DDiissccuussssiioonn
V. DISCUSSION
The results of the present study have been discussed under the following
headings:
5.1 Chemical composition of Azolla
5.2 Metabolizability of energy and other nutrients of AZM in broilers
5.2.1 Composition of experimental diets
5.2.2 Metabolizability of energy and other nutrients of experimental diets
5.2.3 Metabolizability of energy and other nutrients of AZM
5.3 Metabolizability of energy and other nutrients of AZM in layers
5.3.1 Composition of experimental diets
5.3.2 Metabolizability of energy and other nutrients of experimental diets
5.3.4 Metabolizability of energy and other nutrients of AZM
5.4 Performance of broiler birds fed AZM based diets
5.4.1 Composition of experimental diets
5.4.2 Body weight gain and livability
5.4.3 Feed consumption and efficiency
5.4.4 Carcass characteristics and organometry
5.4.5 Digestive tract measurements
5.4.6 Economics
5.5 Performance of layer birds fed AZM based diets
5.5.1 Chemical composition of experimental diets
5.5.2 Egg production
5.5.3 Feed consumption and efficiency
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5.5.4 Body weight changes and livability
5.5.5 Egg characteristics
5.5.6 Efficiency of utilization of energy and protein
5.5.7 Economics
5.1 Chemical Composition of Azolla
The dry matter content of Azolla pinnata samples obtained in this study are 92.85,
91.35, 91.85 and 90.93 (Table 4.1) which are in close agreement with results of Tamang
and Samanta (1993), Ali and Leeson (1995) and Khatun (1996) and Balaji et al. (2009)
obtained lower value than the values obtained in the present study.
The Total ash content of Azolla pinnata samples obtained in this study are 18.75,
19.25, 18.98 and 29.17 per cent. The values recorded by Singh and Subudhi (1978),
Tamang and Samanta (1993), Parthasarathy et al. (2002), Alalade and Iyayi (2006),
Anand Titus and Geeta Pereira (2007) and Balaji et al. (2009) are lower than the values
obtained in the present study. However, Ali and Leeson (1995) reported a high value of
36.10 % total ash in Azolla. Such variation could be due to type of Azolla cultivation
practices.
The crude protein content of Azolla estimated in the present study are 25.82,
24.15 24.55 and 24.12 per cent is in close agreement with the results of Singh and
Subudhi (1978), Parthasarathy et al. (2002), Alalade and Iyayi (2006), Anand Titus and
Geeta Pereira (2007) and Balaji et al. (2009) who reported the CP content of Azolla meal
in the range of 20.00 to 26.02 per cent. Contrary to this, Tamang and Samanta (1993) and
Ali and Leeson (1995) obtained only a lower CP content of 15.37 to 16.50 per cent in
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Azolla meal, where as Khatun (1996) obtained higher CP content of 28.54 per cent in
Azolla meal.
The crude fibre content (17.53, 19.75, 19.85 and 16.25 %) obtained in the present
study is slightly higher than the reports of Singh and Subudhi (1978), Tamang and
Samanta (1993), Ali and Leeson (1995), Khatun (1996), Parthasarathy et al. (2002),
Alalade and Iyayi (2006) and Balaji et al. (2009) who reported the CF content of Azolla
in the range of 9.10 to 14.90 per cent.
The ether extract content obtained in the present study are 4.85, 3.95, 4.12 and
3.80 per cent are higher than the observations of Singh and Subudhi (1978), Tamang and
Samanta (1993), Ali and Leeson (1995), Parthasarathy et al. (2002), Alalade and Iyayi
(2006) and Balaji et al. (2009) who reported the EE content in the range of 1.60 to 3.70
per cent.
The NFE content of Azolla pinnata (33.05, 32.90, 32.50 and 26.66 %) recorded in
this study is in close agreement with the results of Ali and Leeson (1995) who reported
the NFE content of 33.20 per cent in azolla meal. On contrary to this, higher values
obtained by Tamang and Samanta (1993), Parthasarathy et al. (2001b), Alalade and Iyayi
(2006) and Balaji et al. (2009), who reported 39.90 to 45.71 per cent in Azolla meal.
The calcium level of Azolla (1.95 %) obtained in this study are higher than the
observations of Singh and Subudhi (1978), Tamang and Samanta (1993), Ali and Leeson
(1995), Parthasarathy et al. (2002),. Alalade and Iyayi (2006) and Anand Titus and Geeta
Pereira (2007)., where as Balaji et al. (2009) observed higher values of 2.14 per cent
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calcium. The phosphorus level of 0.40 per cent in the present study are in close
agreement with the observations of Tamang and Samanta (1993), Ali and Leeson (1995),
and Balaji et al. (2009), where as the higher values were obtained by Singh and Subudhi
(1978), Parthasarathy et al. (2002) and Alalade and Iyayi (2006).
The proximate constituents of dried Azolla microphylla sample analysed in the
present study: dry matter 91.98, total ash 24.17, crude protein 24.56, crude fibre 15.17,
ether extract 3.38 and NFE 32.72 per cent with the AIA of 7.19 are in close agreement
with the proximate constituents of dried Azolla microphylla sample as reported by Seyed
Mozafar et al., (1990) and Becerra et al. (1995).
The variation in the nutrient composition of Azolla meal in different studies could
be attributed to differences in the response of Azolla strains due to environmental
conditions such as temperature, light intensity and soil nutrients which consequently
affect their growth morphology and composition. Moreover, species difference of Azolla
could alter their composition. Further more, contamination with epiphytic algae could
also be important to such a degree as to affect the results of chemical composition
(Sanginga and Van Hove, 1989).
5.2 Metabolizability of energy and other nutrients of dried AZM in broilers
The results of 3-day metabolism trial are discussed as follows:
5.2.1 Chemical composition of experimental diets
As expected, the contents of total ash, ether extract and crude fibre in the
experimental diets tended to increase with the incremental level of dried AZM (0, 10, 20
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and 30%) while the trend was declining for NFE and inconsistent for crude protein
(Table 4.2). Such a pattern was obviously due to the chemical composition of AZM per
se. However, the proximate constituents of diets supplemented with enzymes were
similar to that of corresponding un-supplemented group.
5.2.2 Metabolizability of energy and other nutrients of experimental diets
a) Dry matter and other proximate constituents
The results of this trial clearly indicated a decreased metabolizability coefficient
of different components of experimental diets with the incremental level of AZM ( 0, 10,
20 and 30%) (Table 4.3). The lower metabolizability of diets incorporated with AZM was
due to the higher crude fibre (16.25%) and total ash (29.17%) content of AZM.
b) Metabolizable Energy
It is clearly evident that the ME content of AZM included diets were significantly
lower (P
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c) Ileal nitrogen absorbability
Nitrogen absorbability in general, was found to be non-significantly increased as
the level of incorporation of AZM increased from 0 to 20 per cent but non-significantly
decreased at 30 per cent level which is slightly higher than control (Table 4.4). However,
non-significantly better ileal nitrogen absorbability values were observed with non-
supplementation of enzyme. The diets with fibre degrading enzymes showed lower ileal
nitrogen absorbability.
d) Regression equations for prediction of energy values of diets
In this trial, the predicted values are in close association with the assayed values.
However, the relationship between the metabolizability of individual nutrients to that of
ME values was not significant (p>0.05). The results indicated that the energy content
(ME) of a broiler diet can be predicted based on DM or OM metabolizability with
greatest accuracy (Table 4.4).
5.2.3 Metabolizability coefficient of energy and other nutrients in AZM
The absolute metabolizability values of experimental diets (Table 4.4) have
enabled to arrive at the metabolizability coefficient of various nutrients in test feed
ingredient (AZM) by applying simultaneous equations. The results are similar to those of
Parthasarathy et al. (2002) who reported that the apparent and true metabolizable energy
values of A. pinnata were 1529 and 1855 kcal/kg DM, respectively. The apparent ME
content of AZM is also similar to leaf meals viz. 1568, 1620, 1795, 1730 and 1815
kcal/kg DM respectively in mulberry leaf meal (Narayana and Shetty, 1977), groundnut
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plant meal (Eshwaraiah, 1971), Stylosanthes scraba, S. guianensis and S. seabrana
(Krishna et al., 2008).
Irrespective of its level of inclusion and supplementation of enzyme, on an
average the metabolizabiliy of different component of AZM was as follows: Dry matter:
34.23, organic matter: 52.42, crude protein 30.84, ether extract: 35.56, gross energy:
57.40 per cent and ME: 1725 kcal. The absorbability of its nitrogen in the ileum was
about 71.61 per cent. The results revealed that the metabolizability coefficient of various
components of AZM was poor and it has lower energy content when compared to bran
and oil cakes such as sunflower meal.
5.3 Metabolizability of energy and other nutrients of dried AZM in layers
In this trial the efficiency of adult birds (laying hens) to metabolize the different
nutrient components of dried AZM containing experimental diets and in turn that of the
AZM were studied. The result of 3-day metabolism trial in layers is discussed here under.
5.3.1 Chemical composition of experimental diets
The nutrient composition of basal diets (T1 and T2) which were used in layer
metabolism trial (Table 4.5) was more or less conforming to that of BIS (1992)
specifications. However, the NFE and gross energy of the basal diets gradually
decreased as the level of AZM increased from 10 to 30 per cent in diets either with non-
supplemented or supplemented with fibre degrading enzymes. On the other hand, the
total ash, crude protein, ether extract and crude fibre contents in test diets were increasing
as the level of inclusion of AZM increased ( 0, 10, 20 and 30%), a pattern similar to
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those diets employed in broiler metabolism trial. It was essentially due to the nutrient
profile of AZM perse which was substituted part by part in the basal diets.
5.3.2 Metabolizability of energy and other nutrients of experimental diets
a) Proximate constituents
A linear decrease in metabolizability of the proximate principles was observed
with increasing substitution level of AZM (Table 4.6). Such a trend in metabolizability
coefficient values for various proximate principles were very much similar to that of
those obtained during metabolism trial in broiler birds. Although the gastro-intestinal
system of laying hen is well equipped for efficient digestion of nutrients particularly
crude fibre when compared to broilers, the reasons for such a variation between
metabolizability coefficient of basal diets and AZM based diets were same. No
improvement in metabolizability coefficient values was evident with supplementation of
fibre degrading enzyme as well.
b) Metabolizable energy
It was clearly evident that the ME content of AZM included test diets was
significantly lower (P
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c) Regression equations for prediction of energy values of diets
The simple regression equations for the prediction of energy values of
experimental diets used in the metabolism trial were derived wherein the ME were
regressed on the metabolizability coefficients of DM and OM. The correlation between
the metabolizability coefficient of DM and OM to that of ME values was highly
significant (p
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5.4 Performance of broilers fed dried AZM based diets
5.4.1 Composition of experimental diets
The analyzed per cent chemical composition of experimental diets compounded
for starter, grower and finisher phases ( Table 4.8 ) during the broilers’ performance trial
are discussed as under;
In all the cases, the analyzed values were fairly in close agreement with the
calculated values, based on which the formulation of diets was attempted. However, the
analyzed CP values of 7.5 and 10 per cent AZM based diets were slightly lower than the
calculated values in starter and grower diets (Table 4.8). As per the CF content the
analyzed samples had higher values than the calculated values in all the three diets
(starter, grower and finisher diets) because AZM contained relatively higher content of
CF. Total phosphorus content in starter and grower diet was similar in analyzed and
calculated values except in finisher diet, where as the analyzed sample had higher
phosphorus content than the calculated values. Although the diets were made iso-
calorific, there may be difference in actual ME values of the diets due to the difference
existed in the analytically obtained proximate values. The small differences between
analyzed and calculated values can be attributed to variation in the analytical procedures
and experimental error.
5.4.2 Body weight gain and livability
a. Body weight gain
It was clearly evident from the Tables 4.9 and 4.10 that the groups fed diets
incorporated with either 2.5, 5. 7.5 or 10 per cent AZM tended to gain more or less
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similar body weights when compared to control diet. The decreased body weight gain in
broilers fed AZM based diets during certain weeks of trial was mainly attributable to the
reduced feed consumption (Sec 4.4.3) up to 5 per cent. However, the compensatory
growth rate which was suspected at the later phase of growth must have resulted in
comparable cumulative body weight gains in birds at the end of the trial. The results are
similar to the findings of Parthasarathy et al. (2002), Balaji et al. (2009) and Dhumal et
al. (2009) who have reported that AZM can be included up to 5 per cent in broiler diet
without affecting body weight gain. However, Basak et al. (2002) observed significant
(P
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Other reports (Kumar et al., 2007) also indicated that the supplementation of fibre
degrading enzyme preparation to palm kernel cake containing diets yielded inconsistent
results.
Thus, it can be inferred that the inclusion of AZM up to 5 per cent in broiler diets
helped to attain the optimal growth rate and further higher levels of AZM may not be
relevant. Fibre degrading enzyme supplementation had no effect on growth performance
of broiler birds.
b. Livability
The present study indicated that the inclusion of AZM up to 10 per cent in broiler
diets has no significant (P>0.05) influence on livability of birds. This indicates that AZM
had no deleterious effects on broilers. The higher survivability values recorded in the
present trial was due to the better management and bio-security measures adopted during
the course of the experiment. These findings are in agreement with reports of Castillo et
al. (1981), Khatun (1996), Basak et al. (2002), Parthasarathy et al. (2002), Balaji et al.
(2009) and Dhumal et al. (2009).
5.4.3 Feed consumption and efficiency
a) Feed consumption
The treatment and main factor wise data on average feed consumption of broiler
birds under various dietary groups during different weeks of the experimental period
were non-significant (P>0.05) (Table 4.11). These findings are similar to the results
reported by Balaji et al. (2009) and Dhumal et al. (2009) who observed non-significant
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differences in feed consumption up to 5 per cent of AZM inclusion. Similarly, Querubin
et al. (1986a), Sreemannarayana et al. (1993), Ali and Leeson (1995), Bhuyan et al.
(1998) and Basak et al. (2002) reported that the inclusion of AZM in broiler diets did not
affect feed consumption up to 15 per cent while Parthasarathy et al. (2002) observed that
no significant differences in feed consumption were evident among the broiler birds fed
diet included AZM up to 20 per cent. However, Alalade and Iyayi (2006) reported that
the average feed intake of chicks fed diets containing 10 and 15 per cent AZM were
significantly lower than diet containing 0 and 5 per cent AZM. Bested and Morento
(1995) stated that Azolla affected the palatability of the feed and reduced the feed
consumption. On the other hand, Parthasarathy et al. (2001a) reported that mean
cumulative feed intake was decreased when azolla was increased from 0 to 15 per cent,
but slight incrase in feed intake was observed at 20 per cent level.
Pertaining to the supplementation of fibre degrading enzymes, no significant
differences were observed. Such findings are in agreement with reported results of Rama
Rao et al. (2006) who reported that the supplemental NSP hydrolyzing enzymes to corn-
soybean meal or corn-sunflower extractions based diets did not alter the feed
consumption.
From the results of the present study it may be of the view that the inclusion of
AZM up to 10 per cent in diets of broiler did not affect their feed intake. Thus, it can be
inferred that the feed consumption was not affected by incorporation of AZM as a feed
ingredient up to 10 per cent level.
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b) Feed conversion ratio (FCR)
The results revealed that the feed conversion ratio became poorer and poorer with
inclusion of AZM, however, not consistent with the level of inclusion either at 2.5, 5, 7.5
or 10 per cent. This is in agreement with reports of Muzafar et al. (1978), Querubin et al.
(1986a), Parthasarathy et al. (2002) and Basak et al. (2002). However Balaji et al. (2009)
and Dhumal et al. (2009) reported no significant difference in feed conversion ratio of
birds fed up to 5 per cent Azolla diet.
Taking into account of all the above discussed growth performance parameters
viz., body weight gain, feed consumption and its efficiency, it was concluded that the
inclusion of AZM at 5 per cent level did not affect the growth performance of the broiler
birds. Hence, AZM can be included up to 5 per cent in diets for better results in broiler
birds. It was also concluded that the fibre degrading enzyme supplementation was not
beneficial in improving the utilization of AZM incorporation at 2.5, 5, 7.5 and 10 per cent
level in broiler diets.
5.4.4 Carcass characteristics and organometry
The treatment and main factor wise average dressing percentage, meat to bone
ratio, drum stick yield (% of carcass), abdominal fat content (g/bird or % of live body
weight) and breast meat of broilers under different dietary groups at the end of 42-day
experimental period are discussed as follows.
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a) Dressing percentage
The results indicated that the inclusion of AZM up to 10 per cent in broiler diets
did not cause any adverse effect on the dressing percentage (Table 4.15). This is in
agreement with the findings of Dhumal et al. (2009). Contrary to the present finding,
Bacerra et al. (1995), Basak et al. (2002), Parthsarathy et al. (2002) reported that the
broiler birds fed 5 per cent Azolla diet had significantly (P
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d) Abdominal fat
The results clearly indicated that the abdominal fat of broilers was not influenced
by the AZM inclusion in their diets (Table 4.15). This is in agreement with the findings
of Basak et al. (2002) and Dhumal et al. (2009) who have reported that no significant
differences in abdominal fat percentage within the different groups fed diets incorporated
with AZM up to 10 per cent.
The results indicated that the inclusion of AZM up to 10 per cent in broiler diets
did not alter the abdominal fat deposition.
e) Breast meat yield
The results indicated that the inclusion of AZM up to 10 per cent in broiler diets
has influence on the breast meat yield. No literature is available to confirm the same.
From the present study, it was concluded that, the inclusion of AZM up to 10 per
cent in broiler diets has no influence on carcass characteristics parameters namely
dressing percentage, meat to bone ratio, drum stick yield and abdominal fat deposition.
But it has influence on the breast meat yield of birds.
f) Organometry
In the present study, weight of the giblets viz., liver, heart and gizzard were not
influenced by various treatments and main factors (Table 4.16). Contrary to this,
Parthasarathy et al. (2002) reported significant difference (P
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(6.44) was observed by Basak et al., (2002). This is because of higher ash and high level
of fibre content (NDF) of AZM based diets that have caused numerically higher relative
gizzard weight in such groups.
Thus it was implied that the development of vital organs, viz., heart, gizzard,
liver, proventriculus and spleen except bursa was not affected by AZM inclusion up to 10
per cent.
5.4.5 Digestive tract measurements
The length of different segments of small intestine viz., duodenum, jejunum and
ileum of birds was not influenced by the AZM inclusion up to 10 per cent level when
compared to control (Table 4.17). However, Sarmiento et al. (2002) reported that with
chaya leaf meal at 15g and 25g/kg level, the length of the intestine were higher than with
control while Krishna et al. (2008) reported that the length of intestines were slightly
higher at higher levels of stylosanthes leaf meal inclusion in broiler diet.
The length of different segments of small intestine viz., duodenum, jejunum and
ileum of birds was not influenced by the AZM inclusion up to 10 per cent level when
compared to control.
5.4.6 Economics
a) Net returns
In this study, the AZM incorporated diets showed poorer net profit when
compared to the control groups and in many cases diets fortified with fibre degrading
enzyme failed to improve the net returns (Table 4.18). It was due to higher cost of AZM
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(Rs.18/kg) when compared with other feed ingredients. Hence, it was inferred that the
preparation of diets using AZM as a feed ingredient replacing the conventional feed
ingredients was not economical. It may be economical if AZM is cultivated intensively
and priced at affordable price. However, Dhumal et al (2009) and Basak et al. (2002)
reported that the net profit was significantly higher in treatment groups with 5 per cent
Azolla in broiler bird diet.
b) Performance Scores
The production performance index scores in terms of both PIS and EIS were
better in control diets compared to diets prepared with AZM either at 2.5 per cent or 5 per
cent or 7.5 per cent or 10 per cent inclusion.
By considering the parameters of economic importance, it is not feasible to
include AZM at either of the levels of 7.5 and 10 per cent.
5.5 Performance of layer birds fed AZM based diets
After the metabolism trial in layers, a trial was also conducted to include dried
Azolla in layer bird rations to asses its effect on their production performance. The results
are discussed as under.
5.5.1 Chemical composition of experimental diets
The analyzed results revealed that the proximate constituents viz., CP values of
experimental layer diet was similar at 0 and 2.5 per cent level and comparably little lower
at 5, 7.5 and 10 per cent level when compared to calculated values (Table 4.19). As far
as CF content was concerned the analyzed values were similar at 0 and 2.5 per cent level
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when compared to calculated values but slightly higher at 5, 7.5 and 10 per cent level.
The analyzed values of EE were higher in experimental layer diet at different levels of
AZM inclusion when compared to calculated values. As expected, the content of CF and
TA in layer diets tended to increase with incremental levels of AZM in such diets.
The calculated metabolizable energy values of 0, 2.5, 5, 7.5 and 10 per cent AZM
based layer diets were 2439, 2439, 2439, 2440 and 2439 kcal/kg, respectively
(Table 4.19). The ME content of all the experimental layer diets were almost the same
and such diets were considered as iso-caloric.
5.5.2 Egg production
In general, the birds fed diets incorporated with AZM at lower levels (2.5 and 5%)
showed increase in egg production while its inclusion at higher level (7.5 and 10%)
showed reduction in egg production when compared to control (Table 4.20). Hence, it
was clear that higher level of inclusion of AZM in the diet, lower was the egg production
and at lower level it showed better egg production which was evident in all periods as
well as cumulatively. The present results are in tune with those of Khatun (1996) who
reported that hen-day egg production with 5 per cent Azolla meal was improved over that
of control diet in one study and reduction in hen-day egg production of birds fed 20 per
cent Azolla in other study. Similar results are also observed by Khatun et al., (1999) and
Alalade et al. (2007) in layers and Cariaso (1992) and Lawas et al., (1998) in laying
ducks.
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Most strains of Azolla have a well balanced array of essential amino acids (Van
Hove, 1989) and also posses apparent capacity to supply vitamins and minerals when
included in diets (Bacerra et al., 1995).
Since the results clearly indicated that the egg production reduced with the
inclusion of AZM at 7.5 and 10 per cent and that it got increased at 2.5 and 5 per cent
AZM inclusion, it can be inferred that the egg production can be sustained when AZM is
included below 7.5 per cent in layer diets.
5.5.3 Feed consumption and efficiency
a) Feed consumption
The results indicate that the inclusion of AZM up to 10 per cent has not affected
the birds’ appetite and there was no reduction in feed intake between control and
experimental birds (Table 4.21). Contrary to these findings, Alalade and Iyayi (2006)
reported that average weekly feed intake was similar up to 5 per cent Azolla meal
inclusion in diets while significantly reduced in 10 and 15 per cent Azolla meal based
dietary groups. However, in another study, no significant difference in feed intake among
the groups fed diets containing Azolla meal up to 15 per cent (Alalade et al., 2007).
This reflects that even adult birds also failed to adopt for the diets containing 7.5
and 10 per cent AZM. Thus it can be inferred that the effective acceptability of AZM by
the birds was questionable when included as a ingredient in their diets above 7.5 per cent
AZM.
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b) Feed efficiency
The feed efficiency (FE) expressed as kg feed / dozen eggs among different
treatment groups was found to be highly significant (P
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5.5.4 Body weight changes and livability
The body weight pattern as influenced by main factors, during initial (1st day)
(1441-1476g) and final body weights (1529-1574 g) were non- significant when viewed
for AZM level (Table 4.23).
The body weight changes during Period I, II III and on cumulative basis, were
found to be highly significant (P
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treatment groups. The results conformed to the reports of Suma (2005) who indicated
non-significant increase in egg weight with incremental level of dried sugarcane press
residue from 0 to 15 per cent in layer diets. The results are also in confirmation with the
findings of Suresh (2007) who reported that the egg weight was highly significantly
increased when compared with the control.
b) Egg shape index
The results suggested that the AZM at any given level in diets did not affect the
shape index of the eggs except during 28th day ( I- period ) production (Table 4.25) and
thus the hatchability also. Such results were also observed by Suma (2005) and Suresh
(2007).
c) Albumen Index
As regards the main factors, the albumen index scores (Table 4.26) were found to
be highly significant (P0.05) during period II, period
III and cumulatively.
As regards the main factors of enzyme supplementation, the albumen index scores
were found to be highly significant (P0.05) during period II, period
III.
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d) Haugh unit score (HUS)
As regards the main factors of AZM level, the HUS were found to be highly
significant (P0.05) influenced by the enzyme supplementation during all the
periods. But the values were highly significant (P
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present in AZM. As regards main factors, the yolk colour scores were significantly
(P
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The results suggested that the AZM at any given level in diets affected the shell
thickness of the eggs.
5.5.6 Efficiency of utilization of protein and energy
a) Efficiency of Protein utilization (EPU)
Efficiency of protein utilization was also found to be highly significant (P
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by Reddy (1979), Nandhagopala (1991), Umashankar (1998) and Srinivasa kuja (2000).
But however, these values are slightly higher than the values reported by Jayanaik (1989)
who fed broiler breeders with different levels of dried silk worm excreta, the composition
of which is also similar to that of AZM. Enzyme supplementation had no affect on energy
utilization.
Results indicate that efficiency of protein and energy utilization is not uniform
among different dietary treatment groups and even when the data was analyzed on the
basis of main factors (Table 4.31). Thus, the inclusion of AZM either at 2.5, 5, 7.5 and 10
per cent in the diets did affect the ability of birds to transfer dietary protein and energy to
the egg not withstanding the apparently low nutritive value of AZM.
5.5.7 Economics
The effect of main factors of AZM revealed that the net returns were not
significantly (P>0.05) affected by the main factor during Periods I and II. The net returns
were highly significant (P