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Research
1.
Effects of dietary minerals on postmolt
performance of laying hens - Sohail Hassan Khan, Abdul Rehman, Ansari Jehanzeb
Vet World. 2011; 4(9): 389-395
doi: 10.5455/vetworld.2011.389-395
Abstract
Four
hundred and fifty Single Comb White Leghorn
commercial layers (66-67 weeks-old) were housed 2
birds per cage for the molting procedure. The hens
were divided into 5 treatment groups with 90
layers per treatment and 30 layers in each
replicate per treatment group following completely
randomized design. During molt period (2 Weeks),
experimental birds were randomly assigned to
five-treatment groups viz., A (15 ppm copper
sulphate), B (20 ppm zinc oxide), C (20 ppm
aluminium oxide), D (balanced layer diet without
added minerals) and E (without induced molting as
control). The birds in groups A, B, C and D were
offered respective experimental diets at the rate
of 30 g/bird except bird's in-group E (ad libitum)
and lighting program was followed as 12L: 12D.
During rest period (3 Weeks) the birds in groups
A, B, C and D were given respective experimental
diet at the rate of 50 g/bird for first 2 weeks of
the rest period. During 3rd week of rest period
the birds in groups A, B, C and D were given
experimental diets at the rate of 60 g/bird and
were placed on lighting program of 14L:10D. During
production phase, the birds of all groups were fed
a balanced layer diet (ad libitum) and birds were
placed again on lighting program of 16L:8D. The
results showed that the birds fed diets A, B and C
showed greater (p<0.05) percentages of body mass
loss than those fed the diet D. The birds fed diet
E (Full feed-non molted group) exhibited the least
amount of body mass loss when compared with all
other treatments of molted hens. Un-supplemented
mineral group and un-molted hens had higher
(p<0.05) ovarian weights than hens on all other
molted treatments. No significant differences
(p>0.05) in ovarian weights were found among
minerals supplemented groups A, B and C. The
non-molted birds (group E) exhibited the greatest
(p<0.05) feed intake over the 2 weeks molt whereas
birds on minerals supplemented diets ate the least
(p<0.05) feed. On average non-molted hens fed a
balanced layer diet and molted hens fed without
minerals diet had lower (p<0.05) egg production
when compared with molted hens fed mineral added
diets after 20 weeks post molt. However, molted
hens fed without minerals diet had significantly
higher egg production than that of non-molted hens
fed a balanced layer diet. Egg shell quality and
Haugh unit score improved (p<0.05) in molted hens
compared to non-molted hens. Based on the results
of this study, mineral feeding appears to be the
best alternative to without mineral feeding in
molting methods and yield comparable results.
Key words: Zinc oxide, copper sulphate,
aluminium sulphate, performance.
