Biomedical subjects

G F Krause

Publications and source records attributed to G F Krause.

At least 37 records · Page 2Linked to original sources

PubMed1987

Isoleucine requirement of young growing male guinea pigs.

The isoleucine requirement of young, growing male guinea pigs was investigated by use of crystalline amino acid diets containing 3.65% nitrogen. Three-week-old guinea pigs were fed one of eight crystalline amino acid diets ranging from 0.2 to 1.2% isoleucine for 22 d. Diets were evaluated on the basis of body weight changes, nitrogen retention, carcass weight, liver weight, hematocrit, hemoglobin and carcass and liver weights expressed as percentages of live body weight. A 0.5% level of dietary isoleucine (2.2% of total nitrogen X 6.25) was the lowest level fed that did not have a response significantly lower than the higher levels fed, and that generally promoted a thrifty and well-groomed appearance of the animals.

Aging↗

PubMed1987

Ovarian follicular populations and in vitro steroidogenesis on three different days of the bovine estrous cycle.

This study was undertaken to determine changes in follicular populations on ovaries of dairy cows during three stages of the estrous cycle and their steroidogenic capacity in vitro. Numbers of small (2.0 to 5.0 mm), intermediate (5.1 to 10 mm) and large (greater than 10 mm) antral follicles on ovaries of multiparous cows and heifers (n = 31) in the early luteal (d 4), mid-luteal (d 12) and follicular phase (d 19) of the estrous cycle were determined (d 0 = estrus), and steroidogenic capacity of intermediate and large follicles was measured in vitro. Total number of follicles and number of small follicles were greatest (P less than .05) on d 19 compared with d 12, with numbers on d 4 not different from either d 12 or 19. Intermediate follicles were fewer (P less than .05) on d 19 compared with d 4 or 12. Numbers of large follicles did not change. The proportion of estrogen active (EA) follicles was greater (P less than .05) on d 19 compared with d 4 or 12. Accumulation of estradiol-17 beta (E) into culture medium by intermediate follicles decreased (P less than .05) with increasing days of the estrous cycle, while accumulation of progesterone (P) was greater on d 19. In large follicles, accumulation of E into culture medium was greatest (P less than .05) on d 19 and the lowest on d 12 (P less than .05). In summary, the proportion of EA follicles increases during the preovulatory period, and E production increases in large EA follicles.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1987

Physiological, productive, and economic benefits of shade, spray, and fan system versus shade for Holstein cows during summer heat.

During the 1984 summer, effects of spray and fan in freestall areas and feeding areas on milk yield, plasma growth hormone and prolactin, freestall utilization, and economic significance for Holstein cows were studied. Weekly milk and rectal temperatures at morning and afternoon milkings were higher for cows in shade than in shade with spray and fan cooling. Compared with rectal temperature, milk temperature measured in the clawpiece provided a more reliable indicator of heat stress than in the milk meter. Diurnal pattern of rectal temperature from 4-h measurements showed an average of 12 h in which maximal rectal temperatures of cows in shade were greater than 39 degrees C, but cows in the shade plus spray plus fan group had rectal temperatures below 39 degrees C all day. Plasma growth hormone was higher and prolactin lower for cows in shade plus spray and fan than cows in shade only. Cows cooled with spray and fan under shade produced 2 kg/cow per d more than cows in shade alone. Economic analysis showed a net income of 22 cents/cow per day for spray plus fan under shade. Results suggest that milk temperature is a practical technique to assess heat stress in dairy cattle, and the use of spray plus fan is a profitable means to maximize cow comfort and lessen stress-induced decline in milk production.

Animals↗

PubMed1986

Factors related to obesity in preschool children.

The purpose of this research was to examine the following variables for their relationship to the prevalence of preschool obesity: familial aggregation of obesity, infant feeding practices, socioeconomic status, and parents' attitudes toward the use of food for non-nutritive purposes. Parents completed a biographical data form. Height, weight, and skinfold measurements were obtained from 94 preschool children and their biological parents. Both parents answered a Child Feeding Opinion Questionnaire. Anthropometric measurements were evaluated using percentile rankings from NHANES. On the assumption that subjects over the 75th percentile for triceps skinfold were overweight and those above the 90th percentile were obese, 23.4% and 7.5% of the children, 9.6% and 5.3% of the mothers, and 29.8% and 10.6% of the fathers were overweight or obese, respectively. Most parent-child anthropometric correlations were statistically significant. No statistically significant relationships were found between infant feeding practices and childhood obesity. Mothers' educational level varied inversely with the children's weight for height. Mothers and fathers opposed the use of food for reward, punishment, soothing, or affection. The parents' child feeding attitudes had no obvious relationship with the children's anthropometric measurements.

Attitude↗

PubMed1985

The lysine requirement of young growing male guinea pigs.

The lysine requirement of young, growing male guinea pigs was investigated by using crystalline amino acid diets containing 3.58% nitrogen. One hundred eighty-seven 3-wk-old guinea pigs were fed one of 10 crystalline amino acid diets ranging from 0.4 to 2.0% lysine or the control diet consisting of 30% casein in four 21-d performance trials. Diets were evaluated on the basis of changes in body weight, nitrogen retention, carcass weight, gastrointestinal tract weight, liver weight, hematocrit and hemoglobin plus carcass weight, gastrointestinal tract weight and liver weight as percentages of live body weight. A 0.7% dietary lysine level (0.875% lysine X HCl) was the lowest that gave results similar to those attained when casein or higher levels of lysine were fed.

Amino Acids↗

PubMed1984

Long-term effects of low histidine intake on men.

The purpose of this 85-day study was to investigate the long-term effects of histidine depletion on nitrogen utilization in young adult men. A low nitrogen (6.3 g/day), low histidine (10 mg/day) amino acid diet was fed to seven men for 8 weeks. Mean nitrogen balance became negative at the end of the 8-week period. Free histidine in postabsorptive plasma and 24-hour urine decreased significantly during the first 2 weeks of the depletion and remained low and constant for the remaining 6 weeks. Hemoglobin concentration decreased somewhat, and serum iron concentration increased significantly during histidine depletion. Lean body mass, urinary N'-methylhistidine and total creatinine did not change significantly. On addition of histidine to the low histidine diet for 2 weeks, nitrogen retention became positive, plasma and urinary histidine returned to initial values, serum iron fell, and hemoglobin concentration slowly increased. These parameters remained unchanged in two control men fed the same diet supplemented with histidine (1.05 g/day) for 8 weeks. The results suggest that histidine is indispensable for young men consuming a low nitrogen diet.

Adult↗

PubMed1984

Efficacy of ethylenediamine dihydriodide as an agent to prevent experimentally induced bovine foot rot.

Ethylenediamine dihydriodide (EDDI) was administered by capsule and as a feed premix to cattle in 2 studies. In study I (32 steers), EDDI was given at 0, 12.5, 50, and 200 mg/animal each day and in study II (36 steers) at 0, 30, and 200 mg/animal each day. Serum iodine levels were monitored during the studies. The cattle were inoculated intradermally in the interdigital space with a mixture of Fusobacterium necrophorum and Bacteroides melaninogenicus to induce acute foot rot at day 15 (study I) or day 28 (study II) after EDDI administration was started. Lesions and lameness were evaluated 5 days after challenge exposure, using a subjective scoring system. The cattle receiving EDDI had significantly less severe lesions and lameness than control cattle in both studies (study I, P less than 0.003; study II, P less than 0.001). The results indicated that EDDI was efficacious in prevention of foot rot. The studies demonstrated a direct relationship between dosage levels of EDDI and serum iodine levels. However, at the large dosage level (200 mg) there were some individuals that showed an inability to metabolize and excrete the iodine as demonstrated by high serum iodine levels (600 to 700 micrograms of iodine/dl of serum).

Animals↗

PubMed1983

Alteration of the GnRH-induced LH release by steroids in postpartum dairy cattle.

The effect of elevated plasma concentrations of estradiol-17 beta (E2 beta), estrone (E1) and progesterone (P), in concentrations similar to those observed at the end of pregnancy, on the gonadotropin releasing hormone (GnRH)-induced luteinizing hormone (LH) release in postpartum dairy cows was studied. Twenty-five dairy cows in late gestation were assigned to five groups of five each to receive daily steroid treatments as follows: 1 and 2) no exogenous steroids; 3) 20 mg E2 beta and 30 mg E1; 4) 150 mg P and 5) 20 mg E2 beta + 30 mg E1 + 150 mg P. Steroids were dissolved in alcohol (vehicle) and injected sc twice daily. Cows receiving no steroids were given vehicle. Administration of steroids or vehicle began immediately after parturition (d 0) and continued for 7 d to maintain concentrations of steroids in plasma similar to prepartum concentrations. Cows in groups 2 through 5 received an injection of 100 micrograms GnRH on d 2, 8, 16, 24 and 32 postpartum, while those in group 1 received water (vehicle for GnRH) on the same days. Plasma for hormonal determinations was collected on alternate days beginning 10 d before the expected day of parturition, daily through the period of steroid treatments (d 0 to 6, postpartum) and on alternate days thereafter until d 40 postpartum. In addition, plasma was collected immediately before GnRH or water administration and at .5 h intervals thereafter for 4 h. Trends in response to treatment over days postpartum were studied by partitioning sums of squares due to linear, quadratic and cubic polynomial responses.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1977

Effects of dietary histidine and arginine on nitrogen retention of men.

Effects of dietary histidine and arginine on nitrogen retention were compared in six young men consuming for 1 week, each of six semipurified diets containing eight indispensable amino acids proportioned as in casein and 6.3 g nitrogen daily. Nonspecific nitrogen was either A) a mixture of six dispensable amino acids and arginine (diet 1) or arginine and histidine (diet 2) in casein proportions, or B) an isonitrogenous mixture of glycine and diammonium citrate alone (diet 3), with histidine (diet 4), arginine (diet 5), or histidine and arginine (diet 6). Nitrogen retention was significantly greater when the nonspecific nitrogen source was dispensable amino acids, arginine and histidine (diet 2) than when it was glycine and diammonium citrate (diet 3). mean balances were positive only when diets contained histidine (diets 2, 4, and 6). Histidine with arginine (diets 2 and 6) significantly improved nitrogen retention compared to arginine alone, but the balance, although positive, was not significantly improved when histidine was fed without arginine (diet 4). Urinary urea nitrogen confirmed these data. Indicators of erythrocyte status, plasma enzyme activities and proteins, and creatinine clearance were unaffected by diet. In summary, histidine supplementation of the low nitrogen diet improved total nitrogen utilization when arginine was present in the diet.

Adult↗

PubMed1977

Effects of dietary histidine and arginine on plasma amino acid and urea concentrations of men fed a low nitrogen diet.

The effects of dietary histidine and arginine on fasting and 1 and 2 hour postprandial plasma free amino acid and urea concentrations were studied in six young men. For 1 week each, they were fed six different diets containing 6.3 g of nitrogen daily. Each diet contained eight indispensable amino acids, cystine and tyrosine proportioned as in casein and a different mixture of dispensable nitrogen: A) six dispensable amino acids plus argine (diet 1) or plus histidine and arginine (diet 2) in the casein pattern, or B) an isonitrogenous amount of glycine and diammonium citrate alone (diet 3), with histidine (diet 4), with arginine (diet 5) or with histidine and arginine (diet 6). The fasting plasma concentrations of the seven indispensable amino acids assayed and their similar postprandial patterns were unaffected by the dietary treatments. Both fasting and postprandial plasma histidine concentrations were significantly lower when the histidine-low diets were fed than when the histidine-supplemented diets were fed. Histidine supplementation promoted a reduction in fasting plasma urea nitrogens. Proline concentrations were lowered significantly when proline was removed from the dietary amino acid mixtures, but plasma arginine concentrations were unaffected by arginine removal. Plasma histidine was maintained at lower concentrations in dietary histidine deficiency than when histidine was added to the low nitrogen diets.

Adult↗

PubMed1974