title: The effect of environmental temperature on immune response and metabolism of the young chicken. 4. Effect of environmental temperature on some aspects of energy and protein metabolism.
abstract: The effect of environmental temperature on some aspects of energy and protein metabolism of 3 to 6-weeks-old pullets was investigated in a combined immunological and physiological study. Four experiments were performed in two climate respiration chambers. In each experiment a constant standard temperature of 25 C was maintained in one chamber. The temperature regimens in the other chamber were: a constant temperature of 15 C (Experiment 1) and 35 C (Experiment 3) and temperatures that fluctuated between 10 to 20 C (Experiment 2) and between 30 to 40 C (Experiment 4). Four groups of 60 pullets were held at each temperature regimen. Treatments differed between groups in type of injection (phosphate buffered saline or sheep red blood cells); feeding level (ad libitum vs. +/- 80% of ad libitum); and length of acclimation period. At low temperatures, feed conversion (g feed/g growth) was higher (P less than .05) than at 25 C. Feed intake was increased by 12.9 (at 15 C) and 10.5% (at 10 to 20 C) compared to intake at 25 C. Growth rate and protein gain were not significantly affected by low temperatures. High temperatures reduced (P less than .05) feed intake (15.9% at 35 C and 14.9% at 30 to 40 C) and growth rate (12.3% at 35 C and 12.5% at 30 to 40 C) compared to 25 C. Protein gain and feed conversion were not significantly affected by high temperatures. Restricted feeding reduced (P less than .05) growth rate (Experiments 1 to 4) and increased (P less than .05) feed conversion (Experiments 3 and 4). Differences due to type of injection and degree of acclimation were not significant.
mesh_terms: D000818:Animals; D001273:Atmosphere Exposure Chambers; D001835:Body Weight; D002645:Chickens / Q000276:immunology / Q000378:metabolism*; D004032:Diet; D004435:Eating; D004734:Energy Metabolism; D004912:Erythrocytes / Q000276:immunology; D005260:Female; D007114:Immunization / Q000662:veterinary*; D011506:Proteins / Q000378:metabolism*; D012756:Sheep / Q000276:immunology; D013696:Temperature
chemical_list: D011506:Proteins