DEVELOPMENT OF A MEAT LINE OF KUTTANAD DUCKS (Anas platyrhynchos domesticus)
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Date
2016-12-30
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COLLEGE OF VETERINARY AND ANIMAL SCIENCES MANNUTHY, THRISSUR
Abstract
A selection experiment was conducted in Kuttanad ducks at University Poultry Farm,
Mannuthy under Kerala Veterinary and Animal Sciences University with the objective of
developing a meat line.
One thousand and eighty eight day-old Kuttanad ducklings procured from
progressive farmers of Kerala formed the base generation (S0). Based on body weight at
eighth week, top ranking 150 females and 25 males were selected through individual
selection method. From the 25 sire families, 979, 969 and 1610 ducklings were produced
by artificial insemination in S1, S2 and S3 generation in pedigreed hatches.
Body weight, feed consumption and mortality were recorded at fortnightly intervals
till 12th week of age in each generation. Genetic parameters for body weight at 8, 10 and 12
weeks were estimated using full sib correlation method. Selection differential, intensity of
selection and response to selection were calculated for body weight at 8 weeks. Carcass
characteristics were evaluated at 8, 10 and 12 weeks of age in four generations. The body
weight at 18 and 40 weeks, feed consumption from 13 to 40 weeks, age at first egg and age
at 10 and 50 per cent production, duck housed egg production and egg weight at 30 and 40
weeks were recorded in the selected parent stock of S0, S1 and S2 generations.
The mean body weight at 8 weeks was 1103.38 g in the S0 generation. An
improvement of 270.51 g could be recorded at 8 weeks in S3 generation. The period of
active weight gain was shifted to 4th and 6th week in S3 generation whereas it was 8th week
in the previous generations. The total per cent of observations above 1200 g weight
increased over generations and the increase is more pronounced at 8 weeks of age. The
results also indicate that a compensatory growth mechanism is present in ducks wherein
the lower body weight in the early stages of growth are compensated in the subsequent
weeks and they attain 90 per cent of the adult body weight by 12 weeks of age.
The heritability estimates for body weight at 8 weeks of age based on sire plus dam
components (h2
s+d) were 0.251, 0.313 and 0.243 in S1, S2 and S3 generations. The realised
heritability was 0.60. High values were observed for phenotypic correlation between body
weight at 8 and 10, 8 and 12 and 10 and 12 weeks of age. The genetic correlations were
higher than the environmental correlations except in the sire component in S1 generation.
The regression coefficients indicate that higher increase in body weight per generation was
obtained for body weight at 8 weeks (94 g) rather than for body weight at 10 (56 g) and 12
weeks (55 g).
S3 generation showed the lowest cumulative feed conversion ratio of 2.39 up to 8
weeks. The carcass characteristics of male and female Kuttanad ducks at 8, 10 and 12
weeks of age showed that there was improvement in the eviscerated yield of carcass over
generations and S3 generation attained the highest yield at 8 weeks. The performance of
parent stock indicated that selection had not altered their egg production performance.
Artificial Insemination at 5 days interval could achieve 89 per cent fertility in the
parent stock.
The results of the selection experiment indicate that selection for body weight at 8
weeks was effective in improving the body weight and a line of Kuttanad ducks with meat
characteristics could be developed. The higher body weight, body weight gain and the
distribution of birds in the higher weight groups reveal that the S3 generation of Kuttanad
ducks possess the characteristics of a meat line. The trend observed in body weight gain,
frequency distribution, response to selection and correlated responses as well as the high
heritability and phenotypic correlation for body weight at 8 weeks establish that the
criterion for selection (8th week body weight) employed in the present study was
appropriate. The carcass characteristics especially the eviscerated yield and yield of cut-up
parts over generations indicate that the meat producing potential of Kuttanad ducks has
improved as a result of selection. It could be concluded that Kuttanad ducks could attain its
optimum meat production characteristics at 8 weeks and hence it could be considered as
the ideal age for processing.
Description
thesis submitted in partial fulfillment of the requirement for the degree of Doctor of Philosophy in Poultry Science.