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A MacPherson

Publications and source records attributed to A MacPherson.

31 records · Page 2Linked to original sources

Evaluation of the efficacy of trace element supplementation of an anthelmintic.

The efficacy of the selenium and cobalt contents of a trace element supplemented anthelmintic was evaluated in a series of trials with lambs in Scotland and Northern Ireland. The product was compared with other methods of supplementation and was found to be an adequate source of selenium when administered at monthly intervals. Its cobalt content was shown to be of some nutritional benefit on four of five sites but not as effective as the monthly 250 mg oral cobalt dose, vitamin B12 injection or intraruminal soluble glass bolus treatments also used. No growth responses were obtained and unsupplemented animals generally had an adequate cobalt and selenium status. No toxicity problems were encountered from either element.

Animals↗

Methods of selenium supplementation of ruminants.

Three methods of selenium supplementation, by subcutaneous injection, intraruminal pellet and addition to water, were tested in experiments with cattle and a fourth method, oral supplementation of a sodium selenite solution, was evaluated with lambs. All four methods worked effectively for periods ranging from four months to one year after treatment. It is suggested that choice of treatment will depend on the circumstances of each case, including cost, husbandry system and ease of administration.

Administration, Oral↗

Serum vitamin B12 and methylmalonic acid determinations in the diagnosis of cobalt deficiency in pregnant ewes.

Serum vitamin B12 and methylmalonic acid (MMA) concentrations were used to monitor the development of cobalt (Co) deficiency and repletion from the deficient state in housed pregnant hill sheep. Serum MMA concentrations were less variable and provided a more accurate diagnosis of Co deficiency than serum vitamin B12. This was particularly the case for subclinical disease. However, unlike serum MMA, concentrations of the vitamin in serum could be used prognostically. The most precise diagnosis was provided by serum vitamin B12 and MMA data used in conjunction, but where one technique is to be used, serum MMA determinations are preferred.

Animals↗

The influence of a low cobalt intake on the neutrophil function and severity of Ostertagia infection in cattle.

Two trials involving housed cattle examined the effect of Co depletion and supplementation on immune status as assessed by the neutrophil function test which measures the ability of isolated neutrophils to kill the yeast Candida albicans. A third trial investigated the extent to which Co status influenced the severity of Ostertagia ostertagi infection. In the first two trials liveweight gains were unaffected until some 40-60 weeks on the low dietary Co intake despite very low serum vitamin B12 values being recorded after 10 weeks. However, the immune status as measured by the neutrophil function test was reduced within 10 weeks of commencing the low Co diet. On administration of Ostertagia ostertagi larvae, Co-depleted cattle showed a greater weight loss than Co-supplemented cattle but showed no difference in the length of the prepatent period, worm egg production or serum gastrin and pepsinogen concentrations. After anthelmintic treatment both groups showed a similar response. It is postulated that the lowered immune response of Co-depleted cattle resulted in the greater severity of the Ostertagia ostertagi infection.

Animals↗