From a randombred control population of Coturnix coturnix japonica, four strains were selected respectively for high and low 4-week body weight and high and low total plasma phosphorus (plasma yolk precursor). Based on seven generations of selection, die realized heritabilities plus or minus their standard errors for high and low body weight strains were .37 ± .05 and .44 ± .28, respectively. The total gain and gain per generation were greatest in the low weight strain, primarily due to greater selection differentials.Selection for plasma yolk precursor was more effective in the high than low strain. The respective realized heritabilities plus or minus standard errors were .32 ± .02 and .34 ± .03. The selection differentials were larger in the high strain than in die low strain. There was no significant change in plasma yolk precursor in the weight strains nor in 4-week body weight in die plasma yolk precursor strains, which indicated that the genetic correlation between body weight during the growing period and plasma yolk precursor during the laying period was close to zero. (

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From a randombred control population of Coturnix coturnix japonica, strains were divergently selected for high (HE) and low (LE) 120-day egg production based on individual egg records. Based on five generations of selection, realized heritabilities for HE and LE were .063 +/- .055 and .353 +/- .020, respectively. The total change in number of eggs was 3 and -19, respectively, in HE and LE. Mortality to 4 weeks of age, 4-week body weight, egg weight, total plasma phosphorus (yolk precursor), liver weight, and number and weight of ovarian follicles in rapid development in the ovary did not change significantly in HE and LE. Mature body weight increased in LE with no consistent change in HE. Significant changes in the component parts of the egg occurred in HE and LE. Shell weight increased in HE with no change in LE while the reverse was true for yolk weight. Percent albumin decreased in both selected strains.

Five separate studies were conducted to determine the growth and egg production performance of Itik Pinas (IP) Kayumanggi, a new commercial hybrid egg-type mallard duck in the Philippines under an intensive management system. Results showed that the IP Kayumanggi produced by crossing male IP Khaki and female IP Itim as parents showed significant sexual dimorphism in down feather patterns. The male and female ducklings have 98% black and 99% brown down feathers upon hatch, respectively. In addition, the female ducklings have significantly higher body weight from Weeks 0–4, whereas males were heavier from Weeks 10–18. Cumulative feed consumption was 10.72 kg from brooding (Weeks 1–4) to growing (Weeks 5–16). Daily feed consumption per bird was 124 g during the pre-laying (Weeks 17–18) and laying (Weeks 19–50) periods. Phenotypic characterization revealed that males have predominantly dusky black plumage, green bill, and brown shank, whereas females have mallard-type brown plumage, black bill, and orange shank. The males have significantly higher values for all the body measurements. The average age at first lay was 18 wk, and it reached 80% egg production at 26 wk of age. Average egg weight was 67 g. The average fertility, hatchability, and hatch of fertile were 89, 55, and 62%, respectively. This study provided baseline information on the productive and reproductive performance of IP Kayumanggi.

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