1. Observations were made on the use of food pans and food trays by commercially grown broiler chickens.
2. Birds fed by going inside the feeders on top of the food or from standing around the outside of the feeders. The feeding times of birds inside feeders were significantly longer than those of birds outside. Different reasons to account for this are proposed for the 2 types of feeder.
3. The total number of birds able to feed together from a tray or pan changed as the birds grew. With trays this change in the number of birds was a steady decline. With pans the change was non‐linear and reflected a changing ratio of birds eating in to birds eating out. This ratio was influenced by pan design features and by competition for feeding space.
4. The data suggest that a linear measure of feeding space, as used in research trials and Codes of Practice for Welfare, does not adequately describe birds’ access to and use of feeding space. Implications for both research and the commercial industry are discussed. 相似文献
This paper examines the views of members of the veterinary profession towards the change in orientation of professional practice that is occurring. It contrasts the values of veterinarians with those of doctors, dentists, lawyers and accountants. Particular attention is given to the areas of business efficiency, competition and advertising. Data was derived from self-completion questionnaires containing 40 Likert scales which were mailed to 300 members of each of the five professions. 相似文献
Equine polymorphonuclear (PMN) and mononuclear (MN) leucocytes were separated on Percoll gradients and used to study the chemoattractant properties of the polar ether-linked phospholipid, platelet activating factor (PAF). Six concentrations of PAF ranging from 1 ng/ml to 100 g/ml were studied in each of two in vitro assay systems, the agarose microdroplet and a microfilter technique. Very significant (p<0.01) increases in the movement of both PMN and MN cells were obtained with most concentrations of PAF. In two instances there was no apparent concentration-response relationship, although the action of PAF was approximately bell-shaped in two others. The possible significance of these findings for equine inflammatory conditions is discussed. 相似文献
In conscious pigs the influence of intravenous infusion of live E. coli (7×108/kg), of the equivalent amount of endotoxin (20 g/kg) or of a high dose of endotoxin (2.5 mg/kg) on the hemodynamic, clinical and pathological parameters and on survival rate was studied. E. coli and endotoxin infusion resulted in pulmonary hypertension, systemic arterial hypotension, a decrease in cardiac output and an increase in heart rate. Clinical signs were characterized by respiratory and nervous disturbances, whereas necropsy revealed hemorrhages and edema in several organs. Although these findings were similar in the three groups, a marked difference in lethality was observed. Infusion of E. coli or of the high dose of endotoxin resulted in a significant mortality, whereas all pigs survived the infusion of the low dose of endotoxin. This suggests that the lethal pathophysiological mechanisms may only become activated when a sufficient amount of endotoxin is released into the circulation. 相似文献
Acute phase proteins are serum proteins which increase in concentration during the acute phase response to inflammation or infection. The response occurs in all animals, but in different species the response of individual proteins can be significantly different. Of the numerous acute phase proteins which have been identified in humans, a number have been examined in cattle and dogs but usually on an individual basis with little reference to their part in the acute phase response. Biochemical, physiological and clinical investigations into haptoglobin, fibrinogen, 1-proteinase inhibitor, ceruloplasmin, seromucoid and C-reactive protein of cattle and dogs have therefore been reviewed with the emphasis on their role in this response to tissue damage. 相似文献
An active fold-and-thrust belt in unchanging tectonic and climatic conditions attains a dynamic steady-state in which the influx of accreted material at the toe is balanced by the erosive efflux off the top. The overall balance of energy in such a steady-state fold-and-thrust belt is described by the equation E = W(G) + Q, where E is the rate at which both mechanical and heat energy are added from external sources, W(G) is the rate of work performed against gravitational body forces, and Q is the rate at which waste heat flows out of the upper and lower boundaries. The total amount of power being supplied to the active Taiwan fold-and-thrust belt by the subducting Eurasian plate and in situ radioactivity is 4.2 gigawatts. Because only 0.5 gigawatts are expended in doing useful work against gravity and the remaining 3.7 gigawatts are ejected as heat, the efficiency of brittle frictional mountain building in Taiwan is 11 percent. 相似文献
1. Two environmentally controlled houses at 21°‐30°‐21°C (HT) and 21°C (LT) were used to study the effect of temperature on fatty acid composition of the abdominal fat of male and female broilers fed 13.8 and 13 MJ ME/kg diets and slaughtered at 34 and 54 d.
2. Extracts from the abdominal fat of 160 carcases and of the experimental foods were analysed for fatty acids by gas liquid chromatography.
3. Birds reared in HT had a significantly lower proportion of polyun‐saturated fatty acids (PUFA) in their abdominal fat between 34 and 54 d than birds in LT. The depot fat contents of oleic, linoleic and linolenic acids were all reduced by HT at 54 d.
4. For broilers slaughtered at 54 d, saturated fatty acid (SFA) content was much higher in females at high temperatures than in males while at low temperatures PUFA, especially linoleic, was much lower in males than in females.
5. Early finishing of broilers is advantageous from the viewpoint of fatty acid composition because the PUFA/SFA ratio declines significantly with age regardless of temperature. 相似文献