Publications by authors named "Ayman G El Nagar"

Buffalo bull semen traits are economically important traits that influence farm fertility and profitability. Genetic improvement of semen characteristics is an important detail of the genetic improvement. This study was conducted to assess the relationship between the breeding values as well as the phenotypic values for semen traits (VOL, MM, LS, AS and CONC) of the Egyptian buffalo bulls.

View Article and Find Full Text PDF

The present study aimed to contribute to the limited research on buffalo () semen traits by incorporating genomic data. A total of 8465 ejaculates were collected. The genotyping procedure was conducted using the Axiom Buffalo Genotyping 90 K array designed by the Affymetrix Expert Design Program.

View Article and Find Full Text PDF

Maternal genetic effects (MGE) could affect meat quality traits such as intramuscular fat (IMF) and its fatty acid composition. However, it has been scarcely studied, especially in rabbits. The objectives of the present study were, first, to assess the importance of MGE on intramuscular fat and fatty acid composition by applying a Bayesian maternal animal model in two rabbit lines divergently selected for IMF.

View Article and Find Full Text PDF

This study was conducted to characterize semen traits (ejaculate volume (VOL), mass motility (MM), sperm livability (LS), percentage of abnormal sperms (AS), and sperm concentration (CONC)) of Egyptian buffalo bulls and evaluate the importance of some nongenetic factors (year (YC) and season (SC) of semen collection and age of bull genetically and environmentally at collection (ABC)) affecting the investigated traits. A total of 7761 normal semen ejaculates were collected from 26 bulls from 2009 to 2019. Single-trait and bivariate repeatability animal models using Bayesian methods were used to estimate variance components, heritability, repeatability, and genetic correlations among the investigated semen traits.

View Article and Find Full Text PDF

A simple crossbreeding experiment between Gabali (G) bucks and Hyplus (H) does was performed to estimate crossbreeding effects for post-weaning growth traits (body weight at 5 (BW5), 7 (BW7), 9 (BW9), 11 (BW11), and 13 (BW13) weeks of age and daily weight gains (DG) during (DG5-7), (DG7-9), (DG9-11), (DG11-13) and (DG5-13), weeks of age). Estimates of heritability were mostly low or moderate for growth traits and ranged from 0.12 to 0.

View Article and Find Full Text PDF

The effect of feeding on diets supplemented with L. dry seeds (SMS) on growth performance, mortality percentage, biochemical parameters, the expression profile of related genes, and genotoxic effect in Muscovy ducklings was evaluated during a brooding period of 4 weeks. Two hundred and forty one-day-old Muscovy ducks were randomly assigned to four treatment groups (60 ducklings/group), the first group fed on basal diet with no additives (control), and the second (4 g kg), third (8 g kg), and fourth (12 g kg) groups fed the basal diet supplemented with 0, 4, 8, and 12 g kg diet SMS, respectively.

View Article and Find Full Text PDF

This study was conducted to genetically and environmentally characterize prolificacy (litter size and weight at birth; LSB and LWB and litter size and weight at weaning; LSW and LWW, respectively), milk yield at the 7th (MY7), 15th (MY15), 30th (MY30), 60th (MY60), 90th (MY90) day of lactation and monthly milk yield (MMY) and milk composition traits in Egyptian Zaraibi goats. A total of 443 and 421 records produced by 121 Zaraibi lactating goats were used to assess prolificacy and milk production traits, respectively. The milk composition traits were measured using 371 milk samples obtained at random from 53 goats.

View Article and Find Full Text PDF

The enhancement of rabbit female functional longevity, that is the ability to avoid voluntary culling, is a paramount aspect for the sustainability of meat rabbit production; this trait represents a direct indicator of female robustness. The objective of our study was to compare the functional longevity of five rabbit lines at their foundation and at fixed times during their selection processes. Four of them are maternal lines (A, V, H and LP) selected for litter size at weaning.

View Article and Find Full Text PDF

In a diallel cross between four maternal lines of rabbits, the four maternal lines and the corresponding crossbred females (does) were evaluated concerning functional longevity, estimating their crossbreeding components. Sixteen genetic groups were produced by using four maternal lines of rabbit (A, V, H and LP (L)). The groups were distributed over 4 Spanish farms.

View Article and Find Full Text PDF

Calving ease (CE) is a trait of economic importance that affects animal welfare and farm profitability. The objective of present study was to investigate genetic and environmental factors affecting CE among Primiparous (PP) and multiparous (MP) buffaloes. A total of 9,627 records from 1999 MP and 2,110 PP recorded during the period from 1988 to 2018 were considered.

View Article and Find Full Text PDF