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.
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.
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
D011506:Proteins