Effect of Temperature and Feeding Time on Shell Thickness

The objective of this study was to assess the effect ambient temperature (T) and feeding time (FT) on eggshell thickness (ST) egg weight (EW) broiler breeder hens. Thirty 44-week-old Ross 308 hens were randomly distributed into six environmentally controlled chambers kept in individual cages. Three thermal treatments applied: 20 ºC (T1), cyclic 20-30 (30 °C between 1000 h 1800 h) (T2), 30 (T3). Birds received 180 g commercial food at 0730 (FT1) or 1530 (FT2). There two replications per treatment collection performed for seven days. eggs from birds T1 T2 fed (T1FT2 T2FT2 respectively) significantly heavier than those laid by same T when morning (T1FT1 T2FT1); T1FT1 T2FT1 T3, but there no significant differences them. Both FT had effects ST, interactions found. highest whilst T3 showed lowest. produced thickest shells due a higher ST h. consumed their 2030 h, resulting dietary Ca2 + available during shell mineralization. biphasic feed restricted breeders should be interpreted considering length high phase actual consumption time.