Genetic and phenotypic parameters for production traits and somatic cell count (SCC) for Jersey dairy cattle in Zimbabwe were estimated. A total of 10986 lactation records were obtained from Zimbabwe Livestock Identification Trust, with cows calving in the period from 1996 to 2008. An ASReml program fitting an animal model was used for the analyses. Heritability estimates for milk yield, fat yi...

The expression of sexual signals is often phenotypically plastic and also evolves rapidly. Few studies have considered the possibility that proximate determination -- the pathway between genes and trait expression -- may also be subject to both phenotypic plasticity and evolutionary change. We examined long-term patterns in size, condition- and age-dependence, repeatability and heritability of ...

purpose: to determine the accuracy of photorefraction and autorefraction as compared to cycloautorefraction and to detect the repeatability of photorefraction. methods: this diagnostic study included the right eyes of 86 children aged 7‑12 years. refractive status was measured using photorefraction (plusoptix so4, gmbh, nürnberg, germany) and autorefraction (topcon rm800, usa) with and without ...

A longitudinal Bayesian threshold analysis of insemination outcomes was carried out using 2 random regression models with 3 (Model 1) and 5 (Model 2) parameters to model the additive genetic values at the liability scale. All insemination events of first-parity Holstein cows were used. The outcome of an insemination event was treated as a binary response of either a success (1) or a failure (0)...

Genetic parameters for a subjective milk score given to ewes within 24 h of parturition were estimated to determine the usefulness of milk score as a selection trait to improve milk production, which influences total litter weight weaned. Heritability of milk score and the genetic correlation of milk score with litter weight weaned were estimated by REML separately for four sheep breeds, Rambou...

Mating failure, characterized by the lack of production of offspring following copulation, is relatively common across taxa yet is little understood. It is unclear whether mating failures are stochastic occurrences between incompatible mating partners or represent a persistent, meaningful phenotype on the part of one or other sex. Here we test this in the seed bug Lygaeus simulans, by sequentia...

Footrot is a costly endemic disease of sheep. This study investigates the potential to decrease its prevalence through selective breeding for decreased lesion score. Pedigreed mule and Scottish Blackface (SBF) ewes were scored for lesions on each hoof on a 0 to 4 scale for up to 2 (SBF ewes) or 4 (mules) times over 2 ye...

Abstract Crossovers in meiosis have an important role sexual reproduction ensuring the segregation of chromosomes and shuffling genetic material. Despite their profound importance, little is known about heritability repeatability crossover rate wild. We studied variation outbred nine- (Pungitius pungitius) three-spined (Gasterosteus aculeatus) stickleback populations to estimate its (h2) (R). B...

Abstract To evaluate the relationships among clones and open pollinated families from same plus trees to select elite breeding materials, growth, wood characteristics of 33-year-old Pinus koraiensis were measured analyzed. The results show that growth characters varied significantly. variation due clonal effects was higher than family effects. ratio genetic phenotypic coefficient in traits abov...

Parental effort has a direct impact on individual fitness. Theoretical models exploring how parental effort evolves to cope with offspring demand and sexual conflicts may differ in the assumptions they make in respect to the genetic heritability of parental behaviours. Only a few attempts, however, have been made to estimate the heritability of parental behaviours and their possible co-evolutio...