanted steers tended to be higher (P < .10) than for controls. Implants increased (P < .05) subprimal and total side lean yields (.64 cm) compared to controls; the largest increases of 2.3 and 2.8%, respectively, occurred in steers receiving TBA plus an estrogen. Estrogen plus TBA exhibited favorable effects on gain, efficiency, and composition; however, the single estradiol plus TBA implant (R) decreased quality grade.

Anabolic Agents↗

PubMed1997

Comparison of USDA quality grade with tendertec for the assessment of beef palatability.

Carcasses (n = 265) selected to differ in USDA yield grade were evaluated by expert graders and assessed for tenderness with the Tendertec Mark III Beef Grading Instrument. Tendertec measurements were collected on longissimus lumborum muscles in both sides of each carcass. During fabrication of each left carcass side, a rib section (later converted into three steaks) was removed for aging and subsequent sensory panel evaluation at 14 d and for Warner-Bratzler shear force measurements at 14 and 28 d. Correlation coefficients for repeatability of Tendertec output variables, between left and right carcass sides, were .57, .44, .70, and .65 for Area-2, Area-2B, Power-2, and Power-2B, respectively. Correlations between Tendertec output variables and Warner-Bratzler shear force evaluations performed on steaks aged 14 or 28 d were not different from zero. Sensory panel ratings for amount of connective tissue were correlated (P < .01) with Tendertec output variables Area-2 and Area-2B (r = -.168 and -.154, respectively), and ratings for overall tenderness were correlated (P < .05) with the Area-2 output variable (r = -.131) but the coefficients were very low. Segregation analysis, using Tendertec output variables Area-2 and Power-2, significantly (P < .05) stratified sensory panel ratings for connective tissue amount and overall tenderness. Even though the Tendertec probe detected some differences in connective tissue contributions to rib steak tenderness, it was not better than USDA quality grade at segmenting A-maturity carcasses into anticipated tenderness outcomes, and thus its applicability as a grading instrument may be limited to use on more mature beef carcasses.

Analysis of Variance↗

PubMed1996

Dietary factors influencing levels of food antibodies and antigens in breast milk.

The effect of a milk-free diet during late pregnancy and lactation, on levels of cows' milk specific antibodies and antigens in breast milk, was examined. Women with an allergic condition (defined as atopic) were randomly allocated to a milk-free diet (n = 10) or an unrestricted diet (n = 12). Twelve non-atopic women followed an unrestricted diet. A significant reduction (p < 0.001) in beta-lactoglobulin-specific immunoglobulin A and alpha-casein-specific immunoglobulin A levels was observed over the first 5 days in all groups. The mean level of beta-lactoglobulin antigens in breast milk from women who adhered strictly to the milk-free diet was significantly lower than the levels of the atopic group on the unrestricted diet (p < 0.02). The allergy incidence in the infants born in the atopic diet group was significantly lower compared with that of the atopic group on the unrestricted diet.

Analysis of Variance↗

PubMed1996

Obesity in Bahraini adults.

In this study the prevalence of obesity and the demographic factors associated with it were analysed on 290 adult Bahraini individuals, of whom 137 were males and 153 were females. The overweight and obesity prevalence rates, using the Body Mass Index (BMI) as a criterion, were 26% and 16% in males and 29% and 31% in females, respectively. The prevalence of underweight (BMI < 20) was 16.8% and 11.8% in the males and females respectively. The mean body fat percentage of females, calculated from the skinfold measurements, was 35%; the fat percentage of males was 18.6%. Bahraini women had greater fat deposition in the subscapular region than the amount reported for American women. Females and males living in urban areas had a greater tendency to be obese than those residing in rural areas. Marriage, ownership of a car as well as a large family ( > 7 members) were positively associated with obesity; unmarried women were more likely to be underweight than married women. The educational level was not associated with obesity in either the males or females. The age of adult females was not found to be associated with obesity, whereas in males the incidence of obesity was more frequent among those who were 50 years of age and above than under 50 years of age. Family monthly income was not associated with the incidence of obesity. The high prevalence of overweight and obesity in the women reported in this study and the difference in the distribution of body fat suggest that genetics may be a determinant factor of this disorder in Bahrainis but certainly social factors are also important.

Adult↗

PubMed1996

Genetic influences on beef longissimus palatability in charolais- and limousin-sired steers and heifers.

Random matings of 10 Charolais sires and eight Limousin sires to crossbred cows produced 392 steers and heifers that were used to evaluate genetic influences on beef palatability. Longissimus lumborum steaks were measured for shear force at 1, 4, 7, 14, 21, and 35 d postmortem and for taste panel attributes at 14 d postmortem. Longer postmortem aging periods resulted in lower (P < .05) shear force values for progeny from all 18 sires. Shear force variation among sires did not diminish during postmortem aging; however, shear force variation among progeny within a sire decreased during postmortem aging. Median within-breed heritability estimates from Method-R were .33 for shear force, .49 for 24-h calpastatin activity, and .18 for marbling score. All taste panel attribute heritability estimates were very low. Solid evidence existed for a very high within-breed genetic correlation between calpastatin activity and shear force. However, the across-breed genetic correlation between marbling and shear force seemed to be higher than the correlation between calpastatin activity and shear force. Very few antagonistic genetic relationships existed between production/carcass traits and palatability traits.

Aging↗

PubMed1996

Growth and fresh meat quality characteristics of pigs supplemented with vitamin E.

Crossbred pigs (n = 30) were fed to determine the influence of supplementation with vitamin E on growth and slaughter characteristics of swine and on the quality characteristics of fresh pork. Pigs received either a control diet containing no vitamin E (CON) or a diet formulated to contain 100 mg of vitamin E/kg feed (VITE). During 84 d of feeding, feed intake and weight gain were measured every 2 wk. After the feeding period, pigs were slaughtered and the loin from the left side of each carcass was removed 4 d after death. Alpha-Tocopherol concentration and proximate composition of the longissimus muscle were determined. Loins were sliced into 10-cm sections and stored under vacuum (2 degrees C) for 0, 14, 28, and 56 d. After storage, loins were sliced into 2.54-cm chops, wrapped in polyvinyl chloride film and stored in a retail case (2 to 4 degrees C) for 5 d. Thiobarbituric acid (TBA) values, Hunter L, a, and b values, total plate counts, pH, purge loss, drip loss, cook loss, taste panel characteristics, and visual panel characteristics were evaluated. Growth traits, slaughter characteristics, and proximate composition did not differ (P > .05) between dietary treatment groups. Alpha-Tocopherol concentrations were greater (P < .05) and TBA values during extended retail display were less (P < .05) for VITE chops than for CON chops. Overall palatability ratings were more desirable (P < .05, at 14 d of vacuum storage) for VITE chops than for CON chops. Color measurements, sensory characteristics, total plate counts, pH, purge loss, drip loss, and cook loss were not influenced (P > .05) by vitamin E supplementation. These results indicated that at the tissue alpha-tocopherol concentrations of the present study, vitamin E supplementation of the growing-finishing diet of hogs reduced lipid oxidation in fresh pork but did not influence pork color or tissue drip loss.

Analysis of Variance↗

PubMed1996

Effect of phenotypic expression of Brahman breeding on marbling and tenderness traits.

Steers with known proportions of Brahman and Hereford breeding (80 quarter-bloods, 25% Brahman x 75% Hereford and 79 half-bloods, 50% Brahman x 50% Hereford) were used to determine the effect of phenotype on marbling and beef tenderness characteristics. Three experienced evaluators independently classified each live steer according to estimated proportion of Brahman breeding based on phenotypic evidence of Brahman breed characteristics. The steers were slaughtered, their carcasses were graded, and a carcass. Samples of longissimus muscle were obtained for measurement of 24-h calpastatin activity, sensory panel evaluation, and Warner-Bratzler shear (WBS) force measurements. Paired steaks were aged (6 and 18 d postmortem) and palatability determinations were completed. Estimates of live animal phenotype ranged from 0/16 to 9/16 for quarter-blood Brahman steers and from 1/14 to 13/16 for half-blood Brahman steers. Neither live animal phenotype nor carcass hump height was correlated with marbling score. Live animal phenotype was correlated (P < .01) with taste panel tenderness ratings (rd6 = -.36; rd18 = .36) and shear force values (rd6 = .36; rd18 = .30). Moreover, carcass hump height exhibited low, negative correlations (P < .05) with panel tenderness scores (rd6 = -.16; rd18 = -.28) and low, positive correlations (P < .10) with shear force (rd6 = .13; rd18 = .16). Steaks from steers classified as more than 3/8 Brahman were tougher (P < .05) than steaks from steers classified as 3/8 or less Brahman. Steaks from carcasses with hump height measurements of 7.60 cm or greater had lower panel tenderness ratings and higher WBS values (P < .05) than steaks from carcasses with hump heights less than 6.35 cm. Quarter-blood and half-blood Brahman steers that were similar in phenotype produced steaks that were similar in tenderness. Results of this study suggest that as phenotypic evidence of Brahman breeding increases the tenderness of cooked steaks from Brahman crossbred steers decreases.

Animals↗

PubMed1996

Effects of animal age, marbling score, calpastatin activity, subprimal cut, calcium injection, and degree of doneness on the palatability of steaks from limousin steers.

Strip loin (longissimus lumborum), sirloin (gluteus medius) and round (semimembranosus) subprimals from 114 purebred and crossbred Limousin steers were used to identify main effects and interactions of animal age, marbling score, calpastatin activity, subprimal cut, calcium injection (5% wt/wt with a 200 mM CaCl2 solution at 48 h postmortem), and degree of doneness on the palatability of cooked beef steaks. Steaks were aged for 14 d, frozen, thawed, cooked to different internal temperature end points, visually scored for degree of doneness, sheared on a Warner-Bratzler shear machine, and evaluated by a trained taste panel. Raw and cooked steaks from carcasses of higher USDA quality grades had higher fat and lower moisture percentages (P < .05). Higher degrees of doneness resulted in lower moisture percentages (P < .05). Lower shear force values were associated with less variation in shear force. Younger slaughter age and lower calpastatin activity both resulted in greater tenderness (P < .05). Shear force was lowest between "medium rare" and "medium" and increased toward both ends of the degree of doneness scale for round and sirloin steaks; however, shear force increased linearly with degree of doneness in strip loin steaks (P < .05). Subprimal cut had the largest effect on taste panel tenderness ratings, and degree of doneness had the largest effect on taste panel juiciness ratings. The improvement in shear force due to CaCl2 injection was greater for strip loin and sirloin steaks than for round steaks (P < .05 for the interaction). Injection with CaCl2 improved all taste panel attributes. In addition, CaCl2 injection reduced the toughening effects of cooking (P < .05).

Aging↗

PubMed1996

Modification of early-postmortem muscle pH and use of postmortem aging to improve beef tenderness.

This study was conducted to determine whether modification of early-postmortem muscle pH and(or) control of postmortem aging time could be used to improve tenderness of strip loin (longissimus, LM), top sirloin (GM), and top round (SM) steaks. Muscle pH, at 1.5 and 3 h postmortem, was modified using three 60-Hz electrical stimulation (ES) treatments (240 V, 35 V, or combined use of 240 and 35 V). Vacuum-packaged sections of the LM, GM, and SM were aged for 6, 12, 18, or 24 d postmortem. Use of ES increased rate of postmortem muscle pH decline and decreased shear force of LM steaks but had no effect on tenderness of GM or SM steaks. Reducing 3-h pH of the LM reduced variability in LM shear force but had little effect on tenderness of GM or SM steaks. However, lower values for 24-h pH of the LM were associated with increased tenderness of all three cuts. Tenderness of all cuts also improved as length of the postmortem aging period was increased. For LM and SM steaks, the greatest improvements in tenderness were achieved by 12 d; however, tenderness of GM steaks continued to increase up to 24 d postmortem.

Animals↗

PubMed1996

Implant program effects on performance and carcass quality of steer calves finished for 212 days.

We compared the effects of seven implant treatments combining use of Ralgro (RAL), Synovex-S (SYN), and Revalor-S (REV) on performance and beef quality traits of crossbred steer calves (n = 560) finished for 212 d. A randomized complete block design was used to compare treatments consisting of 1) non-implanted control (CON); 2) RAL on d 0, SYN on d 60, and REV on d 130 (RALSYNREV); 3) RAL on d 0, REV on d 60, and REV on d 130 (RALREVREV); 4) SYN on d 30 and REV on d 130 (SYNREV); 5) REV on d 30 and REV on d 130 (REVREV); 6) REV on d 0, REV on d 75, and REV on d 150, 12.5% crude protein diet (REV3X-12.5); and 7) REV on d 0, REV on d 75, and REV on d 150, 14.5% crude protein diet (REV3X-14.5). All implant groups had higher ADG and gained more efficiently (ADG: feed intake) than the CON group. No distinct performance advantages were noted for particular implant schemes. Implant treatments did not (P > .05) affect dressing percentage, carcass weight, or KPH fat percentage. Fat thickness did not differ (P > .05) for implanted vs CON steers; however, REVREV, SYNREV, and RALREVREV steers produced fatter carcasses than did REV3X-12.5 and RALSYNREV steers. The REV3X-12.5 and REV3X-14.5 treatments increased longissimus muscle area compared with CON; longissimus muscle areas for all other treatments did not differ (P > .05) from CON. No reduction in percentage of Choice and Prime carcasses occurred with use of SYNREV or REVREV; however, all treatments receiving three successive implants had lower (P < .05) percentages of Choice and Prime carcasses than the CON group. Increasing dietary crude protein seemed to lessen the detrimental effect of three successive REV implants on percentages of Choice and Prime carcasses. Loin steaks from REVREV, REV3X-12.5, and REV3X-14.5 steers had higher (P < .05) shear force values than steaks from CON steers.

Anabolic Agents↗

PubMed1996

[Feeding habits of a sample of children under 20 months of age in Madrid].

OBJECTIVE: To know the feeding habits of children of different socioeconomic groups during the first year and a half of life in Madrid. PATIENTS AND METHODS: The mothers of 344 children between 3 and 19 months who attended two vaccination centers of the Regional Health Authorities of Madrid were interviewed in detail using the dietary history method supplemented with questions on milk feeding and weaning. The sample was stratified into three socioeconomic groups, low middle and high, each group comprising about a third of the sample. RESULTS: In general, children were fed according to actual pediatric recommendations. Deviations were that breast-feeding was stopped too early, complementary feeding was introduced somewhat early and mothers were often found not to understand gluten nor did they know which products contain it. The children in this study were remarkably similarly fed regardless of socioeconomic group. CONCLUSIONS: The pediatrician should know where mothers may deviate from the recommendations to prevent feeding errors because o misunderstanding or ignorance.

Breast Feeding↗

PubMed1995

Healthy eating for infants--mothers' attitudes.

Mothers' perceptions of desirable nutritional practices in infant feeding were examined using a questionnaire consisting of open and closed questions. A total of 1004 mother-infant pairs were recruited from a mixture of urban and rural areas in England. The sample represented a cross-section of socioeconomic groups and educational backgrounds. Mothers' attitudes to healthy eating for infants revealed some misconceptions; 83% felt that a high fibre intake was important or very important and 87% that a low fat intake was important or very important, while 20% considered that plenty of calories was not important. Other health guidelines were appropriately applied and most mothers considered a wide variety of foods, plenty to drink and a low sugar and salt intake to be important. These beliefs were representative of the sample population, irrespective of the socioeconomic group, location, age and education of the mother.

Adolescent↗

PubMed1995

Healthy eating for infants--mothers' actions.

The aim of this study was to analyse the nutrient composition, with respect to energy density, protein, fat, carbohydrate, non-starch polysaccharides and certain micronutrients, of home-prepared infant foods and to compare the nutrient composition with the draft European Commission directive for baby foods, the published nutrient content of manufactured baby foods, and with breast milk. Two hundred and sixty-five samples of home-prepared weaning foods for infants aged 3-12 months were collected and chemically analysed. Many of the food samples were low in energy, protein, fat, iron, calcium and zinc and high in non-starch polysaccharides and sodium. Home-prepared weaning foods have some shortcomings in terms of nutrient composition. Advice from health care professionals needs to focus on these areas at the same time as presenting the nutritional merits of manufactured baby foods.

Age Factors↗

PubMed1995

Weaning practices in children up to 19 months of age in Madrid.

The weaning practices of 344 children in Madrid, aged 3-19 months, were investigated by controlled interview of their mothers or caretakers. The results were compared with national and international guidelines for the introduction of complementary foods; there are no Spanish guidelines. We found only minor differences between the practices in three different socioeconomic groups. Generally, mothers in Madrid followed national and international guidelines well. However, more attention should be paid to aspects such as the timing of the introduction of the first complementary food, the nature of gluten, the addition of salt and sugar to baby meals and the introduction of potentially allergenic foods. Also, manufacturers of baby foods that are sold in Spain could play a useful role by reducing the number of ingredients used in products advised for the initial phase of weaning and by avoiding the use of salt and sugar in their products.

Cross-Cultural Comparison↗