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Biomedical subjects

R Blair

Publications and source records attributed to R Blair.

At least 109 records · Page 6Linked to original sources
PubMed1989

Tolerance of weanling pigs for dietary vitamin A and D.

Weanling cross-bred pigs (36 or 48) were caged individually and fed diets containing a supplement of vitamin A (Expt 1) or vitamin D3 (Expt 2) at levels representing 1, 5, 10, 25, 50 and 100 times the NRC (1988) estimated requirements, for 4 weeks. Growth rate, feed intake and feed/gain ratio were not influenced significantly. In Expt 1 the plasma retinol concentrations were at 4 weeks, respectively, 31.7, 39.4, 43.2, 42.9, 44.4, and 46.3 micrograms/dl (P less than 0.05). In Expt 2, the plasma 25(OH)D3 concentrations were at 2 weeks, respectively, 22.5, 29.5, 35.7, 46.2, 79.9, 135.3 ng/ml (P less than 0.001). Histological examination of lung, stomach, kidney, liver and heart indicated no abnormalities, but focal microscopic lesions consistent with osteochondrosis were found in pigs receiving vitamin A at levels over 10 times the requirement. The incidence of osteochondrosis at 2 weeks was, respectively, 0/8, 0/8, 0/8, 0/8, 0/8, and 1/8, and at 4 weeks was, respectively, 0/8, 0/8, 0/8, 2/8, 2/8 and 2/8. The NRC (1988) estimate of the requirement for vitamin D may be somewhat low since the concentration of plasma 25(OH)D was lower with 200 or 1,000 IU vitamin D/kg diet than at the start.

Animal Nutritional Physiological Phenomena↗
PubMed1989

Biotin bioavailability from protein supplements and cereal grains for growing broiler chickens.

A 21d growth bioassay was conducted with broiler chicks to estimate the availability of biotin from canola meal (CM), cereal grains and CM-supplemented cereal diets. A standard biotin response curve was generated with biotin-supplemented diets, using growth rate (g/d) as the dependent variable (X) and biotin intake (micrograms/d) as the independent variable (Y), as follows: Y = 2.28X + 9.76, r = 0.946 (P less than 0.01). Other groups of chicks were fed diets containing CM, soybean meal (SBM), cereal grains or CM + grain as a source of biotin. Results indicated that biotin bioavailability (%) was low in most cereal grains, i.e. wheat 17, triticale 20, barley 21, and sorghum 39; moderate in CM, 66; and high in SBM, 98, and maize, 114. Plasma and liver biotin concentrations in excess of 4000 ng/L and 3000 ng/g, respectively, were indicative of adequate biotin status.

Animal Feed↗
PubMed1988

Biotin bioavailability of protein supplements and cereal grains for starting turkey poults.

Biotin bioavailability was estimated in canola meal (CM), various cereal grains, and protein supplements using turkey poults in a growth bioassay study. Following a 10-day pretest period to deplete the biotin reserves of newly hatched poults, triplicate groups (seven poults each) were fed a basal diet without added biotin, or supplemented with graded levels of d-biotin (100, 200, and 400 micrograms/kg) for 21 days. Poult growth (y, g/day) was positively related to biotin intake (x, micrograms/day), as follows: y = 3.05x + 4.32, r = .997 (P less than .01). Similar groups of poults were fed test ingredients: CM, soybean meal (SBM), or soyprotein isolate (SPI) incorporated at levels of 25% into the diet by partial replacement of casein and carbohydrates; other poult groups were given cereal grain (25%) or cereal grain (25%) + CM (25%) included in the SPI-based diet. Use of the regression equation to compute bioavailable biotin gave bioavailability values (in percentages) that were low for triticale (15.9), wheat (17.0), barley (19.2), and sorghum (29.5), moderate for CM (65.4) and SBM (76.8), and high for corn (95.2). The combination of CM and cereal substantially increased the total biotin available for poult growth, with individual biotin contribution being strongly additive for CM plus barley, sorghum, or wheat, but less so in case of CM plus corn or triticale diets. Therefore, CM seems to be a good source of bioavailable biotin for starting poults. Increased levels of bioavailable biotin reduced the incidence of pathological signs (dermatitis, hock disorders, and broken feathers) and also poult mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1988

The influence of premating feed intake on the reproductive performance of gilts.

In an attempt to improve the reproductive performance of gilts mated at puberty, 70 Yorkshire x Landrace gilts were allocated at 120 d of age and 60 kg body weight to one of two treatments. Restricted gilts were fed 2.0 kg d-1 of a diet formulated to provide 18% crude protein and 14.5 MJ DE kg-1 from selection until mated at their first estrus (n = 35). Flushed gilts were fed 2.0 kg d-1 of the same diet from 120 to 150 d of age, but then had their feed intake increased to 3.5 kg d-1 until mated at their first estrus (n = 35). An additional group of gilts (control fed; n = 33) were fed 3.0 kg d-1 from selection until they were bred at their third estrus in order to investigate the influence of feed restriction on the onset of puberty. During gestation all gilts were fed 1.8 to 2.2 kg d-1 of a 16.8% crude protein diet having 13.7 MJ DE kg-1. Control fed gilts were younger (p less than 0.05) at puberty (150 d) than restricted (165 d) or flushed gilts (165 d). There was no difference in subsequent litter size between the restricted and flushed gilts (7.7 and 8.0, respectively). It is concluded that the institution of a flushing nutritional regime in the prepubertal period will not enhance piglet production from gilts mated at puberty.

Animal Feed↗
PubMed1986

Effect of biotin supplementation of a barley-wheat diet on restoration of healthy feet, legs and skin of biotin deficient sows.

Sixteen sows with induced biotin deficiency were divided into groups of four and fed an egg-white-free barley-wheat based diet without added biotin (control) or supplemented with one of three levels of synthetic d-biotin (100, 200 or 400 micrograms kg-1) for two parities in order to determine the optimal level required to reverse symptoms of the deficiency and to evaluate the relationship among dietary biotin levels, stage of recovery and serum biotin concentrations. Biotin supplementation significantly reduced (P less than 0.05) the incidence of lesions (on the foot pads, above the dew claws and on the skin) and also dry skin, but had no effect (P greater than 0.05) on hoof cracks, hair score or hair density. Time after supplementation had significant effects on reversal of most biotin deficiency symptoms. Interactions between biotin supplementation and time after supplementation suggested that these symptoms were reversed more quickly when higher levels of biotin were fed. Serum biotin concentrations of biotin-supplemented sows were increased with time and exceeded 600 ng litre-1 after 0.5, 1.0 and 1.5 months following biotin supplementation of the basal diet with 400, 200 and 100 micrograms kg-1. In contrast, serum biotin concentrations of the control sows remained low and peaked at 411 ng litre-1 after 2.5 months. The data suggested that supplementation of a barley-wheat diet to provide 147 to 217 micrograms available biotin kg-1 might be adequate to restore healthy feet, legs and skin and concurrently maintain high serum biotin concentrations.

Animal Feed↗
PubMed1985

Evaluation of a rapid method for preparation of fatty acid methyl esters for analysis by gas-liquid chromatography.

The major limitation to fatty acid analysis by gas-liquid chromatography is associated with preparation of fatty acid methyl esters (FAME). In the present study, FAME preparations were made from plant oils (corn, olive, sunflower), sunflower oil margarine, lard and various animal tissue fats by a rapid transesterification involving tetramethylammonium hydroxide in methanol, and also by a longer conventional saponification-esterification method. Fats from animal (beef, mutton, pork) adipose tissues were extracted by a simpler modified procedure and also by the Folch method prior to the rapid and the conventional FAME preparations, respectively. FAME analysis on a gas-liquid chromatograph equipped with a Silar 10C glass capillary column indicated similar fatty acid composition of a given fat or oil, whether FAME was prepared by the rapid or the longer conventional method. The data obtained by both methods were very highly correlated for all the fats (r = 0.9895 - 0.9999). However, the rapid method showed a tendency for enhanced recoveries of lower chain fatty acids (e.g. 14:0), and also of unsaturated C18 isomers. Possibly, losses of fatty acids that occurred during the lengthy fat extraction, fatty acid esterification or ether-evaporation FAME concentration steps (conventional method) were minimised by the single transesterification step (rapid method). This rapid transesterification method appears to be an attractive alternative to FAME preparation from a wide variety of different fats for gas-liquid chromatographic analysis.

Animals↗
PubMed1985

Involvement of water-soluble vitamins in diseases of swine.

The various roles of the water-soluble vitamins (including choline and vitamin C) in diseases of swine are outlined. The most important role is in the prevention of deficiency disease; another important role is in relation to the immune response. Deficiency signs relating to each vitamin are described and the metabolism of each vitamin is outlined. Recent estimates of requirements are set out, together with suggestions on supplementation of practical diets for swine.

Animals↗
PubMed1985

Effects of supplementary vitamin D3 on egg production of two strains of Japanese quail and growth of their progeny.

Two strains (University of Saskatchewan, white egg and wild type) of mature Japanese quail (Coturnix coturnix japonica), following a 4-week depletion period, were fed one of four diets varying in supplementary vitamin D3: a) no supplementary vitamin D3, b) National Research Council (NRC, 1977) recommended level of 1,200 IU vitamin D3/kg feed, c) 10 times, NRC levels, and d) 100 times NRC levels for 4 weeks. Egg production, egg weight, number of softshelled eggs, body weight, and feed consumption were not affected by vitamin D3 treatment. Hatchability of the white egg strain was not affected by vitamin D3 treatment. Hatchability in the wild type strain was reduced in those birds consuming diets unsupplemented with vitamin D3 although not significantly. Tibia ash was not affected by vitamin D3 treatment. Progeny from hens receiving no supplemental vitamin D3 were smaller throughout a 5-week growth period; however, feed consumption and percentage tibia ash content were similar to those of progeny from the other treatments. Progeny fed 480 IU vitamin D3/kg feed were larger, had higher tibia ash, and similar feed consumption compared with those fed a diet with no added vitamin D3.

Animals↗