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Biomedical subjects

A M Baker

Publications and source records attributed to A M Baker.

45 records · Page 3Linked to original sources
PubMed1986

Effects of zeranol implantation and late castration on sexual, agonistic and handling behavior in male feedlot cattle.

Seventy-two Angus feedlot bulls were observed to determine the effects of implanting with zeranol (0, 36 or 72 mg; four groups of six/level) at 8 mo of age (d 0), and of castration midway through the feedlot period (d 115) vs remaining intact (six groups/treatment) on sexual, agonistic and handling behaviors. All 36-mg-treated cattle were re-implanted (36 mg) on d 112; 72-mg-treated cattle were not re-implanted. Each group was observed for a total of 8 h at the time of sunset +/- 30 min for sexual and agonistic behaviors during the trial. Observations on handling were made during 15 weighings and on seven occasions in the pens of the animals. Zeranol did not affect sexual or agonistic behavior. Before imposition of castration, implanted bulls entered the scales more quickly, took longer to stand still on the scales and were less quiet than non-implanted bulls (P less than .05). Castration decreased the sexual behaviors of masturbation (.75 vs .08 X pen-1 X h-1; P less than .05), attempted mounts (.75 vs .33 X pen-1 X h-1; P less than .05) and chinning (10.70 vs 4.75 X pen-1 X pen-1; P less than .10) and the agonistic behavior of butting (42.42 vs 31.50 X pen-1 X h-1; P less than .01) in contrast to intact bulls. Castrated animals entered (P less than .10) and exited (P less than .05) the scales more quickly than did intact males.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Influence of zeranol implants on growth, behavior and carcass traits in Angus and Limousin bulls and steers.

A 2(3) factorial arrangement of treatments was utilized to determine effects of postweaning zeranol implantation, breed (Angus vs Limousin) and castration (bull vs steer) on growth, behavior and carcass traits. An initial slaughter group was used to account for breed differences in composition and to determine fat and lean growth in the 9-10-11th rib section (NTE). The remaining cattle were fed a finishing diet to a fat end point of .76 cm, as determined by a backfat probe. Control bulls outgained (P less than .01) control steers both to the first kill date and over the entire test and did not require significantly more time to reach the fat end point. The implant did not influence gain in bulls but did increase gain in steers. Angus and Limousins were similar in growth rate for the first 126 d before the first slaughter date. Limousins required more (P less than .01) time to reach the fat end point. Bulls and Limousins produced heavier (P less than .01) carcasses and larger rib eyes (P less than .05; bulls; P less than .01; Limousins). Steers and Angus had higher (P less than .01) marbling scores and lower bone maturity. Implanting decreased (P less than .05) marbling and increased carcass maturity. Small but significant shifts in carcass wholesale cut weight distribution were found between breed and sex condition groups. Bulls and Limousins had greater lean growth in the NTE. Bulls and steers were similar in fat growth, but Angus exceeded Limousin in this trait. Zeranol reduced scrotal circumference (P less than .01) and testicle weight at slaughter (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1981

Cell and platelet stability in disodium and tripotassium edta.

The relative stability of blood cells and platelets from 25 donor samples collected in both Na2EDTA and K3EDTA was examined. Twenty-one samples were from normal donors. At designated intervals over a five hour period cell counts and mean cell volumes were determined for each specimen. The separation of plasma from whole blood for future potassium determinations, as well as the preparation of blood smears for determining cellular morphology, were also performed at the designated intervals. The results indicate that no significant changes were observed in the areas investigated. Additional tests should be performed on pathological samples.

Blood Cells↗
PubMedDate not supplied

Natural history and predictors of obesity after orthotopic heart transplantation.

Excessive weight gain resulting in obesity is commonly seen after orthotopic heart transplantation. Obesity increases the risk for the development of many significant health problems and the associated morbidity and mortality. The purpose of this study was to define the occurrence, magnitude, and predictors of overweight/obesity in this group. We followed 47 consecutive patients for 1 year after orthotopic heart transplantation for changes in weight. Weight gain from baseline was significant at months 2, 4, 6, 8, and 10, with significant weight increments between each measurement interval (p < 0.05). The mean weight gain was 10.1 kg +/- 1.6 (standard error [SE]) at 12 months. Based on entry body mass index patients were divided into two groups: group I, overweight/obese, body mass index more than 27 kg/m2 (n = 11); group II, not overweight/obese, body mass index 27 kg/m2 or less (n = 36). No significant difference was found in the amount of weight gained between the two groups (group I, 10.3 kg +/- 1.2 [SE]; group II, 10.1 kg +/- 1.4 [SE]). Only age predicted weight gain, with younger patients gaining more than older patients after transplantation (14.2 +/- 13.2 kg versus 8.8 +/- 7.9 kg; p < 0.05). We found no relationship between the observed weight gain and any of the other measured predictors, that is, history of overweight, age, diabetes, family history of overweight, sex, patient's participation in cardiac rehabilitation. The universal nature of this weight gain and the lack of markers predicting patients at greatest risk for obesity underscores the seriousness of this problem.

Age Factors↗
PubMedDate not supplied

Availability of phosphorus in bone meal.

Two commercially available bone meal products (grades 0-12-0 and 6-12-0) were examined. Samples were prepared according to AOAC method 2.007, and total and available phosphorus contents were determined. Portions of these preparations were reground to pass through successively smaller sieves, and subsequent analyses indicated the availability of phosphorus to be directly proportional to fineness of grind. A quantity of the citrate-insoluble fraction of the bone meal was obtained by following AOAC extraction procedures. Agronomic studies were conducted that compared this insoluble fraction with the original bone meal material and with reagent grade Ca(H2PO4)2.H2O. The data indicated poor correlation between the analytically defined and agronomically determined availability of phosphorus.

Biological Products↗