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D G Fox

Publications and source records attributed to D G Fox.

63 records · Page 4Linked to original sources

Predicting growth and performance of Holstein steers.

Refinements and additions were made to the growing cattle portion of the model of Fox et al. (1988) for predicting growth of Holstein steers. Based on observations of animal weight, DM intake (DMI), ADG, feed per gain (FPG) and diet ME, the modified model was tested on a database that included 299 feeding periods with Holstein steers fed in research trials over a period of 15 yr at Cornell University, the University of Minnesota and the University of Wisconsin. The modified model accounted for 93, 56 and 68% of the variation in DM intake, daily gain and feed required per unit gain, respectively. Averaged over all 299 periods in the database, the error in predicting DM intake, daily gain and feed required per unit gain was 1%, 4% and 2%, respectively. Analysis of residuals indicated that ME level did not influence the difference between predicted and observed values for DMI, ADG and FPG. Residuals analysis indicated that BW did not influence the difference between predicted and observed values for ADG and FPG but DMI of heavier cattle was overpredicted (P less than .01). These results indicated that the 8% increase in DMI for cattle over 318 kg was not warranted for the Holstein steers in this database, which were predominantly less than 15 mo at slaughter. The results of the validation indicate that this model accurately predicted performance of Holstein steers.

Animals↗

The acquired immunodeficiency syndrome: a tuberculosis threat?

In the United States there has been an increase in mycobacterial infections that is attributable to the acquired immunodeficiency syndrome (AIDS). Since 1983, when the first case of AIDS was reported in Australia, there have been 523 patients (to June 30, 1987) notified with group-IV AIDS and, of these, 361 (69%) cases have been in New South Wales. Of these 361 notifications, 59 (16%) patients have had concurrent mycobacterial infection. Seven of these patients had Mycobacterium tuberculosis infection and five of these infections occurred in 1986. This means that, in 1986, patients with group-IV AIDS had a rate of infection with Myco. tuberculosis of 3000 per 100,000 population, compared with 5.2 cases per 100,000 population for New South Wales. We sought to determine whether or not there was any unexplained increase in notifications which might be attributable to AIDS. This paper reports cases that were notified to the AIDS and tuberculosis registers, finds that atypical mycobacterial infections are underreported by at least 19.5%, and examines trends in notifications for mycobacterial disease since the onset of the AIDS epidemic. It also raises the importance of appropriate measures to protect health workers from tuberculosis.

Acquired Immunodeficiency Syndrome↗

Effect of feeding system on performance and carcass characteristics of yearling steers, steer calves and heifer calves.

Three types of cattle (Angus x Hereford yearling steers, Charolais x British breed steer calves and Hereford heifer calves) were evaluated for their response to different feeding systems utilizing high moisture corn, corn silage and soybean meal as major feed ingredients. Feeding ing systems for steers included: A = 85% concentrate; B = 40% concentrate; C = two phase, with switch from all corn silage to 85% concentrate in the middle of the feeding period; D = same as C except switch occurred late in the feeding period; E = all corn silage continuously. Heifer diets consisted of the following ratios of corn silage to concentrate: low energy = 89:11; medium energy = 67:33; and high energy = 100 fed at a moderate (10.9% for low energy and medium energy, and 11.7% for high energy) and high (13.8%) crude protein level. Treatments within each experiment were terminated at approximately the same final weight. Increasing percentage corn added to the total diet increased ADG in most comparisons. Adjusted to a constant carcass weight, increasing dietary energy increased fat thickness and reduced percentage retail product with no effect on quality grade in yearling steers and heifer calves. In Charolais cross-steer calves, increasing energy level increased quality grade with no effect on yield grade or percentage retail product. Energetic efficiency slightly favored system C in yearling steers while steer calves maximized efficiency on A. Hereford heifers were the most energetically efficient on medium energy diets.

Animal Feed↗

Computerized instant drug information.

Challenges facing doctors when prescribing are listed. Immediate access to all known contraindications, side effects and interactions about a drug, or combination of drugs, would be advantageous to all doctors and pharmacists. A proposal for a rapid, readily accessible computerized system on adverse drug information is outlined. Benefits, such as the possible discovery of contraindications of interactions, hitherto unknown, are considered.

Australia↗