Open AccessRELATIONSHIP BETWEEN LAYING AGE AND REPEATABILITY OF EGG QUALITY TRAITS
Author(s) -
S. N. Ibe,
J. C. Okonkwo
Publication year - 2021
Publication title -
nigerian journal of animal production
Language(s) - English
Resource type - Journals
ISSN - 0331-2062
DOI - 10.51791/njap.v21i1.1107
Subject(s) - repeatability , zoology , biology , trait , linear relationship , mathematics , statistics , computer science , programming language
Repeatability of 22 -, 26, 30 - and 32 - week egg weight (EW)., shell thickness (ST), Haugh (1955) unit (HU), yolk index (Yl)and shape, index (SI) was estimated based on the first three eggs laid in the week by fifty - six commercial Harco pullets. There was a consistent increase in repeatability estimates for these traits as laying age progressed. The estimates ranged from 0.67 to 0.85, 0.53 to 0.84., 0.51 to 0.87, 0.20 to 0.61 and 0.26 to 0.52 for EW, ST, HU, YI and Si, respectively. While repeatability of EW increased by 0.02 units per week, that of HU increased by 0.03 and 0.04 unit per week, respectively. Repeatability of EW, ST and HU showed a linear relationship with age, whereas that of YI and ȘI showed a linear relationship with age, whereas that of YI and SI showed a curvilinear relationship with age. The general increase in repeatability of each trait with age indicates that fewer records will be required to adequately characterize the inherent producing ability of each hen for the trait as laying age progressed.