The effect of short periods of fast early in production on subsequent
performance of Gimmizah (G) and 8aheij (B) laying hens was studied. When hens
reached 10% production, fasting program was used, Hens were assigned randomly to
four groups (3 replicates, 10-13 hens each) in floor rearing houses. Those groups
were: the full fed group (control) and the three treated groups which food was fast for
5,7, and 9 days. The G pullets were significantly (P different ages studied. The G showed more reduction in body weight (8W) than 8
while the later grew faster than G -atter refeeding. up to the end of experimental
period (at about 56 weeks of age). Control pullets were significantly heavier than any
of the treated ones at all ages studied. The G pullets produced significantly more
eggs than 8 during the first six weeks post fasting, and during (1-28 wks). No
significant effect of fast periods on either EN or RL during all periods studied. Early
eggs produced by G pullets were significantly heavier than that set by 8 ones during
all periods studied except that during the 3'0 week. During the 6\'t-week post fasting,
the 9-day fast pullets produced eggs significantly lighter than those produced by the
other groups. The G hens produced significantly higher percentage of large and extra
large of eggs during the early interval of laying (1·6 wk) than 8 ones but G pullets
produced twice percentage of extra large eggs during 1-28 wk interval. The 9-day fast
hens produced significantly more small eggs than the other ones. Both 7-day and 9-
day fast produced larger percentages (but not significant) of extra large eggs than the
other two groups. The G pullets had higher viability value than 8 ones and either of
the 5- and 7 -day fast pullets had higher viability than both the control or -9 day fast
pullets.
The G strain significantly (P early periods while no significant effect of strain on feed conversion (FC) during the
long interval. The 5-day and -9- day fast pullets had the best FC (P 2nd and 6ihweek post fasting. There was a significant reduction of fertility and
hatchability of fertile eggs in 8 eggs, also chick body weight at hatch (CBW) for G was
significantly (P<0.001) heavier than that of 8 one. Fasting period affected (P<0.01)
HFE, piped embryos and CBW. Eggs which produced by 7- and 9-day fast pullets
showed highest HFE than those of eggs produced by control or 5-day fast pullets.
Moreover, while no piped embryos (PEj were found in the eggs produced by 7- and 9-
day fast pullets, eggs set by control or 5- fast pullets had (3.70 and 2.22%) PE. In
general, the results showed that there were improving in FC, viability and some of
hatch traits while no significant effects of fast program used were found on the egg
production traits studied of Baheij and Gimmizah pullets.