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Biomedical subjects

R Blair

Publications and source records attributed to R Blair.

At least 91 records · Page 5Linked to original sources
PubMed1991

Lack of an effect of taurine supplementation on the incidence of sudden death syndrome in male broiler chicks.

Two experiments were conducted to study the effect of taurine supplementation on growth and the incidence of Sudden Death Syndrome (SDS) in male broiler chickens. The 4,650 birds were day-old male broiler chickens raised in floor pens to 9 wk of age. In Experiment 1, the birds received diets containing 0, 250, 500, or 1,000 mg taurine/kg. In Experiment 2, the treatments were no added taurine, 500 mg taurine/kg feed, 1,000 mg taurine/kg feed, 250 mg taurine/L water, and 500 mg taurine/L water. Taurine supplementation did not have any significant influence on growth performance although supplementation of the feed at 250 mg/kg reduced the feed:gain ratio from 1.67 to 1.63 in Experiment 1, which was significant (P less than .05). In general, mortality was unaffected by treatment with a few exceptions: in Experiment 2, SDS deaths were reduced significantly (P less than .01) by supplementation of the feed with 500 mg taurine/kg, and at 3 and 6 wk of age, SDS deaths as a percentage of total deaths were reduced significantly with this treatment. The results are interpreted as suggesting that taurine does not play a major role in the etiology of SDS.

Animal Feed↗
PubMed1991

The effect of taurine transport antagonists on cardiac taurine concentration and the incidence of sudden death syndrome in male broiler chickens.

Two experiments were conducted in which 540 day-old male broiler chickens were raised in heated battery brooders to 4 wk of age. Diets contained taurine antagonists to test effects on cardiac taurine content and the incidence of Sudden Death Syndrome (SDS). In Experiment 1 treatments during Weeks 2 to 4 were A) basal diet; B) basal diet supplemented with .25% guanidinoethyl sulfonate (GES) in Week 2 and 1.5% GES in Weeks 3 and 4; and C) basal diet supplemented with .5% GES in Weeks 2 to 4. The taurine content of heart was significantly reduced (P less than .05) with GES supplementation, but no effects on SDS mortality rates were noted. In Experiment 2 birds received diets containing 0. 2.5, or 5% beta-alanine. Supplementation with this compound decreased cardiac taurine concentration to extremely low levels (P less than .05). No significant effects on SDS mortality rates were noted. The results are interpreted as suggesting that taurine does not play a major role in the etiology of SDS.

Animals↗
PubMed1991

Repetitive high magnetic field stimulation: the effect upon rat brain.

The effect on rat brain of a large number of stimulations with a high strength pulsed magnetic field was investigated in 31 rats: 10 naive controls, 10 anesthetized controls, and 11 stimulated and anesthetized rats. An investigational magnetic stimulating device with a circular 5.5 inch diameter stimulating head was used. The stimulating coil was energized by 1000 V, 8000A, 200 microseconds half sine pulses at a rate of 8 Hz. The peak field strength was 3.4 T, and the peak field flux was approximately 53,000 T/sec. Stimulation was performed for 20 min at a rate of 8/stimuli per second, for a total of at least 10,000 stimulations. The rats were sacrificed after 8 days, and their brains were examined using light microscopy with hematoxylin and eosin staining, or electron microscopy. Histological samples were taken from the neocortex, the hippocampus, the basal ganglia, and the cerebellum. No significant changes were seen.

Animals↗
PubMed1990

Dietary energy levels for growing-finishing pigs fed ad libitum. 1. Growth performance.

The NRC (1988) recommendations on nutrient standards for growing-finishing pigs assume a corn-based feeding regimen. However, the diets used in Western Canada are generally barley-based and consequently are usually lower in digestible energy (DE) and result in lower performance. Two experiments were therefore conducted, to evaluate the effect of DE level in relation to growth and feed conversion of pigs, by inclusion of corn and wheat in pelleted diets offered ad libitum. A total of 432 pigs was used, over the 20-98 kg live weight range. The inclusion of wheat or corn to barley-based diets during the grower period to raise the DE level resulted in more rapid and efficient growth. The faster growth obtained with the high-energy grains occurred during the grower period only, and was not observed in the finisher period. Results of including 5% of acidulated fatty acids (AFA) to raise the DE level were unfavourable.

Animal Feed↗
PubMed1990

Dietary energy levels for growing-finishing pigs fed ad libitum. 2. Carcass effects and economic model of the responses.

The NRC (1988) recommendations on nutrient standards for growing-finishing pigs assume a corn-based feeding regime. However, the diets used in Western Canada are generally barley-based and consequently are usually lower in digestible energy (DE) and result in reduced growth rate and feed efficiency. Corn and wheat can be included in the diet to raise the DE level, but since this could affect the carcass quality of pigs fed ad libitum, the influence of DE level in relation to carcass quality was measured in two experiments. An economic assessment of the data was also conducted. A total of 432 pigs was used, over the 20-98 kg live weight range. The inclusion of wheat or corn to barley-based diets during the finisher period resulted in reduced carcass quality, and there was also some evidence that increased dietary energy during the grower stage had the same effect.

Adipose Tissue↗
PubMed1990

Effect of dietary protein source and cereal type on the incidence of sudden death syndrome in broiler chickens.

Three experiments were conducted to compare the incidence of Sudden Death Syndrome (SDS) in male Peterson by Arbor Acre broiler chickens fed diets with either corn or wheat as the grain type and meat meal or soybean meal as the main protein source. In the first two experiments, the broilers were raised in floor pens to 6 wk of age, and in the third experiment they were raised in battery-brooder cages to 4 wk of age. In both floor pen studies, total mortality and the incidence of SDS were significantly higher for wheat-fed birds, while SDS as a percentage of total mortality was not affected by cereal type. In the brooder study, neither total mortality nor mortality from SDS was significantly affected by cereal type. In the floor pen studies, the incidence of SDS as a percentage of the birds housed, was reduced by the inclusion of meat meal in the diet. In the brooder study, total mortality and the incidence of SDS were not affected by protein source, but SDS as a percentage of total mortality was reduced with the inclusion of meat meal in the diet.

Animals↗
PubMed1990

Effect of dietary lactate and glucose on the incidence of sudden death syndrome in male broiler chickens.

An experiment with a factorial arrangement of treatments using four levels of dietary lactate (0, 2.5, 5.0, 7.5% calcium lactate) and four levels of dietary glucose (0, 15, 30, and 45% cerelose) was conducted to determine the effect of these compounds on the incidence of sudden death syndrome (SDS) in 1,280 male broiler chickens reared in battery brooder cages to 4 wk of age. Overall mortality was 6.64% of which 32.9% (or 2.19% of broilers housed) was attributed to SDS. There were no significant differences between treatments in either total mortality or mortality due to SDS.

Animals↗