Biomedical subjects

R L Atkinson

Publications and source records attributed to R L Atkinson.

123 records · Page 7Linked to original sources

PubMed1976

Amino acid supplementation of turkey breeder rations.

Beltsville Small White turkey hens (60) were randomized into four groups of 15 hens each, weighed and placed in individual laying cages. Immediately after lighting to initiate production, they were placed on a practical type turkey breeder diet calculated to contain 18.26% protein, 2893 Cal. M.E./kg., 3.13% Ca, 0.80% available P, 1.04% arginine, 0.86% lysine, 0.50% methionine & cystine and 0.24% tryptophane. Amino acids were added to this diet as follows: (1) none; (2) 0.1% lysine; (3) 0.05% methionine and (4) 0.1% lysine & 0.05% methionine. Lysine (0.1%) had no effect on reproductive performance when added to the basal ration or to the ration containing additional methionine. Methionine addition (0.05%) improved production significantly (P less than or equal to .005), improved feed efficiency, and increased egg size.

Amino Acids↗

PubMed1976

Relationship of biotin to reproductive performance of Leghorn-type hens.

Five floor pens with 14 Leghorn-type breeder hens each, in their 4th month of production, and 2 males per pen were fed a practical-type breeder diet composed largely of soybean meal and milo supplemented with unidentified hatchability factor sources and adequate levels of vitamins and minerals. Five additional pens were fed an identical ration supplemented with biotin at a level of 550 mcg./kg. of diet. Treatment was for a period of 7 months. A 3% improvement in production was obtained by biotin (550 mcg./kg.) supplementation, which was found to be highly significant (P less than or equal to .005) by chi-square analysis. A slight improvement was noted for feed efficiency. Biotin supplementation had no effect on egg size or adult livability. Fertility and hatchability were both significantly improved by biotin supplementation. Fertility and hatchability differences were found to be highly significant by chi-square analyses. Increased hatchability was due to a decreased number of early dead, late dead, and pipped embryos that failed to hatch.

Animals↗

PubMed1975

Acromegaly. Treatment by transsphenoidal microsurgery.

Serum growth hormone levels, thyroid function, and adrenal function were measured before and after surgery in 16 of 17 acromegalic patients undergoing undergoing transnasal transsphenoidal microsurgery of the pituitary. Thirteen patients have been followed up for 12 to 24 months; three patients have been followed up for three to six months. Serum growth hormone levels decreased to less than 5 ng/ml in seven of nine previously untreated patients; thyroid and adrenal function were preserved in eight of these nine patients. In seven patients treated previously by other modes of therapy, growth hormone levels after transsphenoidal surgery decreased to less than 5 ng/ml in three, to between 5 and 10 ng/ml in three, and from 98 to 41 ng/ml in one. Preoperative adrenal function was normal in six of these seven patients and was preserved in four; thyroid function was normal in five patients preoperatively and was preserved in three. Transsphenoidal microsurgery appears to offer an effective means of lowering growth hormone levels and a possiblity of preserving any remaining normal pituitary function. It may be considered for initial treatment in selected patients in whom more rapid arrest of acromegaly is indicated.

Acromegaly↗

PubMed1975

Reproductive performance of caged Beltsville Small White turkeys as affected by choline, bird density and forced molting.

Reproductive performance was determined on Beltsville Small White hens housed 2 or 3 per cage for 10 weeks and then changed to 1 or 2 per cage for 10 additional weeks. Hens were then molted and data collected for a second production cycle of 18 weeks. Hens were fed a basal diet calculated to contain 1230 mg./kg. of choline, or supplemented with choline chloride to provide 1900, 2570 or 3240 mg. of choline per kg. of diet. Variations in production, fertility and hatch were observed between the first and second 10 week periods of the first laying cycle, but differences were affected more by two high choline levels than by number of hens per cage. When data was combined to show the effects of choline supplements for the entire 20 weeks, there were no significant differences in egg production or hatch of fertile eggs due to choline levels. However, significantly lower fertility resulted in groups fed choline at the level of 2570 or 3240 mg./kg. during this 20 wk. laying cycle. During the second production cycle (one hen per cage), choline supplements improved egg production, increased egg weight, depressed fertility and had no effect on hatch of fertile eggs. When data from the first and second production cycles were combined, there was no significant effect of choline on production or hatchability, but all groups supplemented with choline had significantly lower fertility than the basal group, indicating that 1230 mg./kg. of choline was adequate.

Animals↗

PubMed1974