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Biomedical subjects

W M Allen

Publications and source records attributed to W M Allen.

At least 37 records · Page 2Linked to original sources
PubMed1984

Parenteral methods of supplementation with copper and selenium.

Parenteral treatments can provide a rapid successful method of supplementing ruminants with copper and selenium, and avoid the possible interactions between an oral supplement and other dietary constituents. The copper preparations studied contained copper complexed with calcium edetate (EDTA) or copper methionate , copper oxide or copper oxyquinoline sulphonate. The recommended doses of these commercial preparations contain different amounts of copper only part of which is transferred to the liver stores from which it can be released during the following months. The recommended dose of copper oxyquinoline sulphonate contains only 12 mg copper and the duration of its protective effect is short. Only a small proportion of the copper in copper methionate and copper oxide is transferred to the liver whereas nearly all the copper in a single dose of the EDTA complex (50 mg copper for sheep) is transferred to the liver stores. Although no longer recommended for use in sheep the copper EDTA complex can be administered to cattle to provide up to 1 mg copper/kg bodyweight. Selenium deficiency in both cattle and sheep can be corrected by the subcutaneous administration of up to 0.15 mg selenium/kg bodyweight as sodium selenate. However, if a dietary deficiency persists copper and selenium treatments are effective for only a few months. To avoid the need for repeated treatments, slowly dissolving or controlled release systems have been developed. Subcutaneous depots of barium selenate have been used (1 mg selenium/kg bodyweight) but large residues remained at the site of injection for up to three months. Initial trials with controlled release glasses containing copper have shown that they maybe useful for routine parenteral therapy.

Animals↗
PubMed1984

Importance of water for the health and productivity of the dairy cow.

Four lactating Friesian cows (average weight 485 kg, milk yield 22 kg d-1) were maintained in completely controlled circumstances and deprived of water for 72 hours. During this period they were carefully monitored and lost 100 kg in bodyweight, principally accounted for by cumulative losses of water in milk, urine, faeces and respired air. The mean rates of respiration and rumen contraction decreased by approximately 50 per cent. Mean body temperature increased by 0.5 degrees C, but pulse rate did not change significantly. Dry matter intake, particularly of hay, decreased rapidly to less than 10 per cent of normal on the third day. Milk yield decreased only slightly during the first 24 hours but on the third day the average yield was only 28 per cent of normal; the composition of the milk did not change significantly. There were significant progressive increases in serum sodium concentration (after four hours water deprivation), osmolality (after 24 hours), urea (after 38 hours), copper (after 48 hours) and magnesium and total protein concentration (after 62 hours); packed cell volume (measured with a Coulter Counter) increased after 38 hours but packed cell volume (determined in a microhaematocrit centrifuge) increased only after 62 hours. In spite of the dehydration the cows showed no signs of distress. Within 48 hours of the cows being given free access to water, bodyweight, appetite, milk yield and blood composition had returned almost completely to normal.

Animals↗
PubMed1983

Effects of selenium and copper supplementation on the growth of beef steers.

During the grazing seasons of 1978 and 1979, 126 Hereford cross Friesian and 25 Charolais cross Friesian steers were used in controlled trials of the effects of injecting them with copper and, or, selenium. In both seasons the unsupplemented steers had low blood concentrations of copper, selenium and glutathione peroxidase, whereas the supplemented steers maintained their serum copper concentrations within the normal range and had significantly higher whole blood concentrations of selenium and glutathione peroxidase than the unsupplemented animals. Supplementing the steers with 400 mg copper during 1978 increased their growth rate by 0.032 kg/day and supplementing them with 200 mg copper during 1979 increased it by 0.080 kg/day. Supplementing the steers in each year with two doses of selenium, each of 0.15 mg selenium/kg bodyweight, increased their growth rate by 0.041 kg/day in 1978 and by 0.060 kg/day in 1979. There was no interaction between the selenium and copper treatments and the total increases in liveweight gains due to both supplements were around 11 kg in 1978 and 16 kg in 1979.

Animals↗
PubMed1981

Field trial to determine the efficacy of two doses of 1 alpha-hydroxycholecalciferol in the prevention of milk fever.

The efficacy of 1 alpha-hydroxycholecalciferol (1 alpha-HCC) for the prevention of milk fever has been tested in a controlled field trial using a total of 601 cows on 18 farms with a history of a high incidence of milk fever. The trial protocol proposed two doses of 1 alpha-HCC with the first injection seven days before the predicted calving date and a second injection five to seven days later if the cow had not calved. Of 301 cows receiving either one or two injections of 1 alpha-HCC, 70 had milk fever, and of 300 cows that received a placebo, 102 had milk fever. The difference in incidence between the two groups was statistically significant (P = 0.005) and indicated an overall efficacy of 32 per cent for treatment with 1 alpha-HCC. An improved efficacy was demonstrated in 67 cows that received two injections of 1 alpha-HCC with the second injection administered either on the day of calving or one day previously (60 per cent efficacy). For 42 cows that received a single injection of 1 alpha-HCC between two and five days before calving an efficacy of 79 per cent was achieved.

Animals↗
PubMed1980

Effect of reduced water intake by lactating dairy cows on behaviour, milk yield and blood composition.

A herd of lactating British Friesian cows was divided into two equal groups. After 14 days during which all the cows had free access to water one group (restricted) was allowed only 50 per cent of the voluntary water intake of the other group (control). After four days when the experiment was terminated, the milk yield of the restricted group had fallen to 74 per cent of that of the control group and their mean body-weight was reduced by 14 per cent. In the restricted group there were significant increases in the concentrations of urea, sodium, total protein and copper in serum, in the osmolality of serum, in the plasma activities of the enzymes creatine kinase and glutamate-oxaloacetate transaminase and in the packed cell volume of blood. The restricted cows behaved very aggressively around their water trough and spent more time in its vicinity. They spent less time lying down than the cows of the control group and some of them were not seen to drink and were withdrawn from the experiment before the end of four days. In a second experiment half the herd was allowed approximately 90 per cent of the water intake of the control group for 14 days. Decreases in milk yield and body-weight and changes in blood composition were much smaller and difficult to detect. However, changes in behaviour were still easily recognised although not as marked as in the first experiment.

Aggression↗
PubMed1978

A field trial of 1alpha-hydroxycholecalciferol (1alpha-OH D3) in the prevention of milk fever.

The efficacy of 1alpha-OH cholecalciferol for the prevention of milk fever has been tested in a controlled field trial using 597 cows on 19 farms all of which had previously had a high incidence of milk fever. Of 293 cows receiving 1alpha-OH cholecalciferol 34 had milk fever and of 304 control cows 51 had milk fever. Although there was an apparent efficacy of 31 per cent the difference in incidence was not statistically significant. There was no effect if 1alpha-OH cholecalciferol was administered less than 24 hours before the cows succumbed to milk fever. However, if 1alpha-OH cholecalciferol was administered more than 24 hours and less than one week before the occurrence of milk fever the efficacy increased to 61 per cent and the effect was highly significant.

Animals↗
PubMed1976

Use of 1alpha-OH cholecalciferol in preventing post parturient hypocalcaemia and its potential value for the prevention of milk fever in dairy cows.

Cows which received 250 mug 1alpha-hydroxy cholecalciferol (1alpha-OH D3) intramuscularly within two hours after calving suffered significantly less post-parturinet hypocalcaemia and hypophosphataemia than control cows. There was a small depression in plasma magnesium concentrations in the treated cows. 1alpha-OH D3 shows potential for the prevention or treatment of milk fever.

Animals↗
PubMed1975

Asymmetric hindquarter syndrome (AHQS) in the pig.

Outbreaks of the asymmetric hindquarter syndrome (AHQS) in two pig herds are reported together with the results of test matings and dissection studies on affected pigs. The condition (apparently identical with that described in Germany in 1967), is characterised by a variable asymmetry of the hindquarters and particularly of individual muscles of the posterior, lateral and medial aspects of the thigh. It does not noticeably interfere with locomotion but can adversely affect carcase conformation and may detract from the usefulness of carcase dissection studies as a basis for genetic selection. AHQS has a familial incidence and is usually first detected clinically after weaning. A variety of degenerative and dystrophic changes have been seen in the muscles of AHQS pigs but these are not constantly present in nor confined to 'undersized' muscles. The precise aetiology of AHQS is still unresolved but it is concluded that it probably occurs post-natally and that some pigs have a genetic liability to develop the condition.

Animals↗