Selection for egg production on part records

Ayyagari, V.; Mohapatra, Soudamini; Venkatramaiah, A.; Thiagasundaram, T.; Choudhuri, D. K.; Johri, D. C.; Renganathan, P

doi:10.1007/bf00264955

Cited by 14 publications

(1 citation statement)

References 27 publications

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“…Selection based on early period part records, up to 40 weeks of age, could result in increased egg production of chickens (Fairful and Gowe 1990 ; Poggenpoel et al 1996 ). Estimates for part records can be used as selection criteria to improve both part and annual egg production and any loss in accuracy is compensated by the reduction in generation interval, thus maximizing genetic gain per unit of time (Ayyagari et al 1980 ). Hicks et al ( 1998 ) also showed that selection based on partial records of the individual and all available ancestral records resulted in the shortest generation interval and was the most efficient strategy for maximizing egg production in laying hens compared to other strategies using full records.…”

Section: Discussionmentioning

confidence: 99%

Genetic and phenotypic parameter estimates for body weights and egg production in Horro chicken of Ethiopia

Dana

Waaij

Arendonk

2010

Trop Anim Health Prod

109

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A breeding program has been established in 2008 to improve productivity of Horro chicken, an indigenous population in the western highlands of Ethiopia. The pedigree descended from 26 sires and 260 dams. Body weights were measured every 2 weeks from hatch to 8 weeks then every 4 weeks for the next 8 weeks. Egg production was recorded to 44 weeks of age for one generation. Genetic parameters were estimated using animal model fitted with common environmental effects for growth traits and ignoring common environment for egg production traits. Direct heritabilities ranged from low (0.15 ± 0.08), for body weight at 6 weeks, to moderate (0.40 ± 0.23), for hatch weight. Heritabilities of common environmental effects on growth were high at hatch (0.39 ± 0.10) and remained low afterwards. Age at first egg showed a very low heritability (0.06 ± 0.15). Heritabilities of egg numbers in the first, second, third, and fourth months of laying were 0.32 (±0.13), 0.20 (±0.16), 0.56 (±0.15), and 0.25 (±0.14), respectively. Heritabilities of cumulative of monthly records of egg numbers were from 0.24 ± 0.16 (for the first 2 months, EP12) to 0.35 ± 0.16 (over the 6 months, EP16). Body weight at 16 weeks of age (BW16) has a strong genetic correlation with the cumulative of monthly records: 0.92 (with EP12), 0.69 (with EP36), and 0.73 (with EP16). Besides their strong association, BW16 and EP16 showed higher heritability, relative to their respective trait categories. These two traits seemed to have common genes and utilizing them as selection traits would be expected to improve both egg production and growth performance of local chicken. However, the standard errors of estimates in this study were mostly high indicating that the estimates have low precision. Parameter estimations based on more data are needed before applying the current results in breeding programs.

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Section: Discussionmentioning

confidence: 99%

Genetic and phenotypic parameter estimates for body weights and egg production in Horro chicken of Ethiopia

Dana

Waaij

Arendonk

2010

Trop Anim Health Prod

109

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Selection response for part period egg number and egg mass in chickens — a comparison

Venkatramaiah

Mohapatra

Sinha

et al. 1986

Theoret. Appl. Genetics

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Two sublines from each of four flocks of White Leghorn were subjected to two cycles of selection for part year egg number and part year egg mass. A family index (combined selection) was the selection criterion for each of the two traits. The generation means of an unselected pedigreed randombred control, bred and maintained along with the selected sub-lines, were used for correcting short term environmental trends. The sublines selected for a common selection criterion were considered as replicates. The control corrected generation means, when averaged over replicates, gave the mean direct and correlated responses for the selected and different unselected traits. The average genetic change per generation was 2.16 eggs in egg number selected sublines and 146 g of egg mass in egg mass selected sublines. The direct response marginally exceeded the correlated response for both part period egg number and egg mass seen in the corresponding sublines. Except for egg weight the correlated responses for different unselected traits were in the same direction in both egg number and egg mass selected sublines. While the egg weight in egg number lines did not change, its response was positive in egg mass selected lines. A comparison between the lines revealed that the egg mass selected lines matured later and laid heavier but slightly less numerous eggs than the egg number selected sub-lines.

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