Ecuación 2. Hidrólisis oxidativa del etileno
6.8 Ligandos y N-heterociclos como ligandos (2-ampy, 4-ampy)
Table 3.4 and Figures 3.2 and 3.3 summarise the principal egg quality indices in the four treatment groups in this experiment. The data for all three ARA treatment tanks were also pooled for comparison with the control group.
In Group A (control), the total number of eggs produced per kg female was 590,185 the mean number per batch of eggs produced per kg female was 9,675. The total weight of eggs collected was 24660 g. The number of batches collected was 61 (out of the total 92 days of spawning). Spawning started on the 1st March 2006 and continued until the 31st May 2006. The cumulative egg production was less than from each of the groups fed ARA i.e. diets B, C or D (Fig.3.3). The total number of collected eggs per kg female was 376,339 and the mean number per batch of eggs collected per kg female was 6169. Approximately 47 % of the eggs sank and were discarded and the remaining eggs floated.
There was a total weight of 13,118 g of floating eggs which gave a mean weight per batch of floating eggs of 215 g. and a total number of floating eggs per kg female of 200,195 eggs. The mean number per batch of floating eggs per kg female was 3282 (Table 3.4).
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Mean percentage fertilization (as % floating eggs) was 55 % and the total number of fertilised eggs per kg female 125,222. The total number of batches with fertilised eggs was 59. The mean number per batch of fertilised eggs per kg female was 2,122 and the mean percent hatch was 24 % equivalent to a total of 48462 hatched larvae per kg female (12.8 % of the total eggs collected).
Cumulative egg production Group C fed ARA for 3 months before peak spawning.
In Group B (Fed ARA 1 month), the total no. of eggs produced per kg female was 738,132 the mean number per batch of eggs produced per kg female was 11,905.
The total weight of eggs collected was 34,220g. The number of batches collected was
th
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31st May. This group started spawning last when compared to other groups (Fig 3.2).
The mean weight of collected egg batches was 552 the total number of collected eggs per kg female was 556,097 and the mean number per batch of eggs collected per kg female was 8,969 (Table 3.4).
Approximately 49 % of the eggs sank and were discarded and the remaining eggs floated. There was a total weight of 17,352g of floating eggs which gave a mean weight per batch of floating eggs of 284 g. and a total number of floating eggs per kg female of 281,981. The mean number per batch of floating eggs per kg female was 4,623 (Table 3.4).
In terms of fertilization, the mean rate (as % floating eggs) was 56 % and the total number of fertilised eggs per kg female 171,736. The total number of batches with fertilised eggs was 57. The mean number per batch of fertilised eggs per kg female was 3,013 and the mean percent hatch was 18 % of floating eggs i.e. 9.4 % of total eggs collected. The total number of hatched larvae per kg female was 52,005 (Table 3.4).
In Group C (Fed ARA 2 months), the total number of eggs produced per kg female was 356,707 the mean number per batch of eggs produced per kg female was 7,134. The total weight of eggs collected was 20,729 g. The number of batches collected was 50 (out of the total 92 days of spawning). The mean weight of collected egg batches was 415 g, the total number of collected eggs per kg female was 320,337 and the mean number per batch of eggs collected per kg female was 6,407.
Approximately 41 % of the eggs sank and were discarded and the remaining eggs floated. There was a total weight of 12,161 g of floating eggs which gave a mean
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female of 187,931 eggs. The mean number per batch of floating eggs per kg female was 3,835.
Mean percentage fertilization (as % floating eggs) was 70 % and the total number of fertilised eggs per kg female 140,817. The total number of batches with fertilised eggs was 48. The mean number per batch of fertilised eggs per kg female was 2,934 and the mean % hatch was 20 % (as percent of floating eggs). This equated to 12
% hatch of total eggs collected.. The total number of hatched larvae per kg female was 38,526 (Table 3.4).
In Group D (fed ARA for 3 months), the total number of eggs produced per kg female was 572,813 the mean number per batch of eggs produced per kg female was 10,415. The total weight of eggs collected was 26,537. The number of batches collected was 55 (out of the total 92 days of spawning). The mean weight of collected egg batches was 482 g, the total number of collected eggs per kg female was 442,727 and the mean number per batch of eggs collected per kg female was 8,045 (Table 3.4).
Approximately 48 % of the eggs sank and were discarded and the remaining eggs floated. There was a total weight of 13,877g of floating eggs which gave a mean weight per batch of floating eggs of 262 g and a total number of floating eggs per kg female of 227,011eggs. The mean number per batch of floating eggs per kg female was 4,283 (Table 3.4).
Mean percentage fertilization (as % floating eggs) was 60 % and the total number of fertilised eggs per kg female 152,231. The total number of batches with fertilised eggs was 50. The mean number per batch of fertilised eggs per kg female was
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equated to 8.2 % hatch of total eggs collected. The total number of hatched larvae per kg female was 36,225 and the mean no. per batch of hatched larvae per kg female 683 (Table 3.4).
The differences in the total numbers of eggs produced were because of the differences in the number and size of batches. For example, Group A and Group B produced more batches of eggs than Groups C and D. In addition Groups B and D, fed ARA for 1 month and 3 months respectively, produced the highest number of eggs per batch (Table 3.4). Egg production was therefore greatest in the Group B and lowest in Group C. Statistically significant differences in the numbers of eggs produced per batch were found between group B and the group C. However, there was no statistically significant difference in the number of eggs collected per batch between groups.
There was also a statistically significant difference found between the mean number per batch of eggs collected per kg female (Parameter No 7 in Table 3.4). This was significantly higher in group B than group A (Kruskal-Wallis, p<0.05). However, there was no other consistent increase in egg production in the groups fed ARA (B-D).
In addition there was no statistically significant correlation between the total number of eggs produced by each group and the duration of ARA supplementation.
Egg quality was better in the groups which received the ARA-supplemented diet for 1, 2, 3 months when compared to the control group. The mean weight per batch of floating eggs per kg per female (Parameter No. 11, Table 3.4) was significantly greater in Group C and D when compared to group A and group B. In addition, the mean number per batch of floating eggs per kg female (Parameter No. 15, Table 3.4) was
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significantly higher in the pooled ARA-treated groups when compared to Group A (Mann Whitney U = 5914.0, P< 0.05).
The mean number of floating eggs from the pooled Group fed ARA was 1.29 times greater than Group A. The number of floating eggs per batch was also greater in the groups that received the ARA diet (Fig 3.4).
The mean number per batch of viable (fertilized) eggs per kg female was significantly higher in the ARA-treated Groups (B-D) than in Group A (Fig 3.4). The mean number of viable eggs (measured as totally number of floating eggs) in the pooled ARA group was 1.41 times higher than in Group A. In addition the number of viable eggs per batch was higher in the pooled ARA group when compared to Group A.
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0.0 2000.0 4000.0 6000.0 8000.0 10000.0 12000.0 14000.0
Group A Group B Group C Groud D
mean no of eggs produced/kg/batch mean no of eggs collected/kg/batch mean no of floating eggs/kg/batch mean no of viable eggs/kg/batch
Figure 3.4 Egg production and egg quality parameters in cod broodstock fed an ARA supplement.
Group A (control), Group B fed ARA for 1 month, Group C fed ARA for 2 months, Group C fed ARA for 3 months before peak spawning.
Table 3.4 Egg production and egg quality indicators in experiment 1.
Egg numbers are expressed as numbers per kg female. Values within a row with a different superscript letter are significantly different (p <0.05). Values within a row with * are significantly different (p<0.05), comparison only between Group A and all ARA treatment tanks pooled (B-D).
Comparison made using Krusk Wallace test. Group A (control), Group B fed ARA for 1 month, Group C fed ARA for 2 months, Group C fed ARA for 3 months before peak spawning.
Group A Group B Group C Group D + ARA pooled
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Table 3.5 Fatty acid composition (% by weight of total fatty acids) of Atlantic cod eggs.
Group A (control), Group B fed ARA for 1 month, Group C fed ARA for 2 months, Group C fed ARA for 3 months, before peak spawning. Data from Group B, C and D were pooled in + ARA pooled column. Data analysed using ANOVA.
Fatty Acid Group A Group B Group C Group D ARA Pooled
Values within a row with the different superscript letter are significantly different p <0.05. Total saturated includes
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