Abstract:
Two consecutive experiments were conducted with the objective of evaluating the performance of
Koekoek and Sasso T44, exposed to temperature variation with coriander seed supplementation.
The first experiment was conducted with the use of growers at an age of 9-20 weeks and the
second experiment was continued from week 21 to 40 (layers phase). In both experiments, groups
of Sasso T44 and Koekoek breeds of growers and layers were exposed to two different room
temperature (heated and normal rooms) with the supplementation of three levels (0,5 and 10
g/kg) of coriander seed powder. Each treatment was replicated three times. A total of 756
growers (378 of each breed) in the growers experiment and 504 of pullets in the layers
experiment were used. The results indicated that significantly lower (P<0.05) feed intake was
obreved in Koekoek placed in a heated room with or with out coriander supplemented groups
compared to groups placed in normal room temperature. However, temperature was interacted
with coriander seed supplementation for weight gain and feed conversion ratios (FCR) with
groups supplemented with 5-10 g/kg of coriander seed in a heated room achieved comparable
weight gain to the groups supplemented with 0-5 g/kg coriander in a normal room. Similarly,
groups supplemented with coriander seed in both temperature rooms had comparable FCR with
those in the normal room and the non-coriander supplemented groups in heated room had higher
FCR (P<0.05) compared to those supplemented 10 g/kg of coriander in both rooms. In contrary,
there was no significant difference (P>0.05) between the Sasso T44 groups placed in heated and
normal rooms in feed intake, weight gain and FCR, whiles: significantly lower weight of cecum
and liver were observed from the groups of Sasso T44 placed in heated room. Koekoek and Sasso
T44 growers exposed to heated room drank slightly higher (P<0.05) volume of water i.e. higher
by 1.8 % and 1.1%, respectively. Regarding the meat quality at 48 h after slaughtered, breast
from cockerels placed in a heated room had slightly lighter (L*; P<0.05) compared to groups
reared at normal room. However, the overall meat colour did not categorized under the paled
colour of meat. The breast of Koekoek at an hour after slaughter was more yellow (P<0.05) in
colour and higher in chroma values, while at 48 hours after slaughtered, Sasso T44 had redder
meat (P<0.05) than that of Koekoek. Sasso T44 breast had lower in drip loss percentage
(P<0.05) than Koekoek. Furthermore, exposing layers to the heated room with or with out
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coriander supplemented groups showed a slightly lower (P< 0.05) egg mass and egg weight.
However, high temperature with or with out coriander supplemention did not affect feed intake,
hen day egg production (HDEP), FCR, egg quality, fertility and hatchability of layers. Groups
supplemented with the 10g/kg of coriander seed powder in both temperature rooms had slightly
higher (P< 0.05) feed intake, daily egg mass and HDEP than those non supplemented groups.
Similarly, egg quality parameters such as shell thickness at the age of week 34 and albumen
percentage were affected positively due to coriander seed supplementation. Moreover, Koekoek
had slightly higher (P<0.05) yolk percentages than Sasso T44 at the age of week 28 and 34.
There were no significant (P>0.05) variations among the treatments for fertility and chick yield.
More importantly, Sasso T44 had higher egg weight, Haugh unit, albumin height and percentage,
shell thickness and shell percentage than Koekoek. Similaly, the groups of growers placed in
heated room with or without coriander supplementation showed significantly higher (P<0.05)
level of creatinine, alanine aminotransferase and mean corpuscular haemoglobin concentration
than those placed in a normal room temperature. On the other side, temperature had no effect
(P>0.05) on blood serum and haematological parameters of the experimental layers. Decreased
glucose and cholesterol levels were observed in growers supplemented with 10 g/kg of coriander
seed in both temperature rooms. Similarly, the 10 g/kg of coriander seed supplementation
reduced (P<0.01) white blood cells in growers but increased haemoglobin in layers. Under high
temperature growth performance especially in Koekoek and carcass traits in both breeds were
lower compared to those in the normal room. However, the supplementations of coriander seed
poweder improved performance parametres and blood profiles of the experimental chickens and
the 10 g/kg of coriander seed powder alleviated the negative effect of high temperature on weight
gain and FCR of Koekoek. Thus coriander seed can be used as supplementary intervention to
reduce the effect of heat stress on growth performance of chickens.