The Effect Of Open Poultry Houses Design On Physiological Performance Of Layer Hens

This study was conducted to investigate the impact of the structure of open poultry housing on the physiological performance of layer birds, in two seasons, namely, winter and summer. The investigation involved (11) open houses which were surveyed in Khartoum State. The parameters tackled in the similar breeds, with more or less similar management; however, the only variables were the house structure, dimensions and shape. The same production parameters were measured in the eleven houses during winter and summer seasons; including: rectal temperature, feed intake, egg production, egg shell thickness and egg weight. The summer parameters in all the houses were compared with an extra house (house12) in the Department of Physiology which was considered, according to its structure and dimensions, to be an ideal open poultry house in which extra blood parameters (haemoglobin, packed cell volume, leukocytes count, calcium level, total plasma proteins and albumin) were recorded to evaluate the choice of this (ideal) house and correlate these values with the production parameters. All the houses structures were photographed and their lay-out sketches were drawn. The birds (at 8 months of age) were housed with similar stoking density. Meteorological, house environment, body temperature and production parameters were surveyed. Statistical analyses were performed in the two seasons and between the different houses in the two seasons separately. There were significant difference in houses temperature during summer (P<0.001) and winter (P< 0.05); the lowest temperature, in winter and summer was recorded in house (11) which was the best structured, house while the highest one was recorded in house (6) due to its poor structure. Humidity decreased significantly in winter (P< 0.05) with the lowest value in house (4), however, humidity increased significantly in summer in all houses (P< 0.001) with the highest value observed in house (2). Radiation temperature ranged between 30.73°C – 34.34°C in winter, and 43.72c – 48.92c in summer showing significant difference (P<0.001) between houses . Nevertheless, radiation values in house (11) and house (12) were almost similar, 43.72c and 43.83c respectively. Rectal temperature increased significantly (P< 0.001) in all houses during summer. However, it’s with similar level was in house (11) and house (12). The different in egg production between the houses in winter and summer were highly significant (P<0.001). House (6) showed the least production in summer and winter compared with house (11) which was comparable with house (12). There was no significant difference in egg weight and egg shell thickness in winter, however, the thickness and weight decreased significantly in summer (P< 0.001) in all houses and houses No 11and 12 showed the highest egg shell thickness. The food intake followed the accepted pattern during winter and summer; birds consumed more food in winter than summer. Feed intake ranged between 741.92 – 790.75 g/week in winter. During summer season it ranged between 587.25 – 687.67 g/week in all the houses, however, 697.67 g/week and 682.75 g/week were observed in house (12) and (11) respectively. This might reflect the similarity in structure between the two houses. In house (12) blood parameters were stable for 12 weeks in summer season. It was concluded that the house structure, size, height and the materials used, have a positive effect on the productivity when the heat