Int J Biometeorol DOI 10.1007/s00484-014-0827-3
SHORT COMMUNICATION
The relationship between corn particle size and thermoregulation of laying hens in an equatorial semi-arid environment João Batista Freire de Souza Jr & Vanessa Raquel de Morais Oliveira & Alex Martins Varela de Arruda & Aurora de Melo Silva & Leonardo Lelis de Macedo Costa
Received: 23 December 2013 / Revised: 20 March 2014 / Accepted: 21 March 2014 # ISB 2014
Abstract Heat stress is one of the main factors affecting egg production. One way to improve egg production is physical processing of the feed ingredients, allowing for better utilization of nutrients. In this study, the relationship between the corn particle size, measured as the geometric mean diameter (GMD), and thermoregulation was evaluated by determining the effect of the GMD on performance, egg quality, and physiological responses. Feed intake, eggshell quality (weight and thickness), rectal temperature (TR), respiratory rate (RR), and surface temperature (TS) were recorded in sixty 20-weekold naked neck laying hens that were fed corn of different particle sizes. Ambient temperature (TA) was also recorded during the trial. The GMD of corn particles was determined using a screens granulometer, resulting in sizes of 605, 1,030, and 2,280 μm. The analysis of variance (ANOVA) of a completely randomized design showed a significant effect (P
SHORT COMMUNICATION
The relationship between corn particle size and thermoregulation of laying hens in an equatorial semi-arid environment João Batista Freire de Souza Jr & Vanessa Raquel de Morais Oliveira & Alex Martins Varela de Arruda & Aurora de Melo Silva & Leonardo Lelis de Macedo Costa
Received: 23 December 2013 / Revised: 20 March 2014 / Accepted: 21 March 2014 # ISB 2014
Abstract Heat stress is one of the main factors affecting egg production. One way to improve egg production is physical processing of the feed ingredients, allowing for better utilization of nutrients. In this study, the relationship between the corn particle size, measured as the geometric mean diameter (GMD), and thermoregulation was evaluated by determining the effect of the GMD on performance, egg quality, and physiological responses. Feed intake, eggshell quality (weight and thickness), rectal temperature (TR), respiratory rate (RR), and surface temperature (TS) were recorded in sixty 20-weekold naked neck laying hens that were fed corn of different particle sizes. Ambient temperature (TA) was also recorded during the trial. The GMD of corn particles was determined using a screens granulometer, resulting in sizes of 605, 1,030, and 2,280 μm. The analysis of variance (ANOVA) of a completely randomized design showed a significant effect (P
