Biomedical subjects

W Smink

Publications and source records attributed to W Smink.

3 recordsLinked to original sources

PubMed1998

Requirement of the laying hen for apparent fecal digestible lysine.

A study was conducted to determine the requirement for lysine of a White Leghorn strain of hens with a body weight of approximately 1,600 g. Before starting the experiment, apparent fecal digestibility of amino acids of the basal diet was determined in an in vivo digestibility trial with six individually housed hens. The basal diet used was based on corn and soybean meal and contained 0.65% total and 0.49% apparent fecal digestible lysine. To the basal diet, seven graded dose levels (0.04, 0.08, 0.12, 0.16, 0.20, 0.24, and 0.28%) of lysine as L-Lysine x HCl were added. The experimental diets were fed for 12 wk, covering the early stage of laying from 24 to 36 wk of age. Each experimental diet was fed to 60 individually caged housed birds. The dietary lysine requirement was found to be higher for maximizing efficiency of feed utilization than for obtaining maximum egg mass yield. Based on the feed conversion efficiency and at an egg mass yield of 57 g/hen-d, the requirement for total lysine was estimated to be about 900 mg/hen-d. From the results of the digestibility trial, it was calculated that the estimated requirement for total lysine was equivalent to 720 mg apparent fecal digestible lysine per hen-day.

Animals↗

PubMed1997

Replacement value of betaine for DL-methionine in male broiler chicks.

The effect of DL-methionine and betaine supplementation on growth performance of 2,400 male broilers in the age period of 1 to 38 d, and on carcass composition of a subsample of 384 birds was examined. Three dose levels of DL-methionine (0, 0.05, and 0.10%) and two doses of betaine (0 and 0.04%) were supplemented in different combinations to methioninedeficient diets. Two types of diets were fed as starters and growers: either corn-soybean diets or practical diets typical for the Dutch broiler industry. All diets were fortified with 220 ppm choline in order to avoid a deficiency in methyl groups. Increasing DL-methionine supplementation significantly improved daily weight gain and feed conversion efficiency. Supplemental betaine did not affect bird growth. Betaine slightly improved feed conversion in diets without supplemental DL-methionine, but did not affect this parameter in diets with added DL-methionine. Breast meat yield was significantly increased by about 1.5 percentage points by the addition of 0.05% DL-methionine, whereas 0.04% betaine only tended to increase breast meat yield in the range of 0.3 to 0.6 percentage points. The type of diet did not have any effect on the responses obtained. In summary, there was no evidence for betaine to spare DL-methionine as an essential amino acid supplement in broiler diets.

Analysis of Variance↗

PubMed1987

Fully automated sample handling system for liquid chromatography based on pre-column technology and automated cartridge exchange.

The design of an automated cartridge exchange module for on-line sample handling in liquid chromatography is described. When combined with a low-cost purge pump, a solvent selection valve and an auto-sampler, a fully automated sample handling system is obtained. Samples are sorbed on a disposable cartridge packed with 40 micron octyl-bonded silica, purged for clean-up and eluted on-line to the analytical column. Unattended operation of the system is demonstrated for various examples, i.e., the determination of anti-epileptic drugs in serum, an anti-cancer drug in plasma, barbiturates in urine, phenylurea herbicides in river water and caffeine in a soft drink.

Autoanalysis↗