Nutritional effects on the growth and fatness of broilers

1. Broiler chickens given diets high in protein, or choice-fed on a high protein balancer, had much lower abdominal fat contents than those reported in many recent experiments. The values for males were 10.8 g/kg liveweight at 56 d at 2.43 kg liveweight in one experiment in Scotland and 16.0 g/kg liveweight at 42 d at 1.93 kg liveweight in another in South Africa. For females the values were 18.8 g/kg liveweight at 56 d at 2.15 kg liveweight in Scotland and 15.7 g/kg liveweight at 42 d at 1.60 kg in South Africa. 2. The content of abdominal fat was, in general, increased by reducing the protein content of the diet or by dilution of the food with oil or starch. It was, in general, reduced by diluting the food with dietary fibre which also reduced liveweight gain. 3. The results are consistent with the idea that chickens attempt to control their food intake so that they achieve a particular fatness. This level of fatness differs between the sexes and between degrees of maturity.     

Antigen-specific lymphocyte proliferative responses in vaccinated and Hypoderma lineatum-infested calves.

Cattle infested with the common cattle grub, Hypoderma lineatum (Villers) develop specific humoral antibodies and a cellular immune reaction, defined by delayed-type hypersensitivity, to purified H. lineatum proteins. This investigation was designed to study the antigen-specific bovine lymphocyte response to hypodermin A (HyA), a serine protease of larval first-instar H. lineatum. Calves were vaccinated with either native or denatured HyA, and challenge-infested with H. lineatum. The kinetic development of a cellular immune response to HyA was monitored during vaccination and infestation. The HyA-specific responses were highly variable and weak during vaccination and infestation. Although HyA-specific lymphocyte blastogenic responses were observed, no correlation was noted between the magnitude of antigen-specific, peripheral lymphocyte proliferation and larval mortality. In striking contrast to responses observed during infestation, intense HyA-specific lymphocyte responses were observed with 3 calves 6 months after recovery from infestation. In addition, those responses were further heightened by a 250 micrograms booster injection of pure HyA.     

Metabolic responses to ammonium acetate infusion in exercising horses.

The relationship between elevated plasma ammonia (NH3) levels, fatigue development and muscle metabolism were examined in horses during a submaximal fatigue test. Eight Quarter Horse mares were intravenously infused prior to exercise with either sodium acetate (control) or ammonium acetate (AMINF), and exercised to fatigue on an 11% grade treadmill, carrying 27 kg of lead. Time to fatigue was not different (P greater than 0.05) between groups. Intramuscular NH3 and lactate increased (P less than 0.001) during exercise; however, the treatment did not (P greater than 0.05) affect either. A treatment by exercise interaction (P less than 0.01) occurred for plasma NH3. The reciprocal relationship between changes in plasma and intramuscular alanine (ala) and glutamate (glu) indicated activation of the glucose-alanine cycle. Plasma glutamine (gln) increased (P less than 0.001) during exercise; however intramuscular gln was not (P greater than 0.05) altered. The excretion of urea-N was depressed as a result of exercise while the orotic acid/creatinine ratio did not (P greater than 0.05) change. The amino acids and urinary metabolites were not (P greater than 0.05) affected by treatment. These results did not show any metabolic evidence for a role of increased plasma NH3 levels in fatigue development. However this study did provide insight into other aspects of nitrogen metabolism during exercise in the horse.     

Toxicosis in dairy cattle exposed to poison hemlock (Conium maculatum) in hay: isolation of Conium alkaloids in plants, hay, and urine.

Cattle in two herds developed signs of bloating, increased salivation and lacrimation, depression, respiratory distress, ataxia, and death after ingestion of hay that contained large amounts of poison hemlock (Conium maculatum). Twenty of 30 Angus cows and calves were affected in the first herd (2 died). In the second herd, 5 of 30 Holstein heifers were affected (1 died). The Conium alkaloids, coniine and gamma-coniceine, were quantified in the hay, the plants from the responsible hayfield, and the urine of affected animals.     

Long-distance commuting and population change in Georgia, 1960-80

The authors investigate counter-urbanization and population change in Georgia between 1960 and 1980 by examining commuting patterns. "The immediate objective is to construct the entire set of commuting fields of both large metropolitan areas to metropolitan and nonmetropolitan employment centers. We then proceed to the relationship between commuting from nonmetropolitan areas to all levels of Georgia's urban hierarchy and population change in these nonmetropolitan settings. By matching population growth and decline areas with explicit employment ties...the nature of the population changes is much better understood." Data from the 1960, 1970, and 1980 censuses for 581 Census County Divisions (CCDs) in Georgia are analyzed. It is concluded that "most nonmetropolitan growth taking place in Georgia is associated with intensification of metropolitan commuting fields along with growth of nonmetropolitan centers and their influence along the very periphery of metropolitan spheres of employment influence. However, a significant share of Georgia's nonmetropolitan population revitalization is explained by growth independent of direct metropolitan influence. It would appear then that nonmetropolitan growth centers are an important part of the basis for population decentralization in Georgia. Metropolitan spill-over alone cannot account for counterurbanization on this portion of the American economic landscape."     

Pedogenesis within the archaeological landscape at south lodge camp,Wiltshire, England

The properties of soils associated with the Bronze Age site near the South Lodge of Rushmore Park, Wiltshire, are described. Three primary soil types are identified: rendzinas (Rendolls), argillic brown earths (Hapludalfs) and a brown calcareous earth (Eutrochrept). The mapped distribution of these soil types is related to the archaeological landscape. The argillic brown earths are limited in extent to the deeper soils of the positive (accumulating) lynchets of the field system, whereas rendzinas occupy the negative (eroding) lynchets and the remainder of the fields. The only occurrence of a brown calcareous earth is in a positive lynchet within the enclosure. From the distribution of soil types and analogies with the soils of other prehistoric field systems on the Chalk, it is concluded that the argillic brown earths have formed from a highly calcareous colluvial deposit since abandonment of the field system in the later Bronze Age. Further, the development of this soil type appears to be controlled by lateral throughflow of soil water combined with the re-establishment of a wooded landscape. Formation of the argillic brown earth at this site appears to be more recent than at any other site in southern England for which information has been published.